U.S. patent application number 15/470009 was filed with the patent office on 2019-01-24 for carrier, carrier leadframe, and light emitting device.
This patent application is currently assigned to EVERLIGHT ELECTRONICS CO., LTD.. The applicant listed for this patent is EVERLIGHT ELECTRONICS CO., LTD.. Invention is credited to Yung Chieh CHEN, Chung-Chuan HSIEH.
Application Number | 20190027665 15/470009 |
Document ID | / |
Family ID | 59497901 |
Filed Date | 2019-01-24 |
View All Diagrams
United States Patent
Application |
20190027665 |
Kind Code |
A9 |
HSIEH; Chung-Chuan ; et
al. |
January 24, 2019 |
CARRIER, CARRIER LEADFRAME, AND LIGHT EMITTING DEVICE
Abstract
A light emitting device may comprise a wing portion of an
electrode exposed from the resin housing. The wing portion may be
made by a single or multiple stamp cutting process. To increase the
connecting region between the electrode and solder, the outer side
surface of the wing portion is an uneven surface. The device may
further comprise a protective plating layer and an external
protective plating layer. The protective plating layer may be
coated on the top surface, bottom surface and a portion of the side
surface of the electrode. The external portative plating layer
would be coated on the outer surface of the wing region. The light
reflection of the device from top surface of the electrode portion
can be maintained and the outer side surface of wing portion can be
protected for improving the reliability of connection between light
emitting device and outer substrate.
Inventors: |
HSIEH; Chung-Chuan; (New
Taipei City, TW) ; CHEN; Yung Chieh; (New Taipei,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EVERLIGHT ELECTRONICS CO., LTD. |
New Taipei City |
|
TW |
|
|
Assignee: |
EVERLIGHT ELECTRONICS CO.,
LTD.
New Taipei City
TW
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20170229625 A1 |
August 10, 2017 |
|
|
Family ID: |
59497901 |
Appl. No.: |
15/470009 |
Filed: |
March 27, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14720230 |
May 22, 2015 |
9640733 |
|
|
15470009 |
|
|
|
|
62331984 |
May 5, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 2224/48247
20130101; H01L 24/73 20130101; H01L 33/62 20130101; H01L 33/486
20130101; H01L 2933/0066 20130101; H01L 2924/00014 20130101; H01L
2224/92247 20130101; H01L 24/48 20130101; H01L 2924/181 20130101;
H01L 33/60 20130101; H01L 33/483 20130101; H01L 2933/0033 20130101;
H01L 2224/32245 20130101; H01L 24/97 20130101; H01L 24/92 20130101;
H01L 2224/73265 20130101; H01L 24/32 20130101; H01L 2924/00014
20130101; H01L 2224/45099 20130101; H01L 2924/181 20130101; H01L
2924/00012 20130101; H01L 2224/73265 20130101; H01L 2224/32245
20130101; H01L 2224/48247 20130101; H01L 2924/00014 20130101; H01L
2924/00014 20130101; H01L 2224/29099 20130101; H01L 2224/92247
20130101; H01L 2224/73265 20130101; H01L 2224/32245 20130101; H01L
2224/48247 20130101; H01L 2924/00 20130101 |
International
Class: |
H01L 33/62 20060101
H01L033/62; H01L 33/48 20060101 H01L033/48; H01L 33/60 20060101
H01L033/60 |
Foreign Application Data
Date |
Code |
Application Number |
May 23, 2014 |
TW |
103118060 |
Feb 3, 2015 |
TW |
104103527 |
Claims
1. A light emitting device comprising: a light emitting chip; at
least one electrode portion covered by a protective plating layer;
and a resin housing containing a reflecting material; wherein said
at least one electrode portion with the protective plating layer is
partially covered by the resin housing, wherein said at least one
electrode portion further comprises a wing portion, at least a
portion of said wing portion including an external protective
plating layer, wherein the thickness of the protective plating
layer and the external protective plating layer is not the
same.
2. The light emitting device according to claim 1, wherein the
thickness of the external protective plating layer is not
uniform.
3. The light emitting device according to claim 2, wherein the wing
portion further comprises a central area and at least one edge
area.
4. The light emitting device according to claim 3, wherein the at
least one edge area protrudes from the central area.
5. The light emitting device according to claim 4, wherein the
outer side surface of the central area is covered by the external
protective plating layer.
6. The light emitting device according to claim 5, wherein the edge
area comprises an electrode portion cross section.
7. The light emitting device according to claim 6, wherein the
electrode portion cross section is covered by the external
protective plating layer.
8. The light emitting device according to claim 7, wherein the
thickness of the external protective plating layer of the central
area is the same as the protective plating layer.
9. The light emitting device according to claim 8, wherein the
thickness of the external protective plating layer of the central
area is thicker than the thickness of the external protective
plating layer of the electrode portion cross section.
10. The light emitting device according to claim 9, wherein the
external protective plating layer of the electrode portion cross
section extends from the protective plating layer.
11. The light emitting device according to claim 10, wherein upper
region of the electrode portion cross section is covered by the
external protective plating layer.
12. The light emitting device according to claim 11, wherein the
electrode portion cross section comprises a curved surface.
13. The light emitting device according to claim 12, wherein the
housing cross section is located in the vicinity of the corner of
the resin housing.
14. The light emitting device according to claim 13, wherein the
resin housing further comprises at least one housing cross
section.
15. The light emitting device according to claim 14, wherein the
housing cross section is located in the vicinity of the four
corners of the resin housing.
16. The light emitting device according to claim 15, wherein the
housing cross section is not level with the electrode portion cross
section.
17. A light emitting device comprising: a light emitting chip, a
resin housing containing a reflecting material, and at least one
electrode portion covered by a protective plating layer, wherein
said at least one electrode portion with the protective plating
layer is partially covered by the resin housing, wherein said at
least one electrode portion comprises an electrode portion cross
section covered by an external protective plating layer, wherein
said the external protective plating layer extends from the
protective plating layer.
18. The light emitting device according to claim 18, wherein the
housing cross section is located in the vicinity of the corner of
the resin housing.
19. The light emitting device according to claim 19, wherein the
thickness of the protective plating layer is thicker than the
thickness of the external protective plating layer.
20. The light emitting device according to claim 20, wherein the
external protective plating layer covers the upper region of the
electrode portion cross section.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 14/720,230 which was filed on May 22, 2015 and
claims the priority benefit to said application as well as U.S.
Provisional Application 62/331,984 filed on May 5, 2016, Taiwan
Patent Application No. 103118060, filed on May 23, 2014, and Taiwan
Patent Application No. 104103527, filed on Feb. 3, 2015, all of
which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The present disclosure relates to a carrier leadframe and a
light emitting device made from the carrier leadframe. More
particularly, the present disclosure relates to a carrier leadframe
for receiving a light emitting diode (LED) chip and a light
emitting device made from the leadframe.
BACKGROUND
[0003] Unless otherwise indicated herein, approaches described in
this section are not prior art to the claims listed below and are
not admitted to be prior art by inclusion in this section.
[0004] Light emitting diodes (LEDs) have such advantages as a long
service life, a small volume, high resistance to shock, low heat
generation and low power consumption, so they have been widely used
as indicators or light sources in household appliances and various
other appliances. In recent years, LEDs have developed towards
multicolor and high brightness, so applications thereof have been
extended to large-sized outdoor signboards, traffic signal lamps
and related fields. In the future, it is even possible that the
LEDs become mainstream illumination light sources having both
power-saving and environmental protection functions. To impart the
LEDs with good reliability, most of the LEDs are subjected to a
packaging process to form durable light emitting devices.
[0005] In recent years, a dicing-type carrier leadframe has been
developed by manufacturers in the art to which the present
disclosure belongs. Specifically, a plastic body is molded on a
metal sheet material, then a die bonding process, a wire bonding
process and an encapsulation process are performed, and then the
metal sheet material and the plastic body are diced away
simultaneously to form individual light emitting devices that are
separate from each other. However, a large amount of plastic and
metal dusts tend to be produced during the dicing process, which
seriously pollute the surfaces of the final products and thus
degrade the reliability of the products. Additionally, this process
does not allow for a light-on test prior to the encapsulation
process, and measurements can only be made after the products are
singulated. However, the final products that have been singulated
are piled randomly, and machine measurements on them can only be
made after surface orientation and direction adjustment. This
requires use of additional instruments and is time consuming.
SUMMARY OF THE PRESENT INVENTION
[0006] The following summary is for illustrative purpose only and
is not intended to be limiting in any way. That is, the following
summary is provided to introduce concepts, highlights, benefits and
advantages of the novel and non-obvious techniques described
herein. Select implementations are further described below in the
detailed description. Thus, the following summary is not intended
to identify essential features of the claimed subject matter, nor
is it intended for use in determining the scope of the claimed
subject matter.
[0007] In view of the aforesaid problems, the present invention
provides a carrier and a carrier leadframe, which has at least one
carrier that is separated in advance and mechanically engaged with
the leadframe, thereby facilitating quick release of material after
die bonding, wire bonding and encapsulation. the finished carrier
can also be rapidly detached after the above process. Besides, in
the carrier leadframe of the present invention, each carrier is
electrically isolated from other carriers, so after LEDs are die
bonded and wire bonded to the carriers, the electric measurement
can be performed before the release of material. Furthermore, a
light emitting device made from the carrier leadframe is also
provided in the present invention, and with the advantages of the
aforesaid carrier leadframe, the production speed and yield of the
light emitting device can be greatly improved.
[0008] Moreover, the present light emitting device may comprise a
wing portion as a portion of the electrode portion exposed from
housing. The wing portion may be made by a single or multiple stamp
cutting process, for example a stamp process. The wing portion may
be divided the wing portion is further divided into a central area
and two edge areas which would be located at the two opposite side
of the central area. In order to increase the connecting region
between the electrode portion and the solder, it is preferably to
design outer side surface of the wing portion as an uneven surface.
For example, the outer side surface of edge area may be not level
with the outer side surface of the central area.
[0009] The electrode portion may be plated with a protective
plating layer. The plating layer would be placed before the
following molding process or stamp process. After the molding and
stamp process, the protective plating layer would still exist on
the top surface, bottom surface and a portion of side surface of
the electrode portion. The outer side surface of the wing portion
may also comprise an external plating layer. The thickness of the
external plating layer may not be uniform through the whole outer
side surface of the wing portion. For the present invention, the
thickness of the outer side surface of the central region can be
thicker than the outer side surface of the edge area. In addition,
the thickness of the external plating layer is not required to be
the same as the protective plating layer as well, but the external
plating layer of the central layer can be the same as the thickness
of the plating layer on the top surface of the electrode portion.
As a result, the light reflection from top surface of the electrode
portion can be maintained and also the outer side surface of wing
portion can be protected by the external protective plating layer
for improving the reliability of connection between light emitting
device and outer substrate, for example a PCB substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings are included to provide a further
understanding of the disclosure, and are incorporated in and
constitute a part of the present disclosure. The drawings
illustrate implementations of the disclosure and, together with the
description, serve to explain the principles of the disclosure. It
is appreciable that the drawings are not necessarily in scale as
some components may be shown to be out of proportion than the size
in actual implementation in order to clearly illustrate the concept
of the present disclosure.
[0011] FIG. 1 is a partial schematic view of an exemplary
embodiment of a carrier leadframe according to the present
disclosure.
[0012] FIG. 2 is a partial schematic view of a conductive sheet
used in the carrier leadframe of FIG. 1.
[0013] FIG. 3 is a partial schematic view of the carrier leadframe
of FIG. 1 after a plastic body is formed.
[0014] FIG. 4A and FIG. 4B are partial schematic views of the
carrier leadframe of FIG. 1 after the residual material is
removed.
[0015] FIG. 5 is a partial schematic view of an exemplary
embodiment of the carrier leadframe according to the present
disclosure.
[0016] FIG. 6 is a top view of a light emitting device according to
an embodiment of the present disclosure.
[0017] FIG. 7 is a top view of a light emitting device according to
another embodiment of the present disclosure.
[0018] FIG. 8 is a top view of a light emitting device according to
a further embodiment of the present disclosure.
[0019] FIG. 9 is a top view of a light emitting device according to
yet another embodiment of the present disclosure.
[0020] FIG. 10 is a top view of a light emitting device according
to yet a further embodiment of the present disclosure.
[0021] FIG. 11 is a top view of a light emitting device according
to still another embodiment of the present disclosure.
[0022] FIG. 12A to FIG. 12D are respectively a top view, a
cross-sectional view taken along the front-to-back direction, a
cross-sectional view taken along the left-to-right direction, and a
partially enlarged view of a carrier leadframe according to an
embodiment of the present disclosure.
[0023] FIG. 13A to FIG. 16 are schematic views illustrating steps
of a method for manufacturing a carrier leadframe according to an
embodiment of the present disclosure.
[0024] FIG. 17A to FIG. 17D are respectively a top view, a
cross-sectional view taken along the front-to-back direction, a
cross-sectional view taken along the left-to-right direction, and a
partially enlarged view of a carrier leadframe according to an
embodiment of the present disclosure.
[0025] FIG. 18A to FIG. 22 are schematic views illustrating steps
of a method for manufacturing a carrier leadframe according to an
embodiment of the present disclosure.
[0026] FIG. 23 to FIG. 26B are schematic views illustrating steps
of a method for manufacturing a carrier leadframe according to an
embodiment of the present disclosure.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] A carrier leadframe of the present invention comprises a
frame body and a carrier, and the carrier includes a housing and at
least one electrode portion. In the present invention, the frame
body includes at least one supporting portion and is mechanically
engaged with the carrier so that the carrier is supported on the
frame body. In a specific embodiment of the present invention, the
housing may have a concave portion mating with the supporting
portion, and the carrier is supported on the frame body through the
engagement between the supporting portion and the concave portion.
The position of the concave portion is not particularly limited in
the present invention, and the concave portion may be located at a
side surface or at the border between a bottom surface and the side
surface of the carrier. The supporting portion goes deep into the
carrier or is only positioned on the bottom surface of the carrier
with a half thereof being exposed outside.
[0028] FIG. 1 is a partial schematic view of an embodiment of a
carrier leadframe according to the present disclosure. As shown in
FIG. 1, a carrier leadframe 100 comprises a carrier 110 and a frame
body 120, and the carrier 110 comprises a housing 111 and two
electrode portions 112. The frame body 120 comprises a plurality of
supporting portions 121. As shown in FIG. 1, the frame body 120
beneath the carrier leadframe 100 comprises four supporting
portions 121, and four concave portions are formed at the border
between the side surfaces and the bottom surface of the housing 111
(corresponding to positions of the supporting portions 121) so that
each of the four supporting portions 121 is positioned on the
bottom surface of the carrier 110 with a half thereof being exposed
outside. In an embodiment, the carrier 110 further comprises a
reflection concave cup to expose a part of each of the electrode
portions 112. The electrode portion 112 extends outwardly from the
reflection concave cup through the housing 111 to the outside.
[0029] The frame body 120 may also have a runner area 122 and a
side portion 123, and the runner area 122 is disposed on the side
portion 123. The runner area 122 is a through area that allows a
plastic body 150 (as shown in FIG. 3) to be described later to flow
therethrough, and the supporting portion 121 is disposed also on
the side portion 123.
[0030] Additionally, each of the electrode portions 112 may also be
formed with pinholes, grooves (linear slits on the surface of the
electrode portion) and steps in the present disclosure. The
mechanical binding force between the housing and the electrode
portion of the carrier can be increased due to the pinholes, the
grooves and the steps. As shown in FIG. 1, each of the two
electrode portions 112 in the carrier 110 comprises two pinholes
141 and three grooves 143, and steps 142 are provided on edges of
the two electrode portions 112 that are surrounded by the housing
111, thereby increasing the binding strength between the housing
111 and the electrode portions 112.
[0031] Each carrier in the carrier leadframe of the present
disclosure is supported on the frame body via the mechanical
engagement between the concave portion and the supporting portion,
and the electrode portions of different carriers are electrically
isolated from each other. Thus, after the die bonding process, the
wire bonding process and the encapsulation process subsequently
performed on the light emitting devices, the electric measurement
can be made on the light emitting devices that have not been
singulated (i.e., the light emitting devices that are still
supported on the frame body in a regular way). Since the light
emitting devices are arranged regularly, equipment and time
required for surface orientation and direction adjustment are
eliminated and the production speed of the light emitting devices
can be greatly improved.
[0032] The carrier leadframe of the present disclosure may be
manufactured in the following way. First, a conductive sheet is
provided. The conductive sheet comprises a frame body, at least one
void area and at least one extending portion, and the frame body
comprises at least one supporting portion. Then, a plastic body is
formed on the conductive sheet to cover at least a part of the
extending portion and at least a part of the supporting portion and
to fill at least a part of the void area. Subsequently, the part of
the extending portion exposed outside the housing and a part of the
plastic body filled within the void area are respectively removed
so as to form the carrier. In particular, after the two removing
steps, the housing of the carrier is formed by the remaining
plastic body, and the electrode portion of the carrier is formed by
the extending portion remaining on the plastic body.
[0033] Hereinafter, the manufacturing process of the carrier
leadframe 100 of FIG. 1 will be detailed with reference to FIG. 2
to FIG. 4A. First, a conductive sheet 160 as shown in FIG. 2 is
provided. The conductive sheet 160 comprises a frame body 120, a
plurality of void areas 130 and a plurality of extending portions
140. The frame body 120 also comprises a plurality of supporting
portions 121, and each of the extending portions 140 comprises a
plurality of pinholes 141, grooves 143 and steps 142. Finally, the
part of each of the extending portions 140 exposed outside the
housing is removed to form the carrier leadframe 100 of FIG. 1.
[0034] In the present disclosure, the conductive sheet may be made
of a metal sheet, including a pure metal sheet, an alloy sheet, and
a metal composite sheet, and the composite sheet is preferably a
metal sheet cladded with a conductive layer having a relatively
high resistance to oxidation or a relatively high solder binding
force (e.g., a silver-plated copper sheet, or the like). The frame
body, the extending portion and the void portion are formed in an
appropriate way. When the conductive sheet is made of a metal
sheet, the frame body, the extending portion and the void portion
may be preferably formed through a stamping process; however, they
may also be formed through a dicing process or a mold casting
process. Moreover, if the conductive sheet has insufficient
conductivity, a conductive layer (not shown) may be formed on the
conductive sheet after the conductive sheet is provided (the
conductivity of the conductive layer is higher than that of the
conductive sheet) so as to increase the reliability of the
subsequent test. The material of the conductive layer may include
materials having high conductivity (e.g., silver, or the like).
[0035] After the conductive sheet is provided, a plastic body is
then formed on the conductive sheet. The way in which the plastic
body is formed is not limited. For Example, the plastic body may be
formed through transfer molding, injection molding, etc. The
material of the plastic body is not limited. For example, it may be
selected from plastic materials commonly used in this industry,
e.g., epoxy compositions, silicon compositions, polyphthalamide
compositions, or polyethylene terephthalate compositions. In a
specific embodiment of the present disclosure, the plastic body is
made of an epoxy composition through transfer molding. In another
embodiment, the plastic body may be a thermosetting material and
may further comprise a reflective material, e.g., titanium dioxide
(TiO2), zinc oxide (ZnO) or boron nitride (BN).
[0036] Next, a plastic body 150 is formed on the conductive sheet
160 as shown in FIG. 3. The plastic body 150 covers a part of each
of the extending portions 140 and completely covers all of the
pinholes 141 and grooves 143. The plastic body 150 also fills a
part of the void area 130 (the part of the void area 130 above and
below the extending portion 140 is not filled) and completely
covers all of the supporting portions 121. The plastic body 150
also fills the runner area 122 and is formed integrally with
another adjacent plastic body 150.
[0037] Further speaking, during the formation of the plastic body
150 in the present disclosure, the material of the plastic body 150
will fill the mold cavity of the mold and the void area. In this
step, the housing 111 and the residual material 151 are still held
together. The scope of the residual material 151 is defined
depending on the subsequent application of the product. As shown in
FIG. 3, what denoted by dotted lines is the residual material 151
defined in this embodiment. Thereafter, the defined residual
material 151 is removed as shown in FIG. 4A, thereby forming the
housing 111 of the carrier 110.
[0038] If the runner area 122 is filled with the plastic body 150,
the residual material 151 may be removed in at least two steps,
e.g., by firstly removing the residual material 151 filled in the
runner area 122 and then removing the residual material 151 filled
in the void area 130 or vice versa. This can simplify the
arrangement of knives for removing the residual material 151 in
each step so that the knives have sufficient distances therebetween
and desirable strength.
[0039] Finally, the part of each of the extending portions 140
exposed outside the housing 111 is removed to form the carrier
leadframe 100 as shown in FIG. 1. Before the part of each of the
extending portions 140 is removed, the part of the frame body 120
at two sides of the runner area 122 may be removed optionally with
a knife of a length larger than that of the runner area 122 so as
to thoroughly remove the residual material 151 possibly left in the
runner area 122; thus, the damage to the electrode portions 112 or
the light emitting diode (LED) chips can be avoided by preventing
the residual material 151 from falling off onto the electrode
portions 112 or the LED chips. After the part of the frame body 120
at the two sides of the runner area 122 is removed, the length of
the runner area 122 is increased as shown in FIG. 4B.
[0040] Therefore, the manufacturing method of this embodiment may
optionally perform two or more removing steps on the conductive
sheet 160 and may also perform two or more removing steps on the
plastic body 150 (the residual material 151).
[0041] In the present disclosure, the residual material 151 and
parts of the extending portions 140 are removed separately. In
particular, the order in which the residual material 151 and the
parts of the extending portions 140 are removed is not particularly
limited as long as they are separately removed. For example, it may
be that all the parts of the extending portions 140 are
simultaneously removed after all the residual material 151 is
simultaneously removed, or all the residual material 151 is removed
after all the parts of the extending portions 140 are
simultaneously removed, or part of the residual material 151 and
parts of the extending portions 140 are removed alternately in
different stages. The way in which the removing steps are performed
is not limited, and the removing steps may be accomplished for
example through a dicing process or a stamping process but
preferably be accomplished through the stamping process. The
stamping process is taken as an example in the embodiments of the
present disclosure.
[0042] The tools and the working strength can be adjusted depending
on the mechanical properties of the parts to be removed in the
present disclosure. In particular, the respective removing steps
can avoid drawbacks resulting from removing different materials
simultaneously, e.g., plane defects or damage to the removing tools
(knives) due to non-uniform stresses. Additionally, dusts of the
plastic body tend to be produced during the removal of the plastic
body as compared to the removal of the extending portion. The dusts
can only be removed by a strong external force, e.g., through
strong air blowing, shaking, or ultrasonic waves. If the cleaning
step is to be performed after the residual material and the
extending portion are simultaneously removed, it is possible that
the bonding force between the carrier and the frame body is
insufficient to avoid falling off of the material. Thus, in the
present disclosure, the cleaning step (i.e., the cleaning of the
plastic body) is preferably performed after the residual material
is removed and before the extending portion is removed. This can
enhance the connection strength between the carrier and the
leadframe by means of the extending portion so as to avoid falling
off of the material during the cleaning step, and finally the
extending portion is removed.
[0043] After the removing steps, at least one electrode portion
cross section will be formed on the electrode portion of the
carrier, and a housing cross section will be formed by the residual
material on the housing of the carrier. In the present disclosure,
the electrode portion cross section and the housing cross section
may be located on a same surface or different surfaces of the
carrier depending on the safety specification of the final product
or depending on the customer requirements. Further speaking, when
the electrode portion cross section and the housing cross section
are located on the same surface of the carrier, the electrode
portion cross section and the housing cross section may be level
with each other (i.e., form a flat surface) or may not be level
with each other (i.e., do not form a flat surface).
[0044] As shown in FIG. 1, the electrode portion 112 has a wing
portion 112A exposed outside the housing, and the wing portion 112A
comprises a central protruding area (or called central area) 112A1
and two outer edge areas (or called edge areas) 112A2. In the
embodiment of FIG. 1, each of the edge areas 112A2 comprises an
electrode portion cross section 203, and the electrode portion
cross sections 203 are level with a part of the housing cross
section 111A of the housing 111; and in this case, the carrier has
a relatively flat appearance. However, as shown in FIG. 5, the wing
portion 112A of the electrode portion 112 comprises a central
protruding area 112A1 and two outer edge areas 112A2, and the
electrode portion cross section 203 of the electrode portion 112 is
not level with the housing cross section 111A of the housing 111;
and in this case, the electrode portion 112 has an additional
lateral area that can increase the binding force with the solder so
as to increase the component bonding strength of the light emitting
devices after the subsequent component bonding process.
[0045] Moreover, in case where the conductive sheet is a metal
composite sheet with an antioxidant layer, a cross section
uncovered with the antioxidant layer will be formed on the
electrode portion cross section 203. In the present disclosure, the
cross section uncovered with the antioxidant layer is preferably
formed integrally with the central area of the electrode portion.
During the subsequent component bonding process, the solder may
climb along the side surface of the wing portion and cover the side
surface, and in this case, at least a part of the cross section
uncovered with the antioxidant layer can be covered by the solder
to reduce the probability that the cross section portion is
oxidized. Additionally, the cross section uncovered with the
antioxidant layer and the surface of the adjacent central area are
at the same side, and preferably form a continuous surface so as to
reduce sharp points or rough edges of the electrode portion.
Otherwise, the sharp points or rough edges would cause wear of the
subsequent processing machine, and what is worse, a charge
accumulation effect might occur at the sharp points or the rough
edges to influence the reliability of the finally product.
[0046] The present disclosure also provides a light emitting device
made from the carrier leadframe of the present disclosure, and the
light emitting device comprises a carrier, an LED chip and an
encapsulant. The LED chip is carried within the carrier and covered
by the encapsulant. The material of the encapsulant in the present
disclosure may be a plastic composite of epoxy resins or silicone.
Moreover, the light emitting device of the present disclosure may
optionally have fluorescent materials added into the encapsulant,
and examples of the fluorescent materials include: aluminate
fluorescent materials (e.g., doped yttrium aluminum oxide
compounds, doped lutetium aluminum oxide compounds, doped terbium
aluminum oxide compounds, or combinations thereof), silicate
fluorescent materials, sulfide fluorescent materials, oxynitride
fluorescent materials, nitride fluorescent materials, fluoride
fluorescent materials, or combinations thereof.
[0047] The light emitting device of the present disclosure may be
manufactured in the following way. First, a carrier leadframe as
described above is provided. Then, an LED chip is provided and die
bonded and wire bonded into the reflection concave cup of the
carrier. Thereafter, the reflection concave cup is filled with an
encapsulant so as to encapsulate the LED chip to form a light
emitting device on the frame body. Finally, the light emitting
device is separated from the frame body (i.e., the carrier is
separated from the frame body for example through extrusion) to
form a separate light emitting device.
[0048] A plurality of LED chips may also be provided within the
carrier in the present disclosure, and these LED chips can emit
lights of the same or different spectrums. After the LED chips are
fixed, the wire bonding process may be performed to electrically
connect the LED chips with the electrode portion. Other electronic
elements, e.g., a Zener diode or a thermistor, may also be provided
depending on requirements of the final product.
[0049] Referring to FIG. 6, a top view of a light emitting device
according to an embodiment of the present disclosure is shown
therein. The wing portion 112A of the electrode portion 112 has a
central area 112A1 and two edge areas 112A2, and the central area
112A1 protrudes from the two edge areas 112A2. The wing portion
112A protrudes out of the housing cross section 111A of the housing
111 so that the central area 1112A1 of the wing portion 112A of the
electrode portion 112 is not coplanar with the housing cross
section 111A of the housing 111. An interval D1 is the distance
between the central area of the wing portion 112A of the electrode
portion 112 and the inner side of the housing cross section 111A of
the housing 111, and the interval D1 is about 0.1 mm. An interval
D2 is the distance between the central area 112A1 of the wing
portion 112A of the electrode portion 112 and the outer side of the
wing portion 112A of the housing 111 (i.e., the central area 112A1
of the wing portion 112A of the electrode portion 112 and the wing
portion 112A of the housing 111), and the interval D2 is about 0.05
mm.
[0050] Referring to FIG. 7, a top view of a light emitting device
according to another embodiment of the present disclosure is shown
therein. The wing portion 112A of the electrode portion 112 has a
central area 112A1 and two edge areas 112A2, and the wing portion
112A protrudes out of the housing cross section 111A of the housing
111 so that the wing portion 112A of the electrode portion 112 is
not coplanar with the housing cross section 111A of the housing
111. The interval D1 is the distance between the central area of
the wing portion 112A of the electrode portion 112 and the inner
side of the housing cross section 111A of the housing 111, and the
interval D1 is about 0.1 mm. An interval D3 is the distance between
the central area 112A1 of the wing portion 112A of the electrode
portion 112 and the outer side of the cross section 111A of the
housing 111, and the interval D3 is about 0.075 mm.
[0051] Referring to FIG. 8, a top view of a light emitting device
according to a further embodiment of the present disclosure is
shown therein. The wing portion 112A of the electrode portion 112
has a central area 112A1 and two edge areas 112A2, the central area
112A1 is recessed from the two edge areas 112A2, and the electrode
portion cross sections 203 of the two edge areas 112A2 are sloping
surfaces. The wing portion 112A is recessed into the cross section
111A of the housing 111 so that the wing portion 112A of the
electrode portion 112 is not coplanar with the cross section 111A
of the housing 111. An interval D4 is the distance between the
outer side and the inner side of the cross section 111A of the
housing 111, and the interval D4 is about 0.05 mm. An interval D5
is the distance between the central area of the wing portion 112A
of the electrode portion 112 and the outer side of the cross
section 111A of the housing 111, and the interval D5 is about 0.025
mm.
[0052] Referring to FIG. 9, a top view of a light emitting device
according to yet another embodiment of the present disclosure is
shown therein. The wing portion 112A of the electrode portion 112
has a central area 112A1 and two edge areas 112A2, the central area
112A1 protrudes out of the two edge areas 112A2, and the electrode
portion cross sections 203 of the two edge areas 112A2 are sloping
surfaces. The wing portion 112A protrudes out of the cross section
111A of the housing 111 so that the wing portion 112A of the
electrode portion 112 is not coplanar with the cross section 111A
of the housing 111.
[0053] Referring to FIG. 10, a top view of a light emitting device
according to yet a further embodiment of the present disclosure is
shown therein. The wing portion 112A of the electrode portion 112
is a convex curved surface, i.e., the external surface of the
central area and the outline (the electrode portion cross sections
203) of the edge areas together form a continuous convex curved
surface. The wing portion 112A protrudes out of the cross section
111A of the housing 111 so that the wing portion 112A of the
electrode portion 112 is not coplanar with the cross section 111A
of the housing 111.
[0054] Referring to FIG. 11, a top view of a light emitting device
according to still another embodiment of the present disclosure is
shown therein. The wing portion 112A of the electrode portion 112
is a concave curved surface, i.e., the external surface of the
central area and the outline (the electrode portion cross sections
203) of the edge areas together form a continuous concave curved
surface. The wing portion 112A is recessed into the cross section
111A of the housing 111 so that the wing portion 112A of the
electrode portion 112 is not coplanar with the cross section 111A
of the housing 111.
[0055] Referring to FIG. 12A to FIG. 12D, schematic views (i.e., a
top view, a cross-sectional view taken along the front-to-back
direction, a cross-sectional view taken along the left-to-right
direction, and a partially enlarged view) of a carrier leadframe
100' according to an embodiment of the present disclosure are shown
therein. The carrier leadframe 100' is similar to the aforesaid
carrier leadframe 100. That is, the carrier leadframe 100' also
comprises a frame body 120 and a carrier 110, the frame body 120
comprises at least one supporting portion 121, the carrier 110
comprises a housing 111 and at least one electrode portion 112, and
the housing 111 is mechanically engaged with the frame body 120 via
the supporting portion 121. Thus, for the technical contents of the
aforesaid elements, reference may be made to the counterparts of
the carrier leadframe 100.
[0056] Preferably, the at least one electrode 112 may be two
electrode portions 112 spaced apart from each other to respectively
serve as an anode terminal and a cathode terminal of the carrier
110. The two electrode portions 112 are surrounded by the frame
body 120, i.e., the two electrode portions 112 are located within a
space surrounded by the frame body 120 itself. The two electrode
portions 112 may be separated from the frame body 120 by at least
one void area 130 so that the two electrode portions 112 will not
make contact with the frame body 120 and thus be electrically
isolated from the frame body 120.
[0057] The supporting portion 121 of the frame body 120 extends
towards one of the two electrode portions 112, but will not make
contact with the electrode portion 112. In this embodiment, there
are four supporting portions 121 that are distributed at two sides
of the electrode portions 112. The housing 111 may at least cover
the supporting portions 121 and at least a part of the two
electrode portions 112, and is at least disposed within a part of
the void area 130. Thereby, the housing 111 is mechanically engaged
with the frame body 120 via the supporting portions 121, and the
housing 111 is also mechanically engaged with the two electrode
portions 112 so that the housing 111 and the two electrode portions
112 can be held within the frame body 120 without falling off from
the frame body 120.
[0058] The shape features of the electrode portions 112 will be
further described. Referring to FIG. 13A, each of the two electrode
portions 112 has a wing portion 112A and an inner side surface 112B
that are disposed opposite to each other (i.e., disposed
oppositely), the wing portion 112A may be exposed outside the
housing cross section 111A of the housing 111 (reference may be
made to the aforesaid relevant descriptions of FIG. 6 to FIG. 11)
and does not face the wing portion 112A of another electrode
portion 112. The inner side surfaces 112B of the two electrode
portions 112 may face each other, and at least a part of the two
electrode portions 112 may be covered by the housing 111.
[0059] Each of the two electrode portions 112 further comprises two
connecting surfaces 112C disposed opposite to each other, and each
of the connecting surfaces 112C connects the wing portion 112A with
the inner side surface 112B. That is, an edge (e.g., a front edge)
of the connecting surface 112C connects with an edge (i.e., a left
edge) of the wing portion 112A, while another edge (e.g., a back
edge) of the connecting surface 112C connects with an edge (i.e., a
left edge) of the inner side surface 112B. The wing portion 112A,
the inner side surface 112B and the two connecting surfaces 112C
may not be flat surfaces. That is, the wing portion 112A, the inner
side surface 112B and the two connecting surfaces 112C may be
uneven or stepped surfaces.
[0060] Each of the two electrode portions 112 may further comprise
at least one recess 1121, and the recess 1121 may be disposed on
the connecting surface 112C so that the connecting surface 112C
becomes an uneven surface. The recess 1121 can increase the contact
area between the electrode portion 112 and the housing 111 (the
plastic body 150) and strengthen the fastening effect between the
electrode portion 112 and the housing 111 by virtue of the
corresponding geometric relationships so that the binding force
between the electrode portion 112 and the housing 111 is relatively
strong. If there are a plurality of recesses 1121, the recesses
1121 may be sized differently according to different binding forces
required at different positions between the electrode portion 112
and the housing 111.
[0061] The wing portion 112A, the inner side surface 112B and the
two connecting surfaces 112C of the two electrode portions 112 may
have the at least one void area 130 divided into a plurality of
void areas 130, namely a gap 131, two first through grooves 132 and
two second through grooves 133 in communication with each other.
The gap 131 is disposed between the inner side surfaces 112B of the
two electrode portions 112, and the two first through grooves 132
are disposed along the two connecting surfaces 112C of the two
electrode portions 112. That is, one of the first through grooves
132 extends from an edge of one connecting surface 112C of one
electrode portion 112 to an edge of one connecting surface 112C,
which faces the same direction, of the other electrode portion 112.
The two first through grooves 132 are spaced apart from each
other.
[0062] The two second through grooves 133 are disposed along the
wing portions 112A of the two electrode portions 112. That is, each
of the second through grooves 133 extends only along the wing
portion 112A of one of the electrode portions 112. The two second
through grooves 133 are also spaced apart from each other.
[0063] The supporting portion 121 of the frame body 120 may extend
towards one of the two connecting surfaces 112C of the two
electrode portions 112 into one of the two first through grooves
132. The housing 111 may be optionally disposed within the two
first through grooves 132 and/or the gap 131. Additionally, the
housing cross section 111A of the housing 111 may at least comprise
a curved surface, e.g., may have a rounded corner 111R as shown in
FIG. 12D. The housing cross section of the housing 111 has the
rounded corner that is connected to the electrode portion cross
section 203 of the electrode portion 112. The rounded corner 111R
can disperse the impact force so that the rounded corner 111R is
unlikely to be broken or cracked by the impact force during a
vibration test of the singulated carrier 110. Moreover, in the
embodiment as shown in FIG. 12D, the housing cross section and the
electrode portion cross section do not form a flat surface, i.e.,
the housing cross section is not level with the electrode portion
cross section.
[0064] According to the above descriptions, the carrier leadframe
100' can also allow the electrode portions 112 of the carriers 110
to be electrically isolated from each other. Thus, after the die
bonding process, the wire bonding process and the encapsulation
process are subsequently performed on the light emitting devices,
the electric measurement can be directly performed on the light
emitting devices that are not singulated, and this greatly improves
the production speed of the light emitting devices. It shall be
further appreciated that, the technical contents of the carrier
leadframe 100' may also be used as a reference for the carrier
leadframe 100.
[0065] An embodiment of the present disclosure further provides a
method for manufacturing a carrier leadframe, which can at least
manufacture the aforesaid carrier leadframe 100'. The method for
manufacturing the carrier leadframe 100' is similar to the method
for manufacturing the aforesaid carrier leadframe 100 and comprises
the following steps.
[0066] Referring to FIG. 13A to FIG. 13C, first a conductive sheet
160 is provided. The conductive sheet 160 comprises a frame body
120, and the frame body 120 comprises at least one supporting
portion 121, at least one void area 130 and at least one extending
portion 140. The at least one void area 130 may correspond to a gap
131, two first through grooves 132 and two second through grooves
133 of the carrier leadframe 100', but at this point, the two first
through grooves 132 are not in communication with the two second
through grooves 133 yet. The at least one extending portion 140 may
correspond to the two electrode portions 112 of the carrier
leadframe 100', but at this point, the two electrode portions 112
have not been separated from the frame body 120 yet.
[0067] Referring to FIG. 14, then a plastic body 150 is formed in a
second step. The plastic body 150 covers at least a part of the
extending portion 140 and at least a part of the supporting portion
121, and the plastic body 150 fills at least a part of the void
area 130. For example, the plastic body 150 covers a part of the
two electrode portions 112 of the extending portion 140 and
completely covers the supporting portion 121, and the plastic body
150 fills the gap 131 and the two first through grooves 132 of the
void area 130 but does not fill the second through grooves 133 of
the void area 130. Furthermore, the plastic body 150 may make
contact with the recess 1121 (as shown in FIG. 13A) of the
extending portion 140 so as to increase the contact area between
the plastic body 150 and the extending portion 140.
[0068] Referring to FIG. 15, part of the plastic body 150 filled in
the void area 130 is removed in a third step. That is, part of the
plastic body 150 filled in the two first through grooves 132 is
removed. The plastic body 150 to be removed is called the residual
material 151 (as shown in FIG. 14), and the scope of the residual
material 151 is defined depending on the specific shape of the
product. In this embodiment, the plastic body 150 filled in two end
areas of the two first through grooves 132 is removed so that
convex corners at four corners of the plastic body 150 are removed.
The remaining plastic body 150 forms the housing 111 of the carrier
leadframe 100'.
[0069] Referring to FIG. 16, the part of the extending portion 140
exposed outside the plastic body 150 is removed in a fourth step so
that the remaining extending portion 140 is separated from the
frame body 120. In other words, the part of the extending portion
140 at two sides of the second through groove 133 (as shown in FIG.
15) will be removed in this step so that the second through groove
133 is in communication with the first through groove 132. The
remaining extending portion 140 forms the electrode portions 112 of
the carrier leadframe 100'.
[0070] After the aforesaid steps, the carrier leadframe 100' is
formed. For detailed technical contents of the aforesaid steps,
reference may be made to the method for manufacturing the carrier
leadframe 100. For example, a conductive layer may be firstly
formed on the conductive sheet 160, the third step and the fourth
step may be swapped with each other, and the plastic body 150 may
be cleaned before the fourth step.
[0071] Referring to FIG. 17A to FIG. 17D, schematic views (i.e., a
top view, a cross-sectional view taken along the front-to-back
direction, a cross-sectional view taken along the left-to-right
direction, and a partially enlarged view) of a carrier leadframe
100'' according to an embodiment of the present disclosure are
shown therein, where more than one carrier leadframe 100'' are
shown.
[0072] The carrier leadframe 100'' is similar to the aforesaid
carrier leadframes 100 and 100', so reference may be made to each
other for the technical contents of the carrier leadframes 100'',
100, and 100'. However, it shall be appreciated that, the frame
body 120 of the carrier leadframe 100'' has a side portion 123 and
a runner area 122, and the side portion 123 may be commonly owned
by the leadframes 120 of two carrier leadframes 100''. In other
words, the frame body 120 of the two carrier leadframes 100'' may
be formed integrally via the commonly owned side portion 123.
Moreover, the carriers 110 of the two carrier leadframes 100'' are
separated from each other by the side portion 123. The runner area
122 is disposed in the side portion 123 and is in communication
with one of the two first through grooves 132 of each carrier
leadframe 100''. It shall be further appreciated that, the housing
cross section 111A of the housing 111 may at least comprise a
curved surface, e.g., may have a rounded corner 111R, and the
rounded corner 111R is connected to the side portion 123 of the
frame body 120. Additionally, the electrode portion cross section
of the electrode portion 112 may also at least comprise a curved
surface, and the aforesaid curved surfaces are not limited to a
single curvature. That is, the outline of the edge areas of the
electrode portion 112 is a curved line. The electrode portion cross
section 203 is not adjacent to the rounded corner 111R. The impact
force can be dispersed due to the curved cross section. Meanwhile,
in the embodiment as shown in FIG. 17D, the housing cross section
and the electrode portion cross section 203 do not form a flat
surface, i.e., the housing cross section is not level with the
electrode portion cross section 203.
[0073] In terms of the effect, the carrier leadframe 100'' can also
allow the electrode portions 112 of the carriers 110 to be
electrically isolated from each other. Thus, after the die bonding
process, the wire bonding process and the encapsulation process are
subsequently performed on the light emitting devices, the electric
measurement can be directly performed on the light emitting devices
that are not singulated, and this greatly improves the production
speed of the light emitting devices.
[0074] An embodiment of the present disclosure further provides a
method for manufacturing a carrier leadframe, which can at least
manufacture the aforesaid carrier leadframe 100''. The method for
manufacturing the carrier leadframe 100'' is similar to the method
for manufacturing the carrier leadframe 100', so identical
descriptions will be omitted or simplified. The method for
manufacturing the carrier leadframe 100'' may comprise the
following steps.
[0075] Referring to FIG. 18A to FIG. 18C, first a conductive sheet
160 is provided. Two conductive sheets 160 are provided in this
embodiment as an example. Each of the conductive sheets 160
comprises at least one frame body 120, and the frame body 120
comprises at least one supporting portion 121, at least one side
portion 123, at least one runner area 122, at least one void area
130 and at least one extending portion 140. The runner area 122 is
disposed on the side portion 123 and is in communication with the
void area 130.
[0076] Referring to FIG. 19, then a plastic body 150 is formed in a
second step. The plastic body 150 covers at least a part of the
extending portion 140 and at least a part of the supporting portion
121 of each conductive sheet 160, and the plastic body 150 fills at
least a part of the void area 130. The plastic body 150 also fills
the runner area 122; that is, the plastic body 150 passes through
the runner area 122 to cover another conductive sheet 160.
Moreover, the plastic body 150 makes contact with the recess 1121
(as shown in FIG. 18A) of the extending portion 140 to increase the
contact area between the plastic body 150 and the extending portion
140.
[0077] Referring to FIG. 20, the plastic body 150 within the runner
area 122 is removed in a third step. The plastic body 150 can be
removed in one step or in several steps. Specifically, if the
plastic body 150 is to be removed in one step, then a knife of a
length larger than that of the runner area 122 will be used to
remove the part of the frame body 120 at the two sides of the
runner area 122 as well as the plastic body 150 within the runner
area 122 together. Thus, after the plastic body 150 within the
runner area 122 is removed, the runner area 122 will be slightly
elongated.
[0078] If the plastic body 150 is to be removed in several steps,
then first a knife of a length slightly smaller than that of the
runner area 122 will be used to remove part of the plastic body 150
within the runner area 122, and then another knife is used to
scrape off the remaining plastic body 150 within the runner area
122.
[0079] Referring to FIG. 21, part of the plastic body 150 filled
within the void area 130 is removed in a fourth step. That is, part
of the plastic body 150 filled within the two first through grooves
132 (e.g., the residual material 151 at the four corners as shown
in FIG. 20) is removed. After the third and the fourth steps, the
remaining plastic body 150 that is not removed forms the housing
111 of the carrier leadframe 100''.
[0080] Referring to FIG. 22, the part of the extending portion 140
exposed outside the plastic body 150 (as shown in FIG. 21) is
removed in a fifth step so that the remaining extending portion 140
is separated from the frame body 120. In other words, the part of
the extending portion 140 at the two sides of the second through
groove 133 will be removed in this step so that the second through
groove 133 is in communication with the first through groove 132.
The remaining extending portion 140 forms the electrode portions
112 of the carrier leadframe 100''.
[0081] After the aforesaid steps, the carrier leadframe 100'' is
formed. It shall be noted that, the order in which the third step
to the fifth step are executed is not limited, but can be swapped
with each other.
[0082] FIG. 23 to FIG. 26B schematically shows the manufacturing
process of the carrier leadframe of the present invention.
[0083] First of all, a carrier leadframe as shown in FIG. 23 is
provided. The carrier leadframe is a processed metal plate
including a frame body 120 and a plurality of void areas 130. The
frame body includes a plurality of extending portions 140, a
plurality of side portions 123, supporting portions 121 and a
plurality of tie bars 202. The void area may include a plurality of
gaps 131, a plurality of running areas 122, and a plurality of
grooves 132. More specifically, the carrier leadframe is a metal
plate with a plurality of the void areas 130 formed by stamping or
etching process. Preferably, the carrier leadframe is plated after
the void area 130 is formed such that the top and bottom surface of
the carrier leadframe and the side surface of the void area 130 are
plated with a protective plating layer. The present invention does
not have special limitations on the material of the metal sheet,
although copper or aluminum is preferred. The protective plating
layer must be more resistant to oxidation than the metal sheet and
is preferably silver or gold. The supporting portion 121 generally
is placed at the side surface of the extending portion, A portion
of the supporting portion 121 may extend toward to the extending
portion 140 for increasing the binding force between resin and the
frame body 120, however the supporting portion 120 would not
contact with the extending portion 140. The extending portion 140
may connect with the frame body 120 through a plurality of tie bars
202. A plurality of tie bars 202 are generally disposed at one side
end of the extending portion 140. For the present embodiment, there
are two tie bars 202 are disposed at one of the extending portion
140. Moreover, in order to reduce the cutting region for the follow
step, there would be a void area 130 between the two tie bars 202,
therefore, the cutting speed may improve and reduce the cost for
cutting step.
[0084] For the present embodiment, the different grooves 132 may
connect with each other through the gap 131 and the runner area
122. However, the runner area 122 maybe placed depending on the
molding process. If the transfer molding process is being selected,
it may necessary to have the runner area between the different
grooves 132.
[0085] Following that, the carrier leadframe is then provided with
a molded body by a molding process, as shown in FIG. 24. In this
step, molding is carried out by holding the carrier leadframe
within a mold with a plurality of blocks in order to form a
plurality of carriers on the carrier leadframe. More specifically,
a plastic material enters the plurality of grooves 132, a plurality
of gaps 131 and a plurality of runner areas 122 by filling the
cavities of the mold. The plastic material would be cured in
further to form a plurality of carriers. Each of the carriers would
comprise a housing 111 and a plurality of residual material 151,
and the housing 111 would comprise a reflection concave cup on the
portion of the extending portion 140. The housing portion 111 may
partially covers a portion of the extending portions 140 and
includes plastic body that extends through the corresponding
locking holes 141 to reinforce connection between the housing
portion 111 and the corresponding extending portions 140. Each
housing portion 111 may also cover a portion of the supporting
portions 121 so the housing portion 111 may be mechanically coupled
to the corresponding supporting portions 121. In the subsequent
stamping process, each housing portion 111 is supported by the
corresponding supporting portions 140 and is thus temporarily fixed
to the frame body.
[0086] Then, the molded body of this embodiment is cut by a stamp
process as shown in FIG. 25. In this step, a portion of the
residual material 151 and a portion of tie bar 202 are removed by
one or multiple stamping operations, with a view to forming several
separated carriers. If only one stamping operation is used, a
portion of the residual material 151 and a portion of tie bar 202
will be removed at the same time. If multiple stamping operations
are used, it is preferable that a portion of the residual material
151 is removed in advance, and then followed by the a portion of
tie bar 202 would be removed, and separates from the frame body in
the final. The separated carrier would be still temporarily fixed
to the frame body 120 by the supporting portions 121 such that a
carrier leadframe with a plurality of separated carriers is formed.
More specifically, the cut surface of the residual material and the
cut surface of the tie bar would result a curved structure at the
cut surface of the tie bar or a multi-step surface as detailed
further below. For the other stamping process is similar as the
stamping process involving in the present exemplary embodiment
shown in FIGS. 1 to 5.
[0087] After stamping process, a carrier leadframe with a plurality
of separated carriers is formed. The plurality of separated
carriers can be detached from the carrier leadframe as a single
carrier by pushing them with an external force. FIG. 26A is a
perspective view of a carrier thus obtained, and FIG. 26B is an
enlarged view of the dashed-line encircled area in FIG. 26A. As
shown in FIG. 26B, the housing has a lateral side provided with a
residual material 151 projected from the concave reflecting cup of
housing, wherein the residual material 151 has a width T1 for the
top surface of the residual material 151. FIG. 26B also shows an
electrode portion with a wing portion 112A protruding beyond the
housing, wherein the wing portion 112A is further divided into a
central area 112A1 and two edge areas 112A2 which would be located
at the two end side of the central area. The top surface of the
central region 112A1 and the edge area 112A2 comprise a width as T2
and T3 accordingly. In the present invention, the relationship
between T1, T2, and T3 is (T1<T2<T3). Preferably, T3 is at
least 1.2 times as large as T2, and T2 is 1.2 times as large as T1.
Besides, the difference between T2 and T3 is preferably greater
than that between T1 and T2, namely (T2-T1)>(T1-T2). The lateral
side of the central area 112A1 used to be the wall surface of a
lateral through hole and therefore has a protective plating layer.
The edge areas 112A2, on the other hand, are where tie bars 202 are
cut and therefore each have a electrode portion cross section 203,
in which the material of the metal sheet, e.g., copper, is
completely exposed. The electrode portion cross section 203 of each
edge areas 112A2 has a smaller area than the outer side surface of
central area 112A1. As the exposed metal portions may result the
reliability issue when the separated carrier connects to a PCB,
therefore an external plating layer is provided for protection.
Preferably, if the external plating layer is used for protection,
the external plating layer would cover the electrode portion cross
section 203 entirely. If it is impossible for the external plating
layer to cover the electrode portion cross section 203 entirely,
the external plating layer should at least cover the upper region
of the electrode portion cross section 203 so that, when the
separated carrier is connected to the PCB, the lower region of the
electrode portion cross section 203 can be isolated from the
environment by soldering material while the upper region of the
electrode portion cross section 203 can be protected by the
external plating layer.
[0088] When forming the aforesaid plating layers, the thickness of
the external plating layer is not required to be the same as the
protective plating layer. Normally, the protective plating layer is
thicker than the external plating layer. Moreover, the external
plating layer can be formed by barrel plating, or the protective
plating layer can extend downward through the cutting operation so
as to cover the electrode portion cross section 203 partially.
Preferably, the extended protective plating layer covers the
electrode portion cross section 203 in their entirely. Referring
again to FIG. 26B, the residual material has a resin cross section
201, and the resin cross section area 201 is preferably smaller
than the outer side surface of the wing portion 112A. Preferably,
the resin cross section 201 forms a rough surface after the cutting
operation. An additional plating layer may be further formed on the
lateral side of the carrier to protect the electrode portion cross
section 203. Apart from that, the resin cross section 201 and the
outer side surface of the reflective wall are preferably to be
substantial coplanar in order to increase the area of the outer
side surface of the electrode for soldering material.
[0089] The above description is related to the detailed technical
contents and inventive features thereof. People skilled in this
field may proceed with a variety of modifications and replacements
based on the description and suggestions of the present disclosure
as described without departing from the characteristics thereof.
Nevertheless, although such modifications and replacements are not
fully disclosed in the above descriptions, they have substantially
been covered in the following claims as appended.
* * * * *