U.S. patent application number 09/745933 was filed with the patent office on 2001-05-10 for method for improving the liquid dispensing of ic packages.
This patent application is currently assigned to NeoPac Semiconductor Corp.. Invention is credited to Chung, Chin-Hsing, Hsu, Chi-Hsing, Hsu, Wen-Fu.
Application Number | 20010001070 09/745933 |
Document ID | / |
Family ID | 22811826 |
Filed Date | 2001-05-10 |
United States Patent
Application |
20010001070 |
Kind Code |
A1 |
Hsu, Chi-Hsing ; et
al. |
May 10, 2001 |
Method for improving the liquid dispensing of IC packages
Abstract
A flat plate mold with special treatment or a metallic flat
plate mold is adopted to flatten the resin painted over on IC chips
during package dispensing process, such that it is able to maintain
a consistent flatness of the surface of IC products after
dispensing for laser or ink marking. And heat sinks can be attached
to the flat plate mold to increase the heat-dissipating rate of IC
products after dispensing.
Inventors: |
Hsu, Chi-Hsing; (Hsinchu,
TW) ; Chung, Chin-Hsing; (Hsinchu, TW) ; Hsu,
Wen-Fu; (Hsinchu, TW) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 Slaters Lane, 4th Floor
Alexandria
VA
22314-1176
US
|
Assignee: |
NeoPac Semiconductor Corp.
|
Family ID: |
22811826 |
Appl. No.: |
09/745933 |
Filed: |
December 26, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09745933 |
Dec 26, 2000 |
|
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09217622 |
Dec 22, 1998 |
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Current U.S.
Class: |
438/126 ;
257/796; 257/E23.092; 257/E23.14; 438/122; 438/127 |
Current CPC
Class: |
H01L 2924/15311
20130101; H01L 2924/181 20130101; H01L 2224/48091 20130101; H01L
2224/48091 20130101; H01L 2224/48227 20130101; H01L 2924/14
20130101; Y10T 29/49146 20150115; H01L 24/48 20130101; H01L
2924/12042 20130101; H01L 2224/85399 20130101; H01L 2224/05599
20130101; H01L 2924/00014 20130101; H01L 2924/00014 20130101; H01L
23/4334 20130101; H01L 2224/85399 20130101; H01L 2224/97 20130101;
H01L 2924/181 20130101; H01L 2224/97 20130101; Y10T 29/49171
20150115; H01L 2924/00 20130101; H01L 2224/85 20130101; H01L
2224/45099 20130101; H01L 2224/45015 20130101; H01L 2924/207
20130101; H01L 2924/00014 20130101; H01L 2924/00014 20130101; H01L
2924/00014 20130101; H01L 2924/12042 20130101; H01L 2924/00012
20130101; H01L 2924/15311 20130101; H01L 2224/97 20130101; H01L
2224/05599 20130101; H01L 23/24 20130101; H01L 2924/00014 20130101;
Y10T 29/49172 20150115; H01L 24/97 20130101 |
Class at
Publication: |
438/126 ;
438/127; 438/122; 257/796 |
International
Class: |
H01L 021/44; H01L
021/48; H01L 021/50 |
Claims
What is claimed is:
1. A method for improving the liquid dispensing of IC packages,
during a liquid dispensed package process of an IC chip, after
filling liquid resin but before being solidified, a flat plate mold
having a shape to be fitted with the shape of liquid resin on said
IC package and painted over by a coating which is hard to adhere
with said liquid resin and an air vent being provided at proper
position of said flat plate mold is adopted to flatten said resin;
extra resin and air between said liquid resin and said flat plate
mold can be vented away smoothly through said air vent; after said
liquid resin is solidified and said flat plate mold is removed, a
marker of pin one dot will be left on the upper smooth surface of
said resin.
2. A method for improving the liquid dispensing of IC packages
according to claim 1, wherein the circumference of said flat plate
mold is bent downward and is able to cover a substrate of said IC
chip when said flat plate mold covers said resin; and an air vent
is provided at where said circumference of said flat plate mold
covers said substrate; to be used for flattening said liquid resin
on said IC chip after dispensing.
3. A method for improving the liquid dispensing of IC packages,
during a liquid dispensed package process of an IC chip, after
filling liquid resin but before being solidified, a flat plate mold
having a shape to be fitted with the shape of liquid resin on said
IC chip is made of a metal and an air vent is provided at proper
position of said flat plate mold, a surface of said flat plate mold
is treated by roughening or protruding for pressing over said
liquid resin on said IC chip tightly, to be used for flattening
said liquid resin on said IC chip after dispensing and for heat
dissipation; extra resin and air between said liquid resin and said
flat plate mold can be vented away smoothly through said air vent;
after said liquid resin is solidified, said flat plate mold remains
on said resin for heat dissipation.
4. A method for improving the liquid dispensing of IC packages
according to claim 3, wherein the circumference of said flat plate
mold is bent downward and is able to cover a substrate of said IC
chip when said flat plate mold covers said resin; and an air vent
is provided at where said circumference of said flat plate mold
covers said substrate; to be used for flattening said liquid resin
on said IC chip after dispensing and for heat dissipation.
5. A method for improving the liquid dispensing of IC packages
according to claim 3, wherein a metal heat sink is provided at a
surface of said flat plate mold pressed over said resin, and is
formed integrally or adhered with said flat plate mold; when said
flat plate mold is tightly pressed over said resin, said metal heat
sink will be extended into said resin to contact or approach to
said IC chip, thus said IC chip is easy to dissipate heat; a front
surface of said metal heat sink is also treated by roughening or
protruding.
6. A method for improving the liquid dispensing of IC packages
according to claim 4, wherein a metal heat sink is provided at a
surface of said flat plate mold pressed over said resin, and is
formed integrally or adhered with said flat plate mold; when said
flat plate mold is tightly pressed over said resin, said metal heat
sink will be extended into said resin to contact or approach to
said IC chip, thus said IC chip is easy to dissipate heat; a front
surface of said metal heat sink is also treated by roughening or
protruding.
7. A method for improving the liquid dispensing package of MAP IC
chip, during a liquid dispensed package process of a matrix array
package (MAP) IC chip, after filling liquid resin but before being
solidified, a flat plate mold is designed to be fitted with many
MAP IC chips on a substrate, such that each IC chip has a
corresponding air vent respectively on said flat plate mold; and to
be used for flattening the surface of said resin after filling said
resin; extra resin and air between said liquid resin and said flat
plate mold can be vented away smoothly through said air vents;
after said liquid resin is solidified and said flat plate mold is
removed, a marker of pin one dot for each IC chip will be left on
the upper smooth surface of said resin; and then said MAP is sawed
into many individual IC products.
8. A method for improving the liquid dispensing package of MAP IC
chip, during a liquid dispensed package process of a matrix array
package (MAP) IC chip, after filling liquid resin but before being
solidified, a flat plate mold made of a metal is designed to be
fitted with many MAP IC chips on a substrate, such that each IC
chip has a corresponding air vent respectively on said flat plate
mold; and to be used for flattening the surface of said resin after
filling said resin and for heat dissipation; extra resin and air
between said liquid resin and said flat plate mold can be vented
away smoothly through said air vents; after said liquid resin is
solidified, said flat plate mold remains on said resin for heat
dissipation, a marker of pin one dot for each IC chip will be left
on upper surface of said flat plate mold; and then MAP is sawed
into many individual IC products.
9. A method for improving the liquid dispensing package of MAP IC
chip according to claim 8, wherein a metal heat sink is provided
respectively for each IC at a surface of said flat plate mold
pressed over said resin, and is formed integrally or adhered with
said flat plate mold; when said flat plate mold is tightly pressed
over said resin, said metal heat sinks will be extended into said
resin to contact or approach to IC chips, thus IC chips are easy to
dissipate heat; a front surface of said metal heat sink is also
treated by roughening or protruding.
Description
FIELD OF THE INVENTION
1. The present invention relates to an improvement of IC package,
and more particularly to the use of a flat plate mold with special
treatment during IC package dispensing process, such that it is
able to improve the surface flatness of an IC product after
dispensing; and a heat sink can be attached to the flat plate mold
to improve the heat-dissipating problem of IC product.
BACKGROUND OF THE INVENTION
2. In traditional plastic ball grid array (PBGA) package dispensing
process, the surface of an IC package is not so smooth as that of a
molding process.
3. Please refer to FIG. 1, which shows the traditional
manufacturing processes of a liquid encapsulated plastic ball grid
array, and has steps as below:
4. (1.1) Preparation of a substrate 1
5. (1.2), Mounting IC chip 2 (die attach)
6. (1.3) Bonding wire 3
7. (1.4) Dispensing liquid dam resin 4
8. (1.5) Filling liquid resin 5
9. (1.6) Mounting balls 6
10. Due to the surface tension of liquid resin 5, it is possible to
form an arc or spherical shape on the surface of resin 5 after
solidification. The non-flatness of the resin surface will directly
affect the quality of laser marking or ink marking. Also in
traditional IC package dispensing process, there is no such a way
of attaching heat sink. Therefore, the heat dissipation of a
dispensing-type product will become a serious problem.
OBJECTS OF THE INVENTION
11. Therefore, one of the objects of the present invention is to
adopt a flat plate mold with special coating treatment to flatten
resin surface of IC package, such that the surface flatness of a
dispensing-type IC product will be improved. The coating of flat
plate mold is teflon or any other coatings which are hard to adhere
with liquid resin. A vent or pin one dot is provided on the flat
plate mold for venting away of liquid resin, solvent or diluent to
avoid generation of voids. The pin one dot is used for recognition
for a surface mount device. Therefore, after removing the flat
plate mold, it is adapted to a marking process of the resin surface
of IC package. A convex point will be formed on the resin surface
simultaneously, which can be used as a marker for pin one dot.
12. Another object of the present invention is to adopt a metal
flat plate mold, and in particular, to be designed with a heat
sink. After the metal flat plate mold flattens the resin surface,
the heat sink can contact with or approach to IC chip for heat
dissipation. The metal flat plate is provided with a vent or pin
one dot, and its inner surface can be treated by roughening or
protruding process to increase the adhesion between heat sink and
resin, and prevent from delamination.
13. A further object of the present invention is to adopt a flat
plate mold structure with special design for the dispensing
manufacturing of matrix array package (MAP). On the special flat
plate mold, a vent or pin one dot has been provided for each IC in
MAP respectively, to be adapted for the package of multiple chip
modules (MCM) to increase the productivity of the process and raise
the yield of the product.
BRIEF DESCRIPTION OF THE DRAWINGS
14. FIG. 1 is a process drawing of the formation of a traditional
PBGA liquid dispensed package;
15. FIG. 2 is a process drawing of a first embodiment of the liquid
dispensed package of the present invention;
16. FIG. 3 is process drawing of a second embodiment of the liquid
dispensed package of the present invention;
17. FIG. 4 is a process drawing of a third embodiment of the liquid
dispensed package of the present invention;
18. FIG. 5 is a process drawing of a fourth embodiment of the
liquid dispensed package of the present invention;
19. FIG. 6 is a process drawing of a fifth embodiment of the liquid
dispensed package of the present invention;
20. FIG. 7A and FIG. 7B are schematic views of the inner surface on
the flat plate mold after roughening or protruding treatment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
21. Please refer to FIG. 2, it is a process drawing of a first
embodiment of a liquid dispensed package of the present invention.
After filling the thermosetting liquid resin 5 but before being
solidified, a flat plate mold 7 with a special treatment surface is
adopted (step 2.1) to flatten the resin 5 (step 2.2). The flat
plate mold 7 is pressed over on resin 5, and is provided with a
vent 71 or pin one dot at proper position (we can design several
air vents 71 if necessary), therefore it can smoothly vent away the
extra resin 5 and air. After the resin 5 is solidified and the flat
plate mold 7 is removed (step 2.3), a marker of pin one dot will be
left on the resin surface. Finally, balls 6 are mounted on the back
of the substrate 1 (step 2.4). The shape of flat plate mold that
fits with the shape of resin, can be circular or polygon. This
method can be applied to flatten the epoxy resin of either cavity
up or cavity down PBGA package.
22. Please refer to FIG. 3, it is a process drawing of a second
embodiment of a liquid dispensed package of the present invention.
After filling the thermosetting resin 5 but before being solidified
(step 3.1), a flat plate mold 7' with a special treatment surface
is adopted to flatten the resin 5 (step 3.2), but the flat plate
mold 7' can be bent downward at the dam resin 4 to cover the
substrate 1. The flat plate mold 7' is pressed over on resin 5, and
is provided with an upper air vent 71' or pin one dot at proper
position (we can design several air vents 71' if necessary); a
lower side vent 72' is provided at where the flat plate mold 7'
being bent downward to cover the substrate 1 (we can design several
air vents 72' if necessary), therefore extra resin 5 and air can be
vented out smoothly, and resin 5 can be formed according to the
shape of the flat plate mold 7'. After the resin 5 is solidified
and the flat plate mold 7 is removed (step 3.3), a marker of pin
one dot will be left on the resin surface. Finally, balls 6 are
mounted on the back of the substrate 1 (step 3.4). The shape of
flat plate mold that fits with the shape of resin, can be circular
or polygon.
23. Please refer to FIG. 4, which is a process drawing of a third
embodiment of liquid dispensed package of the present invention.
After filling the thermosetting resin 5 but before being
solidified, a flat plate mold 8 that is designed to have a metal
heat sink 82 (step 4.1), is adopted to cover the resin 5 (step
4.2). The flat plate mold 8 is provided with a vent 81 or pin one
dot at proper position (we can design several air vents 81 if
necessary) to smoothly vent away the extra resin 5 and air. Resin 5
can be formed according to the shape of the flat plate mold 8. The
heat sink 82 is formed integrally or adhered with the flat plate
mold 8, and both are made of the same metal; the position of the
heat sinks 82 is just corresponding to the IC chip in the resin 5.
When the flat plate mold 8 is pressed closely over the resin 5, the
heat sink 82 is just contacted or is very close to the IC chip 2,
therefore it will enhance the heat dissipation of the IC chip 2. An
inner surface 84 of the flat plate mold 8 is roughened or by
protruding treatment (see FIG. 7A and FIG. 7B) to enhance the
adhesion between flat plate mold 8/heat sink 82 and resin 5, and
prevent from delamination. The flat plate mold 8 remains on the
resin 5, then balls 6 are mounted on back of the substrate 1 (step
4.3). The shape of flat plate mold that fits with the shape of
resin, can be circular or polygon. This method can be adapted for
the package flattening of a cavity up or cavity down of an IC
package.
24. Please refer to FIG. 5, it is a process drawing of a fourth
embodiment of a liquid dispensed package of the present invention.
After filling the thermosetting resin 5 but before being
solidified, a flat plate mold 8', which is designed to have a metal
heat sink 82' (step 5.1), is adopted to cover the resin 5 (step
5.2). But the flat plate mold 8' is bent downward at dam resin 4 to
cover the substrate 1. The flat plate mold 8' is provided with an
upper air vent 81' or pin one dot at proper position (we can design
several air vents 81' if necessary). A lower air vent 83' is
provided at where the flat plate mold 8' being bent downward to
cover the substrate 1 (we can design several air vents 83' if
necessary), therefore extra resin and air can be vented out
smoothly, and resin 5 can be formed according to the shape of the
flat plate mold 8'. An inner surface 84 of the flat plate mold 8'
is roughened or by protruding treatment (see FIG. 7A and FIG. 7B)
to enhance the adhesion between flat plate mold 8'/heat sink 82'
and resin 5, and prevent from stripping. The flat plate mold 8
remains on the resin 5, then balls 6 are mounted on back of the
substrate 1 (step 5.3). The shape of flat plate mold that fits with
the shape of resin, can be circular or polygon.
25. Please refer to FIG. 6, it is a process drawing of a fifth
embodiment of a liquid dispensed package of the present invention,
which is used for manufacturing of a matrix array package (MAP) in
the dispensing packages process, and adopts a flat plate mold 9 of
special matrix array package (MAP) design for the liquid dispensed
packing (step 6.1). After filling the thermosetting resin 5 on the
matrix array packaged IC chips 2, but before being solidified, the
special designed flat plate mold 9 is pressed over on the resin 5
(step 6.2). The flat plate mold 9 fits with those MAP IC chips 2,
and is provided with a vent 91 or pin one dot respectively for each
IC to smoothly vent away extra resin 5 and air. If the flat plate 9
is with special treatment (i.e. painted with a layer of teflon or
any other coating which is hard to adhere with the liquid resin),
it will be removed after the resin 5 is solidified. If the flat
plate mold 9 is designed by metal, many heat sinks 92 are designed
respectively for each IC chip 2, such that heat generated by each
IC chip 2 can be smoothly vented away. These heat sinks can contact
or approach the IC chip 2 (the one shown in FIG. 6 is a design of
metal heat sink). An inner surface 84 of the flat plate mold 9 is
roughened or by protruding treatment (see FIG. 7A and FIG. 7B) to
enhance the adhesion between the flat plate mold 9/heat sink 92 and
the resin 5 to prevent from delamination. Then, balls 6 are mounted
on back of the substrate (step 6.3), and after sawing of the
substrate, many individual IC packages 10 are obtained (step
6.4).
26. One skilled in this art can make various alterations without
departing from the spirit and scope of the present invention after
reading the present invention. Therefore, the appended claims are
intended to embrace all these variations.
* * * * *