U.S. patent application number 11/053478 was filed with the patent office on 2005-09-08 for discrete electronic component and related assembling method.
This patent application is currently assigned to Askoll Holding S.r.l.. Invention is credited to Marioni, Elio.
Application Number | 20050195586 11/053478 |
Document ID | / |
Family ID | 34684823 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050195586 |
Kind Code |
A1 |
Marioni, Elio |
September 8, 2005 |
Discrete electronic component and related assembling method
Abstract
The present invention relates to a substantially package-like
discrete electronic component of the type comprising a power
electronic circuit, a body or casing, substantially parallelepiped,
and electric connecting pins connected inside the body with said
circuit and projecting from said body for an electric connection on
the electronic printed circuit board. The body has a heat
dissipating header having at least one surface emerging from the
body and laying on a plane whereas the pins project from the body
for a first section initially extended parallel to the plane.
Advantageously a pair of pins has a substantially U-shaped bending,
after the first section parallel to the plane for allowing a more
stable bearing of the component during the step of welding to a
heat dissipating intermediate die.
Inventors: |
Marioni, Elio; (Dueville
(Vicenza), IT) |
Correspondence
Address: |
AKERMAN SENTERFITT
P.O. BOX 3188
WEST PALM BEACH
FL
33402-3188
US
|
Assignee: |
Askoll Holding S.r.l.
Povolaro di Dueville (Vicenza)
IT
|
Family ID: |
34684823 |
Appl. No.: |
11/053478 |
Filed: |
February 8, 2005 |
Current U.S.
Class: |
361/807 |
Current CPC
Class: |
H05K 2201/1056 20130101;
H05K 2201/10757 20130101; H05K 1/0209 20130101; H05K 2201/09781
20130101; H05K 3/3426 20130101; H05K 3/3447 20130101; H05K 1/145
20130101; H05K 2201/10522 20130101; H05K 2201/10204 20130101; Y10T
29/4913 20150115; H05K 2201/10166 20130101 |
Class at
Publication: |
361/807 |
International
Class: |
H05K 007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 12, 2004 |
EP |
04425094.2 |
Claims
1. A substantially package-like discrete electronic component of
the type comprising a power electronic circuit, a body or casing,
substantially parallelepiped, and electric connecting pins
connected inside the body with said circuit and projecting from
said body for an electric connection on a printed circuit
electronic board, said body having a heat dissipating header having
at least one surface emerging from the body and laying on a plane;
said pins projecting from said body for a first section initially
extended parallel to said plane, characterised in that at least one
of said pins has a substantially U-shaped bending, after said first
section, with the base of the U tangent to said plane).
2. A discrete electronic component according to claim 1,
characterised in that the free end sections of the pins and of said
at least one pin with U-shaped bending extend substantially
perpendicularly to said plane in the opposite direction with
respect to said header.
3. A discrete electronic component according to claim 1,
characterised in that said header and said at least one pin are
tied to an intermediate die for connecting with a heat sink.
4. A discrete electronic component according to claim 1,
characterised in that it comprises two pins with U-shaped bending
and in that said header and said pins are tied to an intermediate
die for connecting with a heat sink.
5. A discrete electronic component according to claim 3,
characterised in that the tie is obtained by welding with alloy
paste.
6. A discrete electronic component according to claim 3,
characterised in that at least three components are tied to a same
intermediate die and in an adjacent position.
7. A method for assembling discrete electronic components as in
claim 1 on printed circuit boards, characterised in that it
comprises the following steps: predisposing an intermediate die
equipped with first pads defined in predetermined positions with
alloy cream for welding and each conterformed at the header of said
body and second pads counterformed at the base of the U-shaped
bending of said at least one pin; laying discrete components on
said die with number and order corresponding to said first and
second pads; assembling, by means of automatic assembling machines,
the group of the die and of the components placed thereon and
transferring them into a remelting oven obtaining, by welding, a
single modular element; assembling, on a corresponding area of the
electronic printed circuit board multiple modular elements by means
of automatic assembling machines.
8. A method according to claim 7, characterised in that said pads
are provided to lay said components in an adjacent position with
pins facing the same direction.
9. A method according to claim 7, characterised in that said alloy
paste is silk-screen printed on said die.
Description
FIELD OF APPLICATION
[0001] The present invention relates to a discrete electronic
component such as for example a power switch. The invention also
relates to a related assembling method of this discrete electronic
component on an electronic board.
[0002] During recent years the use of these discrete electronic
components in printed circuit boards has undergone a considerable
increase being the same simple to be controlled and reliable in the
applications.
PRIOR ART
[0003] As it is well known, the substantially package-like discrete
electronic components comprise a power electronic circuit assembled
on a small metallic frame, wherein some electric connecting pins
are defined, and a protecting body or casing realised with
insulating plastic material, for example an epoxy resin. The
connecting pins project from said body and they allow, once the
discrete electronic components are assembled on a printed circuit
board, the transmission of electronic signals from and towards
conduction paths defined in the board itself.
[0004] As it is known, these discrete electronic components have a
high dissipation of energy and they are provided with an internal
heat sink element. This element can comprise for example a header
associated with the discrete electronic component and incorporated
in the body of plastic material.
[0005] During the assembling step of the component on the board the
header, in many cases, happens to stay at the opposite part with
respect to the board itself and it facilitates the dissipation of
heat.
[0006] During the designing step of the board attention has to be
paid on where these discrete electronic components are installed by
using some solutions which allow a good thermal conduction capacity
so as to convey and evacuate the energy dissipated therefrom.
[0007] When more discrete electronic components are in a same board
it is known that it is preferable to group all the components on a
single area and to equip the area with a big heat sink of the type
with fins.
[0008] It is known technical teaching to interpose, between the
heat sink with fins and each header of the discrete electronic
components, an intermediate die realised with an electric
insulating material and good conductor of heat, for example
alumina. This intermediate die also allows to block two or more
adjacent discrete components for being assembled together on the
printed circuit board. This blocking occurs by means of check means
such as clips or the like.
[0009] During the assembling step it will thus be needed to place
the electronic components on the printed circuit board, to place
the intermediate dies, to fix the clips and then to place on top
the heat sink with fins.
[0010] Although advantageous under several aspects, and
substantially meeting the aim, this first known technical solution
has a drawback hereafter underlined. The assembly thus described
cannot occur mechanically, in fact the clips will have to be
manually placed by an operator and this with a considerable
expenditure of time and increased costs.
[0011] A second solution to the underlined technical problem could
be that of fixing, by means of a fixer of metallic alloy paste, the
headers of the discrete electronic components to the intermediate
die and thus placing the obtained component on the board.
[0012] Also this second solution is not exempt from drawbacks; in
particular, once the header of each discrete component is placed on
the intermediate die, everything must be transferred into a
remelting oven. During this fixing step the headers of each
discrete electronic component could rotate fixing on the die in a
wrong and/or misaligned position. This would make the operation
itself vain and useless in fact the obtained component could not be
installed on the board since there would not be correspondence
between the pins of the discrete electronic components and the
printed circuit.
[0013] The technical problem underlying the present invention is
that of devising a discrete electronic component having such
structural and functional characteristics as to allow a simple,
fast and univocal fixing of the same on a supporting die for being
subsequently assembled together with other components on a printed
circuit board overcoming the drawbacks cited with reference to the
prior art.
SUMMARY OF THE INVENTION
[0014] The solution idea underlying the present invention is that
of realising a discrete electronic component which can be tied
easily and with geometrical precision to the intermediate die for
subsequently allowing a fast and easy assembly also of groups of
these components on the printed circuit board and by means of
manipulation automatic means such as for example machines of the
pick-and-place type.
[0015] In substance, according to the invention, each discrete
electronic component stays blocked on the intermediate die also
during the fixing step in the remelting oven.
[0016] On the basis of this solution idea the technical problem is
solved by a discrete electronic component of the previously
indicated type and characterised in that at least one of said pins
has a substantially U-shaped bending, after said first section,
with the basis of the U being tangent to said plane.
[0017] The characteristics and advantages of the discrete
electronic component according to the invention and of the related
assembling method will be apparent from the following description
of an embodiment thereof given by way of indicative and
non-limiting example making reference to the annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows a schematic perspective view of a discrete
electronic component realised according to the present
invention;
[0019] FIG. 2 shows an exploded perspective view of a printed
circuit board with some discrete electronic components and other
components such as for example a heat sink with fins;
[0020] FIG. 3 shows a plan view of an intermediate die provided
between the discrete components and the heat sink with fins;
[0021] FIG. 4 shows a front view of three discrete electronic
components, realised according to the present invention, connected
with an intermediate dissipating die;
[0022] FIG. 5 is a side view of FIG. 4;
[0023] FIG. 6 is a bottom view of FIG. 4.
DETAILED DESCRIPTION
[0024] With reference to these figures, and in particular to the
example of FIG. 1, 1 globally and schematically indicates a
discrete electronic component realised according to the present
invention.
[0025] The discrete electronic component 1 is substantially of the
package-like type and it comprises a body or casing 2,
substantially parallelepiped, and some electric connecting pins 3
projecting from at least one side face 2a of the body 2.
[0026] More in particular, the component 1 incorporates a power
electronic circuit mounted on a small metallic frame, not shown
because conventional, wherein the electric connecting pins 3 are
defined; and the body 2 is a protection casing realised with
insulating plastic material.
[0027] The pins 3 are destined for the electric connection on a
printed circuit electronic board 4, wherein predetermined
conduction paths are defined referring to the pins of the various
electronic components.
[0028] For convenience in the drawing the reported pins 3 are
three. Nothing obviously forbids they can be more or less.
[0029] The body 2 is also provided with an internal heat sink
element which is represented by a header 5 associated with the
supporting small frame of the power electronic circuit and which
emerges on top from the body 2 itself.
[0030] The header 5 has a width substantially identical to that of
the body 2 and it has such a length as to project from the part
opposite to the side face 2a wherefrom the pins 3 project. An
in-view surface of the header 5 lays on a plane P and it emerges
from the body 2.
[0031] The pins 3 projecting from the side face 2a have a first
section initially extended parallelly to the plane P.
[0032] An intermediate pin indicated with number 6 has a standard
conformation substantially L-shaped, being initially realised as
prolongation of the first section parallel to the plane P and
further extending perpendicularly to the plane P, from the opposite
part with respect to the header 5, with such a length as to be
interconnected with the printed circuit electronic board 4.
[0033] The two external pins, 7 and 8, have instead, after the
first section parallel to the plane P, a U-shaped bending
comprising two sections 7a, 8a and 7b, 8b of unequal length.
[0034] Each section 7a and 8a extends along the direction of the
header 5, perpendicularly to the plane P, and it has such a length
as to allow the base 7c, 8c of the U to be tangent to the plane
P.
[0035] The terminal sections 7b and 8b of these pins 7 and 8 have
instead such a length as to allow them to interconnect with the
printed circuit electronic board 4. In substance, the free end
sections of the pin 6 and of the pins 7, 8 with U-shaped bending
are substantially perpendicular to said plane P and they extend in
the opposite direction with respect to the header 5.
[0036] In order to improve the heat dissipation an intermediate
heat dissipating die 9 is used, for example of good heat conductor
metallic material but of reduced cost such as aluminium.
[0037] The intermediate die 9 has a first pad 10 counterformed as
the header 5 of the discrete electronic component 1; as well as a
second pad 11 and a third pad 12 placed and counterformed in order
to respectively correspond to the bases 7c and 8c of the two
external U-bent pins 7 and 8.
[0038] More in particular on the first die 9 a vetronite insulating
bearing is pressed-packed with the pads 10, 11 and 12 being
silk-screen printed.
[0039] The first pad 10, the second 11 and the third pad 13 are
silk-screen printed with a cream or alloy paste 13 of the usual
type for welding.
[0040] This obviously before the automatic assembly of the discrete
electronic component 1, facilitated by its particular conformation,
on the intermediate die 9 and of their transfer to the remelting
oven.
[0041] During the stay in the remelting oven the header 5 would
tend to make all the body 2 boat on the melted alloy cream 13,
however the presence of the further bearings represented by the
bases 7c and 8c of the external pins 7 and 8 prevents the discrete
electronic component 1 from any rotation. Out of analogy, it is as
if the component 1 can be equalised to a table with three bearing
points with a first bearing represented by the large portion of the
header 5 and further points or bearing legs represented by the
U-like bendings of the pins 7 and 8.
[0042] Preferably, three discrete electronic components 1 are
associated with the intermediate die 9, in the case shown by way of
indicative example, according to a predetermined arrangement,
adjacent one another with all the pins facing the same
direction.
[0043] At the output of the remelting oven the three discrete
electronic components 1 and the intermediate die 9 become a single
module 14 to be associated with the printed circuit electronic
board 4.
[0044] According to the needs, the printed circuit electronic board
4 can contain more modules 14.
[0045] Once the modules 14 are fixed on the printed circuit
electronic board 4 above the intermediate die 9 a heat sink 15 with
fins of the known type is generally associated.
[0046] The main advantage of the present invention is that the
discrete electronic component 1, thus realised, results to be
blocked according to a predetermined position on the intermediate
die 9 before the final assembly thereof on the electronic
board.
[0047] Moreover, all the pins 3 of each discrete electronic
component 1 blocked on the intermediate die 9 result to be aligned
in the desired way.
[0048] The module 14 manageable like a usual component of the
printed circuit electronic board 4 can be assembled without any
difficulty by means of an automatized system. Even the modules 14
can be tape supplied to the apparatuses of the pick-and-place type
predisposed for automatized assembly of the components on the
board.
[0049] The assembling system is thus simple, fast and low cost.
[0050] Obviously, variations such as for example discrete
electronic components 1 with one single pin with substantially
U-shaped bending or three or more pins having the same bending will
be considered being part of the scope of protection of the
invention itself.
* * * * *