Semiconductor-component device assembled on a heat sink, assembly method, and lighting device for a motor vehicle including such a device

Abstract

A device including at least one semiconductor component connected to an electrical connection element, the electrical connection element is attached to a heat sink and connected to a group of electrical wires, the group being linked mechanically and electrically to the electrical connection element by a single connector, the group being linked to the heat sink by holding means.

Claims

1. A device including at least one semiconductor component connected to an electrical connection element, so that the at least one semiconductor component is in contact with a first surface of the electrical connection element, the first surface of the electrical connection element is in contact with a heat sink and connected to a group of electrical wires, the first surface of the electrical connection element radiating heat to the heat sink, the group being linked mechanically and electrically to the electrical connection element by a single connector in contact with a second surface of the electrical connection element opposite to the first surface, wherein the group is linked to the heat sink by a holder, and wherein the holder comprises at least a first lug projecting from a side surface of an orifice of the heat sink, the group of electrical wires being held between the first lug and an edge of the orifice.

2. The device according to claim 1, wherein the at least one semiconductor component comprises at least one semi-conductive emitter chip.

3. The device according to claim 2, wherein the electrical connection element is a printed circuit board.

4. The device according to claim 2, wherein the heat sink is substantially L-shaped.

5. The device according to claim 2, wherein the heat sink has openings.

6. The device according to claim 1, wherein the heat sink is linked to a supporting element in a motor vehicle lamp or inside a vehicle rear-light supporting element.

7. The device according to claim 6, wherein the electrical connection element is a printed circuit board.

8. The device according to claim 6, wherein the heat sink has openings.

9. The device according to claim 1, wherein the electrical connection element is a printed circuit board.

10. The device according to claim 1, wherein the heat sink is substantially L-shaped.

11. The device according to claim 10, wherein the holder is on one of the branches of the L-shape of the heat sink.

12. The device according to claim 1, wherein the heat sink has openings.

13. A lighting device for a motor vehicle, wherein the lighting device for a motor vehicle includes the device according to claim 1.

14. A device including at least one semiconductor component connected to an electrical connection element so that the at least one semiconductor component is in contact with a first surface of the electrical connection element, the first surface of electrical connection element is attached to a heat sink and connected to a group of electrical wires, said group being linked mechanically and electrically to said electrical connection element by a single connector in contact with a second surface of the electrical connection element opposite to the first surface, wherein said group is linked to said heat sink by a holder, wherein said group is linked mechanically to said heat sink by said a holder comprising a first portion formed by a clamping ring through which said group passes and a second portion formed by a click-fit foot made of a thermally insulating material attaching said clamping ring to said heat sink, wherein the click-fit foot is inserted in an orifice of the heat sink, and wherein the click-fit foot is thermally decoupled from the heat sink.

15. The device according to claim 14, wherein the click-fit foot includes a click-fit branch comprising two fins that bear against a front side of the heat sink.

16. The device according to claim 14, wherein the click-fit foot includes a click-fit branch comprising two elbows protruding from the click-fit branch in mutually opposing directions forming a click-fit arrow, wherein the click-fit arrow is inserted in the orifice of the heat sink.

17. The device according to claim 14, wherein the click fit foot includes a click-fit branch comprising two fins that bear against a front side of the heat sink around the orifice, and two elbows protruding from the click-fit branch in mutually opposing directions forming a click-fit arrow, wherein the click-fit arrow is inserted in the orifice of the heat sink, and wherein the two elbows bear against a back side of the heat sink around the orifice.

18. A method for assembling a semiconductor component on a heat sink, the semiconductor component being connected to an electrical connection element, so that the semiconductor component is in contact with a first surface of the electrical connection element, wherein the method comprises: a first step in which a group of electrical wires is attached and connected to the electrical connection element using a single connector in contact with a second surface of the electrical connection element opposite to the first surface, a second step in which the group is attached to the heat sink using a holder, and a third step in which the electrical connection element is attached to the heat sink; wherein the holder comprises at least a first lug projecting from a side surface of an orifice of the heat sink, the group of electrical wires being held between the first lug and an edge of the orifice, and the first surface of the electrical connection element is in contact with the heat sink and connected to the group of electrical wires, the first surface of the electrical connection element radiating heat to the heat sink.

Description

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

(1) FIGS. 1A to 1E show a first embodiment of the method for assembling a semiconductor component on a heat sink according to the invention;

(2) FIGS. 2A and 2B show a second embodiment of the method for assembling a semiconductor component on a heat sink according to the invention;

(3) FIGS. 3A and 3B show the device resulting from the first embodiment of the method according to the present invention; and

(4) FIGS. 4A and 4B show the device according to FIGS. 3A and 3B in a lamp.

(5) In these figures, similar elements are indicated using the same reference sign.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) The steps for assembling an electronic semiconductor component 1 on a heat sink according to the first embodiment of the method according to the present invention are illustrated in FIGS. 1A to 1E.

(7) The assembly method mentioned above includes a first step 1a in which a group 3 of electrical wires is attached to a rear face of an electrical connection element 5, which is a printed circuit board (PCB), the front face 6 of which carries the semiconductor component, for example a light emitting diode (LED) 1 (FIG. 1A). A variant of the embodiment in which the LED 1 is assembled on the PCB 5 involves the LED 1 being assembled directly on the heat sink, then connected to the PCB 5, for example by wire solder.

(8) During this first step 1a, the group 3 of electrical wires is attached to the PCB 5 by means of a one-piece connector 7 (or single connector) linked electrically and mechanically to the group 3 such that the PCB 5 is connected physically and electrically to each of the electrical wires in the group 3.

(9) The connection is made by insertion, from the rear face of the PCB 5, of a plurality of contacts 7a present on the one-piece connector 7 into the metallized connection holes 7b formed in the PCB 5, the connector 7 being then wave soldered directly to the PCB 5.

(10) FIG. 1b shows the second step 1b in which the group 3 is attached to the heat sink 2 using means 8 for holding the group 3.

(11) The heat sink 2 is formed by a first portion P.sub.1 and a second portion P.sub.2 linked together directly and for example in a substantially L-shape, i.e. oriented such that a first plane tangential to the first portion P.sub.1 and a second plane tangential to the second portion P.sub.2 form a substantially right angle.

(12) Preferably, the heat sink 2 has openings to enable the circulation of air.

(13) In the first embodiment of the method according to the invention, the second step 1b involves moving the group 3 through a first portion of the holding means 8, which is a clamping ring 8a, the ring 8a being extended by a second portion of the holding means 8, which is a click-fit foot 8b.

(14) The foot 8b has a click-fit branch 8c and two fins 8d, 8d that bear against the heat sink 2.

(15) The click-fit branch 8c comes from an extremity of the foot 8b to which each of the fins 8d, 8d are linked and has two elbows 8e, 8e (or fins) protruding from the click-fit branch 8c in mutually opposing directions such as to form a click-fit arrow comprising the click-fit branch 8c and the two elbows 8e, 8e, this arrow being arranged to be inserted in a first orifice 8f in the heat sink 2, for example in the second portion P2 of same.

(16) Once the group 3 is engaged in the clamping ring 8a, the click-fit branch 8c is inserted (FIG. 1C) in the first orifice 8f such that the elbows 8e, 8e pass through the first orifice 8f entirely and that, once the click-fit branch 8c has been inserted in the first orifice 8f, the two fins 8d, 8d bear against a first face 9 of the second portion P.sub.2, while the elbows 8e, 8e bear against a second face 9 of the second portion P.sub.2 opposite the first face 9. Consequently, the foot 8b is held against each of the first and second faces 9, 9 of the second portion P.sub.2 of the heat sink 2, thereby linking the ring 8a to the heat sink 2.

(17) Preferably, the click-fit branch 8c and the two elbows 8e, 8e form a single arrow-shaped attachment part made of a flexible material, such that this attachment part can be easily inserted into the first orifice 8f by simply pressing same, the connection part, and in particular the elbows 8e, 8e being deformable as they pass through the first orifice 8f before subsequently returning to the original arrow shape, such that the elbows 8e, 8e can bear against the second face 9 of the second portion P.sub.2 of the heat sink 2.

(18) Preferably, the foot 8b is made of a thermally insulating material such that the group 3 is thermally decoupled from the heat sink 2 when the LED 6 is in operation and the heat sink 2 is being heated.

(19) Once the group 3 has been attached to the heat sink 2, the PCB 5 is attached, during a third step 1c (FIG. 1C) to the first portion P.sub.1 of the heat sink 2.

(20) The PCB 5 (FIG. 1C) is attached by any known means, for example by crimping at least one substantially cylindrical pin 51 protruding from the first portion P.sub.1 of the heat sink 2 and arranged to be inserted into a second orifice 52 (or a cavity) made in the PCB 5 designed to tightly fit the pin 51, which is then crushed to fill the orifice 52 such as to irreversibly connect the PCB 5 to the first portion P.sub.1 of the heat sink 2.

(21) Preferably, the PCB 5 is in thermal contact with the heat sink 2 to enable same to control the temperature of the heat sink 2 and to modulate the intensity of the electrical current passing through the LED 1 in order to guarantee the reliability of same by preventing the minimum junction temperature of same from being exceeded. The temperature can be controlled using a thermistor connected to the LED 1 and to the PCB 5.

(22) Preferably, steps 1a to 1c of the first embodiment of the claimed method are carried out consecutively, although this is not obligatory.

(23) Advantageously, the second step 1b of attaching the group 3 is carried out before or after the third step 1c of attaching the PCB 5.

(24) Since the group 3 and the PCB 5 are attached to the heat sink 2 to form a device forming a heat sink 2/group 3/PCB 5 assembly, as shown in FIGS. 3A and 3B, this assembly can then be assembled, during a fourth step 1e illustrated in FIG. 1E, on a supporting element 10 of a motor vehicle lamp.

(25) In a variant embodiment, the assembly can also be assembled on a lamp supporting element before it is assembled on a rear light supporting element of the vehicle.

(26) As shown in FIGS. 3A and 3B, performance of steps 1a to 1c results in a first device comprising an LED 1 carried by the PCB 5 to which the LED 1 is electrically connected. The PCB 5 is attached to the first portion P.sub.1 of the heat sink 2 and connected to the group 3 of electrical wires by the one-piece connector 7. The group 3 is attached to the second portion P.sub.2 of the heat sink 2 using the holding means 8 comprising the clamping ring 8a through which the group 3 passes and the foot 8b attaching the clamping ring 8a to the heat sink 2.

(27) The fourth step 1e for assembling the heat sink 2 on a supporting element 10 of a motor vehicle lamp is shown in FIGS. 4A and 4B. It is done by linking for example the first portion P.sub.1 of the heat sink 2 to the supporting element 10 using connection means comprising for example: a screw 10a arranged to pass through a third orifice present in the first portion P.sub.1 and to be seated in a second cavity 10b of the supporting element 10 having an internal screw thread matching the screw thread of the first screw, and a positioning pin 10e of the reflector enabling the cooling rib to be positioned in the direction Y (horizontal axis perpendicular to the movement of the vehicle, the normal referenced used by the operator) through the oblong hole 10d.

(28) As shown in FIGS. 4A and 4B, the fourth step 1e results in a lighting device for a motor vehicle comprising the first device described above connected to the supporting element 10 of the lamp.

(29) When carrying out this fourth step 1e, placement of the heat sink 2 on the supporting element 10 is not hindered by the presence of floating electrical wires and is therefore quicker to complete than the assembly method in the prior art.

(30) Furthermore, in the method according to the invention, the connector, since it is connected to the PCB 5 before attachment of this latter to the heat sink 2, need not be a two-part connector, in particular, as explained above, a one-piece connector is preferred since this choice represents a material saving and, furthermore, this connector no longer needs to be soldered using a soldering method requiring a material specifically designed to withstand high temperatures of between 200 C. and 300 C.

(31) A second alternative embodiment of the method according to the invention is shown in FIGS. 2A and 2B.

(32) The second and fourth steps 2b, 2e of this second embodiment are the same as in the first embodiment.

(33) On the other hand, this second embodiment differs from the first embodiment in that the second step 2b involves moving the group 3 between a first lug 11a and a second lug 11b and a surface S of the heat sink 2 defined on the first face 9 of the heat sink 2. As a result, the group 3 is held between the lugs 11a, 11b and the surface of the heat sink 2, each of the lugs 11a, 11b projecting from the surface S. In a variant embodiment, only one lug is formed from the heat sink 2 to hold the group 3, and it may be folded as required following positioning of the group in order to prevent any relative movement of the electrical group.

(34) Potentially, the second portion P.sub.2 of the heat sink 2 has a fourth orifice 12, each of the lugs 11a, 11b projecting from the edge of the fourth orifice 12 beneath the lugs 11a, 11b linking the first face 9 to the second face 9.

(35) The presence of this fourth orifice 12 facilitates the placement of high-diameter groups 3 since, when placing this type of group 3 between the heat sink 2 and each of the lugs 11a, 11b, a portion of the group 3, the diameter of which is for example greater than the distance L between the lugs 11a, 11b and a horizontal plane passing through the surface S, may be seated in the orifice 12 and the group 3 is clamped between firstly the two lugs 11a, 11b and secondly a first portion 13 and a second portion 14 of the surface S on either side of the orifice 12.

(36) In this context, the second embodiment of the assembly method is less costly and quicker than the first embodiment for this method. Indeed, since the group 3 is directly linked to the heat sink 2 by the lugs 11a, 11b projecting from the surface S of the heat sink 2, there is no need to use a specific part on the electrical group of the cooling rib.

(37) The device obtained in the second embodiment of the method according to the invention therefore differs from the first device from the first embodiment of the assembly method in that the holding means 8 are first and second lugs 11a, 11b projecting from the surface S (FIG. 2A) of the heat sink 2, the group 3 of electrical wires being held between the first and second lugs 11a, 11b and the surface S.

(38) Although the description relates to a preferred embodiment of the method according to the invention and of the device obtained from such a method in which the semiconductor component is a light-emitting diode 1, the heat sink 2 is a lamp cooling rib and the electrical connection element is the PCB 5, it is understood that the present invention is not limited to these features, but that it also covers other embodiments involving other semiconductor components, other heat sinks for the semiconductor component, and other electrical connection elements.

(39) While the system, apparatus, process and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise system, apparatus, process and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.