JP2010034255A - Optical semiconductor device module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem with an optical semiconductor device module for vehicle use that a coupler for clamping and fixing a supporting substrate with an optical semiconductor device mounted thereon has a weak joint and lighting and non-lighting are repeated. <P>SOLUTION: A coupler 6 is composed of a housing 61 and power supply irregularities 62a and 62b fixed to an upper part 61U of the housing 61. The power supply irregularities 62a and 62b have a metal coating, e.g., by gold plating, and wiring pattern layers 24a and 24b of a mounting substrate 2 also have a metal coating of the same material. If the mounting substrate 2 is pressed into the coupler 6, the metal coating of the power supply irregularities 62a and 62b and the metal coating of the wiring pattern layers 24a and 24b of the mounting substrate 2 are diffusion-bonded by friction heat at press-fitting. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical semiconductor device module, and more particularly to an in-vehicle optical semiconductor device module such as a headlamp.

  In general, in-vehicle optical semiconductor device modules, such as light-emitting diode (LED) modules, are mounted on a mounting board and fixed together with a coupler for lead wire extraction in the same manner as electronic component modules such as chip resistors and capacitors. Consists of.

  That is, as shown in FIG. 8, the LED 101 is mounted on the mounting substrate 102, and the lead frame (conductive terminal) (not shown) of the LED 101 is connected to the wiring pattern layer on the mounting substrate 102 by bonding wires or wedges (not shown). 102a and 102b are connected. A coupler (connector) 103 having lead wires 103a and 103b is also mounted on the mounting substrate 102 and fixed.

  As shown in FIG. 9, the conductive terminals 103c and 103d of the coupler 103 are fixed to the mounting substrate 102 by solders 104a and 104b.

  The conductive terminals 103c and 103d of the coupler 103 can be fixed to the mounting substrate 102 by screws, resistance welding or laser welding.

  However, as shown in FIG. 9, in fixing the coupler 103 with the solders 104a and 104b, as a result of the heat shock test, a solder crack is caused at the joint between the solders 104a and 104b due to the difference in the linear expansion coefficient between the coupler 103 and the mounting substrate 102. Will occur. In addition, when mounted near the engine, metal diffusion occurs between the conductive terminals 103c and 103d and the solders 104a and 104b in a high temperature environment, and an intermetallic compound is formed. Since this intermetallic compound is generally brittle, solder cracks are generated at the joints of the solders 104a and 104b due to vibration, impact, and bending of the lead wires 103a and 103b. As a result, there is a possibility that non-lighting due to power feeding failure, deterioration of heat dissipation, and dropping of the coupler 103 may be caused. In addition, in-vehicle components that are becoming lead-free are also becoming solder-free.

  Further, when the coupler 103 is fixed with a screw, the rotational torque of the screw is applied to the conductive terminals 103c and 103d, and the conductive terminals 103c and 103d may be deformed, resulting in unlighting.

  Furthermore, in the fixing of the coupler 103 by resistance welding or laser welding, very strong joining can be performed. However, it is very difficult to replace the coupler 103 as compared with the fixing by the solders 104a and 104b and the fixing by screws.

  As described above, fixing of the coupler 103 that directly processes or deforms the conductive terminals 103c and 103d of the coupler 103 causes solder cracks at the joints of the conductive terminals 103c and 103d, deformation of the conductive terminals 103c and 103d, and dropping of the coupler 103. There was a fear.

In recent years, couplers (connectors) that sandwich and fix a mounting substrate (or heat sink) have been employed as an alternative to the above-described direct processing or deformation of the conductive terminals of the coupler. That is, a coupler that is fixed by coupling a male terminal and a female terminal (see: Patent Document 1), a coupler that is sandwiched and fixed by a clip (see: Patent Document 2), and a coupler that is sandwiched and fixed by an attachment (see: Patent Document 3). Alternatively, there is a coupler that is fixed by a leaf spring (see Patent Document 4). In both cases, fixing and feeding are performed simultaneously.
JP 2007-194172 A JP 2007-207594 A JP 2007-242267 A JP 2007-200757 A

  However, when the coupler is fixed by coupling the male terminal and the female terminal, the bonding area cannot be increased. As a result, the male terminal on the mounting board side may be peeled off by the insertion / removal of the male terminal and the female terminal. Also, in coupler fixing by a clip or coupler fixing by an attachment, the clip or attachment vibrates due to engine vibration and power supply is cut off. Further, when the coupler is fixed by a leaf spring, the leaf spring becomes fragile in a high temperature environment, and furthermore, because of a single point contact, if it changes with time, a contact failure occurs and power supply is cut off. In either case, there is a problem that repeated lighting / non-lighting may occur, leading to a vehicle accident.

  In order to solve the above-described problems, an optical semiconductor device module according to the present invention includes an optical semiconductor device having a light emitting portion on an upper surface, and a support having a wiring pattern layer mounted with the optical semiconductor device and connected to the optical semiconductor device. The substrate includes a base and a coupler that press-fits and fixes the support base, and the coupler has a power supply uneven portion for contacting the wiring pattern layer. As a result, the power supply uneven portion of the coupler and the wiring pattern layer are in a two-dimensional multipoint contact, and the bonding area thereof is increased. As a result, the bonding between the support base and the coupler becomes strong.

  The power supply uneven portion has a metal film on the surface, and the wiring pattern layer has a metal film made of the same material as the metal film on the surface. As a result, the power supply uneven portion and the wiring pattern layer are joined by diffusion bonding of the metal film of the power supply uneven portion and the metal film of the wiring pattern layer, and the connection between the support base and the coupler becomes stronger.

  According to the present invention, since the bonding between the support base and the coupler is strengthened, it is possible to prevent repeated lighting / unlighting.

  1A and 1B show an embodiment of an optical semiconductor device module according to the present invention, where FIG. 1A is an exploded perspective view and FIG. 1B is an assembled perspective view.

  In FIG. 1, the LED 1 has a light emitting portion on the upper surface, and has lead frames 1a and 1b for anode and cathode at both ends thereof.

  The mounting substrate 2 mounts the LED 1 and includes a metal layer 21 with good heat dissipation, an insulating layer 22, a resist layer 23, and wiring pattern layers 24a and 24b. This metal layer 21 is made of, for example, Cu, Al or the like because of workability and mass productivity. Wiring pattern layers 24a and 24b are formed at locations opened in the resist layer 23. The wiring pattern layers 24a and 24b are made of copper (Cu) foil and gold (Au) plating having a thickness of 35 to 100 μm, and tin (Sn). It consists of plating or a metal coating made of these alloys. Screw holes 2a, 2b, 2c, and 2d for inserting screws to be described later are provided.

  A heat radiator such as a heat sink may be used instead of the mounting substrate 2.

  In order to make it easier to mount the LED 1 on the mounting substrate 2, a resist layer 23 at the mounting position is opened, and a heat conductive adhesive (silicone heat dissipation grease layer) 3 is applied to the mounting position before mounting the LED 1. Mounted on the substrate 2.

  The leaf springs 4a and 4b (not shown in FIG. 1A and shown in FIG. 1B) fix the LED 1 to the mounting substrate 2 and have conductivity to supply power. The leaf springs 4a and 4b are fixed to the screw holes 2a and 2b of the mounting board 2 by insulating screws 5a and 5b. At this time, the leaf springs 4a and 4b are positioned below the light emitting portion of the LED 1 so as not to change the light distribution characteristics of the LED 1, and the leaf springs 4a and 4b are particularly spring-acting in order to act as a spring. The part is preferably thinner. However, the mounting method of the mounting substrate 2 may be wire bonding using Au wires or AI wires in addition to the leaf springs 4a and 4b.

  The mounting board 2 is press-fitted into the coupler 6, whereby the coupler 6 sandwiches and fixes the mounting board 2. Further, the coupler 6 is fixed to the screw holes 2c and 2d of the mounting substrate 2 via the fixing members 8a and 8b with the insulated screws 7a and 7b. The fixing members 8a and 8b are made of heat resistant resin or metal.

  2A and 2B are diagrams for explaining the leaf springs 4a and 4b of FIG. 1, in which FIG. 2A is a top view, FIG. 2B is a cross-sectional view along line BB ′ in FIG. CC 'line sectional drawing of (A), (D) is DD' line sectional drawing of (A).

As shown in FIG. 2, each leaf spring 4a, 4b has a plurality of, for example, five thin strip-shaped terminals 401, 402, 403, 404, 405 that act as springs. The lengths L ₁ , L ₂ , L ₃ , L ₄ , and L ₅ of the strip-shaped terminals 401, 402, 403, 404, and 405 are different from each other. For example,
L ₁ = 1mm
L ₂ = 2mm
L ₃ = 3mm
L ₄ = 4mm
L ₅ = 5mm
It is. Thereby, the natural frequency of each strip-shaped terminal 401, 402, 403, 404, 405 is made different. Here, since one of the strip-shaped terminals 401, 402, 403, 404, and 405 is a fixed end and the other is a supporting beam, the natural frequency f is
f = k _n ² / 2πL ² × (EI / ρA) ^1/2 (1)
Where k _n is a constant of the n th order vibration, k ₁ = 3.927, k ₂ = 7.069, k ₃ = 10.210,.
L is the length of the strip terminal,
E is the Young's modulus of the strip terminal,
I is the moment of inertia of the strip-shaped terminal,
ρ is the density of strip terminals,
A is a cross-sectional area of the strip-shaped terminal. Therefore, if the material of the strip-shaped terminal is Cu, the thickness is 1 mm, and the width is 1 mm,
L ₂ = 1.8L ₁ (2)
L ₃ = 2.6L ₁ (3)
L ₄ = 3.4 L ₁ (4)
L ₅ = 4.2L ₁ (5)
In this case, the strip-shaped terminals 401, 402, 403, 404, and 405 vibrate simultaneously, that is, resonate, and problems such as LED1 dropping and repeated lighting / unlighting occur. However, in the case of FIG. 2, the lengths L ₁ , L ₂ , L ₃ , L ₄ , and L ₅ are made different, but the expressions (2), (3), (4), and (5) are not satisfied. Like that. For example, as described above, if L ₁ = 1 mm, L ₂ = 2 mm, L ₃ = 3 mm, L ₄ = 4 mm, and L ₅ = 5 mm, equations (2), (3), (4), (5) As a result, simultaneous vibration (resonance) of the strip-shaped terminals 401, 402, 403, 404, and 405 is suppressed.

In FIG. 2, the vibration of the leaf spring can be suppressed if the lengths of at least two strip-like terminals are different. Further, the strip-shaped terminals 401, 402, 403, 404, and 405 of the leaf spring 4a and the strip-shaped terminals 401, 402, 403, 404, and 405 of the leaf spring 4b can be arranged point-symmetrically with respect to the LED1. Thus, when the strip-shaped terminal with the leaf spring 4a vibrates, the strip-shaped terminal of the leaf spring 4b located on a pair of diagonal lines with respect to the LED 1 vibrates, but the strip-shaped terminals located on other diagonal lines do not vibrate. . Furthermore, instead of the length of the strip terminals 401, 402, 403, 404, 405 of the leaf springs 4a, 4b, the metal materials can be made different from each other. For example, from workability, conductivity (resistivity), etc.
401: Copper 402: Aluminum 403: SUS304
404: Gold 405: Silver. When the materials are different, the Young's modulus E is different, and the natural frequencies of the respective strip-shaped terminals 401, 402, 403, 404, and 405 are different from the above equation (1). Also in this case, the materials of at least two strip terminals may be different from each other, and the strip terminals of the leaf spring 4a and the strip terminals of the leaf spring 4b may be arranged symmetrically with respect to the LED 1. Good. Further, instead of changing the material of the strip-shaped terminal, the geometric shape of the strip-shaped terminal other than the length, for example, the thickness or the cross-sectional area can be varied. This is because the sectional secondary moment I and the sectional area A of the equation (1) are different, and as a result, the natural frequency of the equation (1) is different.

  In FIG. 2, the leaf springs 4a and 4b are fixed to the mounting substrate 2 with screws 5a and 5b. The rivets are inserted and crimped, the press-fit pins are inserted, and the hook members are mounted. It may be bitten in the groove of the substrate 2.

  3A and 3B are diagrams for explaining the coupler of FIG. 1. FIG. 3A is a top view in the vicinity of the coupler, FIG. 3B is a cross-sectional view taken along line BB ′ in FIG. It is CC 'sectional view taken on the line.

  As shown in FIG. 3, the coupler 6 includes a housing 61 including a bottom 61B that joins an upper portion 61U, a lower portion 61L, an upper portion 61U, and a lower portion 61L, and power supply uneven portions 62a and 62b fixed to the upper portion 61U of the housing 61. It is configured.

  The housing 61 is made of a nonconductive and heat resistant resin or ceramic. For example, it is made of polyphenylene sulfide (PPS), polycardinate, kapton material, alumina, and AlN.

  The power supply irregularities 62a and 62b are made by applying gold (Au) plating, tin (Sn) plating or a metal film made of these alloys to a copper (Cu) alloy such as phosphor bronze or brass having springiness and conductivity. The surface has a fine uneven shape of the order of 0.1mm. This uneven shape is formed in advance by circle punching, molding press processing, injection molding or the like.

  The power supply uneven portions 62a and 62b are molded or fitted with resin or ceramic of the housing 61.

  When the mounting board 2 is press-fitted into the coupler 6, the metal film oxide film of the wiring pattern layers 24 a and 24 b of the mounting board 2 and the metal film oxide film of the power supply uneven portions 62 a and 62 b are destroyed. , Tin or an alloy thereof is diffusion bonded by frictional heat generated during press-fitting. At this time, it becomes a pressure state by the spring property of the power supply uneven portions 62a and 62b, and promotes the above-described diffusion bonding.

  Gold has a high melting point of 1064 ° C, but has a large self-diffusion coefficient and is easy to be diffusion bonded. In particular, the diffusion bonding between simple gold is extremely resistant to heat and can reduce cracks such as heat shock. On the other hand, since tin has a low melting point of 232 ° C. and a large self-diffusion coefficient, it is easy to perform diffusion bonding.

  Furthermore, if the mounting substrate 2 is sealed in the coupler 6 and then annealed at, for example, about 150 ° C. for several hours, diffusion bonding is promoted.

  As described above, in the embodiment of the present invention, the electrical connection of the coupler 6 is performed by the power supply uneven portions 62a and 62b, and the mechanical fixing of the coupler 6 is performed by the bolts 7a and 7b. In addition, it is possible to avoid problems such as dropouts and to supply power with high reliability.

  FIG. 4 is a cross-sectional view showing a first modification of the coupler of FIG. 1 and corresponds to FIG. That is, rivets 7a-1 and 7b-1 made of heat-resistant resin or metal are inserted in place of the screws 7a and 7b in FIG.

  FIG. 5 is a cross-sectional view showing a second modification of the coupler of FIG. 1, and corresponds to FIG. That is, press-fit pins 7a-2 and 7b-2 are inserted in place of the screws 7a and 7b in FIG.

  Further, FIG. 6 is a cross-sectional view showing a third modification of the coupler of FIG. 1, and corresponds to FIG. That is, instead of the screws 7a and 7b in FIG. 3, a fixed uneven portion 62c is provided. The fixed concavo-convex portion 62c is formed at the same time as the power supply concavo-convex portions 62a and 62b, and is therefore made of the same material as the power supply concavo-convex portions 62a and 62b. However, unlike the power supply uneven portions 62a and 62b, the fixed uneven portion 62c is not connected to the wiring pattern layers 24a and 24b.

  Thus, the mechanical fixing of the coupler 6 is performed by the screws 7a and 7b, the rivets 7a-1 and 7b-1, the press-fit pins 7a-2 and 7b-2, or the fixing uneven portion 62c.

  FIG. 7 is a cross-sectional view showing a fourth modification of the coupler of FIG. 1, and corresponds to (C) of FIG. That is, the lower part 61L of the housing 61 in FIG. 3 is changed to a lower part 61L ′, a hook 61H is provided, and a groove is provided on the back surface of the mounting substrate 2. As a result, the coupler 6 can be mechanically fixed by engaging the hook 61H in the groove of the mounting substrate 2, and at this time, the hook 61H is pressed by the springs of the extension portions of the power supply uneven portions 62a and 62b. As a result, it is possible to avoid problems such as contact failure and dropout of the coupler 6. The fourth modification example in FIG. 7 can be combined with the first, second, and third modification examples in FIGS. 4, 5, and 6.

1 shows an embodiment of an optical semiconductor device module according to the present invention, wherein (A) is a perspective view and (B) is an assembled perspective view. It is a figure for demonstrating the leaf | plate springs 4a and 4b of FIG. 1, (A) is a top view, (B) is BB 'sectional drawing of (A), (C) is C- of (A). C 'sectional view, (D) is a DD' sectional view of (A). It is a figure for demonstrating the coupler of FIG. 1, (A) is a top view of the coupler vicinity, (B) is BB 'sectional view taken on the line of (A), (C) is CC of (A). FIG. It is sectional drawing which shows the 1st modification of the coupler of FIG. It is sectional drawing which shows the 2nd modification of the coupler of FIG. It is sectional drawing which shows the 3rd modification of the coupler of FIG. It is sectional drawing which shows the 4th modification of the coupler of FIG. It is sectional drawing which shows the conventional optical semiconductor device module. It is sectional drawing explaining fixation of the coupler of FIG.

Explanation of symbols

1: LED
1a, 1b: lead frame 2: mounting substrate 2a, 2b, 2c, 2d: screw hole 3: thermally conductive adhesive 4a, 4b: leaf spring 6: coupler 7a, 7b: screw 8a, 8b: fixing member 21: metal Layer 22: insulating layer 23: resist layer 24a, 24b: wiring pattern layer 61: housing 61U: upper part 61L, 61L ': lower part 61H: hook 61B: bottom part 62a, 62b: power supply uneven part 62c: fixed uneven part

Claims (9)

An optical semiconductor device having a light emitting portion on the upper surface;
A support substrate having the wiring pattern layer mounted thereon and connected to the optical semiconductor device;
A coupler for press-fitting and fixing the support substrate,
The coupler is an optical semiconductor device module having a power supply uneven portion for contacting the wiring pattern layer.   The optical semiconductor device module according to claim 1, wherein the power supply uneven portion is a material having springiness and conductivity.   The optical semiconductor device module according to claim 1, wherein the power supply uneven portion has a metal film on a surface thereof.   The optical semiconductor device module according to claim 3, wherein the metal film is one of gold (Au), tin (Sn), and an alloy thereof.   The wiring pattern layer has a metal film made of the same material as the metal film on the surface, and the power supply uneven part and the wiring pattern layer are a metal film of the power supply uneven part and a metal film of the wiring pattern layer. The optical semiconductor device module according to claim 3, which is bonded by diffusion bonding. Furthermore, it comprises a conductive leaf spring for fixing the optical semiconductor device to the support base and supplying power to the optical semiconductor device,
The leaf spring is composed of a plurality of strip-shaped terminals, and an optical semiconductor device module having different natural frequencies of at least two strip-shaped terminals of the plurality of strip-shaped terminals.   The optical semiconductor device module according to claim 1, wherein the support base is a metallic substrate.   The optical semiconductor device module according to claim 1, wherein the coupler further includes a housing for fixing the power feeding uneven portion, and the housing is fixed to the support base by a mechanical fixing means. 9. The optical semiconductor device module according to claim 8, wherein a groove is provided on a back surface of the support base, and the mechanical fixing means is inserted into the groove of the support base.

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