JP2001035947A - Semiconductor light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light emitting device for easily insulating and fixing an eyelet and a lead pin, and for preventing the position of the lead pin from being shifted even when the lead pin is connected with an outer circuit by using solder, and for preventing the generation of any fine crack at the insulating fixed part. SOLUTION: A semiconductor light emitting device 1 is provided with a metallic plate-shaped eyelet 2, a block part 3 for heat radiation integrally formed at the eyelet 2 so as to be projected at the upper face side of the eyelet 2, a laser chip 5 mounted on the block part 3, slim lead pins 9a and 9b put through through-holes 13a and 13b formed at the eyelet 2, and electrically connected with the laser chip 5, and a cap body 6 mounted on the upper face side of the eyelet 2 so that the block part 3, the laser chip 5, and the lead pins 9a and 9b can be covered. Then, the lead pins 9a and 9b are electrically insulated and fixed to the eyelet 2 by thermoplastic or heat hardening resin injected into the through-holes 13a and 13b of the eyelet 2, and the heat deforming temperature of the resin is set so as to be made higher than the dissolving temperature of the solder for connecting the lead pins 9a and 9b with an outer circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device, and more particularly to a semiconductor light emitting device in which a laser chip is mounted alone or together with a light receiving element.

[0002]

2. Description of the Related Art Generally, a laser chip is susceptible to humidity, and a semiconductor light emitting device on which the laser chip is mounted has been required to have high airtightness. For this reason, in conventional semiconductor light emitting devices, low melting point glass has been generally used to insulate and fix lead pins inserted through through holes formed in metal eyelets.

[0003] Low melting point glass has the advantages of low humidity permeability and excellent electrical insulation, but has a high material cost, is difficult to process, and has complicated work steps, so that a semiconductor light emitting device has a disadvantage. This was a major cause of increasing manufacturing costs.

As a semiconductor light emitting device in consideration of manufacturing cost, a semiconductor light emitting device in which a resin-based adhesive is filled in a through hole of an eyelet and an eyelet and a lead pin are insulated and fixed is generally known (for example, Japanese Patent No. 2828283). Gazette and Utility Model Registration No. 2588517).

[0005]

However, in a semiconductor light emitting device in which the through hole of the eyelet is filled with a resin-based adhesive to insulate and fix the eyelet and the lead pin, soldering is performed when connecting the lead pin and an external circuit. Thus, there is a problem that the cured adhesive is softened. When the adhesive softens, the position of the lead pin shifts, causing insulation failure due to contact with the eyelet, and the thin metal wire that electrically connects the tip of the lead pin and the laser chip in the semiconductor light emitting device is broken. Was sometimes done. Also,
In some cases, the lead pins come off the semiconductor light emitting device.

[0006] Furthermore, the softened adhesive has a problem in that when the temperature returns to a normal temperature, fine cracks occur due to a difference in thermal expansion coefficient from that of a metal eyelet. When a fine crack is generated in the adhesive, moisture penetrates into the semiconductor light emitting device from a portion where the fine crack has occurred, causing deterioration of the laser chip.

The present invention has been made in view of such circumstances, and can easily insulate and fix an eyelet and a lead pin, and even if the lead pin is connected to an external circuit by soldering, the position of the lead pin is maintained. An object of the present invention is to provide a semiconductor light emitting device which does not shift or cause fine cracks in an insulating fixed portion.

[0008]

According to the present invention, there is provided a metal plate-shaped eyelet, which protrudes from the upper surface of the eyelet,
A heat-dissipating block formed integrally with the eyelet, and a laser chip attached to the block,
An elongated lead pin that is inserted into a through hole formed in the eyelet and is electrically connected to the laser chip;
A cap body that covers the block portion, the laser chip, and the lead pin and is attached to the upper surface side of the eyelet, wherein the lead pin is formed by a thermoplastic or thermosetting resin injected into a through hole of the eyelet. An object of the present invention is to provide a semiconductor light emitting device characterized by being electrically insulated and fixed, and having a heat deformation temperature of the resin higher than a melting temperature of solder for connecting a lead pin to an external circuit.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, the semiconductor light emitting device of the present invention is a thermoplastic resin or a thermosetting resin that insulates and fixes an eyelet and a lead pin, and has a heat deformation temperature of a solder melting temperature (for example, 180 ° C.). Use the above. Examples of such a thermoplastic resin or a thermosetting resin include a glass fiber reinforced heat-resistant resin.

[0010] With this configuration, it is possible to improve the heat deformation temperature of the thermoplastic resin or the thermosetting resin that forms the insulating fixing portion between the eyelet and the lead pin. That is, the lead pin and the external circuit
Even if connection is made using a solder that melts at about 0 ° C., it is possible to prevent the insulating fixing portion between the eyelet and the lead pin from softening, and further to prevent the occurrence of minute cracks in the insulating fixing portion.

The glass fiber reinforced heat resistant resin includes, for example, glass fiber reinforced heat resistant polyphenylene sulfide (hereinafter referred to as reinforced heat resistant PPS), polystyrene reinforced with glass fiber, ABS, polycarbonate, and the like.
A phenol resin, an unsaturated polyester, a melamine resin, an epoxy resin, or the like can be used.

Further, as the material of the eyelet, the block portion, the lead pin and the cap body of the semiconductor light emitting device of the present invention, iron, iron alloy, copper, aluminum and the like can be used.

[0013] In the semiconductor light emitting device of the present invention, the lead pin may have at least one concave portion in a portion fixed to the eyelet. Further, the concave portion may be formed around the lead pin. With such a configuration, the thermoplastic resin or the thermosetting resin is cut into the concave portion of the lead pin, and the contact area between the resin and the lead pin becomes large, so that the lead pin comes off from the eyelet. Can be prevented.

Further, the recess may extend in the longitudinal direction of the lead pin. With this configuration, when the lead pin is inserted into the through hole of the eyelet and a thermoplastic resin or a thermosetting resin is injected into the through hole to insulate and fix the eyelet and the lead pin, the lead pin rotates. Can be prevented. This requires that a flat part be provided on the upper part of the lead pin to facilitate wire bonding using ultrasonic thermocompression bonding, and that the flat part be fixed while maintaining a position parallel to the electrode surface of the laser chip. It is effective in some cases.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments shown in the drawings. The present invention is not limited by the embodiment.

Embodiment 1 Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a front sectional view of the semiconductor light emitting device of the first embodiment, and FIG. 2 is a perspective view of a lead pin of the first embodiment.

In the semiconductor light emitting device indicated by reference numeral 1 in FIG. 1, a disc-shaped eyelet 2 and a heat radiating block 3 are integrally formed. The eyelet 2 and the block 3 are made of an iron alloy, and the surfaces thereof are plated with copper, and the surfaces of the copper plating are plated with gold. A copper submount 4 for further promoting heat diffusion is joined to the block portion 3 by brazing, and the back surface of the laser chip 5 is joined to the surface of the submount 4 by brazing. The submount can be made of ceramic or silicon.

In FIG. 1, reference numeral 6 denotes an iron alloy cap attached to the eyelet 2 by resistance welding to protect the laser chip 5, and its surface is coated with nickel-tin plating. It has been subjected. In addition,
This nickel-tin plating may be only nickel plating. Further, a window glass 7 for transmitting a laser beam is attached to an upper portion of the cap 6 by a low melting point glass 8. If the window glass is made of a transparent resin, the cap and the window glass can be fixed with a resin-based adhesive.

Electrodes (not shown) are provided on the front and back surfaces of the laser chip 5 shown in FIG. 1. The electrodes on the back surface correspond to the flat portion 11a of the lead pin 9a made of copper alloy and the surface of the submount 4. The connection is made electrically by the metal wire 12a. On the other hand, the electrode on the surface is a lead pin 9
b is electrically connected to the plane portion 11b directly by the metal wire 12b.

Note that, as shown in FIG.
After the lead pins 9a and 9b are inserted through the through holes 13a and 13b, reinforced heat resistant PPS in a molten state is injected into the through holes 13a and 13b to form insulating fixing portions 14a and 14b. The insulation fixing portions 14a and 14b are connected to the lead pins 9a.
9b and the eyelet 2 are insulated and fixed, and the semiconductor light emitting device 1 is sealed from external moisture and the like. The reinforced heat-resistant PPS used as the material of the insulating fixing portions 14a and 14b is obtained by adding 40% of glass fiber to polyphenylene sulfide and increasing the heat deformation temperature to 300 ° C to 340 ° C.

With this configuration, the insulating fixing portions 14a and 14b can be formed even when a solder that melts at, for example, 180 ° C. is used when connecting the lead pins 9a and 9b to an external circuit (not shown). Softening of the reinforced heat-resistant PPS can be prevented. Also, the insulation fixing part 14
After a and 14b have become hot, they will be at room temperature (eg, 25
° C), fine cracks do not occur in the insulating fixing portions 14a and 14b, and a good sealing state can be maintained.

As shown in FIGS. 1 and 2,
The lead pins 9a and 9b have recesses 10a and 10b formed of four annular grooves, respectively.
And 10b are through holes 13a and 13 of the eyelet 2.
The insulating fixing portions 14a and 14b are formed in a state where they are located in the area b. With this configuration, the lead pins 9a and 9b and the insulating fixing portions 14a and 14b
The contact area of the lead pins 9a and 9b with the eyelet 2 can be prevented from being increased. The lead pins 9a and 9b shown in FIG. 1 are exactly the same in both material and shape.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the lead pins of the first embodiment are changed. FIG. 3 is a front sectional view of the semiconductor light emitting device of the second embodiment, FIG. 4 is a perspective view of a lead pin of the second embodiment, and FIG.
FIG. 9 is a cross-sectional view of a concave portion of the lead pin according to the second embodiment.

The lead pins 29 shown in FIGS. 4 and 5
In a, there is formed a recess 30a composed of four recesses extending in the longitudinal direction of the lead pin 29a. Also,
A flat portion 31a is formed above the lead pin 29a so that a metal wire can be easily connected. The lead pins 29a and 29b shown in FIG. 3 have exactly the same material and shape.

As shown in FIG. 3, the lead pins 29a
And 29b, lead pins 29a and 29b
b through holes 33a and 33 of eyelet 22
Injecting the reinforced heat-resistant PPS in a molten state into 3b to form insulating fixing portions 34a and 34b, lead pins 29a
And 29b can be prevented from rotating. That is, the front surface of the submount 24, the flat portion 31a of the lead pin 29a, and the electrode (not shown) on the surface of the laser chip 25
And the flat portion 31b of the lead pin 29b can be maintained parallel to each other, so that the metal wires 32a and 32b can be easily connected. Other configurations are the same as those of the semiconductor light emitting device of the first embodiment.

[0026]

According to the present invention, the eyelet and the lead pin can be easily insulated and fixed, and even if the lead pin and the external circuit are connected by using solder, the position of the lead pin is displaced, or the fine portion is formed on the insulating fixed portion. The occurrence of cracks can be prevented.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an embodiment 1 of the present invention.

FIG. 2 is a perspective view of a lead pin according to the first embodiment.

FIG. 3 is a front sectional view showing an embodiment 2 of the present invention.

FIG. 4 is a perspective view of a lead pin according to a second embodiment.

FIG. 5 is a cross-sectional view of a recess of a lead pin according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Semiconductor light emitting device 2 ... Eyelet 3 ... Block part 4 ... Submount 5 ... Laser chip 6 ... Cap 7 ... Glass window 8 ... Low melting point glass 9a, 9b: lead pin 10a, 10b: concave portion 11a, 11b: flat portion 12a, 12b: metal wire 13a, 13b: through hole 14a, 14b: insulating fixing portion

Claims (6)

[Claims] 1. A metal plate-like eyelet, a heat-dissipating block protruding from the upper surface of the eyelet and integrally formed with the eyelet, a laser chip attached to the block, and An elongated lead pin that is inserted into the formed through hole and is electrically connected to the laser chip; and a cap body that covers the block portion, the laser chip, and the lead pin and is attached to an upper surface side of the eyelet. Is fixed by being electrically insulated from the eyelet by a thermoplastic or thermosetting resin injected into a through hole of the eyelet, and a heat deformation temperature of the resin is set by a solder for connecting a lead pin to an external circuit. A semiconductor light emitting device characterized by being higher than a melting temperature. 2. The semiconductor light emitting device according to claim 1, wherein the resin is a glass fiber reinforced heat resistant resin. 3. The semiconductor light emitting device according to claim 2, wherein the glass fiber reinforced heat resistant resin is glass fiber reinforced heat resistant polyphenylene sulfide. 4. The semiconductor light emitting device according to claim 1, wherein the lead pin has at least one concave portion at a portion fixed to the eyelet. 5. The semiconductor light emitting device according to claim 4, wherein the recess extends in a longitudinal direction of the lead pin. 6. The semiconductor light emitting device according to claim 4, wherein the recess is formed around the lead pin.