JP2010045167A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device with high reliability, which is suitable to on-board use with respect to the structure and quality guarantee. <P>SOLUTION: The semiconductor device 1 has a base portion 20 having a mounting surface on which a semiconductor element 10 is mounted and a back surface opposed to the mounting surface, and a pair of lead terminals 22 electrically connected to the semiconductor element 10. The base portion 20 has a projection portion 20b projecting from the mounting surface, and a lower surface of the projection portion 20b is in the same level with respective lower surfaces of the mounting portion or protrudes from a surface that the respective lower surfaces of the mounting portion form to constitute a junction surface that can abut against a mounting substrate. The base portion 20 has a pair of through-holes 23, reaching the back surface from the mounting surface, on both sides across the semiconductor element 10. The pair of lead terminals 22 are each fixed to the base portion 20 through hard glass 21 in the pair of through-holes 23 and are bent in a direction leaving each other from the extension direction of the through-holes 23 along the back surface of the base portion 20, so that lower surfaces thereof form the junction surface for the mounting substrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor device, and more particularly to a surface-mount type semiconductor device on which a semiconductor light emitting element is mounted.

  Semiconductor light-emitting devices equipped with high-intensity, high-power light-emitting diodes (LEDs) have features such as small size, long life, and low power consumption compared to conventional incandescent bulbs. Widely used in the field of devices and the like. On the other hand, as a package for a semiconductor light emitting device, demand for surface mount type is increasing due to demands for downsizing and thinning of devices.

For example, Patent Document 1 discloses a light emitting element, a base on which the light emitting element is mounted, a lead terminal electrically connected to the light emitting element via a bonding wire, and a light emitting element. A semiconductor light emitting device comprising: a sealing resin that covers the entire element and the base and fixes the lead terminal; the lower surface of the base is exposed on the lower surface of the sealing resin and is located on the same surface as the lower surface of the lead terminal The device is shown.
JP 2002-252373 A

  Since the semiconductor light emitting device has the advantages as described above, it is being adopted for in-vehicle applications such as a headlight and a brake lamp of an automobile and a display panel in an automobile. However, the usage environment inside the automobile may vary, for example, from −20 ° C. to 80 ° C. due to fluctuations in the outside air temperature, and vibrations are always applied during traveling. Thus, when semiconductor light-emitting devices are used for in-vehicle applications, the use environment is severe compared to general products, so high reliability that can withstand thermal shocks and mechanical vibrations over multiple times and for a long time. Will be required. Further, in the surface mount type semiconductor light emitting device, not only the reliability of the semiconductor light emitting device itself but also the durability at the junction with the mounting substrate is important.

  However, when the semiconductor light-emitting device having the structure described in Patent Document 1 is soldered to the mounting substrate by the reflow method, the semiconductor light-emitting device is exposed to rapid temperature fluctuations. There is a risk of cracks occurring in the sealing resin. When cracks enter the sealing resin, moisture or the like enters from there, and there is a concern that corrosion of the light emitting elements, bonding wires, and the like inside the sealing resin proceeds.

  In addition, by directly soldering the exposed portion of the lower surface of the base and the mounting substrate, it is possible to efficiently dissipate the heat generated by the light emitting element to the mounting substrate, but the solder wetness at the joint is poor, When the bonding failure occurs, sufficient heat dissipation cannot be obtained, and if the use is continued in a state where the rated temperature of the light emitting element is exceeded, the light emission luminance is deteriorated with time. In general, in order to determine the quality of the solder joint, it is observed that the fillet shape of the solder joint is observed. However, as described in Patent Document 1, the exposed portion of the base is in the same plane as the sealing resin. In the structure existing in the above, a solder fillet cannot be formed at the joint, and it is difficult to ensure the joint strength and confirm the joint state. That is, the semiconductor light-emitting device described in Patent Document 1 has a problem in terms of structure and quality assurance, and has not been a structure suitable for in-vehicle use that requires high reliability.

  The present invention has been made in view of the above points, and an object thereof is to provide a highly reliable semiconductor device suitable for in-vehicle use in terms of structure and quality assurance.

  A semiconductor device of the present invention includes a base portion having a mounting surface on which a semiconductor element is mounted and a back surface facing the mounting surface, and a pair of lead terminals electrically insulated from the base portion. The base portion has a protruding portion on the back surface side, and each of the pair of lead terminals includes a through portion that penetrates the base portion and an end portion on the back surface side of the through portion. A mounting portion formed by being bent in a direction away from each other along the back surface of the base portion, and the lower surface of the protruding portion is the same surface as the lower surface of each of the mounting portions of the pair of lead terminals, or It protrudes from the lower surface of each mounting part.

  The protruding portion extends in a direction intersecting with the extending direction of the mounting portion, and the length in the extending direction is longer than the width of the pair of lead terminals.

  The base portion has a pair of through holes that reach the back surface from the mounting surface on both sides of the semiconductor element, and each of the pair of lead terminals is inserted through a hard glass inside each of the pair of through holes. It is fixed to the base part.

  A part of the mounting part of the pair of lead terminals is fixed to the base part via a hard glass provided between the upper surface of the mounting part and the back surface of the base part.

BEST MODE FOR CARRYING OUT THE INVENTION

  Embodiments of the present invention will be described below with reference to the drawings. 1A is a plan view of a semiconductor light emitting device 1 according to an embodiment of the present invention as viewed from the upper surface (element mounting surface) side, and FIG. 1B is a plan view of the semiconductor device 1 from the lower surface (mounting surface) side. It is the top view which looked. 2A is a cross-sectional view taken along line 2a-2a in FIG. 1A, and FIG. 2B is a cross-sectional view taken along line 2b-2b in FIG. 1A.

  The semiconductor light emitting device 1 includes a base portion 20 as a base having an element mounting surface on which an LED chip 10 as a light emitting element is mainly mounted and a back surface facing the element mounting surface, and an element mounting surface of the base portion 20. A pair of lead terminals 20 that form a joint between the LED chip 10 mounted in the center of the LED and a mounting board (not shown), relay power supplied from the mounting board to the LED chip 10, and elements of the base part 20 A reflection frame 40 having a ring-shaped light reflection surface provided along the outer edge of the mounting surface, and a light-transmitting resin 50 filled so as to embed the LED chip 10 inside the reflection frame 40. Composed.

  The base portion 20 is a base on which the LED chip 10 as a light emitting element is mounted, and a material having high thermal conductivity and low thermal resistance is preferable from the viewpoint of ensuring heat dissipation, for example, oxygen-free copper (OFC: Oxygen-Free Copper). ) Or a Cu material containing a Cu alloy. Further, the entire surface of the base portion 20 is subjected to, for example, an Ag alloy plating process by a barrel plating method. By performing a glossy metal plating process on the base portion 20, the element mounting surface of the base portion 20 functions as a light reflecting surface. In addition to the Cu material, Al, Fe, or the like can be used as the constituent material of the base portion 20. Further, as the plating material, Ag, Au or the like can be used in addition to the Ag alloy. In order to define the outer shape of the semiconductor light emitting device 1, the base portion 20 preferably has a polygonal shape in consideration of convenience in mounting on the mounting substrate. As shown in FIGS. 1A and 1B, the outer shape of the base portion 20 can be a rectangular shape of 4 mm × 4 mm when the chip size of the LED chip 10 is about 1 mm square, for example.

  The base portion 20 has a plate thickness of about 1 mm, and as shown in FIGS. 2A and 2B, a cross section in which the height position of the upper surface protrudes from the peripheral portion in the center portion of the element mounting surface. It has a trapezoidal raised portion 20a. The upper surface of the raised portion 20a is a flat surface, and the LED chip 10 is mounted on the upper surface of the raised portion 20a via a bonding material such as solder or conductive adhesive. The shape and dimensions of the upper surface of the raised portion 20a are substantially the same as the shape and dimensions of the LED chip 10, thereby preventing the bonding material from creeping up to the side surface and the surface of the LED chip 10.

  Moreover, the base part 20 has the protrusion part 20b in the position which the lower surface protruded from the peripheral part in the mounting surface side center part. The lower surface of the projecting portion 20b is a flat surface parallel to the peripheral portion of the projecting portion on the back surface of the base portion 20 and the element mounting surface, and the lower surface of the projecting portion 20b is bonded to the mounting substrate that can come into contact with the mounting substrate. Make up surface. Since the base portion 20 is directly bonded to the mounting substrate via the protruding portion 20b by soldering, the heat generated by the LED chip 10 mounted on the element mounting surface is efficiently radiated to the mounting substrate. As shown in FIG. 1B, the protruding portion 20b extends so as to cross the central portion of the back surface of the base portion 20 from one end to the other end. In this way, since the bonding area with the mounting substrate is secured by extending the formation region of the protruding portion 20b, the heat dissipation efficiency can be improved and the mounting stability can be improved.

  Moreover, it is preferable that the protrusion part 20b is extended including the directly lower part of the protruding part 20a which is a mounting part of the LED chip 10. FIG. That is, when the semiconductor light emitting device 1 is mounted on a mounting substrate extending on a horizontal plane, it is preferable that the protruding portion 20b extends below the LED chip 10 in the vertical direction. Thereby, when the semiconductor light emitting device 1 is mounted on the mounting substrate, the heat dissipation path from the LED chip 10 which is a heat generation source to the mounting substrate is shortened, and as a result, the heat resistance is reduced, so that the heat dissipation efficiency is improved. Is possible.

  The base portion 20 is provided with a pair of through holes 23 that reach the back surface of the base portion from the element mounting surface at both side positions sandwiching the raised portion 20a. Each of the pair of lead terminals 22 is embedded in the insulating material 21 made of, for example, hard glass and fixed to the base portion 20 inside the through hole 23. More specifically, the base portion 20 is provided with a through hole 23 having an opening area larger than the area of the upper end surface of the connection portion 22 a formed at the tip portion of the lead terminal 22. The lead terminal 22 is supported in a state of being inserted into the through hole 23 after being subjected to a predetermined bending process described later. Subsequently, a substantially cuboid borosilicate glass is put into the through hole 23 in a state where one of the opening surfaces of the through hole 23 is closed. Thereafter, the lead terminal 22 is fixed inside the through hole 23 by heating and melting and hardening the borosilicate glass. As described above, the insulating material 21 fixes the lead terminal 22 provided separately from the base portion 20 in the through hole 23 while ensuring insulation and airtightness. Since the insulating material 21 is made of hard glass, there is little deterioration over time and it is resistant to thermal shock, so that a highly reliable semiconductor light emitting device can be formed.

The lead terminal 22 forms a joint with the mounting substrate and supplies light emission driving power from the mounting substrate to the LED chip 10 mounted on the element mounting surface. The lead terminal 22 is a flat lead material having a plate thickness of about 0.1 mm and a lead width of about 1.2 mm. As a constituent material of the lead terminal 22, for example, Kovar formed by mixing Ni and Co with Fe is suitable. Kovar has a linear expansion coefficient around room temperature of about 5.0 × 10 ⁻⁶ / K, which is low compared to other metals, and is equivalent to borosilicate glass constituting the insulating material 21. Accordingly, even when the semiconductor light emitting device 1 is exposed to an environment where the reflow process performed when the semiconductor light emitting device 1 is mounted on the mounting substrate or the ambient temperature fluctuates for a long time, the volume expansion / contraction rate of the lead terminal 22 and the insulating material 21 is high. Since the stress is almost the same and the stress applied to the insulating material 21 can be reduced, the occurrence of cracks in the insulating material 21 can be prevented.

  Further, the lead terminal 22 is subjected to, for example, an Ag alloy plating process on the entire surface. When the lead terminal 22 is plated, a connection portion 22a of the lead terminal 22 described later exhibits a function as a light reflecting surface. In addition to Ag alloy, Ag or Au can be used as the plating material for the lead terminals 22, and these plating materials may be used in combination.

  The lead terminal 22 is bent on a flat lead material and has a crank-shaped forming shape as shown in FIG. Each side of the lead terminal 22 subjected to the bending process constitutes a connection part 22a, a through part 22b, a mounting part 22c, and a fillet forming part 22d. In this way, the lead terminal 22 is configured by bending a plate-like lead material into a crank shape and firmly fixed by the insulating material 21, so that, for example, lead disconnection occurs as compared with a cylindrical lead material. It has a difficult structure.

  The through portion 22b penetrates through the insulating material 21 filling the through hole 23 of the base portion 20, and extends from the upper end surface of the insulating material 21 to the same surface as the lower surface of the protruding portion 20b. That is, the extending direction of the penetrating portion 22 b is the thickness direction of the base portion 20. The penetration part 22b derives the light emission driving power supplied from the back side of the base part to the element mounting surface side on which the LED chip 10 is mounted. The position where the penetrating portion 22b penetrates the insulating material 21 is displaced so that the separation distance becomes larger than the center position of the through hole 23 in the approaching and separating direction from the LED chip 10. That is, the through portion 21 b penetrates the insulating material 21 at a position outside the center position of the through hole 23.

  Each of the connecting portions 22a of the pair of lead terminals 22 is bent by about 90 degrees so that the upper end surfaces thereof are substantially parallel to the light emitting surface from the extending direction of the penetrating portion 22b toward each other. Is formed. That is, each of the connection portions 22a is formed by being bent toward the LED chip 10 from the end portion on the element mounting surface side of the through portion 22b. Thus, the connection part 22a comprises the flat surface where the main surface extends in a horizontal direction in the both-sides position which pinches | interposes the LED chip 10 on an element mounting surface. As shown in FIG. 1A, the upper end surface of the insulating material 21 filling the inside of the through hole 23 of the base portion 20 and extending on the element mounting surface of the base portion 20 is covered with the connection portion 22a. Each lead terminal 22 is electrically connected to the LED chip 10 by connecting the upper surface of the connection part 22a and an electrode pad (not shown) on the surface of the LED chip 10 with a bonding wire 30. Since the upper surface of the connection portion 22a has a sufficiently large area with respect to the bonding wire diameter, it is possible to prevent the bonding wire from being damaged.

  Furthermore, the height position of the upper end surface of the connection portion 22a is configured to be lower than the upper surface of the raised portion 20a that is the LED chip 10 mounting surface, and the lead terminal 22 is subjected to an Ag alloy plating process on the entire surface. As a result, the connecting portion 22a also functions as a light reflecting surface. That is, since the upper surface of the plated connection part 22a has a high reflectance and is located rearward in the light projecting direction with respect to the LED chip 10, the connection part 22a is emitted from the LED chip 10 and is a light reflection frame. The light reflected by 40 and the light scattered inside the light-transmitting resin 50 are reflected toward the light projecting direction. Since the insulating material 21 extending on the element mounting surface of the base portion 20 is made of hard glass as described above, its reflectance is low, and the insulating material 21 is exposed on the element mounting surface of the base portion 20. If it is in the state, the light extraction efficiency decreases. Therefore, in this embodiment, the surface of the insulating material 21 is covered with the connecting portion 22a of the lead terminal plated with a metal having a high reflectance so that the light functions in the light projecting direction by functioning as a light reflecting surface. The amount of light is increased, and the substantial light emission luminance is improved.

  Each of the mounting portions 22c of the pair of lead terminals 22 is formed by bending on the mounting surface side in a direction away from each other along the back surface of the base portion 20 from the extending direction of the through portion 22b. That is, each of the mounting portions 22c extends toward the outer edge portions of the base portion 20 facing each other and terminates at a position exceeding the outer edge portion. Further, bending is performed so that the lower surface of the mounting portion 22c and the element mounting surface and mounting surface of the base portion 20 are parallel to each other. The lower surface of the mounting portion 22c constitutes a bonding surface with the mounting substrate. By securing the length of the mounting portion 22b in the extending direction to some extent, the bonding area between the mounting portion 22c and the mounting substrate is increased, so that the mounting stability is improved.

  However, even if the length of the mounting portion 22c is secured to some extent, if the lead width is about 1.2 mm with respect to the external dimensions of the semiconductor light emitting device 1, the mounting stability in the lead width direction cannot be said to be sufficient. Therefore, in the present embodiment, the protruding portion 20b formed on the back surface of the base portion 20 complements this. That is, similar to the mounting portion 22c, the protruding portion 20b that forms the joint surface with the mounting substrate extends in a direction perpendicular to the separation direction of the mounting portion 20c at the center portion of the pair of mounting portions 22c that are separated from each other. The length in the longitudinal direction is, for example, about 3 mm, which is long enough for the lead width. Therefore, the mounting stability in the lead width direction of the lead terminal 22 is complemented by the protrusion 20b. As described above, in the semiconductor light emitting device 1 of this example, the mounting stability is ensured by the bottom surface structure including both the mounting portion 22c and the protruding portion 20b.

  Since both the lower surface of the mounting portion 22c and the lower surface of the protruding portion 20b form a joint surface with the mounting substrate, the lower surface of the mounting portion 22c and the lower surface of the protruding portion 20 are preferably located on the same plane. However, considering the processing accuracy of the bending process of the lead terminals 22, it is actually difficult to form them completely on the same plane. In consideration of such manufacturing variation, in the semiconductor light emitting device 1 of the present embodiment, even if the lower surface of the protruding portion 20b protrudes from the surface formed by the lower surface of the mounting portion 22c within a predetermined range, that is, the mounting portion is not mounted. Even if the lower surface of 22c is located above the lower surface of the protrusion part 20b, it has a structure which can be mounted on a mounting board without a problem. That is, when the lower surface of the mounting portion 22c is positioned above the lower surface of the projecting portion 20b, the lower surface of the mounting portion 22c cannot contact the mounting substrate. If there is, the mounting portion 22c is attracted to the mounting substrate when the melted solder is solidified in the reflow process, and the mounting portion 22c is bent downward, that is, downward, so that the mounting portion 22c is joined to the mounting substrate without any problem. It will be. As described above, in the semiconductor light emitting device of the present embodiment, the mounting portion 22c has a structure that can be deformed. Therefore, even if a positional shift between the lower surface of the mounting portion 22c and the lower surface of the protruding portion 20b occurs, such a positional shift is The terminal 22 is absorbed by the deformation.

  Further, as shown in FIG. 2A, a bent portion which is a connecting portion between the penetrating portion 22 b of the lead terminal 22 and the mounting portion 22 c and a part of the upper surface of the mounting portion 22 c are covered with an insulating material 21. That is, the gap between the upper surface of the mounting portion 22c and the lower surface of the base portion 20 is filled with the insulating material 21 made of hard glass, and not only the through portion 22b of the lead terminal 22 but also the mounting portion 22c includes the base portion 20. It is fixed against. Thereby, it is possible to prevent the forming shape of the lead terminal 22 from being deformed due to an external force. For example, when an external force is applied to the tip of the mounting portion 22c and the bending angle of the lead terminal 22 changes, the horizontality of the mounting portion 22b cannot be ensured, not only the mounting stability is impaired, but also in the light projecting direction. Deviation may occur. Therefore, as in the present embodiment, the bent portion that is the connecting portion of the lead terminal 22 and the mounting portion 22c and a part of the upper surface of the mounting portion 22c are covered with the insulating material 21, and the mounting portion 22c base portion 20 is covered. By fixing to the lead terminal 22, even when an external force is applied to the lead terminal 22, the structure is not easily deformed.

  Further, the mounting portion 22c is partially fixed to the base portion 20, that is, the insulating material 21 provided between the upper surface of the mounting portion 22c and the back surface of the base portion 20 is in the extending direction of the mounting portion 22c. It is preferable to terminate between the both end portions. Thereby, as described above, it is possible to ensure the bonding with the mounting board by utilizing the deflection of the mounting portion 22c, and it is possible to suitably improve the mounting stability.

  In this embodiment, the insulating material filled in the through hole and the insulating material provided between the upper surface of the mounting portion 22c and the back surface of the base portion 20 are formed continuously and integrally. Both are made of hard glass.

  Each of the fillet forming portions 22d of the pair of lead terminals 22 is formed by bending upward from the extending direction of the mounting portion 22c at the end of the mounting portion 22c. In other words, the fillet forming portion 22d extends substantially upward in the vertical direction with respect to the mounting substrate. It is considered that it is difficult to form a good fillet shape at the end portion of the mounting portion 22c only by the plate thickness of the lead terminal 22. For this reason, by providing the fillet forming portion 22d at the end of the mounting portion 22c, the solder crawls up along the fillet forming portion 22d to form a good fillet shape, and the bonding strength and mounting stability with the mounting substrate. Can be secured. A good fillet shape can be formed by setting the height of the fillet forming portion 22d to about 0.4 mm.

  FIG. 3 is a cross-sectional view of the semiconductor light emitting device 1 mounted on the mounting substrate by soldering. As described above, the lower surface of the protruding portion 20b of the base portion 20 and the lower surface of the mounting portion 22c of the lead portion 22 serve as a bonding surface with the mounting substrate. Each of the mounting portions 22c extends along the surface of the mounting substrate toward the outer side of the semiconductor light emitting device 1 to a position beyond the end of the base portion 20 as described above, thereby securing a bonding area and mounting. Stability is improved. Further, since the solder is soaked up along the fillet forming portion 22d provided at the end of the mounting portion 22c, a good solder fillet can be formed in this portion as shown in FIG.

  In addition, since the protruding portion 20b protrudes from the periphery at the height position, a gap is formed between the side surface of the protruding portion 20b and each lead terminal 22 when mounted on the mounting substrate. As a result, the solder wets so as to scoop up along the side surface of the protruding portion 20b inside the gap, so that a solder fillet is also formed on the side surface of the protruding portion 20b. Therefore, it is possible to ensure the mounting strength and the durability against thermal shock and mechanical vibration at the joint portion between the mounting portion and the base portion 20 that forms the heat radiation path while ensuring mounting stability, and can be applied to in-vehicle products. A reliable semiconductor light emitting device can be formed. In addition, the quality of the solder joint is generally determined by observing the solder fillet shape. According to the structure of this example, the solder joint is formed on the side surface of the protruding portion 20b after being mounted on the mounting board. Since the fillet shape can be easily recognized, it is possible to check the bonding state between the base portion 20 and the mounting substrate. Accordingly, it is possible to reliably eliminate the solder with poor soldering and poor bonding, and it can be said that the structure is suitable for in-vehicle products in terms of quality assurance.

  Here, if the distance between the projecting portion 20b and the lead terminal 22 is short, there is a possibility of causing a solder short inside the gap, so it is necessary to secure these distances to some extent. In view of this point, in this embodiment, each of the through portions 22b of the pair of lead terminals 22 is disposed outside the center position of the through hole 23 provided in the base portion 20, thereby protruding from the lead terminal 22. A separation distance from the portion 20b is secured.

On the other hand, a ring-shaped light reflecting frame 40 is formed on the element mounting surface of the base portion 20 along the outer edge of the base portion 20. That is, the LED chip 10 mounted on the base portion 20 and the connection portion 22a of the lead terminal 22 that functions as a light reflecting surface are accommodated inside the light reflecting frame 40. The light reflecting frame 40 is made of fine ceramics such as alumina (Al ₂ O ₃ ), for example, and is bonded to the surface of the base portion 20 with a silicon resin adhesive. Alumina itself is white and has light reflectivity, so that it is irradiated within the light reflecting frame 40, and the scattered light is reflected by the inner wall of the light reflecting frame 40, and the light emitted from the LED chip 10 diverges over a wide range. Thus, the substantial luminance is prevented from being lowered. Alumina is excellent in heat resistance and chemical stability, so it is a material with less deterioration over time compared to metal, and its reflectance hardly changes even when used over a long period of time. Therefore, by using alumina as a constituent material of the light reflecting frame 40, it is possible to suppress aged deterioration of light emission luminance substantially, and a highly reliable semiconductor light emitting device can be configured. In addition, when using for the use for which high reliability is not requested | required, it is good also as comprising the light reflection frame 40 with the metal by which the plating process was performed.

  The inside of the ring-shaped light reflecting frame 40 is filled with a light transmissive resin 50 made of silicon resin or the like. As a result, the LED chip 10, the bonding wire, and the like in the reflection frame 40 are embedded in the light-transmitting resin 50 in a state where confidentiality is maintained, and these components are protected from dust, moisture, vibration, and the like. The Since the upper surface of the light transmissive resin 50 is flat and does not have a lens shape, light is extracted from the entire element mounting surface. With such a structure, uniform light emission can be obtained over a wide range, which is suitable for illumination, display devices, and the like. It should be noted that a phosphor may be added to the light transmissive resin 50 as appropriate depending on the application and emission color.

  As is clear from the above description, according to the semiconductor light emitting device of this embodiment, the LED mounted on the base portion is bonded to the mounting substrate at the protruding portion provided on the lower surface of the base portion as well as the lead terminal. The heat generated by the chip can be efficiently radiated to the mounting substrate. Further, since a space is formed on the side surface of the protruding portion when mounted on the mounting substrate, a solder fillet can be formed on the side surface of the protruding portion. As a result, the bonding strength between the mounting substrate and the base portion is ensured, and the durability against thermal shock and mechanical vibration can be improved, so that high reliability that can be applied to in-vehicle products can be realized. Furthermore, since the shape of the solder fillet formed on the protruding portion can be visually observed, it is possible to surely eliminate defective joints such as insufficient solder wetting, and in terms of quality assurance, it is suitable for in-vehicle use. obtain. In addition, since the protruding portion extends in a direction orthogonal to the extending direction of the lead terminal mounting portion, the bonding area with the mounting substrate is expanded, mounting stability is ensured and heat dissipation efficiency can be increased.

  In addition, since the lead terminal is fixed to the base part by hard glass with the same linear expansion coefficient, there is little deterioration over time, and rapid temperature fluctuation in reflow processing performed when mounting on the mounting board. It has a structure that can withstand high reliability. In addition, since the mounting portion of the lead terminal is partially fixed to the back surface of the base portion through hard glass, deformation of the lead terminal can be prevented and mounting stability can be improved by utilizing the deflection of the mounting portion. .

  In the above embodiment, the configuration of the semiconductor light emitting device on which a single LED chip is mounted is shown. However, two or three or more LED chips may be mounted. FIG. 4A shows a configuration of a semiconductor light emitting device in which two LED chips 10 are mounted. When two LED chips are mounted, the LED chips 10a and 10b are mounted on the upper surfaces of the two raised portions 20a juxtaposed at the center of the element mounting surface of the base portion 20, as shown in FIG. Each LED chip and a pair of lead terminal connection portions 22 a are connected by a bonding wire 30. Even if the number of wires connected to each lead terminal increases, there is no problem because the connecting portion 22a has a sufficiently large area.

  FIG. 4B shows a plan view viewed from the mounting surface side. As shown in the figure, the structure on the mounting surface side is the same as when a single LED chip is mounted. The protruding portion 20b formed at the center of the mounting surface side surface of the base portion 20 has a longitudinal shape as described above, and the protruding portion 20b extends directly below the two LED chips 10a and 10b. Therefore, even in a configuration having two LED chips, it is possible to efficiently dissipate heat generated by each LED chip to the mounting substrate.

FIG. 1A is a plan view of a semiconductor light emitting device according to an embodiment of the present invention viewed from the light emitting surface side, and FIG. 1B is a plan view viewed from the mounting surface side. 2A is a cross-sectional view taken along line 2a-2a in FIG. 1A, and FIG. 2B is a cross-sectional view taken along line 2b-2b in FIG. 1A. It is sectional drawing of the semiconductor light-emitting device which is an Example of this invention mounted in the mounting board | substrate. FIG. 4A is a plan view of a semiconductor light emitting device according to another embodiment of the present invention viewed from the light emitting surface side, and FIG. 4B is a plan view viewed from the mounting surface side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 LED chip 20 Base part 20a Protruding part 20b Protruding part 21 Insulating material 22 Lead terminal 22a Connection part 22b Through part 22c Mounting part 22d Fillet formation part 30 Bonding wire

Claims (9)

A semiconductor device comprising a base portion having a mounting surface on which a semiconductor element is mounted and a back surface opposite to the mounting surface, and a pair of lead terminals electrically insulated from the base portion,
The base portion has a protruding portion on the back side,
Each of the pair of lead terminals includes a penetrating portion that penetrates the base portion, and a mounting portion that is formed by bending from the end portion on the back surface side of the penetrating portion along the back surface of the base portion in a separating direction. And having
The semiconductor device according to claim 1, wherein a lower surface of the protruding portion protrudes from the same surface as the lower surface of each of the mounting portions of the pair of lead terminals or from the lower surface of each of the mounting portions.   The semiconductor device according to claim 1, wherein the protruding portion extends in a direction intersecting with the separation direction. Each of the pair of lead terminals has a flat plate shape,
The semiconductor device according to claim 2, wherein a length of the protruding portion in the extending direction is longer than a width of the pair of lead terminals. The base portion has a pair of through holes that reach the back surface from the mounting surface on both sides of the semiconductor element.
Each of the pair of lead terminals is embedded in a hard glass filled in each of the pair of through holes and fixed to the base portion. The semiconductor device described.   A part of the mounting part of the pair of lead terminals is fixed to the base part via a hard glass provided between an upper surface of the mounting part and a back surface of the base part. Item 5. The semiconductor device according to Item 4.   6. The semiconductor device according to claim 1, wherein each of the mounting portions of the pair of lead terminals is terminated at a position exceeding an outer edge portion of the base portion.   7. A fillet forming portion formed by bending toward the mounting surface side is provided at the tip of each of the mounting portions of the pair of lead terminals. The semiconductor device according to claim 1. The semiconductor element is mounted on a central portion of the mounting surface of the base portion,
8. The semiconductor device according to claim 1, wherein the projecting portion extends including a portion directly below the semiconductor element. The base portion is made of a metal containing copper,
9. The semiconductor device according to claim 1, wherein each of the pair of lead terminals is made of Kovar.

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