JP5150384B2 - Semiconductor light emitting device - Google Patents

Description

  The present invention relates to a semiconductor light-emitting device, and more particularly to a semiconductor light-emitting device including a semiconductor light-emitting element and a sealing resin in a recess formed of a laminated substrate.

  2. Description of the Related Art Conventionally, a semiconductor light emitting device mounted with a semiconductor light emitting element has been required to increase the output of a semiconductor light emitting element as a light emission source in order to increase the brightness of the semiconductor light emitting device (increase the amount of irradiation light). High efficiency of the light conversion efficiency of the device and high driving power of the semiconductor light emitting device have been attempted.

  However, when the semiconductor light emitting device is driven with high power, the temperature of the semiconductor light emitting device itself rises due to self-heating during light emission, leading to performance degradation such as a decrease in light conversion efficiency and a shortened light emission lifetime. Therefore, in order to suppress the temperature rise of the semiconductor light emitting element itself due to self-heating during light emission, the semiconductor light emitting element is mounted on a substrate with high thermal conductivity, or the substrate on which the semiconductor light emitting element is mounted is further dissipated in a metal such as a heat sink. A heat dissipating means such as mounting on a member is provided.

  Incidentally, in order to drive (emit) the semiconductor light emitting element, a drive control circuit including a wiring pattern and circuit components (for example, a resistor, a diode, a connector, etc.) is necessary. The device is not equipped with such a drive circuit and does not support a wide range of applications.

  Therefore, there has been proposed a semiconductor light emitting device that has good heat dissipation performance and can be mounted with a drive control circuit. As shown in FIG. 5, the semiconductor light emitting device 50 has a multilayer structure of a heat radiation support film 51, a bottom substrate 52, an insulating intermediate layer 53, and an upper substrate 54, which are sequentially positioned from the lower side.

  The insulating intermediate layer 53 includes an insulating layer 55 and an insulating adhesive layer 56 provided on both surfaces of the insulating layer 55. The upper substrate 54 is located on the upper side of one insulating adhesive layer 56, and the other The bottom substrate 52 is located below the insulating adhesive layer 56, and the heat dissipation support film 51 made of copper foil or the like is located below the bottom substrate 52.

  The bottom substrate 52 is provided with a conductor layer 57. The conductor layer 57 is further provided with an Ag plating layer 71 to form a reflection portion 72 (a two-layer structure of the conductor layer 57 and the Ag plating layer 71). The emitted light from the semiconductor light emitting element 62 to be directed is directed in the irradiation direction so as to improve the light use efficiency.

  The bottom substrate 52, the insulating intermediate layer 53, and the upper substrate 54 are provided with a first through hole 58, a second through hole 59, and a third through hole 60, respectively, and the second through hole 59 and the third through hole 60 are provided. Are substantially the same size, and the first through hole 58 is smaller than the second through hole 59 and the third through hole 60.

  A semiconductor light emitting device 62 is mounted on the heat dissipation support film 51 via a bonding layer 61, and an electrode (not shown) of the semiconductor light emitting device 62 located in the first through hole 58 of the bottom substrate 52 and the bottom substrate. 52 electrode portions (a two-layer structure of a conductor layer 57 and an Ag plating layer 71) 73 are electrically connected via a bonding wire 63.

  The first through-hole 58, the second through-hole 59, and the third through-hole 60 are filled with a sealing resin 67 in which a phosphor 65 and a light-transmitting particle 66 are mixed in a light-transmitting resin 64, and semiconductor light emission. The element 62 and the bonding wire 63 are sealed with resin.

As a result, the self-heating during light emission of the semiconductor light emitting element 62 is dissipated by the support film 51 for heat dissipation, and the sealing resin 67 containing translucent particles 66 having a large specific heat capacity such as quartz glass particles is used as the resin. By sealing, the temperature rise of the semiconductor light emitting element 62 is suppressed, and since the drive control circuit can be disposed on the upper substrate 54, the semiconductor light emitting elements 62 can be densely disposed. ing. Further, by sealing the semiconductor light emitting element 62 with a sealing resin 67 in which a phosphor 65 is mixed in a translucent resin 64, it is possible to emit light having a color tone different from the light source light of the semiconductor light emitting element 62. The semiconductor light emitting device 50 is realized (for example, refer to Patent Document 1).
JP 2007-150228 A

  By the way, in a semiconductor light emitting device configured by laminating a plurality of substrates as in the semiconductor light emitting device having the above configuration, the insulating adhesive layer is often configured by bonding via an insulating adhesive layer. As a result, the insulating adhesive layer deteriorates due to ultraviolet light that contaminates the electrode portion 73 including the wire bonding region and the upper portion of the wire bonding region.

  Here, in order to prevent the insulating adhesive layer from protruding, the inventors have at least the end of the insulating adhesive layer exposed in the recess formed by the through hole of the substrate outside the inner peripheral surface of the through hole. It was considered to form a concave shape.

  However, when the sealing resin 67 is filled, the sealing resin 67 is difficult to flow into the recessed portion of the insulating adhesive layer 56, and an air layer may be formed. This air layer is pushed out by the sealing resin 67 whose viscosity has been reduced during thermosetting, and becomes air bubbles in the sealing resin 67. At this time, since the thermosetting of the sealing resin 67 is gradually progressing, the sealing resin 67 is cured before the bubbles 70 are released to the outside of the sealing resin 67, and the bubbles 70 are accumulated in the sealing resin 67. .

  When the bubble 70 travels in the direction of the bonding wire 63, it comes into contact with the bonding wire 63 and causes a problem such as cutting the bonding wire 63. In particular, when a metal layer such as the reflective portion 72 separated from the electrode portion 73 is provided on the bottom substrate 52 in addition to the electrode portion 73 other than for the purpose of wiring, air is formed in the gap between the electrode portion 73 and the reflective portion 72. Layers are easily formed, and defects due to bubbles traveling toward the bonding wire are likely to occur.

  Therefore, the present invention was devised in view of the above problems, and the object of the present invention is to direct the bubbles generated during the heat curing of the sealing resin for sealing the semiconductor light emitting element in a direction away from the bonding wire. An object of the present invention is to provide a semiconductor light emitting device capable of preventing the occurrence of an electrical failure caused by bubbles coming into contact with a bonding wire.

In order to solve the above problems, the invention described in claim 1 of the present invention is:
A first insulating substrate;
A second insulating substrate having a through-hole bonded to the first insulating substrate via an insulating adhesive layer;
A semiconductor light emitting device disposed in a recess including at least the through hole;
A semiconductor light emitting device having a sealing resin filled in the recess,
A first conductor pattern formed on the first insulating substrate and electrically connected to the semiconductor light emitting element via a bonding wire;
A second conductor pattern formed on the first insulating substrate and formed separately from the first conductor pattern;
At least a part of the end portion exposed in the concave portion of the insulating adhesive layer is disposed at a position retracted from the inner peripheral surface of the through hole,
The first conductor pattern and the second conductor pattern each extend from a region where the insulating adhesive layer is formed on the first insulating substrate to a region exposed in the recess, The thickness of one conductor pattern is thicker than the thickness of the second conductor pattern.

Further, the invention described in claim 2 of the present invention, in claim 1, wherein the first insulating substrate includes a second through hole smaller than the through hole, the second of said first insulating substrate A support plate disposed so as to close the second through hole on the opposite side of the surface to which the insulating substrate is bonded, and the semiconductor light emitting element is mounted on the support plate. It is a feature.

  According to a third aspect of the present invention, in any one of the first and second aspects, the gap between the first conductor pattern and the second conductor pattern, and the end of the insulating adhesive layer. The parts intersect at least at one place or more.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the thickness of the first conductor pattern is greater than the thickness of the second conductor pattern. It is characterized by being thicker than half the thickness of the layer.

  The semiconductor light emitting device of the present invention includes a semiconductor light emitting element and a first insulating substrate bonded together via an insulating adhesive layer and a semiconductor light emitting element in a recess including at least the through hole of the second insulating substrate having a through hole. A semiconductor light emitting device having a sealing resin, wherein the first conductor pattern electrically connected to the semiconductor light emitting element via a bonding wire on the first insulating substrate and the first conductor pattern are separated The second conductor pattern is formed, and at least a part of the end portion exposed in the concave portion of the insulating adhesive layer is disposed at a position retracted from the inner peripheral surface of the through hole.

  At this time, the thickness of the first conductor pattern is formed to be thicker than that of the second conductor pattern, and is generated in the gap between the first conductor pattern and the second conductor pattern when the sealing resin is filled and heat-cured. Air bubbles are directed in the direction of the second conductor pattern with the end face of the first conductor pattern serving as a barrier.

  As a result, the bubbles generated in the gap between the first conductor pattern and the second conductor pattern are directed away from the bonding wire, thereby preventing the occurrence of electrical problems caused by the bubbles contacting the bonding wire. It became possible.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4 (the same reference numerals are given to the same parts). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  In the semiconductor light emitting device of the present invention, when the semiconductor light emitting element serving as the light emitting source of the semiconductor light emitting device is resin-sealed, the bubbles generated in the sealing resin during the heat curing of the sealing resin are located in the vicinity thereof. The structure is directed toward the direction away from the wire. Therefore, the occurrence of electrical and optical defects caused by bubbles contacting the bonding wire is prevented, and a highly reliable semiconductor light emitting device is realized.

  1 to 3 show the structure of a semiconductor light emitting device. FIG. 1 is a top view, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG.

  In the semiconductor light emitting device 1, a lower substrate 2 and an upper substrate 3 each made of an insulating material are bonded together via an insulating adhesive layer 4, and the lower substrate 2 is made of, for example, copper or the like on the opposite side (lower surface side) of the upper substrate 3. A support plate made of metal foil 5 is provided. The insulating adhesive layer 4 is made of, for example, prepreg and has a thickness of about 0.1 mm.

  The upper substrate 3 and the lower substrate 2 are respectively provided with a first through hole 6 and a second through hole 7, and the first through hole 6 of the upper substrate 3 is more than the second through hole 7 of the lower substrate 2. Is also formed large. The end portion 8 of the insulating adhesive layer 4 is formed in a concave shape that is recessed outward from the inner peripheral surface 9 of the first through hole 6 of the upper substrate 3. It is located at a position retracted about 0.1 mm from the inner peripheral surface 9. In the present embodiment, glass epoxy substrates are used for the upper substrate and the lower substrate, and prepregs in which glass fibers are impregnated with an uncured epoxy resin are used for the insulating adhesive layer. Further, the end portion on the through hole side of the insulating adhesive layer of about 0.1 mm was disposed so as to recede by 0.1 mm from the inner peripheral surface of the upper substrate.

  The region 11 exposed in the recess 10 formed of the second through hole 7 of the lower substrate 2, the first through hole 6 of the upper substrate 3 and the metal foil 5 of the lower substrate 2 is interposed via a gap 12. An electrode pattern 13 and a reflection pattern 14 formed separately and independently are formed.

  The electrode pattern 13 extends from the exposed region 11 in the recess 10 on the upper surface of the lower substrate 2 to the end 15, and the reflection pattern 14 is formed on the remaining region other than the electrode pattern 13 in the exposed region 11 in the recess 10 of the lower substrate 2. Is formed. The electrode pattern 13 and the reflective pattern 14 are formed on the lower substrate while being separated by an interval of about 0.1 to 0.2 mm.

The electrode pattern 13 has a four-layer structure in which a Cu pattern formed on the lower substrate 2 is sequentially subjected to Cu plating, Ni plating, and Ag plating, and has an approximately 35 μm Cu pattern, approximately 50 μm Cu plating, It is formed by Ni plating of about 5 μm and silver plating of about 2 μm.
The reflection pattern 14 has a three-layer structure in which Ni plating and Ag plating are sequentially performed on the Cu pattern, and is formed by a copper pattern of about 20 μm, a Ni plating of about 5 μm, and a silver plating of about 2 μm. The thicknesses of the patterns 13 and 14 are different from each other, and the electrode pattern 13 is formed thicker than the reflection pattern 14. In this embodiment, the electrode pattern thickness is formed to be about 65 μm thicker than the reflection pattern thickness.
Both patterns 13 and 14 were formed by the same plating process, and the reflection pattern portion was formed by etching the Cu pattern and the Cu plating layer after the Cu plating process to form a Cu pattern layer of about 20 μm. Thus, the difference in thickness between the electrode pattern 13 and the reflection pattern 14 is set by controlling the thickness of the Cu plating in the four-layer structure.
In addition, since the size of the bubble affects the interval between the upper substrate and the lower substrate, the electrode pattern thickness may be formed to be more than half the interval between the upper substrate and the lower substrate than the reflective pattern thickness. preferable. That is, it is preferable that the insulating adhesive layer is formed to be thicker than half the thickness. Also in this embodiment, although the generation of bubbles having a diameter of about 0.1 mm was confirmed while the distance between the upper substrate and the lower substrate was about 0.1 mm, a difference in thickness of about 65 μm was formed. As a result, contact with the bonding wire did not occur.

  A semiconductor light-emitting element 16 is die-bonded on the metal foil 5 located at the bottom of the second through-hole 7 via a conductive member (not shown) such as solder or silver paste, and is used as an electrode of the semiconductor light-emitting element 16. The other end of the bonding wire 17 to which one end is connected is wire-bonded to the electrode pattern 13 formed in the exposed region 11 in the recess 10 on the upper surface of the lower substrate 2, and the electrode and the electrode pattern of the semiconductor light emitting element 16. 13 is electrically connected via a bonding wire 17.

  The recess 10 in which the semiconductor light emitting element 16 is located is filled with a sealing resin 18 made of a translucent resin, and the semiconductor light emitting element 16 and the bonding wire 17 are sealed with resin. In this case, the sealing resin 18 protects the semiconductor light emitting element 16 from the external environment such as moisture, dust, and gas, and protects the bonding wire 17 from mechanical stress such as vibration and impact. Further, the sealing resin 18 forms an interface with the light emitting surface of the semiconductor light emitting element 16, and the emitted light of the semiconductor light emitting element 16 is efficiently emitted from the light emitting surface of the semiconductor light emitting element 16 into the sealing resin 18. It also has a function to make it. In this embodiment, a silicone resin is used as the sealing resin 18.

  Note that the sealing resin is not limited to the light-transmitting resin, and the semiconductor light-emitting element and the bonding wire can be resin-sealed with a sealing resin obtained by dispersing a phosphor in the light-transmitting resin. In that case, the semiconductor light-emitting device is a light-emitting device that emits light having a wavelength different from that of the light source light of the semiconductor light-emitting element serving as the light-emitting source.

  By the way, in the semiconductor light emitting device 1 having such a structure, the sealing resin 18 for sealing the semiconductor light emitting element 16 and the bonding wire 17 is the first through hole 6 of the lower substrate 2 and the second of the upper substrate 3. The through hole 7 and the metal foil 5 are filled in the recess 10 and then heated and cured.

  Therefore, if there is a small recess such as a groove or a recess in the recess filled with the sealing resin, the sealing resin does not flow into the portion when the sealing resin is filled, and air can be trapped. This pool of air is pushed out by the sealing resin whose viscosity has been reduced during the thermosetting of the sealing resin, and becomes bubbles in the sealing resin. At this time, since the thermosetting of the sealing resin is gradually progressing, the sealing resin is cured before the bubbles are released out of the sealing resin, and the bubbles remain in the sealing resin.

  In the semiconductor light emitting device, as shown in FIG. 3 in particular, the gap between the recess 19 of the insulating adhesive layer 4 and the electrode pattern 13 and the reflective pattern 14 located on the bottom substrate 2 when the sealing resin 18 is filled. Air easily accumulates in a portion overlapping with 12 and tends to remain as bubbles 20 in the vicinity thereof after thermosetting.

  If the thickness of the electrode pattern 13 and the thickness of the reflective pattern 14 are the same at the position where the bubble 20 is generated, the direction of the bubble 20 is not constant and is uncertain. For this reason, there is a risk of causing a problem such as contact with the bonding wire 17 and cutting the bonding wire 17. On the other hand, in the semiconductor light emitting device of the present invention, the thickness of the electrode pattern 13 to which the end portion of the bonding wire 17 is connected is made larger than the thickness of the reflective pattern 14, and the gap between the electrode pattern 13 and the reflective pattern 14 is increased. The bubbles 20 generated in the 12 portions are directed toward the reflective pattern 14 with the end face 21 of the electrode pattern serving as a barrier.

  As a result, the bubble 20 generated in the portion where the recess 19 of the insulating adhesive layer 4 and the gap 12 between the electrode pattern 13 and the reflection pattern 14 overlap is directed away from the bonding wire 17, and the bubble 20 is bonded to the bonding wire 17. It is possible to prevent the occurrence of an electrical failure due to contact with the.

  In the semiconductor light emitting device, the semiconductor light emitting element is disposed on the metal foil 5 located on the lower surface side of the lower substrate 2. However, the structure is not necessarily limited to this structure. 4, a digging portion (concave portion) 22 is provided in the lower substrate 2, the semiconductor light emitting element 16 is mounted on the bottom surface 23 of the digging portion 22, the bonding wire 17 is overlaid, and the second penetration of the upper substrate 3 is performed. It is also possible to have a structure in which the recess 24 formed by the hole 7 and the digging portion 22 of the lower substrate 2 is filled with the sealing resin 18.

In the above embodiment, the insulating adhesive layer 4 has been described using a prepreg in which glass fiber is impregnated with an uncured epoxy resin. However, an adhesive sheet made of an epoxy resin or the like, or both surfaces of a glass epoxy substrate are used. The thing changed according to the use and specification, such as using the thing of the multilayer structure by which the adhesive sheet is arrange | positioned, can be used. In addition, when using a multi-layer structure as the insulating adhesive layer, the layer that recedes from the inner peripheral surface of the upper substrate may be a part of the layer that is likely to protrude, but the entire insulating adhesive layer Also good.
In addition, in the said embodiment, although demonstrated with the structure by which the reflective pattern was formed separately from the electrode pattern, it is not restricted to the reflective pattern aiming at reflection, The conductor formed for the other objective according to a use or improvement A pattern can be used.
As mentioned above, although this invention was demonstrated along embodiment, this invention is not limited to these. Various modifications, improvements, and combinations are possible. For example, a plurality of semiconductor light-emitting elements can be used, or a support plate made of a metal foil can be provided by different manufacturing methods.

It is a top view of the embodiment concerning the present invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is explanatory drawing which shows the application example of embodiment which concerns on this invention. It is explanatory drawing of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor light-emitting device 2 Lower board | substrate 3 Upper board | substrate 4 Insulating adhesive layer 5 Metal foil 6 1st through-hole 7 2nd through-hole 8 End part 9 Inner peripheral surface 10 Recessed part 11 Exposed area | region 12 Gap | interval 13 Electrode pattern 14 Reflective pattern DESCRIPTION OF SYMBOLS 15 End part 16 Semiconductor light-emitting element 17 Bonding wire 18 Sealing resin 19 Depression part 20 Bubble 21 End surface 22 Dimming part 23 Bottom face 24 Recessed part

Claims (4)

A first insulating substrate;
A second insulating substrate having a through-hole bonded to the first insulating substrate via an insulating adhesive layer;
A semiconductor light emitting device disposed in a recess including at least the through hole;
A semiconductor light emitting device having a sealing resin filled in the recess,
A first conductor pattern formed on the first insulating substrate and electrically connected to the semiconductor light emitting element via a bonding wire;
A second conductor pattern formed on the first insulating substrate and formed separately from the first conductor pattern;
At least a part of the end portion exposed in the concave portion of the insulating adhesive layer is disposed at a position retracted from the inner peripheral surface of the through hole,
The first conductor pattern and the second conductor pattern each extend from a region where the insulating adhesive layer is formed on the first insulating substrate to a region exposed in the recess, The thickness of one conductor pattern is thicker than the thickness of said 2nd conductor pattern, The semiconductor light-emitting device characterized by the above-mentioned. Said first insulating substrate, closes the second through hole smaller than the through hole, the second through-hole on the opposite side of the first insulating said second insulating bonded together the surface of the substrate of the substrate The semiconductor light-emitting device according to claim 1, wherein the semiconductor light-emitting element is placed on the support plate.   The gap between the first conductor pattern and the second conductor pattern and the end of the insulating adhesive layer intersect at at least one place. Semiconductor light emitting device.   4. The thickness of the first conductor pattern is one half or more of the thickness of the insulating adhesive layer than the thickness of the second conductor pattern. 5. Semiconductor light emitting device.

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