JP2005353792A - Resin sealing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin sealing semiconductor device preventing the deterioration of heat-dissipating properties and having even excellent shielding characteristics in the semiconductor device coated with a packaging resin having an uneven shape. <P>SOLUTION: In the resin sealing semiconductor device 1 in a form in the operation, a semiconductor bare chip 6 coated with an epoxy resin 9, and a surface mounting part 8 such as a chip capacitor; a chip resistor or the like are mounted on a specified wiring pattern on a glass epoxy board 10, and the packaging resin 12 for an insulation protection is formed on a lead terminal 13 and the board containing these parts. An aluminum plate 2 with an opening section is fitted around the packaging resin 12, and the inwall section of the aluminum plate 2 is coated with a resin 4 having a high elasticity and a high thermal conductivity. The resin 4 is buried between the aluminum plate 2 and the packaging resin 12 when the board 10 sealed with the packaging resin 12 is inserted from the opening section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin-encapsulated semiconductor device in which a semiconductor bare chip or semiconductor package product and a surface-mounted component are mounted on the same substrate. The present invention relates to a semiconductor device capable of shielding from oscillation or external noise.

  In a resin-encapsulated semiconductor device in which a semiconductor chip housed in a semiconductor bare chip or package and a surface mount component are mounted on the same substrate, not only the characteristic variation of the semiconductor chip itself due to heat generated during operation of the semiconductor chip There is also a risk of adversely affecting nearby components. Therefore, in the above resin-encapsulated semiconductor device, how to improve heat dissipation is important.

  Conventionally, as a countermeasure against heat, a substrate having high thermal conductivity is used to reduce the influence of the heat of the semiconductor chip. Especially when the board material is metal, the heat dissipation is very high, but it is necessary to mount many parts on the board and connect each part with a wiring pattern. Resin substrates and ceramic substrates that can be easily formed are often used.

  However, since these materials have poor heat dissipation compared to metals, through holes are provided from the substrate surface to the back side to make thermal contact with the metal heat sink arranged on the back side of the substrate to improve heat dissipation. There are ways to do this, but there are limitations.

  Therefore, in order to further improve the heat dissipation, there is a method in which a metal plate, a heat sink or the like is provided in close contact with an exterior resin for protecting the resin-encapsulated semiconductor device.

  However, since a large number of electronic components are mounted on the resin-encapsulated semiconductor device as described above, a method of giving mechanical damage such as a molding press to form the exterior resin cannot be used. Therefore, resin molding is performed by powder coating or dipping, but in such a method, irregularities are likely to occur on the outer shape of the resin. Further, the surface shape of the substrate in a state where the components are mounted has a large level difference, and the above-described unevenness of the outer shape is further enlarged because the space is covered with resin.

  In order to improve heat dissipation, the metal plate must be in close contact with the exterior resin. However, as described above, irregularities are likely to occur in the exterior resin shape, so there are many gaps if the metal plate is simply in close contact. Since the area is not large, the heat dissipation is not so improved. In order to avoid this, there is a method of injecting grease such as silicon resin into the gap with the metal plate, but it is difficult to wrap the resin all around the minute gap.

  In addition to the above-mentioned problem of heat dissipation, the influence of radiation noise and external noise generated from the semiconductor chip is also a problem.

  FIG. 5 is a cross-sectional view of a conventional resin-encapsulated semiconductor device, and FIG. 6 is a transparent perspective view thereof (see, for example, Patent Document 1).

  5 and 6, a resin-sealed semiconductor element 22 and a passive element 23 are mounted on a circuit board 21, and a lead terminal 24 is connected to a terminal mounting portion of the circuit board 21. The circuit board 21 is covered with a metal case 25, and the ground pattern 21a provided at both ends of the circuit board 21 and the metal case 25 are connected by solder. Further, a metal plate 26 is inserted between the exterior resin of the semiconductor element 22 and the metal case 25, and is in close contact with each of the resin surface and the metal case 25. Further, the sealing resin of the semiconductor element 22 and the metal plate 26 are bonded with a resin 27 having good thermal conductivity. Further, a hole 25 a smaller than the metal plate 26 is formed in a portion on the metal plate 26 of the metal case 25, and the hole 25 a of the metal case 25 and the metal plate 26 are connected by solder 28.

According to this conventional example, by inserting the metal plate 26 between the sealing resin of the semiconductor element 22 and the metal case 25, the heat generated from the semiconductor element 22 is transmitted from the metal plate 26 to the metal case 25. The heat is dissipated into the air outside the metal case 25. Further, the external noise can be shielded by the metal case 25, and the radiation noise generated from the semiconductor element 22 by the metal plate 26 can also be suppressed. In this way, it is possible to keep the temperature of the semiconductor element 22 below the operating temperature range while maintaining the shielding effect.
JP-A-6-97686

  However, in the prior art described in Patent Document 1, it is necessary to bond the metal case 25 and the metal plate 26 with solder, and an adhesive is required for the resin 27 and the metal plate 26. Not easy. Furthermore, since the effect cannot be exerted unless the formation method of the resin 27 is also considered so that surface connection is possible, the shape of the resin 27 and the shape of the semiconductor element 22 are also limited.

  The present invention solves the above-described problems and provides a resin-encapsulated semiconductor device that can improve heat dissipation even in a semiconductor device covered with an exterior resin having a non-flat shape and has good shielding characteristics. For the purpose.

  In order to solve the above-described problems, a resin-encapsulated semiconductor device according to the present invention includes a resin-type semiconductor in which a semiconductor element and passive components are mounted on a substrate, and the substrate including the semiconductor elements and passive components is covered with a resin. In the apparatus, a portion of the substrate covered with the resin excluding the vicinity of a lead terminal extending from the substrate is further covered with a metal plate having an opening, and the inner wall portion of the metal plate is highly elastic. And it is covered with resin which has high thermal conductivity.

  In the metal plate, it is preferable that the opening is bent outward, and the bent portion is a support portion when the resin-type semiconductor device is mounted on a board.

  It is preferable that the bottom of the bent portion and the ground of the board are bonded with a solder material to be grounded.

  It is more preferable that the outer wall of the metal plate is subjected to black metal plating.

  According to the present invention, in order to increase the adhesion between a resin for sealing a circuit mounting board and a metal plate serving as a heat sink, a metal plate having a highly elastic and highly thermally conductive resin that can be flexibly changed in shape on the inner wall. By arranging them so as to surround them, it is possible to efficiently dissipate heat generated from the semiconductor elements, and to easily realize a semiconductor circuit device having a shielding effect by grounding the metal plate to the ground of the board.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  1 is a plan view of a resin-encapsulated semiconductor device according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a cross-sectional view taken along line AA ′ in FIG. 1, and FIG. is there.

  The resin-encapsulated semiconductor device 1 in the present embodiment is configured as follows.

  On a glass epoxy substrate 10 made of 96% alumina having a thickness of about 600 μm, a resist layer 5 having a thickness of about 15 μm is formed on a copper plate inside the substrate, and electrical wiring is selectively applied. A semiconductor bare chip 6 having a thickness of about 500 μm and a surface mount component 8 such as a chip capacitor or a chip resistor are bonded to a predetermined wiring pattern on the substrate with silver paste or solder, and the semiconductor bare chip 6 and the substrate 10 are 28 μm in diameter. Are electrically coupled by the gold wire 7.

  By design, a 0.3 mm diameter through hole 11 penetrating from the front surface to the back surface of the substrate is provided in advance at a location where heat generation is large. Furthermore, in order to improve moisture resistance, heat dissipation, etc., an epoxy resin 9 that protects the semiconductor bare chip 6, a lead terminal 13 for connecting the substrate 10 to a board (not shown), and insulation on the substrate including these components. A protective exterior resin 12 is provided.

  An aluminum plate 2 having an opening is provided so as to surround the exterior resin 12, and the lead terminal 13 extends to the outside through the opening. Further, the aluminum plate 2 has a shape bent outward at the opening. Such a shape can be processed by a simple method such as a molding press.

  A resin 4 having high elasticity and high thermal conductivity is attached to the inner wall portion of the aluminum plate 2, and when the epoxy substrate 10 sealed so as to be surrounded by the exterior resin 12 is inserted from the opening, the aluminum plate 2 and the exterior The resin 4 is filled with the resin 12. Further, the outer wall portion of the aluminum plate 2 is black and has a metal plating 3 applied thereto. The thickness of the metal plating 3 is about several tens of μm. By applying this metal plating, the volume of the metal portion can be increased, the thermal conductivity can be increased, and the heat dissipation can be improved.

  As shown in FIG. 2, the aluminum plate 2 is formed by bending a base portion (B-B ′ portion in FIG. 2), and a solder plating 14 is formed on the lower portion thereof. With such a structure, it is possible to prevent the resin-encapsulated semiconductor device 1 from being overturned when mounted on a board.

  Further, when the resin-encapsulated semiconductor device 1 is mounted on the board, a solder paste is formed so that the bottom of the aluminum plate 2 can be grounded to the board ground, and at the same time as other components mounted on the board, Adhere in the reflow process. Thereafter, the lead terminals 13 and the board are electrically coupled using a solder flow process or a soldering iron.

  As described above, according to the present embodiment, when an aluminum plate serving as a heat radiating plate is attached to a circuit mounting board solidified with a resin, aluminum is provided by providing a highly elastic and high thermal conductive resin on the inner wall portion of the aluminum plate. The thermal contact between the board and the mounting board is maintained well, and the heat dissipation is remarkably improved.

  In addition, since it has a structure that surrounds the circuit mounting board with an aluminum plate except for the vicinity of the lead terminal, the shielding effect is high, and by adopting a configuration in which the bottom of the aluminum plate is grounded to the ground of the board, in particular, Complete shielding can be achieved and noise is greatly reduced.

  In the present embodiment, when the resin-encapsulated semiconductor device 1 is mounted on the board, the semiconductor device can be maintained on the board so that it can be automatically mounted by a machine like a surface-mounted component. It becomes.

  The resin-encapsulated semiconductor device of the present invention has the effect of shielding heat dissipation and radiation and external noise even in products whose exterior resin shape is not determined in production, and is useful for AC-DC converters used in switching power supply circuits, etc. is there.

Plan view of resin-encapsulated semiconductor device in an embodiment of the present invention Side view of resin-encapsulated semiconductor device in an embodiment of the present invention Sectional view taken along line A-A 'in FIG. Transparent perspective view of semi-resin-sealed semiconductor device in an embodiment of the present invention Sectional view of resin-encapsulated semiconductor device in the prior art Transparent perspective view of resin-encapsulated semiconductor device in the prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin sealing type semiconductor device 2 Aluminum plate 3 Metal plating 4 High elasticity, high heat conductive resin 5 Resist layer 6 Semiconductor bare chip 7 Gold wire 8 Surface mount component 9 Epoxy resin 10 Glass epoxy board 11 Through hole 12 Exterior resin 13 Lead terminal DESCRIPTION OF SYMBOLS 14 Solder plating 21 Circuit board 21a Ground pattern 22 Semiconductor element 23 Passive element 24 Lead terminal 25 Metal case 25a Hole 26 Metal plate 27 Resin 28 Solder

Claims (4)

A resin-encapsulated semiconductor device in which a semiconductor element and a passive component are mounted on a substrate, and the substrate including the semiconductor element and the passive component is covered with a resin,
Of the substrate covered with the resin, a portion excluding the vicinity of a lead terminal extending from the substrate is further covered with a metal plate having an opening,
An inner wall portion of the metal plate is covered with a resin having high elasticity and high thermal conductivity. 2. The resin according to claim 1, wherein in the metal plate, the opening is bent outward, and the bent portion is a support when the resin-encapsulated semiconductor device is mounted on a board. Sealed semiconductor device. 3. The resin-encapsulated semiconductor device according to claim 2, wherein a bottom portion of the bent portion and a ground of the board are grounded by bonding with a solder material. The resin-encapsulated semiconductor device according to any one of claims 1 to 3, wherein the outer wall of the metal plate is subjected to black metal plating.

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