JP2007208159A - Semiconductor device - Google Patents

Abstract

A semiconductor device having both functions of a high heat dissipation semiconductor device using a lead frame and an interposer and a multichip semiconductor device having semiconductor elements mounted on both sides of the lead frame is obtained.
A first semiconductor element and a second semiconductor element are mounted above and below a lead frame via an adhesive layer, the first semiconductor element and the second semiconductor element are electrically connected to an interposer, and an upper surface of the interposer is A molded semiconductor device, wherein a lead frame is provided with a plurality of holes, wires are used for connection between the first semiconductor device and the interposer, bumps are used for connection between the second semiconductor device and the interposer, and the first semiconductor device and the interposer The wire used for connection is connected through a hole provided in the lead frame.
[Selection] Figure 2

Description

  The present invention relates to a semiconductor device, and more particularly to a multichip semiconductor device in which semiconductor elements are mounted on both sides of a lead frame.

  In recent years, in response to the demand for higher density and smaller size of a semiconductor device, as one method, two semiconductor elements are mounted on the front and back of a lead frame, and each inner lead and the semiconductor element are connected by wire bonding. Such a structure has been proposed.

  In addition, semiconductor elements tend to increase in calorific value year by year, and the demand for improving heat dissipation has increased. Therefore, a structure as in Patent Document 2 has been proposed in response to demands for higher density, smaller size, and higher heat dissipation. According to Patent Document 2, a first semiconductor element is provided on one side of a metal plate bonded to a lead frame and connected to an inner lead by a wire. A second semiconductor element is also mounted on one of the metal plates, a wiring tape is provided on the circuit forming surface of the second semiconductor element and connected by a wire, and a bump is provided to connect the external substrate and the wiring tape. It has a structure. It is described that the structure of Patent Document 2 can achieve high density and high heat dissipation.

JP-A-8-191129 JP 2002-124623 A

  However, in the method of Patent Document 1, the heat dissipation from the mold resin, which has a lower thermal conductivity than that of metal, and the thermal conductivity transmitted to the wire, the inner lead, and the outer lead are high, but the heat dissipation semiconductor device has only a narrow path and a high heat generation. The structure was unsuitable for mounting.

  Further, in the method of Patent Document 2, heat is spread by a metal plate, but the heat radiation path from the inner lead and outer lead that are signal lines is narrow, and the circuit formation surface of the second semiconductor element is more thermally conductive than metal. There was a limit to heat dissipation due to bumps through low-rate wiring tape.

  An object of the present invention is to provide a high-heat-dissipating and high-density semiconductor device by eliminating the above-mentioned drawbacks of the prior art and directly connecting a heat-dissipation lead mounting a semiconductor element to an external substrate. .

  The semiconductor device of the present invention has a first semiconductor element and a second semiconductor element mounted on the top and bottom of a lead frame via an adhesive layer, and the first semiconductor element and the second semiconductor element are electrically connected to an interposer. A semiconductor device in which the upper surface of the interposer is molded, wherein the lead frame is provided with one or a plurality of holes, wires are used to connect the first semiconductor device and the interposer, and the second semiconductor device and the interposer are connected. The wires used for connecting the first semiconductor device and the interposer using bumps are connected through holes provided in the lead frame.

  In the present invention, a structure in which a plurality of semiconductor elements are mounted can increase the density, and heat can be radiated directly to an external substrate using a lead frame, so that high heat dissipation can be achieved.

  Embodiments of the present invention will be described below.

  FIG. 1 is a schematic sectional view of a first embodiment of the present invention. A first semiconductor element 2 is mounted on the upper surface of the lead frame 1 with a circuit forming surface facing upward via an adhesive layer (not shown), and a second semiconductor element 3 is mounted on the lower surface of the lead frame 1 on the circuit forming surface. It is mounted with an adhesive layer (not shown) facing down. The first semiconductor element 2 is electrically connected to the interposer 5 via the wires 4, and the second semiconductor element 3 is electrically connected to the interposer 5 via the bumps 6. Further, the upper surface of the interposer 5 is protected by a mold resin 7, and external connection bumps 8 are provided on the lower surface of the interposer 5 for connection to an external substrate (not shown). The lead frame 1 is bent like an outer lead of a normal semiconductor device so that the heat generated in the first semiconductor element 2 and the second semiconductor element 3 can be easily connected to the external board via an adhesive member in order to release the heat to the external board. It has a structure. Note that solder, conductive adhesive, or the like is used as the material for the bumps 6 and the external connection bumps 8.

  FIG. 2 is a schematic plan view of the first embodiment of the present invention. The mold resin 7 is not shown in order to make the internal structure easy to see, and instead the area to be sealed is represented by a dotted line. A hole 9 is provided in the lead frame 1, and the wire 4 passes through the hole 9 to connect the first semiconductor element 2 and the interposer 5. If the hole 9 is made large, the path through which heat escapes is reduced and the heat dissipation performance is lowered. Therefore, it is important to make the hole 9 the minimum size through which the wire 9 can pass.

  FIG. 3 is a schematic cross-sectional view when mounted on the external substrate of the first embodiment of the present invention. The lead frame 1 is connected to an external substrate 11 via solder 10. It goes without saying that measures are taken to further diffuse and dissipate heat within the substrate at the location of the external substrate 11 to which the lead frame 1 is connected. Further, although the present invention has been described by the method of connecting the lead frame 1 and the external substrate 11 with solder, it goes without saying that a conductive adhesive may be used.

  By configuring as described above, it is possible to increase the density by incorporating two semiconductor elements in one semiconductor device, and the heat of the semiconductor elements can be directly radiated to the substrate using a lead frame, so that heat is dissipated. It is possible to improve the performance. Furthermore, since the mold resin above and below the lead frame adheres through the hole, the adhesion between the resin above and below the lead frame is improved and the reliability can be improved.

  FIG. 4 is a schematic cross-sectional view of the second embodiment of the present invention. The interposer 5 has an opening 12 that is substantially the same size as the second semiconductor element 3, and the circuit forming surface of the second semiconductor element 3 is exposed from the opening 12, and the external connection bump 8 is formed by the interposer 5. And a circuit forming surface of the second semiconductor element 3 are connected to each other.

  By configuring as described above, the heat of the second semiconductor element can be directly released to the external substrate, so that the heat dissipation can be improved as compared with the first embodiment.

1 is a schematic cross-sectional view of a semiconductor device according to a first embodiment of the present invention. 1 is a schematic plan view of a semiconductor device according to a first embodiment of the present invention. It is a cross-sectional schematic diagram of the semiconductor device when mounted on the external substrate of the first embodiment of the present invention. It is a cross-sectional schematic diagram of the semiconductor device of the 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lead frame, 2 ... 1st semiconductor element, 3 ... 2nd semiconductor element, 4 ... Wire, 5 ... Interposer, 6 ... Single layer thin film, 9 ... Hole, 12 ... Opening part.

Claims (5)

A semiconductor in which a first semiconductor element and a second semiconductor element are mounted on the top and bottom of a lead frame via an adhesive layer, the first semiconductor element and the second semiconductor element are electrically connected to an interposer, and the upper surface of the interposer is molded In the device
A semiconductor device, wherein electrical signals of the first semiconductor element and the second semiconductor element are electrically connected to an external substrate by a connecting member provided on a lower surface of the interposer. The semiconductor device according to claim 1,
A semiconductor device using a wire for connecting the first semiconductor device and the interposer and using a bump for connecting the second semiconductor device and the interposer. The semiconductor module according to claim 1,
A semiconductor device, wherein the lead frame has one or a plurality of holes. The semiconductor module according to claim 2,
A wire used for connecting the first semiconductor device and the interposer is connected through a hole provided in the lead frame. The semiconductor module according to claim 1,
A semiconductor device characterized in that an opening having a size equivalent to that of the second semiconductor element is provided in the interposer, and a connection member electrically connected to the external substrate is provided on the lower surface of the interposer and the circuit forming surface of the second semiconductor element. .

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