JPH06103725B2 - Semiconductor chip carrier - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a heat dissipation type semiconductor chip carrier.

[Prior art]

With the increase in density and output of semiconductors, the heat generated from semiconductor chips is becoming higher, and semiconductor chip carriers that mount semiconductor chips are required to be able to dissipate the heat generated by the semiconductor chips. There is. FIG. 5 shows an example thereof, in which a metal plate 2 is embedded in an insulating substrate 1 formed of a printed wiring board or the like, and the metal plate 2 serves as a bottom surface on one surface (lower surface) of the insulating substrate 1. The cavity recess 3 is provided, and the semiconductor chip 4 is mounted in the cavity recess 3. A circuit (not shown) is formed on the surface of the insulating substrate 1. The semiconductor chip 4 is connected to one end of this circuit via a wire 11 or the like, and the terminal 12 having the base embedded in the insulating substrate 1 is used for other circuits. The ends are connected. In addition, the metal plate 2 is formed on the other surface (upper surface) of the insulating substrate 1.
A heat sink recess 5 having a bottom surface is provided, and a heat sink 7 is attached to the metal plate 2 in the heat sink recess 5 by being joined thereto. FIG. 6 shows another example. In this example, a thick metal plate 2 is used, and the metal plate 2 is embedded in the insulating substrate 1 so that a part thereof projects from the upper surface of the insulating substrate 1. The heat sink 7 is bonded to the protruding surface of the metal plate 2. In both of FIGS. 5 and 6, the heat generated from the semiconductor chip 4 is transferred to the metal plate 2 and also transferred from the metal plate 2 to the heat sink 7 to be radiated.

[Problems to be Solved by the Invention]

However, in the case of FIG. 5 described above, since the metal plate 2 exists at the bottom of the heat dissipation recess 3, the heat sink 7 is provided with a protrusion 7a, and the protrusion 7a is inserted into the heat dissipation recess 3 so that the metal plate Since it is necessary to join the plate 2, the weight of the heat sink 7 is increased by the weight of the protrusion 7a. Further, in the case of FIG. 6, since the metal plate 2 projects from the surface of the insulating substrate 1, the projecting surface of the metal plate 2 is scratched and becomes uneven when molding, and this surface of the metal plate 2 is damaged. When the heat sink 7 is joined to the metal plate 2, the metal plate 2 and the heat sink 7 cannot be brought into close contact with each other, and there is a problem that the efficiency of heat transfer from the metal plate 2 to the heat sink 7 is deteriorated. The present invention has been made in view of the above points, and provides a semiconductor chip carrier capable of preventing the heat sink from being heavy in weight and preventing heat transfer efficiency to the heat sink from being deteriorated. The purpose is.

[Means for Solving the Problems]

In the semiconductor chip carrier according to the present invention, a metal plate 2 is embedded in an insulating substrate 1, a cavity recess 3 whose bottom surface is the metal plate 2 is provided on one surface of the insulating substrate 1, and a semiconductor is provided in the cavity recess 3. The chip 4 is mounted, and the heat dissipation recess 5 whose bottom surface is the metal plate 2 is provided on the other surface of the insulating substrate 1.
The more protruding heat transfer metal body 6 is joined to the metal plate 2 in the heat dissipation recess 5, and the heat sink 7 is attached to the protruding surface of the heat transfer metal body 6.
It is characterized by being formed by joining.

[Action]

In the present invention, the heat transfer metal body 6 protruding from the insulating substrate 1 is bonded to the metal plate 2 in the heat dissipation recess 5, and the heat sink 7 is bonded to the protruding surface of the heat transfer metal body 6. Therefore, it is possible to join the heat sink 7 without providing the heat sink 7 with the protruding portion 7a, and the metal plate 2 is located at the bottom of the heat dissipation recess 5 and the surface is scratched during molding or the like. There is no fear.

【Example】

Hereinafter, the present invention will be described in detail with reference to examples. The insulating substrate 1 is made of a printed wiring board or the like obtained by processing a copper-clad laminate such as an epoxy resin laminate in which copper foil is laminated. A metal plate 2 having good properties is embedded. This metal plate 2 can be embedded at the same time when the laminated plate constituting the insulating substrate 1 is formed. A cavity recess 3 and a heat dissipation recess 5 are provided on one surface (lower surface) and the other surface (upper surface) of the insulating substrate 1 with an area smaller than the area of the metal plate 2, respectively. The bottom surface of the metal plate 2 and the bottom surface of the heat dissipation recess 5 are both formed by the surface of the metal plate 2. On the lower surface of the insulating substrate 1, a plurality of circuits (not shown) are formed radially around the cavity recess 3 by etching a copper foil or the like. The semiconductor chip 4 such as an IC chip is mounted on the surface of the metal plate 2 in the cavity recess 3, and a wire 11 such as a gold wire is provided between the external connection terminal of the semiconductor chip 4 and one end of the circuit. The semiconductor chip 4 is bonded to the circuit by bonding. The insulating substrate 1 has a plurality of terminals 12,1
The base parts are embedded and attached to the insulating substrate 1 so that 2 ... Project from the lower surface thereof, each terminal 12 is connected to the other end part of the circuit, and the semiconductor chip 4 is connected to the terminal 12 via the circuit. It is connected to. On the other hand, the heat sink 7 is made of copper, aluminum, brass or the like by providing the heat radiation fins 17. When mounting the heat sink 7 on the metal plate 2, first, the heat transfer metal body 6 is placed in the heat radiation recess 5. It is bonded to the surface of the metal plate 2. The heat transfer metal body 6 is made of a metal such as aluminum that has good heat conductivity, is lightweight, and is not easily scratched, and is formed in a dimension slightly thicker than the depth of the heat dissipation recess 5, and is welded. The heat transfer metal body 6 is bonded to the metal plate 2 by using a bonding material 13 having a good thermal conductivity such as an adhesive containing metal or metal powder. After the heat transfer metal body 6 is bonded to the metal plate 2 as described above, the heat sink 7 is bonded to the surface of the heat transfer metal body 6 protruding from the upper surface of the insulating substrate 1, as shown in FIG. The heat sink 7 can be joined using a joining material similar to the above. In this case, since the surface of the metal plate 2 is located at the bottom of the heat dissipation recess 5 and does not protrude from the surface of the insulating substrate 1, the surface of the metal plate 2 is damaged when the insulating substrate 1 is molded. There is no risk of sticking. Here, the heat transfer metal body 6
In the case of forming aluminum with aluminium, it is preferable to subject the surface to alumite treatment to increase the surface hardness so that the surface of the heat transfer metal body 6 is not easily scratched. Further, since the heat sink 7 is joined to the metal plate 2 via the heat transfer metal body 6, it is not necessary to provide a protrusion for joining to the heat sink 7, and it is not necessary to form the heat sink 7 with a heavy weight. Although the semiconductor chip carrier in the embodiment of FIG. 1 is of PGA type, it may be formed of QFP type as in the embodiment of FIG. In the embodiment shown in FIGS. 1 and 2, the heat transfer metal body 6 is formed in a rectangular parallelepiped, but as shown in FIG. 3 (a), the rounded portion 14 is provided on the upper edge of the heat transfer metal body 6, or As shown in FIG. 3B, a chamfered portion 15 is provided on the upper end edge of the heat transfer metal body 6, or a concave step portion 16 is provided on the upper end edge of the heat transfer metal body 6 as shown in FIG. 3C. You may keep it. The upper surface and the lower surface of the insulating substrate 1 are sealed with resin 18 (mold sealing). The resin 18 digs into the rounded portion 14 as shown in FIG. As shown in FIG. 4 (c), the resin 18 bites into the chamfered portion 15, and the resin 18 bites into the concave stepped portion 16 as shown in FIG. By holding the above, the bonding strength of the heat transfer metal body 6 to the metal plate 2 can be increased.

【The invention's effect】

As described above, in the present invention, the heat transfer metal body protruding from the heat release recess is joined to the metal plate in the heat release recess, and the heat sink is connected to the protruding surface of the heat transfer metal body. It is possible to join the heat sink via the heat transfer metal body without providing a protrusion on the heat sink,
The heatsink can be made lightweight, and the metal plate is located at the bottom of the heat dissipation recess, so there is no risk of scratches on the surface during molding, etc., and the heat transfer efficiency from the metal plate is reduced. Can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view of another embodiment of the above, and FIGS. 3 (a), (b) and (c) are sectional views of yet another embodiment of the same. Figure, Figure 4 (a) (b) (c)
Is a cross-sectional view showing a resin-encapsulated state of the above embodiment, and FIGS. 5 and 6 are cross-sectional views of a conventional example. 1 is an insulating substrate, 2 is a metal plate, 3 is a cavity recess, 4 is a semiconductor chip, 5 is a heat dissipation recess, 6 is a heat transfer metal body, and 7 is a heat sink.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takeshi Kano 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Toru Higuchi, 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd.

Claims (1)

[Claims] 1. A metal plate is embedded in an insulating substrate, a cavity recess whose bottom surface is the metal plate is provided on one surface of the insulating substrate, and a semiconductor chip is mounted in this cavity recess. A heat dissipation recess whose bottom surface is a metal plate is provided on the surface, a heat transfer metal body protruding from the surface of the insulating substrate is joined to the metal plate in the heat dissipation recess, and a heat sink is joined to the protruding surface of the heat transfer metal body. A semiconductor chip carrier characterized by the above.