JPS6215882A - Chip carrier for electronic element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a chip carrier for an electronic device used as a substrate for an electronic device such as an IC package.

[Background Art I Electronic devices such as IC packages are packaged by attaching electronic component chips such as semiconductor chips to lead frames and sealing them with resin or hermetically sealing them. As the number of terminals increases in such electronic devices, attempts have been made to use printed wiring boards instead of lead frames as carriers for supporting electronic component chips.

Here, the recent increase in the density of electronic component chips is accompanied by heat generation, and it is necessary to devise ways to dissipate this heat. However, printed wiring boards used as carriers are made of resin or ceramic substrates, which have poor thermal conductivity and cannot dissipate heat well, so they are printed as carriers for electronic component chips. This is a problem with using wiring boards.

[Object of the Invention] The present invention has been made in view of the above points, and an object of the present invention is to provide a chip carrier for an electronic device that has excellent heat dissipation properties.

[Disclosure of the Invention J] The chip carrier for electronic devices according to the present invention comprises:
A circuit conductor 3 is provided on one side of a metal substrate 1 via an insulating adhesive layer 2 to form a metal-based printed wiring board 4 in which the other side of the metal substrate 1 is exposed, and an electronic component chip is mounted on this printed wiring board 4. The printed wiring board 4 used as a chip carrier is formed of a metal substrate 1 having excellent thermal conductivity, and one side of the metal substrate 1 is exposed. The above object is achieved by ensuring good heat radiation from this exposed surface.The present invention will be described in detail below with reference to Examples.

The metal-based printed wiring board 4 used as a chip carrier can be produced by applying the method disclosed in Japanese Patent Publication No. 56-37720, for example. That is, first, as shown in Fig. 2(a), a copper plate, a copper alloy plate, a copper plate, etc.
A through hole 11 is provided in a metal substrate 1 made of a copper (Cu-Inv-Cu) alloy plate, an iron-nickel alloy plate, other control plates, iron plates, aluminum plates, etc. A metal foil 13 such as copper foil is layered on one surface with a prepreg 12 interposed therebetween. The prepreg 12 is created by impregnating a base material such as glass cloth with a resin face such as epoxy resin, polyimide resin, or fluorine U (fat) such as Tear-On, and heating and drying it.
By overlapping the prepreg 12 and the metal foil 13 on one side of the surface and performing heat and pressure molding, the impregnated resin in the prepreg 12 oozes out and the resin 14 is used to form the metal substrate 1 as shown in FIG. 2(b). The through hole 11 is filled or at least the inner peripheral surface of the through hole 11 is coated with the resin 14. In this way, the metal foil 13 is attached to the surface of the metal substrate 1 by the insulating adhesive layer 2 formed by hardening the impregnated resin of the prepreg 12. 13 is laminated and the other side of the metal substrate 1 is exposed, thereby obtaining a printed wiring board 10 covered with metal foil on one side.

Through holes 11 are provided in the printed wiring board 10 obtained in this manner.
The resin 14 and the insulating layer have a diameter smaller than the diameter of
2 and the metal foil 13 to form a through hole 15 as shown in FIG. 2(e). The inner peripheral surface of the through hole 15 is coated with a resin 14 to ensure insulation with respect to the metal substrate 1. Then, a circuit is formed in accordance with a conventional method by etching the metal foil 13, and the circuit conductor 3 is provided on the surface of the insulating adhesive M2 as shown in FIG. A printed wiring board 4 is created based on the substrate 1. In this printed wiring board 4, a circuit conductor 3 is provided on one side of a metal substrate 1 via an insulating adhesive layer 2, and one side of the metal substrate 1 is exposed.

Then, an electronic component chip 5 such as a semiconductor chip is mounted on the surface of the printed wiring board 4 formed in this way.At this time, as shown in FIG.
A recess 9 extending from the insulating adhesive layer 2 to the surface layer of the metal substrate 1 is provided by counterboring or the like on the side where the circuit conductor 3 is provided.

Then, the recess 9 of the printed wiring board 4 thus formed is used as a cavity, and the electronic component chip 5 is placed in the recess 9.
Equipped with! As shown in Figure 1, the electronic component chip 5 is mounted on the printed wiring board 4 by applying wire bonding 17 or the like between the electronic component chip 5 and the circuit conductor 3. In this way, the printed wiring board 4 is used as a chip carrier to hold the electronic component chip 5, and is finished as an electronic device by puffing it. Here, we try to finish it as a PGA (pin grid array) type electronic device, or LCC (leadless chip carrier).
It is possible to finish it as a type of electronic element, but when finishing it as a PGA type, it is possible to finish it as a printed wiring board 5.
The terminal pins are attached to the through holes i5, 15, . . . so as to protrude downward or upward.

As described above, the electronic component chip 5 is attached to the printed wiring board 4 based on the metal substrate 1 to form an electronic element. This makes it possible to effectively dissipate heat from the electronic component chip 5. In particular, in this printed wiring board 4, the metal substrate 1 is in a state where the side on which the electronic component chip 5 is mounted and the reflective side are exposed. Therefore, the heat of the electronic component chip 5 transferred to the metal substrate 1 is not trapped inside the metal substrate 1, but is effectively dissipated into the air from this exposed surface of the metal substrate 1. It is possible to effectively prevent the temperature of the electronic component chip 5 from rising by dissipating the heat more effectively, and it is possible to increase the density of the electronic component chip 5.

Furthermore, there are two advantages to the embodiment shown in FIG.

Since the electronic component chip 5 is directly attached to the metal base IR1 in the recess 9, the electronic component chip 5
The heat generated from is transferred to the metal substrate 1, and the electronic component chip 5
This allows for good heat dissipation. Further, since the gold N4 substrate 1 does not allow moisture to pass through, it is possible to prevent moisture from forming on the electronic component chip 5 by blocking it with the metal -1411. In addition, the metal substrate 1 and the electronic component chip 5 have similar coefficients of thermal expansion, and the electronic component chip 5 and the printed wiring board M, which serves as a chip carrier, have similar coefficients of thermal expansion.
This means that it is possible to improve the reliability of the dark connection with 1 and 4.

In the above embodiment, a recess 9 is provided in the metal substrate 1 of the printed wiring board 4 so that the electronic component chip 5 is directly mounted on the metal substrate 1. However, this is not necessarily necessary, and the recess 9 is provided in the metal substrate 1 of the printed wiring board 4. As shown in FIG. I.J.
In this embodiment, an electronic component chip 5 is mounted on the exposed surface of the metal substrate 1 in the print F wiring @4 so as to be in direct contact with the metal substrate 1.

Effects of the Invention I As described above, in the present invention, a circuit conductor is provided on one side of a metal substrate via an insulating adhesive layer to form a metal-based printed wiring board, and an electronic Since the component chips are mounted, the metal substrate is a good conductor of heat and has excellent heat dissipation properties, and can effectively dissipate heat from the electronic component chips.
+1+-◆7R+/II [Since the other side of the metal substrate is exposed in the cable wire plate, the heat of the electronic component chip transferred to the metal substrate is not trapped inside the cell 14 substrate and is transferred to the metal substrate. The heat dissipates well from the exposed surface of the board, and as a result, the heat of the electronic component chip can be efficiently dissipated, effectively preventing the temperature of the electronic component chip from rising, and reducing the attenuated temperature of the electronic component chip. This makes it possible to

[Brief explanation of drawings]

Figure 1 is a sectional view of one embodiment of the present invention, Figure 2 (maple) (b
)(c) is a cross-sectional view showing each step of manufacturing the same printed wiring board as above, 3tA is a cross-sectional view of the same printed wiring board as above, FIG. 4 is a cross-sectional view of another embodiment of the present invention, and FIG. FIG. 3 is a sectional view of still another embodiment of the present invention. 1 is a metal substrate, 2 is an insulating adhesive layer, 3 is a circuit conductor, 4 is a printed wiring board, and 5 is an electronic component chip. -ζ force f also causes e6 to f) 'T' female, and this alint arrangement N1 Figure 2 (b)

Claims (1)

[Claims] (1) A circuit conductor is provided on one side of a metal substrate via an insulating adhesive layer to form a metal-based printed wiring board with the other side of the metal substrate exposed, and an electronic component chip is mounted on this printed wiring board. A chip carrier for electronic devices characterized by comprising: