JPH04346250A - Mounting method for semiconductor device - Google Patents

Abstract

PURPOSE:To increase the heat-dissipating effect of an IC chip mounted in a flip-chip manner. CONSTITUTION:An IC chip 1 is bonded facedown inside a cavity 4 formed in an electric wiring board 3 via electrodes on the IC chip 1 and via electric wiring electrodes 5. It is sealed with a resin whose heat conductivity is high so as to be stretched over the rear 6 of the IC chip 1 and the sidewall 7 of the cavity 4. Heat generated from the IC chip 1 is conducted to the whole of the board 3 and dissipated. Even the IC chip whose heat-generating amount is large can be mounted in a flip-chip manner; it can be mounted at higher density. As a result, an electronic apparatus can be constituted so as to be ultrasmall and ultrathin.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention relates to a method for mounting a semiconductor device such as a flip-chip type (hereinafter referred to as an "IC chip") onto a single-layer or multilayer electrical wiring board (hereinafter referred to as a "substrate"). It is related to.

0002

2. Description of the Related Art Conventionally, one of the methods for mounting an IC chip on a substrate is a flip-chip mounting method. This mounting method is a method in which the electrodes of an IC chip are bonded via bumps to the electrodes of an electric circuit wired on the surface of the board, and has the advantage of increasing the packaging density compared to the so-called wire bond mounting method. be.

0003

However, the flip-chip mounting method has a drawback in that heat dissipation is poor because the back surface of the IC chip does not come into close contact with the substrate. Even if an attempt was made to attach a heat sink directly to the IC chip in order to compensate for this disadvantage, it could not be done and a board or the like had to be inserted between the IC chips, resulting in poor heat dissipation. The present invention aims to provide an IC chip mounting method that solves these drawbacks.

0004

[Means for Solving the Problems] Therefore, the present invention connects the electrodes of an IC chip via bumps to the electrodes of an electric circuit wired in the cavity of a substrate having a cavity, and connects the electrodes of an IC chip in this way. A resin with high thermal conductivity is sealed over the surface of the IC chip where no electrode is provided and at least the side wall of the cavity, and the heat emitted from the IC chip is conducted to and dissipated from the substrate, or the upper part of the cavity is sealed. Attach a heat sink to the resin via the resin,
Improved heat dissipation.

[0005]

[Function] Therefore, with the IC chip mounting method of the present invention, most of the heat generated from the IC chip can be conducted and dissipated through the substrate. Because it is mounted inside the device, thin mounting is possible.

[0006]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view for explaining a first embodiment of the IC chip mounting method of the present invention, FIG. 2 is a cross-sectional view for explaining a second embodiment of the IC chip mounting method of the present invention, FIG. 3 shows the third method of mounting an IC chip according to the present invention.
FIG.

First, a method for mounting an IC chip according to the present invention will be explained with reference to FIG. 1 is an IC chip, and bumps 2 are bonded to a plurality of electrodes (not shown) of the IC chip. 3
is a substrate made of ceramic, glass epoxy resin, etc.
A cavity 4 is formed on its surface, and an electrode 5 is formed on its bottom.
An electrical wiring pattern (not shown) is provided.

The IC chip 1 is placed face down in the cavity 4 of the substrate 3 having such a structure, and the bumps 2 are bonded to the electrodes 5. That is, flip-chip mounting is performed. Thereafter, it is applied over the back surface 6 of the IC chip 1 and the side wall 7 of the cavity 4, and in the embodiment of FIG.
The peripheral surface 8 of the substrate 3 is also covered and sealed with a resin 9 having high thermal conductivity, for example, an epoxy potting resin.

In the second embodiment shown in FIG. 2, similar to the first embodiment shown in FIG. By controlling the amount of resin, the IC chip 1 is sealed with a thin resin, and the heat sink 1 is spread over the surface 8 of the substrate 3 around the cavity 4 via this resin layer.
0 was installed to further increase heat dissipation. 11 is a comb-shaped fin.

In the first and second embodiments described above, the cavity 4 was formed in a single layer of the substrate 3 and the IC chip 1 was placed therein, but in the third embodiment shown in FIG. It was formed on a multilayer substrate 3a. In the embodiment shown in FIG. 3, the multilayer substrate 3a consists of five substrates, and the cavity 4 is formed across three of the substrates. As in the embodiment shown in FIG. 1, the IC chip 1 is placed inside this cavity 4 and sealed with resin 9. 12 indicates an inner layer electrode;
Reference numeral 13 indicates via holes, and these via holes 13 connect the inner layer electrodes 12.

In the above description, the bumps 2 are bonded to the electrodes of the IC chip 1, but these bumps 2 may be bonded to the electrodes 5 of the electrical wiring pattern in advance. Needless to say.

0012

As is clear from the above description, according to the IC chip mounting method of the present invention, most of the heat generated from the IC chip can be conducted and dissipated through the substrate. Therefore, flip-chip mounting is possible even with IC chips that generate a large amount of heat, and even higher density mounting is possible. Furthermore, since the IC chip is mounted within the substrate, thinner mounting is possible compared to the normal flip-chip mounting method. Therefore, desirable effects such as making the electronic device ultra-small and ultra-thin can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view for explaining a first embodiment of the IC chip mounting method of the present invention.

FIG. 2 is a cross-sectional view for explaining a second embodiment of the IC chip mounting method of the present invention.

FIG. 3 is a cross-sectional view for explaining a third embodiment of the IC chip mounting method of the present invention.

[Explanation of symbols]

1 Semiconductor device (IC chip) 2 Bump 3 (Electrical wiring) board 3a Multilayer (electrical wiring) board 4 Cavity 5 Electrode 6 Back side 7 Side wall 8 Surface 9 Resin 10 Heat sink 11 Fin 12 Inner layer electrode 13 Beer hall

Claims (2)

[Claims] Claim 1: An electrode of a semiconductor device is connected via a bump to an electrode of an electric circuit wired in the cavity of an electric wiring board having a cavity, and the electrode of the semiconductor device connected in this way is encapsulating with a resin having high thermal conductivity across the empty surface and at least the side wall of the cavity,
A method for mounting a semiconductor device, comprising conducting and dissipating heat generated from the semiconductor device. 2. The method of mounting a semiconductor device according to claim 1, further comprising attaching a heat sink to the upper part of the cavity via the resin to further enhance heat dissipation.