JPH0380552A - Tape for mounting integrated circuit - Google Patents

Abstract

PURPOSE:To improve heat dissipation, reduce the irregularity of pitch of an outer lead part, and realize superior outer lead bonding, by forming a heat dissipating part on the peripheral surface in the vicinity of a lead frame and a device hole. CONSTITUTION:Bumps 2 to be connected with lead frames 3 are formed on the outer periphery of the surface of an LSI chip 1. On the other hand, by well-known exposure and etching technique of a copper foil, lead frames 3 having an inner lead part B1 and an outer lead part B0, a device hole 5, a heat dissipating part 4, and sprocket holes 6 are formed. Then by performing a specified gold-plating, a tape for mounting an LSI chip is formed. The heat dissipating part 4 is formed so as to have a thickness T larger than the thickness (t) of the lead frame 3, in order to increase heat dissipating effect. As the result, the heat supplied from a bonding tool 10 in the course of bonding diffuses in the heat dissipating part formed on the periphery of the device holes 5, via the lead frames 3, and the temperature rise in the lead frames 3 and on the tape surface can be remarkably restratined, so that extension and deformation of the lead frames 3 can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a TAB (Tape Automated
The present invention relates to an integrated circuit mounting tape using the bonding method, and particularly to the structure of an integrated circuit mounting tape that requires a large number of terminals and a narrow lead width.

[Conventional technology]

Conventionally, this type of terminal connection, which requires a very large number of pins and a narrow lead width, is performed by forming bumps on the periphery of a large-scale integrated circuit chip (hereinafter abbreviated as LSI chip) and placing bumps in device holes on a polyimide film. The TAB technique was used to connect the formed lead frame and the bump. That is, the structure was as shown in FIGS. 6 and 7. In this way, device hole 5 and sprocket hole 6
A predetermined number of lead frames 3 and a plating wiring 9 having a heat dissipating section 4 are fixed to a polyimide film 7 provided with an adhesive 8.

B is bonded to the bump 2 of the LSI chip 1.

In the conventional tape structure of an integrated circuit device that requires a large number of terminals and a narrow lead width, the only metal parts that are in close contact with the polyimide film 7 are the lead frame 3 and the plated wiring 9 connected thereto. Therefore, the heat transmitted from the bonding tool 10 during bonding is poorly dissipated and the temperature does not drop, causing the lead frame 3 to elongate,
There are disadvantages in that the polyimide film 7 and the lead frame 3 and the plating wiring 9 are peeled off at the adhesive portion 8, and the polyimide film 7 is deformed and shrunk.

As a result, the lead pitch P between the leads becomes uneven, and after the inner lead portion B1 of the lead frame 3 and the bump 2 are connected, when the lead flakes are separated and outer lead bonding is performed, the unevenness of the pitch P causes However, there is a drawback that bonding cannot be performed normally.

[Problem to be solved by the invention]

An object of the present invention is to improve the dissipation of heat applied during bonding between the inner lead portion of a lead frame and the bump of an LSI chip, to alleviate uneven pitch of the outer lead portion, and to perform good outer lead bonding. An object of the present invention is to provide a tape for mounting integrated circuits.

[Means to solve the problem]

In the tape structure of the integrated circuit device of the present invention, the lead frame and the outside of the device hole are made of the same metal material, and the lead frame has a lead thickness t around the vicinity of the device hole.
It has a heat dissipation part that is thicker (dimension T). With this configuration, the heat applied during bonding between the LSI chip and the lead frame is dissipated not only from the heat dissipation section, which has a large surface area, but also from the metal tape outside the heat dissipation section, resulting in more efficient heat dissipation. can be done.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view showing a first embodiment of the present invention,
FIG. 2 is a sectional view taken along the line AA' in FIG. 1. L.S.
A bump 2 is formed on the outer edge of the surface of the I-differential 11 for connection to a lead frame 3. On the other hand, the inner lead part B is formed using well-known exposure and etching techniques on the copper foil. and outer lead part B. After forming a lead frame 3, a device hole 5, a heat radiation section 4, and a sprocket hole 6, a predetermined gold plating (or tin plating) is applied to form an LSI chip mounting tape.

Here, the heat dissipation portion 4 is formed to have a dimension T thicker than the wall thickness t of the lead frame 3 in order to enhance the heat dissipation effect.

Next, bonding between the LSI chip 1 and the lead frame 3 will be described with reference to FIGS. 3(a) to 3(c).

As shown in Figure 3(a), bump 2 of LSI chip 1 and LS
The lead frame 3 of the I-chip mounting tape is aligned one-to-one with the inner lead part B, and both are simultaneously heated and pressed together using the bonding tool 10 as shown in FIG. 3(b) to form the inner lead part B. Bonding. Since the heat dissipation part 4 is formed near the device hole 5 of the mounting tape, the heat supplied from the bonding tool 10 during bonding is transmitted through the lead frame 3 to the device hole 5 as shown in FIG. 3(C). It spreads to the heat dissipation part 4 formed around the , and it becomes possible to dissipate heat from the surface. Therefore, the temperature rise on the lead frame 3 and the tape surface can be significantly suppressed, so that the elongation and deformation of the lead frame 3 can be alleviated. In addition, since the LSI chip mounting tape of the present invention is entirely made of copper foil plated with gold, it does not peel off from the polyimide film due to the heat applied during bonding, unlike conventional tapes outside the heat dissipation section 4. Since heat is also radiated from the lead frame, irregular pitches and deformation when the three parts of the lead frame are separated can be prevented.

FIG. 4 is a plan view of a second embodiment of the present invention, and FIG. 5 is a sectional view taken along the line BB'. In this embodiment, the heat dissipation portion 4 formed to surround the device hole 5 is provided as a plurality of convex shapes having a dimension T thicker than the thickness t of the lead frame 3. Therefore, the first
Since the heat dissipation area can be increased compared to the embodiment described above, there is an advantage that the heat dissipation characteristics are even better.

〔Effect of the invention〕

As explained above, the present invention provides an LSI chip mounting tape made of the same metal material, by forming a heat dissipation part 4 around the lead frame 3 and the vicinity of the device hole, so that the bonding tool IO during inner lead bonding can be easily removed. Since the heat can be sufficiently radiated from the heat dissipation section 4 and the tape section outside the heat dissipation section 4, the lead frame 3
Elongation and deformation of the leads can be prevented, and the pitch P between the leads can be ensured. As a result, there is an effect that outer lead bonding can be performed normally.

[Brief explanation of drawings]

FIG. 1 is a plan view of an integrated circuit mounting tape for explaining the first embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA' in FIG. 1, and FIGS. c) is LSI by TAB method
4 is a plan view for explaining the second embodiment of the present invention, and FIG. B-B
6 is a plan view according to the prior art, and FIG. 7 is a sectional view taken along line C-C' in FIG. 6. 1... LSI chip, 2... bump,
3... Lead frame, 4... Heat radiation part, 5... Device hole, 6... Sprocket hole, 7... Polyimide film,
8...Adhesive, 9...Plated wiring, 1
0...Bonding tool, P...Pitch between leads %BI...Inner lead part %
Bo: outer lead part, t: lead frame thickness dimension, T: heat dissipation part dimension.

Claims (1)

[Scope of Claims] 1. An integrated circuit mounting tape comprising a plurality of corresponding lead frames collectively bonded to a plurality of bumps formed on the periphery of a surface of a large-scale integrated circuit chip. 1. A tape for mounting an integrated circuit, characterized in that the mounting tape including a lead frame is made of the same metal material and has a heat dissipation part formed to surround a device hole in which the lead frame is formed. 2. The integrated circuit mounting tape according to claim 1, wherein the heat dissipation portion is formed to be thicker than the lead frame. 3. The integrated circuit mounting tape according to claim 1, wherein the heat dissipation section is formed from several thick film metal sections surrounding the device hole.