JPH03270026A - Manufacture of ic package - Google Patents

Abstract

PURPOSE:To strengthen the bonding power to a sealing resin, to prevent moisture form creeping, to prevent a migration from being caused by the moisture and to prevent the sealing resin from being cracked by a method wherein the surface of a flexible printed circuit board or a carrier tape for tape-automated bonding use is roughened. CONSTITUTION:The face, on which patterns such as leads or the like are not formed, of a carrier tape 3 is roughened by a chemical method or a mechanical method. A chip 7 is mounted on the carrier tape 3 whose surface has been roughened; it is sealed with sealing resin 8 in such a way that leads 5 are exposed partially. Alternatively, the leads 5 are bonded or soldered to a lead frame 9. After that, the tape carrier 3 on which the chip 7 has been mounted and parts of the lead frame 9 are sealed with the sealing resin 8. Thereby, the bonding power of the carrier tape 3 to the sealing resin 8 is enhanced. Consequently, moisture does not creep into a package; it is possible to prevent a migration from being caused and to prevent the sealing resin from being cracked.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for manufacturing an IC package in which a chip is mounted on a carrier tape for tape automated bonding or a flexible printed circuit board and sealed with resin, in order to prevent moisture from entering the package, For the purpose of improving the adhesion between the carrier tape or flexible printed circuit board and the sealing resin, the chip is mounted using a carrier tape for tape automated bonding or a flexible printed board, and then sealed with the sealing resin. In the method for manufacturing an IC package, the surface of the carrier tape or flexible printed circuit board is subjected to surface roughening treatment before chip mounting.

[Industrial application field]

The present invention relates to a method for manufacturing an IC package in which a chip is mounted on a carrier tape for tape automated bonding or a flexible printed circuit board and sealed with resin.

In recent years, new technologies and materials have been increasingly used in IC packages due to demands for increasing the number of pins, making them smaller and thinner, and increasing the reliability of these has become an important issue.

[Conventional technology]

FIG. 3 shows a method of manufacturing an IC package using the conventional tape automated bonding method. First, as shown in figure (a), a carrier tape 3 made of a long sprocket-hole polyimide film with holes 1 for chip mounting and holes 2 for external leads is attached to the carrier tape 3, as shown in figure (b). A copper foil 4 is pasted on the surface, and the copper foil 4 is etched (
C) Form the lead 5 as shown in the figure, and apply S to the lead 5.
After n plating, the chip 7 with Au bumps 6 is continuously bonded with Au-3n eutectic bonding as shown in FIG. and cut it from the Rolo wire, and cut it from the Rolo wire as shown in Figure 4 (
As shown in a), a part of the lead 5 is exposed to the outside and sealed with resin 8, or as shown in FIG. 4(b), the lead 5 is bonded or soldered to a lead frame 9. After that, it is sealed with resin 8.

Further, FIG. 5 is a diagram showing an IC package using a conventional flexible printed circuit board. This involves mounting a chip 7 on a flexible printed circuit board 10 having leads 5, wire-bonding the electrodes and leads 5 with wires 11, bonding or soldering the leads 5 to a lead frame 9, and then 8.

[Problem to be solved by the invention]

In the IC package using the conventional tape automated bonding method or the flexible printed circuit board, the material of the carrier tape 3 or the flexible printed circuit board 10 is polyide, glass epoxy, polyester, etc., so the sealing resin 8 such as epoxy Since the adhesive strength of the resin is weak, it is easy to peel off, and moisture can enter the package from the peeled part, causing migration, or evaporating due to heat during mounting, causing cracks in the resin, which can affect the reliability of the package. There was a problem of lowering sex.

In view of the above conventional problems, the present invention provides a method for manufacturing an IC package that can improve the adhesion between a carrier tape or a flexible printed circuit board and a sealing resin in order to prevent moisture from entering the package. The purpose is to

[Means to solve the problem]

In order to achieve the above object, in the method for manufacturing an IC package of the present invention, a chip 7 is mounted using a tape automated bonding carrier tape 3 or a flexible printed circuit board 10, and an IC package is sealed with a sealing resin 8.
The package manufacturing method is characterized in that the surface of the above-mentioned substrate 3 or flexible printed circuit board 10 is subjected to surface roughening treatment before chip mounting.

[For production]

The surface of the carrier tape 3 or flexible printed circuit board 10 is roughened before chip mounting, and then sealed with resin, so that the roughened surface of the carrier tape 3 or flexible printed circuit board 10 and the resin 8 are sealed. The adhesion between the two is improved by the anchoring effect. As a result, moisture does not enter the package, and migration and cracks in the sealing resin are prevented.

〔Example〕

FIG. 1 shows an embodiment of the present invention. In the figure, 3 is a carrier tape used in the tape automated bonding method, 5 is a lead, 7 is a chip, 8 is a sealing resin, and 9 is a lead frame.

The method for manufacturing the IC package of this example is first shown in Figure 1 (
As shown in the cross-sectional view a), the surface of the carrier tape 3 on which a pattern such as a lead is not formed is roughened by a chemical or mechanical method.

In the chemical surface roughening treatment, when the carrier tape 3 is made of polyimide, a caustic soda solution is used as an etching liquid. In this case, partially etching the dimples (as shown in the figure)
3a or by etching the entire surface to form microscopic asperities.

In the mechanical surface roughening treatment, the surface is polished and roughened using a wire brush or the like.

The carrier tape 3 whose surface has been roughened in this way is mounted with a chip 7 through the same conventional process as explained in FIGS. 3(a) to (e), and this is shown in FIG. 1(b). After sealing with sealing resin 8 or bonding or soldering the leads 5 to the lead frame 9 as shown in FIG. 1(C), The carrier tape 3 on which the chip 7 is mounted and a part of the lead frame 9 are sealed with a sealing resin 8.

In the IC package thus created, the adhesion between the carrier tape 3 and the sealing resin 8 produces an anchoring effect due to the roughened surface of the carrier tape 3, and the adhesion strength is improved. This prevents moisture from entering the package, preventing migration and cracking of the sealing resin.

FIG. 2 is a diagram for explaining a second embodiment of the present invention. In the figure, 5 is a lead, 7 is a chip, 8 is a sealing resin, 9 is a lead frame, 10 is a flexible printed circuit board, and 11 is a wire.

The method for manufacturing the IC package of this example is first shown in Fig. 2 (
As shown in a), the surface of the flexible printed circuit board 10 on which patterns such as leads are not formed is roughened.

The surface is roughened by forming dimples 10a by chemical etching as in the previous embodiment, or by forming microscopic irregularities. Alternatively, the surface is roughened by mechanical polishing. Next, as shown in FIG. 2(b), a chip 7 is mounted on this flexible printed circuit board 10 using an adhesive or the like, and wire bonding is performed between the electrodes of the chip 7 and the leads 5 using wires 11. . Next, as shown in FIG. 2(C), after bonding or soldering the leads 5 to the lead frame 9, the flexible printed circuit board 10 on which the chip 5 is mounted and a part of the lead frame 9 are sealed with a sealing resin 8. That's what I do.

In the IC package thus created, the surface of the flexible printed circuit board 10 is roughened, so that the adhesion with the sealing resin 8 is strengthened by the anchoring effect. This prevents moisture from entering the package, and prevents migration and cracking of the sealing resin due to moisture.

〔Effect of the invention〕

As explained above, according to the present invention, by roughening the surface of a flexible printed circuit board or a carrier tape for tape automated bonding, it is possible to strengthen the adhesive force with the sealing resin and prevent moisture from entering. It is possible to prevent migration caused by moisture and cracking of the sealing resin, which greatly contributes to improving the quality of IC packages.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the first embodiment of the present invention, FIG. 2 is a diagram for explaining the second embodiment of the present invention, and FIG. 3 is a diagram for explaining the conventional tape automated bonding method. Diagrams for explanation: FIG. 4 is a diagram showing an IC package using a conventional tape automated bonding method, and FIG. 5 is a diagram showing an IC package using a conventional flexible printed circuit board. In the figure, 3 is a carrier tape, 3aiOa is a dimple, 5 is a lead, 7 is a chip, 8 is a sealing resin, 9 is a lead frame, IO is a flexible printed circuit board, and 11 is a wire.

Claims (1)

[Claims] 1. An IC package in which a chip (7) is mounted using a tape automated bonding carrier tape (3) or a flexible printed circuit board (10) and sealed with a sealing resin (8). A method for manufacturing an IC package, characterized in that the surface of the carrier tape (3) or the flexible printed circuit board (10) is roughened before mounting the chip (7).