JPH04360562A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve the reliability of a semiconductor device formed by using a film carrier tape by securing isolation, etc., between adjacent leads and between bumps. CONSTITUTION:After aligning leads on a film carrier tape to bumps 8 formed on the electrode terminals of a semiconductor element 7 and performing inner lead bonding, the main surface of the element 7, bumps 8, and a lead section on the inside of a suspender 9 are coated with an insulating film 11.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a semiconductor device using a film carrier tape.

0002

[Prior Art] Conventional semiconductor devices can be roughly divided into two types: resin-sealed type and ceramic-sealed type. However, with recent demands for smaller, thinner, and multifunctional semiconductor devices, Semiconductor devices using film carrier tape (hereinafter referred to as TAB packages) are rapidly becoming popular. That is, as shown in FIGS. 3 and 4, a metal foil such as copper is bonded onto the sprocket hole 2 for conveyance and positioning and the insulating film 6, and the metal foil is etched to form the lead 4 in the desired shape. In the film carrier tape 1 on which the electrical sorting pads 5 are formed, the leads 4 and the bumps 8 formed on the electrode terminals of the semiconductor element 7 are aligned, and the inner leads are bonded by a thermocompression method, a eutectic method, etc. to bond. Here, lead 4
In order to prevent deformation of the insulating film 6, suspenders 9, which are the frame of the insulating film 6, are provided in advance on the film carrier tape 1, and resin 10 is provided in advance to improve reliability and mechanical protection.
In some cases, sealing is performed by potting. Thereafter, the leads 4 are cut to a desired length and outer leads are bonded to bonding pads on a printed circuit board or the like.

[0003] These TAB packages are fast because the bonding process can be performed at once regardless of the number of leads, and can be transported and positioned using sprocket holes;
Since a thin insulating film and metal foil are used, it has the advantage of being extremely thin and making it possible to provide a compact semiconductor device.

0004

[Problems to be Solved by the Invention] In the conventional semiconductor device described above, the bumps formed on the leads on adjacent film carrier tapes or on the electrode terminals of semiconductor elements are not completely insulated from each other. Therefore, there is a drawback that leakage current flows. In response to this,
In order to improve the reliability and mechanically protect semiconductor devices, preventive measures are taken by sealing them with insulating resin, but T
As AB packages become more pin-multifunctional, the distance between adjacent leads and bumps becomes narrower, and the above-mentioned measures using resin are reaching their limits. However, since it becomes difficult for the resin to flow between the narrow leads and between the bumps, the surface of the semiconductor element is not completely covered, and the above-mentioned leakage current still flows. There is a drawback that short circuit failure occurs due to contact with the edge of the surface of the semiconductor element.

[0005]

[Means for Solving the Problems] A semiconductor device of the present invention includes:
A semiconductor device formed by fixing a lead on a film carrier tape and a bump formed on an electrode terminal of a semiconductor element, the semiconductor device having a fixing part formed by fixing the lead and the bump. The method is characterized in that at least the leads and bumps of the fixed portion are covered with an insulating inorganic thin film through a vapor growth process.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of the present invention. As shown in FIG. 1, in this embodiment, the leads 4 on the film carrier tape 1 (see FIG. 3) and the bumps 8 formed on the electrode terminals of the semiconductor element 7 are aligned to form an inner After lead bonding (ILB) and inner lead bonding, the semiconductor element 7 is further bonded.
It is formed by covering the main surface of the main surface, the bumps 8, and the lead portion inside the suspenders 9 with an insulating coating 11. The Si3N4 that forms the insulating film is formed by chemical vapor deposition (CVD), and silane (SiH4
) and ammonia (NH2), and the mixed gas is reacted by light irradiation. 30-60 minutes)
It is possible to easily form a film.

[0008] In order to maintain the reliability of the semiconductor element 7 itself and the inner lead bonding, it is desirable to form the film at low temperature, normal pressure, and in a short time. In addition, the lead part outside the suspenders 9 is used for mounting on the printed circuit board.
That is, it is necessary to shield with a mask or the like for outer bonding (OLB). There is no limit to the film thickness, but in terms of film formation in a short time and prevention of film cracks,
The optimum thickness is approximately 000 to 2000 angstroms.

By forming a semiconductor device having the above-described structure, insulation of the semiconductor element 7, leads 4, and bumps 8 is completely ensured, so that problems such as leakage current defects and short circuit defects are significantly reduced. , it is possible to improve the bonding reliability of the inner lead bonding part. Table 1 below shows the results of confirming the effects of this example, and it is clear that defects related to the bonding reliability of the inner lead bonding portion are completely eliminated.

0010

[Table 1]

FIG. 2 shows a cross-sectional view of a second embodiment of the invention. As shown in FIG. 2, in this embodiment, the leads 4 on the film carrier tape 1 (see FIG. 3) and the bumps 8 formed on the electrode terminals of the semiconductor element 7 are aligned to form an inner After lead bonding and inner lead bonding, the main surface of the semiconductor element 7, the bumps 8, and the lead portions inside the suspenders 9 are coated with an insulating coating 11, and then the suspenders 9 are coated with the resin 10. The inner portion, that is, the main surface and side surfaces of the semiconductor element 7 is sealed, thereby improving the reliability of the semiconductor device and mechanically protecting the leads 4. That is, the difference between this embodiment and the first embodiment is that the inner portion of the suspender 9, that is, the main surface and side surfaces of the semiconductor element 7, are sealed with the resin 10. This sealing resin 10 may be a solvent-type liquid epoxy resin.

By structuring the semiconductor device in this manner, it is possible to improve the bonding reliability of the inner lead bonding portion as in the case of the first embodiment, and it is possible to improve the bonding reliability of the inner lead bonding portion. By covering parts such as the bumps 8 and leads 4, which have poor adhesion, with a Si3N4 film that has good adhesion to the sealing resin, the adhesion is improved, improving the reliability of the semiconductor device, especially the moisture resistance. It becomes possible to improve the performance.

After sealing a semiconductor device using a film carrier tape with a resin, a pressure cooker test (PCT) was conducted to confirm the effects of this example. The results are shown in Table 2 below. From this table, it can be seen that the PCT elapsed time until 50% failure was reached was increased by 2.5 times compared to the conventional semiconductor device, and the moisture resistance of the semiconductor device was improved.

[0014]

[Table 2]

[0015]

As explained above, in a semiconductor device using a film carrier tape, the present invention achieves (1) by covering at least the inner lead portions, that is, the bumps and the fixed portions of the leads with an insulating thin film. Insulation between adjacent leads and bumps is completely maintained, and obstacles such as leakage current are eliminated. (2) Short-circuit failures caused by contact with edges of the semiconductor element surface due to lead deformation are eliminated. (3) The adhesion between the leads and bumps and the resin is improved, and especially the reliability including moisture resistance is significantly improved. There is an effect.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the invention.

FIG. 3 is a top view of a conventional film carrier tape.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

1 Film carrier tape 2 Sprocket hole 3 Device hole 4 Lead 5 Electrical sorting pad 6 Insulating film 7 Semiconductor device 8 Bump 9 Suspenders 10 Resin 11 Insulating thin film

Claims (1)

[Claims] 1. A semiconductor device formed by fixing a lead on a film carrier tape to a bump formed on an electrode terminal of a semiconductor element, wherein the lead and the bump are fixed to each other. 1. A semiconductor device comprising a fixed portion, and at least the leads and bumps of the fixed portion are coated with an insulating inorganic thin film through a vapor growth process.