JPH02143436A - Resin sealing method for film carrier semiconductor device - Google Patents

Abstract

PURPOSE:To prevent resin from permeating into a part between leads, and enable the resin sealing of a surface by forming a frame type resin dam on the periphery of a semiconductor chip surface, dripping and curing resin inside the dam, and covering the chip surface in the resin dam. CONSTITUTION:The chip part of a lead 4 protruding on a device hole 3 of a film carrier tape 6 and a bump 7 being the metal protrusion of a semiconductor chip 2 are subjected to inner bonding. After highly viscous liquid type resin is dripped along the periphery of an electron forming surface of a chip 2, said resin is cured to form a resin dam 8. After resin 9 is dripped inside the resin dam 8, the resin 9 is cured, thereby sealing the semiconductor chip 2.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a method for connecting leads formed on a film carrier tape to bumps, which are protruding electrodes of a semiconductor chip.
The present invention relates to a resin sealing method for a film carrier semiconductor device, in which a bump-formed surface of a semiconductor chip is sealed with a resin.

[Prior Art] After a semiconductor chip is connected to leads formed on a film carrier tape, the bump-forming surface is sealed with resin by potting resin to improve reliability and mechanical protection, or The entire semiconductor chip is sealed with resin.

FIG. 2 is a plan view showing a semiconductor chip bonded to a film carrier tape, and FIG. 3 is a sectional view thereof.

The film carrier tape 6 is a band-shaped insulating film made of polyimide or the like, and on both side edges thereof, subblocks 1 to holes 1 for conveyance and positioning are provided at a predetermined pitch. Further, device poles 3 having rectangular openings are arranged at a predetermined pitch in the longitudinal direction of the film carrier tape 6 at the center in the width direction of the film carrier tape 6, and leads 4 are arranged around each device hole 3.
is located. This lead 4 is made by bonding a metal foil such as copper onto a film carrier tape 6, and forming the metal foil into a desired shape by etching or other methods.
An end of the lead 4 on the device hole 3 side extends into the device hole 3, and an electrical selection pad 5 is formed at the other end of the lead 4 at the same time as the lead 4 is formed.

Suspenders 13, which are frames of an insulating film, are provided around the device hole 3, and the leads 4 whose tips protrude into the device hole 3 are supported by the suspenders 13 at their intermediate portions. Deformation is prevented.

A semiconductor chip 2 is arranged at the center of the device pole 3. Bumps 7, which are metal protrusions, are formed on the electrode terminals of this semiconductor chip 2, and the bumps 7 and the leads 4 of the film carrier tape 6 are bonded by inner lead bonding using a thermocompression method or a eutectic method. It is connected.

In this way, after the semiconductor chip 2 is placed in the device hole 3 and fixed to the film carrier tape 6 via the leads 4 and bumps 7, the semiconductor chip 2 is fixed as shown in FIG. One liquid resin is dropped onto the surface by a so-called potting method. Then, by curing this single resin, the surface of the semiconductor chip 2 is sealed with the resin.

Thereafter, with the semiconductor element 2 mounted on the film carrier tape 6, a contactor is brought into contact with the electrical selection pad 5 to perform an electrical selection test and a bias test on the semiconductor element 2. This completes the manufacturing process of the film carrier semiconductor device.

Next, the film carrier semiconductor device determined to be good in each test is mounted on a printed circuit board 11 as shown in FIG.
implemented on top.

First, the leads 4 are cut to a desired length, and the semiconductor chip 2 is
is separated from the film carrier tape 6. Then, this semiconductor chip 2 is attached to a printed circuit board 11 with an adhesive 10.
stick to the top. Next, the leads 4 are outer bonded to the bonding pads 12 on the printed circuit board 11.

This completes the mounting of the semiconductor chip 2, whose surface (bump electrode forming surface) is sealed with resin, on the printed circuit board 11.

The film carrier semiconductor device includes bumps 7 and leads 4.
Even if the number of bumps 7 and leads 4 is large, all bumps 7 and leads 4 can be bonded at the same time, which has the advantage of shortening the time required for bonding, and since the film carrier tape 6 is used, automation of the work is easy. It also has other advantages.

Note that as a resin sealing method for the film carrier semiconductor device, in addition to the method of sealing only the electrode forming surface of the semiconductor chip with resin as described above, the entire semiconductor chip 2 may be sealed with resin using suspenders as resin dams. There is a way.

[Problems to be Solved by the Invention] However, in the case of semiconductor chips that require high-density packaging, the leads are formed short in order to miniaturize the semiconductor device, and the leads are formed near the edges of the semiconductor chip. Since the semiconductor chip is bent and mounted, the entire semiconductor chip is not sealed, but only the surface thereof is sealed with resin. In this case, when the resin is dropped onto the semiconductor chip, the dropped resin may enter between the leads and harden due to capillary action. In this case, when mounting a semiconductor chip on a printed circuit board or the like, there is a drawback that the leads cannot be molded into a desired shape due to the resin that has entered between the leads and hardened.

Furthermore, in the case of face-down mounting in which the semiconductor chip is mounted with the bump electrode forming surface facing the printed circuit board, it is difficult to pot the resin after mounting, so the phenomenon of resin entering between the leads becomes a particular problem.

Generally, when only the surface of a semiconductor chip is sealed with resin, the surface tension of the resin is used to spread the dropped resin over the surface of the semiconductor chip to the edges thereof. For this reason, the above-mentioned phenomenon in which the resin enters between the leads varies depending on the viscosity of the resin, and this phenomenon appears prominently when a low-viscosity liquid resin is used.

For example, when a general silicone resin is used as the potting resin and the viscosity is about 1000 cp, the resin spreads to the periphery of the upper surface of the semiconductor chip within several minutes after potting. Thereafter, within a few minutes, the resin penetrates between the leads over a length of about 200 to 500 μm. Also,
In order to harden the resin, it is baked at a temperature of about 150°C for about 1 hour.
The resin penetrates between the leads over a length of 0 μm). For this reason, with a low viscosity resin having a viscosity of about 1000 cp, it is extremely difficult to determine conditions such as liquid volume, standing time, baking temperature, and baking time so that the resin does not enter between the leads.

On the other hand, when using a silicone resin with a viscosity of about 10,000 cp, it takes an extremely long time for the botted resin to enter between the leads, and the resin often enters between the leads during beta. However, since the potted resin hardly spreads, the original purpose of sealing the electrode-forming surface of the semiconductor chip may not be achieved. For this reason, it is necessary to pot the resin at several locations on the surface of the semiconductor chip, but it is difficult to pot a small amount of resin with high viscosity, and there is a drawback that appropriate potting conditions cannot be determined.

As described above, in the conventional resin sealing method for a film carrier semiconductor device, it is extremely difficult to obtain a condition in which the entire surface of the semiconductor chip is sealed with resin while avoiding the resin from entering between the leads.

The present invention has been made in view of such problems, and includes:
It is an object of the present invention to provide a method for resin-sealing a film carrier semiconductor device with excellent reproducibility, which prevents resin from entering between the leads and can seal the entire surface of the semiconductor device with resin.

[Means for Solving the Problems] A resin sealing method for a film carrier semiconductor device according to the present invention is a method of sealing the surface of a semiconductor chip with a resin after connecting leads of a film carrier tape and bumps of a semiconductor chip. forming a frame-shaped resin dam on the peripheral edge of the surface of the semiconductor chip; dropping resin onto the inside of the resin dam and then curing it to cover the surface of the semiconductor chip inside the resin dam; It is characterized by having the step of.

[Function] In the present invention, a frame-shaped resin dam is formed using, for example, a relatively high-viscosity or short-curing resin at the periphery of the bump-forming surface of the semiconductor chip that is bonded to the leads of the film carrier tape. Form.

Next, if a resin with a lower viscosity than the resin for the resin dam is dropped inside this resin dam, this resin will be blocked by the resin dam, so it will not enter between the leads, and the surface of the semiconductor chip will be spread to Therefore, it becomes easy to determine the botting conditions and the reproducibility becomes good.

[Example] Next, an example of the present invention will be described with reference to the accompanying drawings.

FIGS. 1A to 1C are cross-sectional views showing a resin sealing method according to an embodiment of the present invention in order of steps.

First, as shown in FIG. 1(a), the tip of the lead 4 extending into the device hole 3 of the film carrier tape 6 and the bump 7, which is a metal protrusion electrode of the semiconductor chip 2, are bonded by thermocompression bonding or co-bonding. Inner bonding is performed using the crystal method.

Next, as shown in FIG. 1(b), a high viscosity liquid resin is dropped along the periphery of the electrode formation surface of the semiconductor chip 2, and then hardened to form a frame-shaped resin dam 8. do.

In this case, the high viscosity resin used for the resin dam 8 includes silicone resin having a viscosity of 3000 to 5000 cp or more. When the viscosity of the resin is low, as described above, the resin enters between the leads 4 in a short time and further spreads during curing, making it difficult to form the resin into a frame shape. For this reason,
The amount of resin for forming the resin dam 8 is 3000 to 500.
It is preferable to use one having a viscosity of 0 cp or more, preferably about 10,000 ep.

However, by baking under predetermined baking conditions within a short time after dropping according to the viscosity of the resin and completing curing,
Resins with viscosities lower than the above ranges can also be used.

Generally, the curing time of silicone resin is about 1 at a temperature of 150℃.
However, since baking is performed again in a post-process, the baking time at this time may be shorter than this.

Moreover, resin such as epoxy resin or polyimide resin can also be used instead of silicone resin.

However, especially in the case of epoxy resins, even though the viscosity is generally high upon dropping, the viscosity drops rapidly immediately after baking and immediately before curing, so this point must also be taken into consideration when selecting an appropriate resin. .

Furthermore, the resin dam 8 may use a short-curing resin that can be completely cured in a short time instead of the above-mentioned high-viscosity resin. For example, JCR-6115 type silicone resin [manufactured by Toshi Silicone Co., Ltd.] is completely cured in 0.02 hours (72 seconds) at a temperature of 175°C.

In this way, in the case of a short-curing resin with a curing time of 1 minute or so, even if the viscosity is low, it cures immediately after dropping.
Curing is completed before the resin enters between the leads. Therefore, it can be used as a resin for forming the resin dam 8. In addition, in the case of this resin, it is also possible to cure the resin before it enters between the leads by dropping the resin while heating the semiconductor chip 2 with a hot plate or the like.

Next, as shown in FIG. 1(C), the hardened resin dam 8
After dropping the resin 9 inside, it is cured. This completes the resin sealing of the semiconductor chip 2.

In this case, the same resin as that used to form the resin dam 8 may be used for the resin 9, but in consideration of the spreadability of the resin, a low viscosity resin with a viscosity of 1000 to 2000 cp or less is used. Then, the workability is good.

Further, the resins used for forming the resin 9 and the resin dam 8 may be different from each other, for example, silicone resin may be used for one side,
On the other hand, if an epoxy resin is used, since these resins have the property of repelling each other, the effect of the resin dam increases and the bump-forming surface of the semiconductor chip can be further easily sealed with the resin.

As described above, in the embodiments of the present invention, it is possible to use various resins, and it is possible to easily prevent the resin from entering between the leads.

[Effects of the Invention] As explained above, according to the present invention, a frame-shaped resin dam is formed at the peripheral edge of the surface of a semiconductor chip, and then resin is dropped inside the resin dam to seal the semiconductor chip with the resin. This prevents the resin from entering between the leads. This has the effect that the leads can always be formed into a desired shape during mounting. In particular, in the case of face-down mounting, in which the semiconductor chip is mounted with the electrode formation side facing the printed circuit board, it is difficult to seal with resin after mounting on the board. The present invention is extremely useful as it allows leads to be molded into shapes.

In addition, since resin sealing is performed in two steps: forming a resin dam and coating the entire bump formation surface with resin, the resin sealing thickness can be easily controlled to the desired thickness. Also plays.

[Brief explanation of the drawing]

1(a) to 1(c) are cross-sectional views showing the resin sealing method according to an embodiment of the present invention in the order of steps; FIG. 2 is a plan view showing a semiconductor chip mounted on a film carrier tape;
4 is a sectional view showing a conventional resin sealing method for a film carrier semiconductor device, and FIG. 5 is a sectional view showing a mounting method for the film carrier semiconductor device. 1; Sprocket hole, 2. Semiconductor chip, 3; Device hole, 4; Lead, 5; Electrical selection pad, 6;
Film carrier tape, 7; hump, 8; resin dam,
9, 19; resin, 10; adhesive, 11 niblint substrate,
12; Pounding pad, 13; Suspender

Claims (1)

[Claims] (1) In a method of sealing the surface of a semiconductor chip with resin after connecting the leads of a film carrier tape and the bumps of a semiconductor chip, the step of forming a frame-shaped resin dam on the peripheral edge of the surface of the semiconductor chip; A method for resin-sealing a film carrier semiconductor device, comprising the steps of: dropping a resin inside the resin dam and then curing the resin to cover the surface of the semiconductor chip inside the resin dam.