JPS63228630A - Method and apparatus for sealing - Google Patents

Abstract

PURPOSE:To enhance the performances of non-airtight sealing package, by potting a sealing material, and performing defoaming of a sealing material layer before curing. CONSTITUTION:When potted resin layer 33 is sent to a facing position in a vacuum defoaming device 25, opened upper and lower chambers 26 and 27 are closed so as to hold a carrier tape 2. The insides of the chambers are closely sealed with sealing members 28 and 29. Then the insides of the chamber are evacuated so as to obtain a vacuum state through an exhausting port 30. At this time, bubbles 34 remaining in the resin layer 33 are sucked into the low pressure chambers and removed from the inside of the resin layer 33. After the defoaming is finished, the upper and lower chambers 26 and 27 are opened. The resin layer 33 is sent into a baking furnace 24 with the movement of the carrier tape 2. The resin layer 33 is heated and baked. The baked resin layer 33 is hardened and rigidly fixed to a group of inner leads 9 and a pellet 11 so as to form a unitary body. Thus a resin sealed package 35 is formed. In this way sealing performance such as moisture resistance, heat resistance and the like can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to encapsulation technology for electronic devices, in particular to resin encapsulation technology, for example, semiconductor integrated circuit devices ( (hereinafter referred to as IC)
This article relates to effective use in sealing technology.

[Conventional technology]

As an IC equipped with a tape carrier type package to achieve thin packaging, the pellet and lead group are configured to be mechanically and electrically connected by tape automated bonding (TAB). There are things that are. That is, the lead group is attached using a conductive material such as copper on a carrier tape made of an insulating resin such as polyimide. The pellets are arranged in a support ring formed on this tape so that each bump is aligned with each lead, and the bumps and leads are connected by thermocompression bonding with a bonding tool. A sealing resin is then potted to seal the support ring, leads and pellets, and then
A resin-sealed package is formed by curing the potting resin in a baking oven.

An example of a tape carrier type package is "RLC Mounting Technology" published by Kogyo Chosenkai Co., Ltd., April 15, 1980, pp. 143-144.

[Problem that the invention seeks to solve]

In such IC encapsulation technology, there is a problem that air bubbles are generated in the resin before potting, and air bubbles that have penetrated into the resin during the potting operation remain inside the package after curing. This was revealed before the present invention.

An object of the present invention is to provide a sealing technique that can prevent air bubbles from remaining inside a package.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

An overview of typical inventions disclosed in this application is as follows.

That is, after potting the sealant and before curing treatment, the sealant layer is subjected to defoaming treatment.

[Effect]

According to the above-described means, since the defoaming treatment is performed after potting and before the curing treatment, all the air bubbles that have entered the sealing material layer before and during the potting operation are removed.

〔Example〕

FIG. 1 is a front view showing an IC sealing device equipped with a tape carrier type package which is an embodiment of the present invention, FIG. 2 is a plan view showing a carrier tape, FIGS. 3, 4, and FIG. 5 is an enlarged partial sectional view for explaining the function.

In this embodiment, the pellet and lead group of this ICI are mechanically and electrically connected by tape auto-made bonding.

That is, the carrier tape 2 is integrally molded using an insulating resin such as polyimide so that the same pattern continues in the longitudinal direction. However, the description and illustration are made for only one unit. Spread holes 3 used for pitch feeding are arranged at equal pitches on both side edges of the tape 2, and support rings 4 are arranged in a single column with equal pitches between the groups of perforations on both sides. has been formed. The support ring 4 is formed in the shape of a substantially rectangular frame, and the inner cavity of the frame substantially constitutes a pellet accommodating portion 5 for accommodating pellets to be described later. Holding members 7 are disposed at the four corners of the outer space 6 of the support ring 4 and are integrally constructed so as to hold the support ring 4.

A plurality of glues 8 for electrically drawing out the integrated circuit to the outside are arranged on one side of the tape 2 and are welded or bonded using a conductive material such as copper foil. It is fixedly attached by suitable means. The lead 8 groups are divided into four sides of the support ring 4 and are arranged to penetrate the support ring 4 in the radial direction, and are formed so that the leads 8 are not electrically connected to each other. . The inner tip of each lead 8 is protruded into the pellet storage part 5 to constitute an inner lead 9, and the outer lead 10, which is protruded outward across the outer cavity 6, is fixed onto the tape 2. has been done.

On the other hand, pellet 1 in which an integrated circuit (not shown) is built
1 is formed into a substantially rectangular small piece that can be accommodated in the pellet storage portion 5 of the support ring 4, and a plurality of bumps 12 are provided on the peripheral portion of the plane on the side where the integrated circuit is built, and each of the bumps 12 on the tape 2 It is arranged and protrudes so as to be aligned with the inner lead part 9. And pellet 1
1 is housed in the pellet housing part 5 from below the support ring 4, and is aligned with each bump 12 to each inner lead part 9 using a pounding tool (not shown).
It is attached to the tape 2 by thermocompression bonding.

Here, in the pellet storage section 5, the support ring 4
The support ring 4 is provided between the inner periphery of the pellet 11 and the outer periphery of the pellet 11 so that the potting resin described later can easily wrap around the entire periphery of the pellet 11, and also because heat is transmitted to the support ring 4 during thermocompression bonding with a bonding tool.
In order to prevent the bonding force between the lead 8 and the lead 8 from deteriorating,
An appropriate gap is provided.

The sealing device 21 used in this embodiment is equipped with a plurality of sprockets 22 (only two are shown) as till feeding means for intermittently conveying the carrier tape in one direction. The carrier tape 2 is intermittently fed in one direction so that the three groups of feed holes are engaged with a tooth row (not shown) of a sprocket 22. At a downstream position of the conveyance line, a potting device 23 for potting a resin (for example, epoxy/phenol resin, hereinafter referred to as resin) as a sealing material is arranged so as to face the carrier tape 2 passing therethrough. The potting device 23 is configured to move three-dimensionally in the XYZ directions to uniformly and thinly apply the resin to a preset area on the carrier tape 2.

Further, at a downstream position of the conveyance line, a baking oven 24 serving as baking means is installed so as to penetrate and surround the carrier tape 2, and the baking oven 24 is configured to heat and hake the potting resin. has been done.

Potting device 23 and baking oven 2 in the conveyance line
4, a vacuum defoaming device 25 as a defoaming means for removing air bubbles in the potting resin is installed so as to penetrate and surround the carrier tape 2. has an upper vacuum chamber 26 and a lower vacuum chamber 27. Upper and lower chambers 26.2
7 is configured to open and close relative to each other in the vertical direction, and seal members 28 and 29 are attached to the mating surfaces thereof to prevent vacuum leakage. Upper and lower chambers 2
6.27 has exhaust ports 30 and 30, respectively, and re-exhaust ports 30 and 30 are vacuum exhaust bags made of vacuum pumps, etc.! (not shown). The bake furnace 24 is also provided with an exhaust port 31 .

Next, a sealing method according to an embodiment of the present invention using the sealing device having the above structure and its operation will be explained.

The carrier tape 2 stretched around the group of sprockets 22 is fed in a predetermined direction by the rotation of the sprockets 22. As shown in FIG.
2 is disposed at the upstream part of the conveyance line, and the pellets 11 are uniformly thinly coated on the inner lead 9 and the pellets 11 inside the support ring 4 of the carrier tape 2 with the pellets 11 on the lower side (for example, 60-7
The coated resin 32 passes through the gap between the adjacent inner leads 9.9 and wraps around to the lower side, so that the resin layer 33 seals the inner leads 9 groups and the pellets 11. is formed.

At this time, bubbles 34 usually enter the inside of the potted resin layer 33.

The air bubbles 34 may be contained in the resin 32 itself supplied to the potting device 23, or may be taken into the resin layer 33 during the potting operation.

If the resin layer 33 is cured with these air bubbles 34 remaining, it will cause a decrease in heat resistance and moisture resistance in the resin-sealed package, resulting in a decrease in the quality and reliability of the IC.

Therefore, in this embodiment, the bubbles 34 in the potted resin layer 33 are evacuated by the vacuum defoaming device 25.

That is, when the potted resin layer 33 is sent to the opposite position of the vacuum degassing device 25, the open upper and lower chambers 26.27 are closed so as to sandwich the carrier tape 2, and the sealing members 28.29 close the open upper and lower chambers 26.27. The inside of the chamber is sealed. Next, the inside of the chamber has an exhaust port 30.
It is evacuated by. At this time, the air bubbles 34 remaining in the resin layer 33 are sucked out into the low-pressure chamber, and thus are removed from the inside of the resin layer 33. When the air bubbles 34 are removed from the resin layer 33 in this manner, the thickness of the resin layer 33 and the resin-sealed package after baking, which will be described later, are made uniform.

When the defoaming process is completed, the upper and lower chambers 26 and 27 are opened, the carrier tape 2 begins to be fed again, and the resin layer 34 that has undergone the defoaming process is transferred to the baking oven 24 as the carrier tape 2 is conveyed. It is fed into the baking oven 24 and heated and baked. The baked resin layer 33 is hardened to form inner leads 9 groups and pellets 11.
The resin-sealed package 35 is formed by being firmly fixed and integrated with the resin-sealed package 35.

After being baked, the carrier tape 2 is again started to be conveyed by the sprocket 22 and is fed to the next process.

According to the embodiment described above, the following effects can be obtained.

(1) By performing defoaming treatment on the resin layer after applying the resin and before curing the resin, air bubbles remaining inside the resin layer can be removed, which improves moisture resistance, heat resistance, etc. in resin-sealed packages. It is possible to improve the ease of sealing.

(2) By removing the air bubbles remaining inside the resin layer, the thickness of the resin layer and the resin-sealed package after curing can be made uniform;
Combined with 1), the quality and reliability of the product can be improved.

(3) By appropriately applying a thin layer of resin regardless of the resin application conditions, it is possible to ease the management of the resin application conditions, thereby increasing productivity.

(4) By applying a thin layer of resin, it is possible to promote thinning of the IC by TAB.
It is possible to realize the manufacture of IC cards and the like.

The invention made by the present inventor has been specifically explained above based on the examples, but it goes without saying that the present invention is not fixed to the examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the defoaming means for removing air bubbles from the resin layer is not limited to a vacuum defoaming device, but may also be an ultrasonic defoaming device that utilizes ultrasonic vibration.

The means for bonding the pellet to the lead group is not limited to the method of bonding bumps formed on the pellet to the lead group, but may also be a method of providing bumps protruding from the lead group side.

The specific configurations of the resin bonding means, the carrier tape conveying means, and the beta means are not limited to those of the embodiments described above, but the configurations described above can be used.

In the above explanation, the invention made by the present inventor was mainly explained in the case where it was applied to the molding technology of the resin-sealed package of IC by TAB, which is the field of application which is the background of the invention, but it is not limited thereto. It can be applied to techniques for molding tape carrier type packages in other electronic devices.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this morning is as follows.

By performing defoaming treatment on the encapsulant layer after potting the encapsulant and before curing, air bubbles remaining inside the encapsulant layer can be removed, improving the performance of non-hermetically sealed packages. can improve product quality and reliability.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an IC sealing device equipped with a tape carrier type package which is an embodiment of the present invention, FIG. 2 is a plan view showing a carrier tape, FIGS. 3, 4, and FIG. 5 is an enlarged partial sectional view for explaining the function. 1... IC (electronic device), 2... Carrier tape,
3... Feed hole, 4... Support ring, 5... Pellet storage section, 6... Outer space, 7... Holding member,
8... Lead, 9... Inner lead, lO... Outer lead, 11... Pellet, 12... Bump,
21... Sealing device, 22... Sprocket, 23...
...Potting device (potting means), 24...
・Bake furnace (beta device), 25... Vacuum infamy device (
defoaming means), 26.27...chamber, 28.29.
...Seal l? Il material, 30.31...Exhaust port, 32
...Resin (sealing material), 33...Fig. 1゛2nd day Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. Potting a sealing material on some of the plurality of leads attached to the carrier tape and the pellets bonded to the lead group, and curing this sealing material layer. 1. A sealing method comprising: performing a degassing treatment on the sealant layer after potting the sealant and before curing. 2. The sealing method according to claim 1, wherein the sealing material layer is degassed using a vacuum. 3. The sealing method according to claim 1, wherein the sealing material layer is degassed using ultrasonic vibration. 4. A conveyance means for conveying a carrier tape to which a group of leads to which pellets are bonded are attached; a potting means disposed along the carrier tape for potting a sealing material into the pellet area; and a position along the carrier tape. a baking means for curing the potted sealing material layer disposed in the potting means, and a defoaming means for defoaming the sealing material layer between the potting means and the baking means. A sealing device characterized in that a sealing device is provided. 5. The sealing device according to claim 4, wherein the defoaming means is configured to defoam using vacuum exhaust. 6. The sealing device according to claim 4, wherein the defoaming means is configured to defoam using ultrasonic vibration.