JPH01100928A - Method and apparatus for sealing - Google Patents

Abstract

PURPOSE:To control the thickness of a sealing material layer adequately, by potting a sealing material, thereafter measuring the thickness of the sealing material layer, and comparing the measured value with a control value. CONSTITUTION:When a pellet 11 faces a pellet-thickness measuring device 25, which is arranged at the most upstream side of a conveying line, the thickness of the pellet 11 is measured. The measured result is transmitted into a controller 30. Then, a resin 35 is thinly applied uniformly on a inner lead 9 at the inner side of a support ring 4 on a carrier tape 2 and on the pellet 11 with a potting device 23. When the pellet 11 faces a resin-layer-thickness measuring device 26, the thickness of a resin layer of 36, which is formed on the pellet 11, is measured. The value of said pellet thickness, which is measured in the pellet-thickness measuring device 25 is subtracted from said measured value of the thickness. Thus the thickness of only the resin layer 36 is obtained.

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, and relates to, 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 chip carrier type package to realize thin packaging, the pellet and lead group are configured to be mechanically and electrically connected by tape automated bonding (TAI3). There are things that are. That is, the blade group is attached to a carrier tape made of an insulating 4Jl resin such as polyimide using a conductive material such as copper. 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.Then, the sealing resin is applied. The support ring, leads, and pellets are potted to be sealed, and then the potting resin is cured in a baking oven to form a resin-sealed package.

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

[Problem that the invention seeks to solve]

In such IC sealing technology, there is a problem that if the sealing resin layer after potting is too thick, cranking will occur, and if it is too thin, insufficient sealing will occur.
revealed by the inventor.

An object of the present invention is to provide a sealing technique that can appropriately control the thickness of a sealing material layer.

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.

In other words, by measuring the thickness of the encapsulant layer after potting the encapsulant and comparing this measured value with the control value,
The thickness of the sealing material layer is appropriately controlled.

[Operation] - According to the above-mentioned means, the thickness of the encapsulant layer after potting is properly controlled by comparing it with a control value, so that cracks and sealing due to irregularities in the encapsulant layer thickness can be prevented. It is possible to prevent defects such as shortages.

〔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 pass through 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 portion 5 to constitute an inner lead 9, and the outer lead 10 protruded outward across the outer cavity 6 is attached to the tape. It is fixed on 2.

On the other hand, pellet 1 in which an integrated circuit (not shown) is built
1 is formed into a small approximately square piece that can be accommodated in the pellet accommodating portion 5 of the support ring 4, and bumps 1 are formed on the periphery of the plane of fJll in which the integrated circuit is fabricated.
2 are arranged and protruded so as to be aligned with each inner lead portion 9 of the tape 2. The pellets 11 are accommodated in the pellet accommodating portion 5 from below the support ring 4, and each bump 12 is aligned with each inner lead portion 9 and bonded by thermocompression using a bonding tool (not shown). , attached to tape 2.

The sealing device 21 used in this embodiment is equipped with a plurality of sprockets 22 as a conveying means for intermittently conveying the carrier tape in one direction.
The three groups of feed holes are engaged with the tooth row (not shown) of the sprocket 22 so that the feed holes are intermittently fed in one direction. At the upstream position of the conveyance line, a resin (e.g., epoxy/phenol resin, hereinafter referred to as resin) is used as a sealing material.
), a bonding device 23 for potting the
The potting device 23 has a structure similar to a syringe, and is supplied with air at a predetermined pressure for a predetermined period of time to discharge and apply resin. is configured to do so. Further, this potting device 23 is configured to be able to uniformly and thinly apply the resin to a preset area on the carrier tape 2 by moving three-dimensionally in the x, y, and z directions.

A baking oven 24 serving as baking means is installed at a downstream position of the conveyance line so as to penetrate and surround the carrier tape 2, and the baking oven 24 is configured to heat and bake the potting resin. There is.

A pellet thickness measuring device 25 is located upstream of the potting device 23 in the conveyance line, and a resin layer thickness measuring device is located downstream of the potting device 23! Further, a post-bake resin layer thickness measuring device 27 is disposed downstream of the baking furnace 24, and each of these thickness measuring devices is configured to be able to measure the thickness in a non-contact manner. There is. In other words, these measuring devices include a suction head 28 that holds the pellet by vacuum suction on the back surface thereof;
It is equipped with an optical range finder 29. The optical range finder 29 includes a light emitting device (not shown) that irradiates the object to be measured with light, and a linear light receiving device (not shown) that receives the light reflected by the object to be measured. , the relative distance of the reflecting surface to the reference position is determined from the light receiving position of the light receiving means.

These measuring devices 25, 26, 27 are connected to a controller 30, and the controller 30 receives the actual resin layer thickness values obtained based on the measurement results of these measuring devices 25, 26, 27, and the setting section 31. The resin layer thickness value is compared with a preset control value (a value with an appropriate tolerance range) to determine whether the resin layer thickness value is appropriate or unbeatable. Further, the controller 30 is connected to the control unit 23a of the potting device 2223, and controls the potting device 2i' by changing and adjusting the discharge pressure and discharge time of the supply air to the potting device 23 via the control 23a. It is configured to control the resin application work by 23.

Post-bake resin layer thickness measurement device v127 on conveyance line
A marking device 32 is disposed downstream of the marking device 32, and the marking device 32 is configured to display a mark such as an ink mark on the surface of a defective product according to a designation of the controller 30. .

In the figure, 33 indicates a loader section from which the carrier tape 2 to be sealed is fed out, and 34 indicates an unloader section from which the sealed carrier tape 2 is wound up.

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.

A bag for measuring pellet thickness installed at the top of the conveyance line! ! When facing E25, pellet 11 is measured for its thickness as shown in FIG. That is, the pellet 11 is vacuum-adsorbed and held on the back side by the suction head 28, and then the optical range finder 29
The measuring light is emitted by the light projecting means, and the reflected light is detected by the light receiving means, thereby measuring the relative distance of the reflecting surface from the head suction surface, that is, the thickness. The measurement results are then transmitted to the controller 30.

Subsequently, as shown in FIG. 3, the resin 35 is made into pellets by the potting device 23 disposed downstream of the pellet thickness measuring device 25. On the support tape 2 with l on the bottom, apply a thin layer uniformly on the inner lead 9 inside the trigger puff 4 and the pellet l (for example,
Approximately 60 to 70 μm) coated line<,! ! 2! The coated resin 35 passes through the gap between adjacent inner leads 9.9 and wraps around to the lower side, thereby forming resin ji 136 to seal the inner leads 9 groups and the pellets 11.

When facing the resin layer thickness measuring device 26 disposed downstream of the potting device 23, the potting device 23
The thickness of the resin layer 36 formed on the pellet 11 is measured and sent to the controller 30. That is, first, as shown in FIG.
1 is vacuum-adsorbed and held by the suction head 28, and the surface of the resin Ji136 is irradiated with measurement light, thereby measuring the relative distance of the surface of the resin layer 36 from the head suction surface, that is, including the pellet thickness. resin rrr
L is measured. Subsequently, the pellet thickness value measured by the pellet thickness measuring device 25 is subtracted from the measured value to determine the thickness of only the resin JW 36. Since this thickness measurement is performed without contacting the resin layer 36, measurement is possible even when the resin layer 36 is wet.

In this way, the actual thickness of the resin layer 36 is measured.
As the carrier tape 2 is transported, it is fed into the baking oven 24, where it is heated and baked. The baked resin layer 36 is hardened and firmly adhered to and integrated with the inner leads 9 group and the pellet 11, thereby forming a resin-sealed package 37 that non-hermetically seals them.

When facing the post-baking resin layer thickness measuring device 27 disposed downstream of the baking oven 24, the thickness of the pan cage 37 whose resin layer has been baked is measured and transmitted to the controller 3G. That is, the thickness of the package 37 is measured by the same function as the pre-baking resin layer thickness measuring device 26 described above.

In the controller 30 to which the measurement results from each measuring device 25, 26, and 27 are input, the thickness of the resin layer 36 before baking and the thickness of the package 37 after baking are set in advance in the setting section 31. The respective control values are compared and the error is determined. If the actual thickness measurement value deviates from the control value, a command signal to eliminate the error is sent to the control unit 23a of the potting device W123. In the potting device 23, the control section 23a changes and adjusts the supply pressure and supply time of air to the potting device 23 in response to this command signal, thereby controlling the amount of resin to be applied.
Feedback control is performed so that the thickness of ii36 falls within a control value.

Further, when the actual thickness measurement value deviates from the control value, the controller 30 sends a command signal to the marking device 32, and marks the defective package 3'7 with a defective mark such as an ink mark (not shown in the figure). ) is displayed.

After passing through all the steps, the carrier tape 2 is wound onto a reel at the unloader section 34 as the sprocket 22 is fed.

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

+11 The thickness of the encapsulant layer can be appropriately controlled by measuring the thickness of the encapsulant layer after potting and comparing this measured value with a preset control value. Therefore, it is possible to prevent defects such as cranking and insufficient sealing due to irregularity in the thickness of the sealing material layer, and it is possible to improve manufacturing yield and product quality and reliability.

(2) Automatically manage the thickness of the encapsulant layer by feeding back the error between the actual measured thickness of the encapsulant layer and the control value to the potting device As a result, productivity can be increased.

(3) By displaying a defective mark on the encapsulant layer whose thickness measurement value deviates from the control value, it is possible to prevent a defective product from being used.

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

For example, if the measured thickness of the encapsulant layer deviates from the control value, the potting device may be configured to perform feedback control based on the fI difference value, or to display a mark on the deviated encapsulant layer. However, the present invention is not limited to this, and the sealing operation may be automatically interrupted and a warning may be issued to that effect.

The measurement of the encapsulant layer thickness is not limited to being performed on the encapsulant layer before and after baking, but may be performed either before or after baking.

The means for measuring the thickness of the encapsulant layer is not limited to measuring the thickness of the pellet 7) and the encapsulant layer and subtracting the thickness of the pellet. It may be configured to measure.

Furthermore, the present invention is not limited to using an optical measuring device, and other non-contact measuring equipment may be used.

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 potting means, the carrier tape conveying means, and the baking means are not limited to those of the above embodiments, but may also be of the following configurations.

In the above explanation, the invention made by the present inventor was mainly applied to the molding technology of a resin-sealed IC package by TAB, which is the field of application in which the invention was made, but the invention 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 application is as follows.

In addition to measuring the thickness of the sealant layer after potting,
By comparing this measured value with a preset control value, the thickness of the encapsulant layer can be properly controlled. The occurrence of defects such as insufficient sealing can be prevented, and manufacturing yield and product quality and reliability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway 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, FIG. 4 and 5 are enlarged partial cross-sectional views for explaining the function.

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. In this method, after potting the sealing material, the thickness of the sealing material layer is measured, and this measured value is compared with a preset control value to perform sealing. A sealing method characterized by appropriately controlling material layer thickness. 2. The sealing method according to claim 1, wherein the sealing material layer thickness is managed by feedback control based on comparison results. 3. The sealing method according to claim 1, wherein the sealing material layer thickness is controlled by continuing or discontinuing the work depending on whether the comparison result is appropriate or not. 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, wherein a thickness measuring means for measuring the thickness of the sealing material layer is interposed behind the potting means. A sealing device characterized in that the thickness measuring means is connected to a controller that compares the measured value with a preset control value and determines whether it is suitable or unbeatable. . 5. The sealing device according to claim 4, wherein the thickness measuring means is disposed after the potting means and after the baking means. 6. The sealing device according to claim 4, wherein the controller is configured to perform feedback control of the potting means based on the comparison result. 7. The sealing device according to claim 1, wherein the controller is configured to continue or interrupt the operation depending on whether the comparison result is favorable or unfavorable. 8. The sealing device according to claim 1, wherein the controller is configured to display a mark on products for which the comparison result is not valid.