JP2004017322A - Mold equipment and compression molding equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide mold equipment which uniformly seals a package part with a resin and also dispenses with scrap handling, by making the sealing resin overflow in an area of a workpiece. <P>SOLUTION: An overflow cavity communicating with a cavity recess part 7 is provided in a clamping face of a top force 6, outside an area P of forming the package part of the workpiece 1 and inside a base plate area Q. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
FIELD OF THE INVENTION
The present invention relates to a mold apparatus for supplying a resin material for compression molding to a workpiece and clamping the work, and a compression molding apparatus for performing compression molding using the mold apparatus.
[0002]
[Prior art]
Various types of resin sealing devices for resin sealing a semiconductor package have been developed and put into practical use. For example, when a single-sided mold type semiconductor package such as QFN (Quad / Flat / Non-leaded) is resin-sealed, a substrate on which a semiconductor chip is mounted or a semiconductor chip is mounted in a matrix on a silicon wafer. There is an apparatus that supplies a prescribed amount of resin material to a semiconductor wafer subjected to compression molding.
[0003]
Specifically, resin sealing has been performed by applying a liquid resin by potting or by spin-coating the liquid resin by flowing it down. In the case of products with small and thin semiconductor packages, in order to make the molding quality uniform, it is easy to cure by heating, and it is necessary to accurately measure the amount of resin without moving the sealing resin as much as possible. Is desired. According to the compression molding, the amount of resin required for the molded article can be measured and sealed, so that there is no waste in the sealing resin, and since the range in which the resin flows is limited, a thin package is sealed. Even in this case, uniform molding is possible. Further, when the semiconductor chip is wire-bonded, the flow of the wire can be suppressed by reducing the movement of the resin.
[0004]
[Problems to be solved by the invention]
However, when performing compression molding, accurate measurement is required because the thickness of the molded product is easily affected by the amount of resin. For this reason, in order to obtain a uniform molded product, it is necessary to accurately measure the amount of resin for each shot. In particular, due to the wear of the nozzle or seal of the dispenser (ejection device) that ejects the liquid resin, the ambient temperature at which the resin is sealed, the air mixed in the liquid resin, the variation in the viscosity of the liquid material itself, etc. The discharge amount of the resin tends to vary.
Further, in an actual manufacturing process, a prescribed number of semiconductor chips may not be mounted on a substrate or a silicon wafer as a molded product. In this state, if a prescribed amount of liquid resin is applied to the molded product, the sealing resin for the insufficient volume of the semiconductor chip becomes insufficient, and the thickness of the entire package portion may be reduced, resulting in molding failure. was there. Also, when the number of defective portions of the semiconductor chip increases, there is a possibility that a semiconductor chip portion that is not completely resin-sealed may occur.
[0005]
Therefore, an overflow cavity or dummy cavity is provided outside the cavity recess to allow the sealing resin to overflow outside the work and be used as an air vent to maintain the resin pressure in the cavity at a constant level, thereby improving molding quality. Molding devices have also been proposed. However, after molding, it is necessary to perform a work of removing the unnecessary resin which has flowed out of the substrate as a molded product to the outside and cured by a gate break, or requires a cleaning such as a mold cleaning, thereby reducing workability.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to mold a mold device that does not require scrap processing while uniformly sealing a package portion by overflowing a sealing resin in an area of a work. It is an object of the present invention to provide a compression molding device that can perform an efficient molding operation using a mold device.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration.
That is, in a mold apparatus for supplying and clamping a resin material for compression molding to one surface of a work in which semiconductor chips are arranged in a matrix on a substrate, a package forming area of the work is provided on a clamp surface of a mold. An overflow cavity communicating with the cavity recess is provided outside and in the substrate area. The overflow cavity is a movable cavity that can be retracted from the clamp surface by resin pressure according to the amount of resin overflowing from the cavity recess.
The compression molding apparatus is characterized in that a workpiece is clamped by using the above-mentioned mold apparatus to perform compression molding.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of a mold apparatus and a compression molding apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, a mold apparatus using a resin substrate as a work will be described.
1 is a cross-sectional explanatory view of the upper die, FIG. 2 is a plan view of a clamp surface of the upper die shown in FIG. 1, FIG. 3 is a cross-sectional explanatory view of the lower die, and FIG. 4 is a plan view of a clamp surface of the lower die shown in FIG. FIGS. 5A to 5G are explanatory views of the compression molding operation.
[0009]
First, a schematic configuration of the compression molding apparatus will be described together with its compression molding operation with reference to FIGS.
The work 1 is of a batch sealing type in which semiconductor chips 1b are mounted in a matrix on a substrate 1a and are molded on one side. A work 1 supplied from a work supply unit (not shown) is supplied with a liquid material (liquid resin) 3 by a liquid material discharge device (dispenser) 2 in a quantitative manner. The dispenser 2 discharges the liquid resin 3 while scanning the work 1 in the XYZ directions. (See FIG. 5A). The work 1 may be coated with the liquid resin 3 before being conveyed to the mold apparatus 4, or may be coated with the liquid resin 3 while being carried into the opened mold apparatus 4.
[0010]
The mold apparatus 4 clamps the work 1 to which the liquid resin 2 has been supplied by the lower mold 5 and the upper mold 6 to perform compression molding. A cavity recess 7 is formed in the upper die 6, and a release film 8 is stretched on the parting surface thereof (see FIG. 5B).
The upper die 6 includes an upper die insert block 9 that forms the bottom of the cavity concave portion 7 and a movable block (clamper) 10 that forms a side wall thereof. Before clamping the work 1, the release film 8 is sucked by the suction device (not shown) through the gap 11 between the upper die insert block 9 and the movable block 10 and is sucked along the cavity recess 7 (FIG. 5C). reference). The lower die 5 positions and fixes the work 1 by sucking the substrate 1a.
[0011]
The release film 8 is a long film. For example, the release film 8 is sent out from a supply reel (not shown) by a film transport mechanism and is wound on a take-up reel via the upper die 6. The release film 8 has heat resistance enough to withstand the heating temperature of the mold, and is easily peeled from the upper mold surface, and is a film material having flexibility and extensibility, for example, PTFE, ETFE, PET, FEP, fluorine impregnated glass cloth, polypropylene, polyvinylidene chloride and the like are preferably used.
[0012]
In the present embodiment, the upper die 6 is fixed and the lower die 5 moves up and down, and the work 1 is clamped by moving the lower die 5 upward. As the workpiece is clamped, the liquid resin 3 applied to the work 1 is filled in the cavity recess 7 (see FIG. 5D), and the movable block 10 is cured (heat-cured) in a mold-clamped state while holding the substrate 1a. Thus, the package portion 12 is formed (see FIG. 5E).
[0013]
When the lower mold 5 moves downward and the mold is opened, the suction of the release film 8 adsorbed on the upper mold 6 is stopped, and the release film 8 is separated from the upper mold surface (see FIG. 5 (f)). Further, the release film 8 and the work 1 are separated by lowering the lower mold 5 while the substrate 1a is being sucked. The molded product (work 1) adsorbed by the lower mold 5 is taken out of the mold when the mold opening is completed. Further, the release film 8 is wound around the winding roll 13 by a predetermined amount in preparation for the next molding operation (see FIG. 5 (g)). The molded product (work 1) in which the semiconductor chips 1b are collectively sealed is diced by a dicing device and cut into individual pieces.
[0014]
Next, a schematic configuration of the mold apparatus will be described with reference to FIGS.
First, the configuration of the lower die 5 will be described with reference to FIGS.
In FIG. 3, a lower die chase 15 is supported on a lower die base 14 by a support block 16 and a support pillar 17. The lower die chase 15 supports a lower die insert block 18. A positioning pin 19 for positioning the substrate 1a is fitted in the lower die insert block 18, and the tip protrudes from the block surface.
In FIG. 4, a plurality of suction holes 18a and suction passages 18b communicating between the suction holes 18a are formed in a substrate area Q of the lower die insert block 18 on which the substrate 1a is mounted. The suction path 18b communicates with a suction path 15a formed in the lower die chase 15.
[0015]
In FIG. 3, an ejector pin plate 20 on which ejector pins 21 are provided is provided between the lower mold base 14 and the lower mold chase 15. The ejector pin plate 20 is suspended and supported by a fixing bolt (not shown) on the back surface of the lower die chase 15. A coil spring is elastically mounted between the fixing bolt and the lower die chase 15, and the ejector pins 21 inserted into the lower die chase 15 and the lower die insert block 18 are moved downward so as not to protrude from the lower die surface. It is energizing. The ejector pin plate 20 is pushed up by an abutment pin (not shown) provided through the lower mold base 14 when the mold apparatus 4 opens the mold and the lower mold 5 moves downward, and the ejector pin plate 20 is ejected. The pins 21 project from the lower mold surface (lower insert block 18) to release the substrate 1a.
[0016]
Next, the configuration of the upper die 6 will be described with reference to FIGS.
In FIG. 1, an upper die chase 23 is suspended from and supported by an upper die base 22 via a support block 24. The upper die chase 23 suspends and supports the upper die insert block 9 and the movable block 10. A movable plate 25 is provided between the upper die base 22 and the upper die chase 23. In the upper insert block 9, the distal end of a stopper pin 26 provided through the movable plate 25 and the upper chase 23 is screwed and supported. Further, the movable block 10 is supported by screwing a distal end portion of a fixing bolt 27 provided through the support block 24 and the upper die chase 23. The movable block 10 is urged downward by a coil spring 29 elastically mounted between a movable bolt 10 and a holding bolt 28 inserted and fitted through the upper chase 23. 23 and a slight gap is formed and suspended. The coil spring 29 is provided so as to absorb the increasing clamping force after the movable block 10 is pressed against the substrate 1a when the mold is closed.
[0017]
The movable plate 25 is fixed to the upper die chase 23 by screw-fitting with the mounting bolt 30. A coil spring 31 is elastically mounted between the movable plate 25 and the mounting bolt 30.
On the lower surface of the movable plate 25, the upper end surface of a pressing member 32 such as a pressing plate having a T-shaped upper end is abutted and sandwiched between the upper surface of the upper die chase 23. An O-ring 33 is fitted between the upper end surface of the pressing member 32 and the upper die chase 23 to maintain airtightness. The lower end surface of the pressing member 32 extends through the upper die chase 23 toward the movable block 10. A movable cavity plate 34 is provided at an interface between the movable block 10 and the upper die insert block 9, and an upper end surface of the movable cavity plate 34 is in contact with a lower end surface of the pressing member 32. The lower end surface of the movable cavity plate 34 forms a lateral side portion of the cavity concave portion 7. An O-ring 35 is fitted around the contact portion between the movable cavity plate 34 and the pressing member 32 so as to maintain airtightness.
[0018]
In FIG. 2, the movable cavity plate 34 can form an overflow cavity communicating with the cavity recess 7 in the substrate area Q outside the package forming area P (cavity recess 7) of the work 1.
That is, the movable cavity is formed in the overflow cavity when the movable cavity plate 34 is retracted from the clamp surface by the resin pressure of the liquid resin 3 overflowing from the cavity concave portion 7. When the resin pressure is applied to the movable cavity plate 34, the movable plate 25 is slightly pushed back through the pressing member 32 so that the coil spring 31 is compressed. By the upward movement of the movable cavity plate 34, an overflow cavity is formed in accordance with the amount of resin.
[0019]
In the upper insert block 9, a plurality of suction holes 9a for sucking the release film 8 and a suction passage 9b communicating the suction holes 9a are formed. The suction hole 9a communicates with a suction passage 23a formed in the upper die chase 23 through a gap between the upper die insert block 9 and the movable block 10.
[0020]
When compression molding is performed using the above-described mold apparatus 4, the overflowed liquid resin 3 always remains on the substrate 1a and does not flow out of the substrate 1a. Therefore, when taking out the molded product from the mold after the compression molding, it is not necessary to take out the unnecessary resin by performing a gate break, and it is not necessary to clean the mold, and the maintenance work can be omitted.
Further, since the overflow cavity is formed in the movable cavity which can be retracted from the clamp surface by the resin pressure, the fluctuation of the resin pressure can be absorbed by the movable cavity, and the resin pressure in the cavity can be maintained uniform.
Further, in the compression molding apparatus, the thickness of the package portion 12 of the molded product becomes constant, and the molding quality can be improved. The unnecessary resin remaining alongside the package portion 12 on the substrate 1a is collected together with the scrap of the substrate 1a when dicing, so that the operation of removing the unnecessary resin can be omitted.
[0021]
As described above, various preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments. For example, the work 1 is not limited to a resin substrate, but may be a film substrate, a lead frame, or a silicon wafer. Other substrate materials such as powder resin and granular resin can be used instead of the liquid resin 3.
Further, the case where the cavity is formed in one place is illustrated in the mold apparatus 4, but the cavity may be provided in a plurality of places in order to reduce the warpage of the work 1.
Further, in the present embodiment, the mold apparatus in which the cavity is formed in the upper mold is illustrated. However, a mold apparatus in which the cavity is formed in the lower mold may be used without departing from the spirit of the invention. Of course, many modifications can be made.
[0022]
【The invention's effect】
According to the mold apparatus of the present invention, the overflow cavity communicating with the cavity concave portion is provided on the clamp surface of the mold outside the package portion forming area of the work and in the substrate area, so that the overflowed sealing is performed. The resin always remains on the substrate and does not flow out of the substrate. Therefore, when taking out the molded product from the mold after the compression molding, it is not necessary to take out the unnecessary resin by performing a gate break, and it is not necessary to clean the mold, and the maintenance work can be omitted.
Further, when the overflow cavity is a movable cavity that can be retracted from the clamp surface by the resin pressure, the fluctuation of the resin pressure can be absorbed by the movable cavity, and the resin pressure in the cavity can be maintained uniform.
Further, in the compression molding apparatus, the thickness of the package portion of the molded product becomes constant, and the molding quality can be improved.
[Brief description of the drawings]
FIG. 1 is an explanatory sectional view of an upper die.
FIG. 2 is a plan view of a clamp surface of the upper die shown in FIG.
FIG. 3 is an explanatory sectional view of a lower mold.
FIG. 4 is a plan view of a lower mold clamping surface shown in FIG. 3;
FIG. 5 is an explanatory diagram of a compression molding operation.
[Explanation of symbols]
Reference Signs List 1 Work 1a Substrate 1b Semiconductor chip 2 Dispenser 3 Liquid resin 4 Mold device 5 Lower die 6 Upper die 7 Cavity recess 8 Release film 9 Upper die insert blocks 9a, 18a Suction holes 9b, 15a, 18b Suction path 10 Movable block 11 Gap 12 Package part 13 Take-up roll 14 Lower die base 15 Lower die chase 16, 24 Support block 17 Support pillar 18 Lower die insert block 19 Positioning pin 20 Ejector pin plate 21 Ejector pin 22 Upper die base 23 Upper die chase 25 Movable plate 26 Stopper pin 27 Fixing bolt 28 Holding bolt 29, 31 Coil spring 30 Mounting bolt 32 Pressing member 33, 35 O-ring 34 Movable cavity plate

Claims (3)

In a mold apparatus for clamping and supplying a resin material for compression molding to one side of a work in which a semiconductor chip is arranged in a matrix on a substrate,
A mold apparatus, wherein an overflow cavity communicating with a cavity recess is provided on a clamp surface of a mold outside a package part forming area of the work and in a substrate area. The mold apparatus according to claim 1, wherein the overflow cavity is a movable cavity that can be retracted from a clamp surface by a resin pressure according to an amount of resin overflowing from a cavity recess. A compression molding apparatus, wherein a compression molding is performed by clamping a workpiece using the mold apparatus according to claim 1.

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