JP2016022671A - Resin molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molding method where air trap is not caused to a large-sized rectangular workpiece, deviation in the fluidization amount of a resin is not generated, and also, productivity can be improved.SOLUTION: Provided is a resin molding method comprising: a step where a first mold resin 10a is fed to the central part O of a rectangular workpiece 1 at a first resin amount; a step where the surface of a diagonal line connecting the corner parts of the rectangular workpiece 1 each other is fed with a second mold resin 10b by a second resin amount smaller than the first resin amount so as to be separated to the outside from the first mold resin 10a; and a step where the rectangular workpiece 1 is clamped with a die, and the melted and joined first mold resin 10a and the second mold resin 10b are filled into a cavity 5 and are heated and cured.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin molding method for resin molding, for example, a large-sized rectangular workpiece.

  In recent years, for example, there is a WLP (Wafer Level Package) as a large size work, which is formed by resin molding of wiring layers and terminals formed on a semiconductor wafer in a lump. As another example, there is an EWLP (Embedded Wafer Level Package), in which a semiconductor element is directly embedded in a printed wiring board, and the resin element is molded together with the built-in semiconductor element. In addition, a large number of semiconductor elements are adhered to a stainless steel carrier or a heat release sheet and collectively resin-molded. These are diced into individual pieces for each semiconductor element after resin molding.

In addition, a rectangular workpiece having a large size (for example, 300 mm □, 500 mm □, etc.) in which a large number of semiconductor elements are arranged in a matrix of n rows × m columns is resin molded on a carrier member such as a resin substrate. ing.
For example, on the release film that covers the lower mold cavity, mold resin is supplied in a line shape along the arrangement direction of the semiconductor chips, or is supplied in a diagonal shape, thereby enclosing air by resin flow and wire flow. It has been proposed to mold the resin so as to prevent it (see Patent Document 1).

Japanese Patent Laid-Open No. 2005-225067

  When a semiconductor element mounted on a rectangular workpiece is resin-molded with a mold having an upper mold cavity, a mold resin (liquid resin, granular resin, or sheet-like resin) is supplied onto the workpiece for resin molding. It will be molded. However, when the applicant conducted an experiment of the resin supply process in order to perform resin molding by supplying mold resin to a large rectangular work, for example, the mold resin was supplied to the center of the work so as to simplify the process. Or, for example, even if it is supplied in the form of dots on the workpiece in order to prevent unfilling, a plurality of mold resins cannot be combined to solve the problem of air traps and unfilling. Further, the corner portion of the rectangular workpiece is likely to be unfilled with mold resin, and there is a problem that it takes time to fill the unfilled area and productivity is lowered.

  The object of the present invention is to solve the above-mentioned problems of the prior art, improve the productivity without generating an air trap for a large rectangular workpiece, without causing a deviation in the flow rate of the resin, and eliminating an unfilled area. It is in providing the resin mold method which can be made.

In order to achieve the above object, the present invention comprises the following arrangement.
A resin molding method in which a mold resin is supplied to a rectangular workpiece to perform resin molding, the step of supplying a first mold resin with a first resin amount to the center of the rectangular workpiece, and a corner of the rectangular workpiece A step of supplying a second mold resin with a second resin amount smaller than the first resin amount on the diagonal line connecting the parts and being spaced apart from the first mold resin; And a step of filling the cavity with the first mold resin and the second mold resin that have been clamped, melted and joined together, and then cured by heating.
Alternatively, the method includes a step of supplying the third mold resin while being spaced apart from the first mold resin by a third resin amount smaller than the second resin amount between the second mold resins, and molding the rectangular workpiece The cavity may be filled with the first mold resin to the third mold resin that have been clamped with a mold and melted and merged.

According to the resin molding method, the first mold resin is supplied to the center portion of the rectangular workpiece with the largest amount of the first resin, and on the diagonal line connecting the corner portions of the rectangular workpiece, outside the first mold resin. The second mold resin is supplied with a second resin amount that is less than the first resin amount while being spaced apart, or the first mold resin with a third resin amount that is less than the second resin amount between the second mold resins. The third mold resin is supplied apart from the first mold resin.
As a result, when the workpiece is clamped with the mold, the first mold resin and the second mold resin merge on the diagonal line, and when the third mold resin is supplied, merge with the first mold resin and then outward. Since it is filled in the cavity so as to spread, it is possible to fill the mold resin while allowing air to escape to the outside without generating an air trap. In addition, the largest first resin amount is supplied to the center of the rectangular workpiece having the largest resin flow amount, and the second mold resin is supplied in a smaller second resin amount, and if necessary, the second mold resin is supplied. By supplying a third resin amount smaller than the second resin amount during this period, it is possible to eliminate unevenness in the resin flow amount of the mold resin filled in the cavity.
Therefore, it is possible to efficiently apply to a relatively large rectangular workpiece without an unfilled area of the mold resin including the corner portion, and productivity can be improved.
The mold resin may be supplied by using either a single nozzle or a multi-nozzle when a granular resin or a liquid resin is used.

It is preferable that the supply positions of the second mold resin and the third mold resin are arranged and supplied concentrically around the supply position of the first mold resin.
Accordingly, the supply positions of the second mold resin and the third mold resin are determined concentrically with the supply position of the first mold resin as the center, so that the resin supply process can be performed uniformly and efficiently.

The first mold resin is supplied to intersect the second mold resin supplied on a diagonal line of the rectangular workpiece and the second mold resin at the center of the rectangular workpiece. You may make it supply by superimposition of mold resin.
Thereby, without supplying the first mold resin to the third mold resin individually, the second mold resin is supplied while scanning along the diagonal line of the work, and intersects with the central part of the rectangular work so that the third mold resin intersects with the third mold resin. By supplying the mold resin while scanning, it can be supplied in an overlapping manner at the center where the first mold resin intersects, and the resin supply process can be performed uniformly and efficiently.

  It is possible to provide a resin molding method capable of improving productivity without generating an air trap with respect to a large rectangular workpiece without causing a deviation in the flow rate of the resin and eliminating an unfilled area. .

It is explanatory drawing which shows an example of the supply process of a mold resin, an example of a nozzle layout, and an example of a resin application pattern. It is explanatory drawing which shows the resin mold process. It is explanatory drawing which shows the filling process of mold resin.

  Hereinafter, preferred embodiments of a resin molding method according to the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, for example, a rectangular substrate in which a large number of semiconductor elements are mounted on a rectangular resin substrate is used as the workpiece. The resin molding apparatus is a compression molding apparatus, and as an example, the lower mold will be described as a movable mold and the upper mold as a fixed mold. The resin mold apparatus includes a mold opening / closing mechanism, but the illustration is omitted, and the configuration of the mold will be mainly described.

The workpiece 1 is a rectangular resin substrate, and the semiconductor elements 2 are mounted, for example, in a matrix shape (matrix shape or map shape) having a plurality of rows and a plurality of columns.
In FIG. 2A, the compression molding apparatus includes an upper mold 3 and a lower mold 4. A workpiece 1 is mounted on the lower mold 4, and a cavity 5 is formed in the upper mold 3.
The upper mold 3 includes a cavity block 3a that forms a cavity bottom and a clamper block 3b around the cavity block 3a.

Either one or both of the cavity block 3a and the clamper block 3b may be configured to be movable. Specifically, it may be supported by being suspended by a coil spring or movably provided by a wedge mechanism that is operated by a drive source.
The upper mold clamping surface including the cavity 5 is covered with a release film 6. The release film 6 is adsorbed and held on the upper mold surface by a suction mechanism (not shown). Further, a sealing material 7 (for example, an O-ring) may be provided on the lower mold surface facing the clamper block 3b, and the sealing material 7 is slidable disposed on the outer periphery of the upper mold 3 and the lower mold 4. It may be provided in a simple block.

The resin molding process will be described with reference to FIGS.
As shown in FIG. 1A, the mold resin is supplied to the rectangular workpiece 1 placed on the lower mold 4 of the mold mold opened. In addition, you may make it supply mold resin to the workpiece | work 1 and carry in to a mold die out of a mold die.
For example, in the case of liquid resin, the mold resin is supplied from the syringe device 8 through the nozzle 9 from directly above the workpiece 1. The nozzle 9 may be a single nozzle or may be supplied all at once with multiple nozzles. An appropriate configuration can be adopted depending on whether priority is given to simplicity of the apparatus or productivity.
Details of the molding resin supply process for the workpiece 1 will be described later.

  In FIG. 2A, the release film 6 is adsorbed and held on the clamp surface of the upper mold 3. When the mold resin 10 is supplied to the workpiece 1 placed on the lower mold 4, the lower mold 4 is raised and mold closing is started.

  In FIG. 2B, when the mold closing operation proceeds, the sealing material 7 abuts against the clamper block 3b of the upper mold 3 to seal the inside of the mold, and when the mold closing operation further proceeds, the sealing material 7 is deformed. The clamper block 3b clamps the outer peripheral edge of the work 1 through the release film 6. As a result, the mold resin 10 is spread to the peripheral portion in the cavity 5. The air remaining in the cavity 5 is preferably exhausted by a decompression mechanism (not shown) that sucks the inside of the cavity.

  As shown in FIG. 2C, when the mold closing operation is completed, the molten mold resin 10 is heated and cured while the rectangular workpiece 1 is clamped by the mold.

Here, an example of the resin supply process will be described with reference to FIGS.
In FIG. 1B, first, the first mold resin 10a is supplied to the central portion 0 of the rectangular workpiece 1 with a first resin amount at a radius R1.

  Further, the second mold resin 10b is separated from the first mold resin 10a by a radius R2 (<R1) with a second resin amount smaller than the first resin amount on a diagonal line connecting the corner portions of the rectangular workpiece 1 with each other. Supply concentric circles at four locations. An actual resin application pattern is shown in FIG.

  As another method, as shown in FIG. 1 (D), the third mold resin 10b is separated from the first mold resin 10a by a third resin amount smaller than the second resin amount between the second mold resins 10b. The mold resin 10c may be further supplied concentrically at four locations with a radius R3 (<R2). The distance from the central part 0 of the rectangular workpiece 1 is supplied so that the supply position of the second mold resin 10b is on the diagonal line so that it is outside the supply position of the third mold resin 10c. An actual resin coating pattern is shown in FIG.

  Accordingly, the supply position (nozzle position) of the second mold resin 10b and / or the third mold resin 10c is determined concentrically around the supply position (nozzle position) of the first mold resin 10a. Uniform and efficient.

Further, as shown in FIG. 1F, the first mold resin 10a intersects the second mold resin 10b supplied diagonally to the workpiece 1 and the second mold resin 10b at the center O of the workpiece 1. Alternatively, the third mold resin 10c supplied may be supplied by being overlapped. The second mold resin 10b is supplied by intersecting at the central portion 0 of the rectangular workpiece 1 while scanning the nozzle 8 in the diagonal direction indicated by the arrow in the figure. The third mold resin 10c is supplied by crossing the position of the nozzle 8 at the central portion 0 of the rectangular workpiece 1 while shifting the position of the nozzle 8 from the second mold resin 10b by, for example, 45 °.
As a result, the first mold resin 10a to the third mold resin 10c are supplied separately while scanning the second mold resin 10b along the diagonal line of the work 1, and intersect with the third mold resin 10c. The first mold resin 10a can be supplied by being overlapped at the central portion 0 of the rectangular workpiece 1 by supplying while scanning, and the resin supply process can be performed uniformly and efficiently. An actual resin coating pattern is shown in FIG.

3 (A) to 3 (C) are diagonal lines around the first mold resin 10a shown in FIGS. 1 (B) and 1 (C), and on a concentric circle centering on the central portion 0 of the rectangular workpiece 1. The supplied second mold resin 10b schematically shows a process of filling the cavity 5 as the mold closing operation of the mold proceeds (see FIG. 3A).
As the mold closing operation proceeds, the first mold resin 10a and the second mold resin 10b spread and merge along the diagonal direction (see FIG. 3B). Since it is pushed and expanded, no air trap occurs and the unfilled area does not appear (see FIG. 3C).

  Specifically, since the adjacent second mold resins 10b are arranged sufficiently apart from each other, even if the second mold resin 10b increases in diameter as the mold is closed, the first diameter increases. By including the outer edge in the mold resin 10a, it is possible to prevent a state in which the outer extensions of the arc-shaped second mold resin 10b come into contact with each other first and cause an air trap. In addition, by supplying the 2nd mold resin 10b to the corner part side of the cavity 5, the flow amount at the time of filling resin can be reduced compared with the case where it supplies only by the 1st mold resin 10a. For this reason, generation | occurrence | production and unfilling of the flow mark in the corner part vicinity of the cavity 5 can be prevented. Moreover, since it can supply in a short time compared with the system which supplies to the whole surface of the cavity 5, productivity can be improved by making a supply process efficient, reducing a flow amount comparatively.

3 (D) to 3 (F) are diagonal lines around the first mold resin 10a shown in FIGS. 1 (D) and 1 (E), and on a concentric circle centering on the central portion 0 of the rectangular workpiece 1. The third mold resin 10c supplied on a concentric circle different from the second mold resin 10b between the supplied second mold resin 10b and the second mold resin 10b, as the mold closing operation of the mold proceeds. A process of filling the cavity 5 is schematically shown (see FIG. 3D).
As the mold closing operation proceeds, the first mold resin 10a and the second mold resin 10b spread and merge along the diagonal direction, and then the first mold resin 10a and the third mold resin 10c merge (FIG. 3 ( E)), air is not confined and is pushed and expanded toward the outer periphery of the cavity as it is, so that no air trap occurs and no unfilled area occurs (see FIG. 3F).

  Specifically, the adjacent second mold resin 10b and the third mold resin 10c are disposed relatively close to each other, but the third mold resin 10c is supplied sufficiently small. For this reason, even if the second mold resin 10b and the third mold resin 10c are expanded in diameter as the mold is closed, air is supplied to the first mold resin 10a which starts to expand in advance by being supplied larger. It is swept toward the outer periphery. At this time, since the outer edges of the second mold resin 10b and the third mold resin 10c are included in the first mold resin 10a that expands in diameter, an air trap is formed on the outer periphery of these mold resins 10a to 10c. The resin can be filled without being done. The third mold resin 10c is supplied to a position close to the side of the cavity 5 so that the resin is filled when compared with the case where the first mold resin 10a and the second mold resin 10b are used alone. The amount of flow can be further reduced. For this reason, generation | occurrence | production and unfilling of the flow mark near the edge | side of the cavity 5 can be prevented.

3 (G) to 3 (I) show that the third mold resin 10c supplied to intersect the second mold resin 10b supplied on the diagonal line of the workpiece 1 shown in FIGS. 1 (F) and 1 (G) is rectangular. FIG. 3 schematically shows a process of filling the cavity 5 as the first mold resin 10a is supplied by overlapping with the central portion 0 of the work 1 and the mold closing operation of the mold proceeds. (See (G)). At this time, the second mold resin 10b supplied on the diagonal line in order to make the resin flow amount in the cavity 5 uniform is supplied to the vicinity of the opposing corner portion so as to be longer than the third mold resin 10c. It is preferable. Further, in order to prevent the flow mark at the corner, the end of the second mold resin 10b has a protruding shape (see arrow J in FIG. 3 (G)) so that it is supplied to a position close to the corner. It is preferable.
In this case, since the second mold resin 10b and the third mold resin 10c are supplied in advance so as to overlap (join) at the center portion 0 of the rectangular workpiece 1, the center portion O is increased as the mold closing operation proceeds. Since the mold resin 10 spreads radially outward from the outside (see FIG. 3 (H)), the air is not confined and pushed toward the outer periphery of the cavity as it is, so that an air trap does not occur and an unfilled area is formed. It does not occur (see FIG. 3 (I)).

According to the resin molding method described above, it is possible to fill the mold resin while releasing air without causing an air trap even if the mold resin clamped on the mold 1 and the mold resin supplied to a plurality of locations merge. it can. Further, the largest amount of the first resin is supplied to the central portion O of the rectangular workpiece 1 having the largest resin flow amount, and the second mold resin is supplied with a smaller second resin amount. By supplying a third resin amount smaller than the second resin amount between the mold resins, it is possible to eliminate the unevenness of the resin flow amount of the first to third mold resins.
Therefore, it can apply | coat efficiently with respect to the comparatively large-sized rectangular workpiece 1 without the unfilled area of the mold resin 10 including a corner part, and can improve productivity.

In the above-described embodiment, the case where the liquid resin is used as the mold resin 10 has been described. However, the resin may be a granular resin, and further, by cutting the sheet resin into an appropriate size (resin amount). It is also possible to use it.
Further, when the mold resin 10 is supplied directly below the rectangular workpiece 1 without scanning the nozzle 8, the resin supply positions are preferably at least five, and the resin supply positions can be arbitrarily increased.

Further, when the mold resin 10 is supplied by scanning the nozzle 8 with respect to the rectangular workpiece 1, the length of the second mold resin 10 b to be supplied on the diagonal line is the center portion O of the rectangular workpiece 1. It is preferable to be supplied so as to be longer than the length of the third mold resin 10c supplied in an intersecting manner. Thereby, the deviation of the resin flow amount is eliminated, and the air trap can be prevented.
Further, when there is a defect in the semiconductor chip 2 mounted on the work 1, it is necessary to adjust and supply the mold resin 10 to fill the defect in the semiconductor chip 2. In this case, the supply amount may be adjusted by any of the first mold resin 10a, the second mold resin 10b, and the third mold resin 10c. Although the example in which the mold resin 10 is supplied to the workpiece 1 has been described, the mold resin 10 may be supplied to the release film 6 and supplied to the mold mold in which the cavity 5 is provided in the lower mold 4 together with the release film 6. Similar effects can be achieved.

  DESCRIPTION OF SYMBOLS 1 Work 2 Semiconductor element 3 Upper mold | type 3a Cavity block 3b Clamper block 4 Lower mold | type 5 Cavity 6 Release film 7 Seal material 8 Nozzle 9 Syringe apparatus 10 Mold resin 10a 1st mold resin 10b 2nd mold resin 10c 3rd mold resin

Claims (4)

A resin molding method in which a mold resin is supplied to a rectangular workpiece and resin molded,
Supplying a first mold resin with a first resin amount to the center of the rectangular workpiece;
Supplying a second mold resin with a second resin amount less than the first resin amount spaced apart from the first mold resin on a diagonal line connecting corner portions of the rectangular workpiece;
Filling the cavity with the first mold resin and the second mold resin, which are melted by clamping the rectangular workpiece with a mold, and heat curing;
A resin molding method comprising:   Including a step of supplying a third mold resin spaced apart from the first mold resin by a third resin amount smaller than the second resin amount between the second mold resins, and the rectangular workpiece is molded into a mold The resin molding method according to claim 1, wherein the cavity is filled with the first mold resin to the third mold resin which are clamped, melted and joined together, and then cured by heating.   3. The resin molding method according to claim 2, wherein the second mold resin and the third mold resin are arranged and supplied concentrically around the first mold resin. 4.   The first mold resin is supplied to intersect the second mold resin supplied on a diagonal line of the rectangular workpiece and the second mold resin at the center of the rectangular workpiece. The resin molding method according to claim 2, wherein the resin molding method is supplied by superposition of molding resins.

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