JP4585321B2 - Resin molding apparatus and resin molding method - Google Patents

Description

  The present invention relates to a resin molding apparatus and a resin molding method using a release film.

2. Description of the Related Art Conventionally, there is a resin molding apparatus that manufactures a semiconductor device by coating a mold surface including a mold parting surface and a cavity surface with a release film and performing resin molding (for example, Patent Document 1).
According to this, (1) the resin can be sealed without adhering the mold resin to the mold, (2) it is easy to release the molded product, and (3) the ejector pin for releasing is unnecessary. Thus, effects such as simplification of the mold structure can be obtained.

By the way, when using a release film, when a release film is adsorbed on a mold surface, wrinkles may occur on the film surface. This is because the release film is heated by the heat of the mold when it comes into contact with the mold surface, and the release film itself is stretched. Yes.
The wrinkles of the release film affect the appearance of the molded product as it is, and thus cause defects in the molded product. In addition, the wrinkle is generated in the release film, so that the molded product cannot be accurately clamped and the resin molding accuracy is inferior.

  Therefore, the present applicant has proposed a resin mold apparatus in which a slack absorbing groove is provided on the mold surface in order to prevent wrinkles of the release film (for example, Patent Document 2). The slack absorbing groove is provided on the mold surface of the mold, and when the release film is air-adsorbed on the mold surface, the release film stretched by heating is drawn into the groove, and the release film becomes slack. Is prevented.

JP-A-8-142105 Japanese Patent Laid-Open No. 11-34066

However, according to the above configuration, when the mold surface is complicated, the arrangement of the slack absorbing grooves is restricted and wrinkle removal becomes insufficient.
In addition, a release film having various functions such as a function of transferring characters to a molded product has a problem in that it cannot be sufficiently wrinkled only by a slack absorbing groove because thermal expansion is not uniform.

  Therefore, the present invention has been made to solve the above-mentioned problems, and the object of the present invention is to efficiently prevent the generation of wrinkles in the release film when the mold surface of the mold is covered with the release film. An object of the present invention is to provide a resin molding apparatus and a resin molding method that can be used.

In order to achieve the above object, the present invention comprises the following arrangement.
That is, the resin mold apparatus of the present invention includes a supply roller around which a release film is wound, and a winding roller that winds up the release film drawn from the supply roller, and between the supply roller and the winding roller. In a resin mold device that is stretched and held between the molds by holding the release film supplied between the molds by suction and holding the molded product through the release film by resin sealing, The release film having a length substantially equal to the length of the mold surface in the feed direction is fed from the supply roller, whereby the release film is newly supplied between the molds.
With this apparatus, wrinkles generated when the release film is heated by the mold can be efficiently reduced.

In addition, a pulling roller is provided to remove wrinkles by stretching the release film in the width direction before the release film is sucked and held on the mold surface. According to this apparatus, the wrinkles of the release film when attracted and held on the mold surface can be reliably reduced.
In addition, a heating mechanism is provided that heats the release film before it is supplied between the molds. By supplying the release film that has been preheated and thermally expanded between the molds, a new thermal expansion due to contact with the mold surface can be reduced.
The heating mechanism may include a heat source that heats the release film by heat radiation. According to this apparatus, a wide range of the release film can be heated at a time.
Further, the heating mechanism is characterized in that a heater is built in the pulling roller. According to this apparatus, it is possible to reliably heat the release film before supplying it between the molds.
The heating mechanism includes a preheating roller that heats the pulling roller, and heats the release film via the pulling roller.
According to this apparatus, it is possible to reliably heat the release film before supplying it between the molds.

Further, the resin molding method of the present invention hangs the release film so that it passes between the molds between the supply roller on which the release film is wound and the take-up roller that winds the release film drawn from the supply roller. Resin mold method for sealing the resin by supplying the release film between the molds, holding the supplied release film by suction on the mold surface of the mold, and clamping the molded product through the release film In the above, a release film having a length substantially equal to the length of the mold surface in the feed direction is fed from a supply roller, whereby a release film is newly supplied between the molds.
The release film is heated before being supplied between the molds.
Further, before the release film is sucked and held on the mold surface, the release film is stretched in the width direction by a pulling roller to remove wrinkles.

  ADVANTAGE OF THE INVENTION According to this invention, the wrinkle which arises when a release film is heated with a metal mold | die can be reduced efficiently. As a result, high-quality resin sealing becomes possible, and generation of defective products can be prevented.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
As shown in FIG. 6, the resin mold apparatus of this embodiment includes a press unit A, a molded product supply unit B, a resin tablet supply unit C, an alignment between the resin tablet and the molded product, an inloader unit D, and a molded product. Unloader section E, molded product storage section F, and release film supply mechanism G.

  The outline of the resin sealing operation by this resin molding apparatus is as follows. First, the resin tablet supplied from the supply part C of the resin tablet is accommodated in the tablet holder and transferred below the inloader part D. The molded product 12 is transferred from the molded product supply unit B to the inloader unit D, and the molded product 12 and the resin tablet are delivered to the inloader by the inloader unit D. The molded product 12 and the resin tablet are transferred to the press part A by the inloader, the resin tablet is put into the pot 26 of the mold, and the molded product 12 is set on the mold. In the press part A, the molded product 12 is clamped via the release film 10 supplied from the supply mechanism G, and the resin 16 is pumped from the pot 26 into the cavity 14a to perform resin sealing. After the mold is opened, the molded product molded in the press section A is unloaded to the degaged section H, and after the unnecessary resin is removed by the degaged, the product is stored in the storage section F.

The resin mold apparatus of this embodiment is an apparatus that uses a BGA substrate as a molded product 12 and seals the resin on one side to obtain a product.
The press part A will be described in detail. FIG. 1 is a schematic view illustrating the configuration of a press part A and a release film supply mechanism G, which are the main parts of the present invention, and FIG. 3 is a cross-sectional view illustrating the configuration of a mold of the press part A. In FIG. 3, the molded product 12 is clamped on the right half of the center line CL in a state in which the molded product 12 is set in the lower mold with the mold open in the left half of the center line CL, and the cavity 14a is filled with resin. Indicates the state. FIG. 4 is a plan view showing a state in which the release film 10 is arranged on the mold surface of the upper mold 20a.
As shown in FIG. 3, the press part A has a die composed of an upper die 20a and a lower die 20b, and a plurality of cavities 14a are provided only in the upper die 20a to seal the molded product 12 on one side with resin. ing.
The molded product 12 has a semiconductor chip 13 mounted only on one side thereof.

  The upper mold 20a and the lower mold 20b are supported by the upper mold base 22a and the lower mold base 22b, respectively. A heater 24 is provided in each of the upper mold base 22a and the lower mold base 22b. Further, while the upper mold base 22a is supported by a fixed platen (not shown), the lower mold base 22b is supported by a movable platen (not shown) and is driven up and down in the mold opening / closing direction. .

  In this mold, the molded products 12 are set one by one on both sides of the pot 26 and resin sealing is performed.

  The release film 10 is configured to cover only the mold surface of the upper mold 20a. As will be described later, the release film supply mechanism G is configured to sequentially supply a long release film 10 having a width that covers substantially the entire mold surface of the upper mold 20a to the lower side of the mold surface of the upper mold 20a. Has been. The release film 10 is supplied in a posture substantially parallel to the mold surface without being in contact with the mold surface of the lower mold 20b by the supply mechanism G. The release film 10 is sucked and held on the mold surface of the upper mold 20a to cover the mold surface.

  The method of adsorbing and holding the release film 10 on the mold surface of the upper mold 20a is based on a method in which the release film 10 is adsorbed on the mold surface by the air suction holes 42a opened on the mold surface of the upper mold 20a. The air suction hole 42a communicates with the air suction flow path 32 at the rear portion of the upper mold 20a, and the flow path 32 communicates with an air mechanism outside the mold.

  As shown in FIG. 4, the release film 10 covers substantially the entire mold surface, whereas the plurality of air suction holes 42 a are arranged around the molding target 12. Further, the upper die 20a is provided with a cull 27 and a runner 28.

A sag absorbing groove 42 for absorbing the sag of the release film 10 is provided around the upper cavity 14a. As shown in FIG. 4, the slack absorbing groove 42 is formed in a groove shape between the cavity 14a and the outer periphery of the upper mold.
A plurality of the air suction holes 42 a described above are provided along the sag absorbing groove 42 at a substantially central portion of the sag absorbing groove 42.
FIG. 5 is a cross-sectional view of the sag absorbing groove 42 taken along the broken line L in FIG. As described above, the air is sucked from the air suction hole 42 a, whereby the release film 10 can be partially drawn into the sag absorbing groove 42. Thereby, when the release film 10 is adsorbed and held on the mold surface, the extension of the release film 10 that is heated and stretched can be drawn into the groove to prevent wrinkles of the release film 10.

  The release film 10 is preferably a film having flexibility and heat resistance, such as an FEP film, a PET film, a fluorine-impregnated glass cloth, a polyvinylidene chloride, an ETFE film, or the like.

Next, the release film supply mechanism G will be described with reference to FIG. The supply mechanism G is supported by the fixed platen 25.
The supply mechanism G includes a supply roller 43 around which a long release film 10 is wound, and a take-up roller 44 that winds up the release film 10 drawn from the supply roller 43. The release film 10 drawn out from the supply roller 43 passes through the vicinity of the mold surface of the upper mold 20a between the molds (between the upper mold 20a and the lower mold 20b), and then is wound by the winding roller 44. Configured to be taken.

  The supply roller 43 and the take-up roller 44 are rotationally driven by a drive unit, respectively, and the release film 10 is intermittently sent from the supply roller side to the take-up roller side by a certain length in accordance with the resin molding operation. The drive unit includes servo motors 43a and 44a, and the supply roller 43 and the take-up roller 44 are controlled to rotate by the servo motors 43a and 44a, respectively, so that the release film 10 is prevented from loosening between them, and with a predetermined tension. It is stretched.

In FIG. 1, the feeding state of the release film 10 conveyed by the release film supply mechanism G is illustratively shown in accordance with the arrangement of the molds.
R1 is a portion where 10c is clamped by the mold in a state where the release film 10 is clamped by the mold. R2 shows a state in which after the resin film is molded using the release film 10, the release film 10 is fed from the supply roller 43 and supplied between the molds for the next resin molding.
As shown in FIG. 1, the release film 10 is sent out from the supply roller 43 in the direction of the arrow X (feeding direction). However, the feeding film X in the feeding direction X of the mold surface of the mold (upper mold 20a) is fed once. The release film 10 is fed out from the supply roller 43 by a length (L) substantially equal to the length. Thereby, a release film (part 10d) is newly supplied between the molds, and the supplied release film (part 10d) is then sucked and held on the mold surface.

The release film 10 drawn out from the supply roller 43 is passed over the first guide roller 51 and the pulling roller 52a, and then passes between the molds, and the pulling roller 52b, the second guide roller 53, and the third guide roller. 54 and is wound around the winding roller 44 in this order.
Pulling rollers 52a and 52b are provided on both sides of the mold. That is, the pulling roller 52a is rotatably provided below the supply roller 43, and the pulling roller 52b is rotatably provided below the winding roller 44. Thus, the release film 10 is guided by the first guide roller 51, the pulling rollers 52a and 52b, the second guide roller 53, and the third guide roller 54 so that the vicinity of the mold surface of the upper mold 20a is substantially the same as the mold surface. Pass in parallel.
Further, the second guide roller 53 is higher than the two rollers 52b and 54 with respect to the pulling roller 52b and the third guide roller 54 that are rotatably arranged at substantially the same height position. The contact surface of the release film 10 with respect to the pulling roller 52b is increased.

Next, the tension rollers 52a and 52b will be described with reference to FIG. The two pulling rollers 52a and 52b have the same configuration. The pulling rollers 52a and 52b are for pulling the release film 10 in opposite directions on both sides to extend in the width direction and remove wrinkles.
The pulling rollers 52 a and 52 b include a fixed shaft 55 and a cylindrical roller collar 56 that is rotatably fitted to the fixed shaft 55. Both ends of the fixed shaft 55 are fixed to the support frame of the supply mechanism G. The width of the roller collar 56 is set slightly longer than the width of the release film 10, and the roller collar 56 is divided into a plurality of cylindrical collar portions arranged in the axial direction of the fixed shaft 55. Then, the two collar portions on both ends of the fixed shaft 55 are separated from each other on the end side of the fixed shaft 55 (see FIG. 7A) from the position near the center of the fixed shaft 55 (see FIG. 7A). b)), and can slide and reciprocate simultaneously from a position away from each other to a position closer to the center (see FIG. 7A).
For example, the pulling rollers 52 a and 52 b have two collar portions, and the two collar portions are movable from positions approaching each other toward the center of the fixed shaft 55 to positions separating from each other.
The pulling rollers 52a and 52b may be provided with two or more collar portions, and the number of the collar portions may be three or four. In any case, the pulling rollers 52a and 52b are provided so that the two collar portions on both ends can be moved toward and away from each other as described above. The contact / separation movement of the two collar portions is driven by a drive portion using a cylinder.

The two pulling rollers 52a and 52b provided on both sides of the mold simultaneously move to the position where the collar portions on both ends are separated from the positions where they are close to each other, so that they are stretched over the pulling rollers 52a and 52b. The release film 10 is pulled by the frictional force against the collar portion on both sides and stretched in the width direction to remove wrinkles.
In order to increase the frictional force with the release film, the outer peripheral surface of the collar portion may be formed of silicon rubber or the like. Note that the pulling roller 52a provided on the supply roller 43 side may not perform the pulling operation. The case where the pulling operation is not performed is, for example, a case where the linear expansion coefficient of the release film 10 is small.

Next, the heating mechanism will be described. The heating mechanism acts to heat the release film 10 at a stage before supplying it between the molds. In the resin mold apparatus of this embodiment, three heating mechanisms are provided.
One is configured such that a heater is built in the pulling roller 52a. In the pulling roller 52a provided on the upstream side of the mold, a heater is built in the longitudinal direction of the pulling roller 52a. Specifically, the heater is disposed in the fixed shaft 55 of the pulling roller 52a.
The second is a preheating roller 57. A heater is built in the preheating roller 57. The preheating roller 57 is disposed in contact with the tension roller 52a provided on the upstream side of the mold so as to heat the release film 10 via the tension roller 52a. Specifically, the preheating roller 57 has a heater built in the center in the longitudinal direction. The preheating roller 57 is in pressure contact with the pulling roller 52a, and is driven and rotated as the pulling roller 52a rotates. Of course, the preheating roller 57 does not hinder the release film wrinkle removal operation of the pulling roller 52a.
The third is a heating unit 58 that includes a heat source such as a heater, an electric lamp, infrared rays, and far infrared rays. The release film 10 is heated by the heat radiation by the heating unit 58. The heating unit 58 is provided on the upstream side of the mold and heats the release film 10 immediately before being supplied between the molds. Specifically, the heating unit 58 is disposed on the upstream side between the molds and on the downstream side of the pulling roller 52a, and heats the release film 10 heated by the pulling roller 52a and the preheating roller 57.
The release film 10 is fed from the supply roller 43 by a length L and supplied between the dies, but is disposed and clamped between the dies by at least the next supply (that is, supplied between the dies). The heating part 58 is arranged so that the entire part (length L) of the release film immediately before is heated.
Moreover, it is good to provide a heating mechanism so that the difference of the temperature of the release film heated by these heating mechanisms and the temperature of a metal mold | die may be 80 degrees C or less.

Next, the resin molding operation by the press part A, the supply mechanism G, and the heating mechanism having the above-described configuration will be described.
First, in a mold opened (see the left side of FIG. 3), the molded product 12 is positioned and arranged on the lower mold 20b. At the same time, the release film 10 fed from the supply roller 43 and supplied between the molds is sucked and held on the mold surface of the upper mold 20a through the air suction holes 42a. Further, air is sucked from the air suction hole 42 a to draw the extension of the release film 10 into the sag absorbing groove 42.

Thereafter, the lower mold 20b is raised to clamp the article 12 between the upper mold 20a and the lower mold 20b, and the resin 16 is pumped from the pot 26 to fill the cavity 16a with the resin 16 and harden. In this case, the mold surface of the upper mold 20a of the molded product 12 is resin-sealed on the surface of the molded product 12 on which the semiconductor chip 13 is mounted while being completely shielded by the release film 10. When the mold is opened, the molded product is released from the mold, and the removed molded product is stored in the storage unit F.
Thus, when one resin molding operation is completed, the molded product 12 and the resin tablet 30 are set again, and the next resin molding operation is started.

The release film 10 is fed out from the supply roller 43 by a length L at a time, and is newly supplied between the molds. The supply of the release film 10 between the molds may be performed for each resin molding operation or may be performed for several resin molding operations.
The release film 10 fed from the supply roller 43 is heated to a predetermined temperature by the heating mechanism and thermally expanded (part 10d) before being supplied between the molds as described above.

Further, before the release film 10 is sucked and held on the mold surface of the upper mold 20a, the release film 10 is stretched in the width direction by the pulling rollers 52a and 52b to perform the wrinkle removing operation. Specifically, after the release film 10 is newly fed below the mold surface of the upper mold 20a, the collar portions on both sides of the pulling rollers 52a and 52b are moved from being close to each other to being separated from each other. Pull both sides of the release film 10 to remove wrinkles. That is, the release film 10 is sucked and held on the mold surface of the upper mold 20a in a state where the wrinkles are removed by the pulling rollers 52a and 52b, and the slack is drawn into the slack absorbing groove 42.
In this case, as described above, only the pulling roller 52b may be operated without moving the pulling roller 52a.

When supplying the release film 10 between the molds every several resin molding operations, the release film 10 is adsorbed to the mold surface of the upper mold 20a, and the state in which the elongation is drawn into the slack absorbing groove is maintained. Then, the molded product 12 on the lower mold 20b is set, and several resin molding operations are continuously performed.
When the supply of the release film 10 is performed for each resin molding operation, or for each of several resin molding operations, the release film is drawn from the supply roller 43 and newly supplied between the molds. Just before the release film is released from the mold surface. (The release film 10 is released from the mold surface by a vacuum breaking mechanism that releases air suction performed through the air suction hole 42a.)
When several times of resin molding operations are performed by supplying the release film 10 once, the release film 10 is released from the mold surface after one molding, and the wrinkles of the release film 10 are stretched by the pulling rollers 52a and 52b. Then, the release film 10 may be formed by adsorbing the release film 10 on the mold surface.

Correspondingly, the pulling rollers 52a and 52b approach from the state in which the collar portions on both sides are separated from each other before the release film 10 is fed from the supply roller 43 after the release film 10 is released from the mold surface. Move to the state you want. That is, when the release film 10 is supplied every several resin molding operations, the collar portions on both sides of the pulling rollers 52a and 52b are separated from each other while the release film is adsorbed and held on the mold surface. And the release film 10 is pulled on both sides.
Further, while the supply roller 43 is rotated and the release film 10 is fed out, the pulling rollers 52a and 52b hold the state where the two collar portions approach each other.

Next, effects of the above embodiment will be described.
As shown in FIG. 2, as a method for supplying the release film, the release film heated by the mold on the side of the mold supply roller 43 is heated so that the thermally expanded release film portion (10e) does not reach the supply position. There is a way to do it. In this method, a portion of the release film that is not affected by the heat of the mold is supplied between the molds.
On the other hand, in the above embodiment, the release film 10 is fed from the supply roller 43 and supplied between the molds by a length L substantially equal to the length of the mold surface in the feed direction X. A portion heated and thermally expanded under the influence of heat from the mold without being in contact is also actively supplied between the molds. Since the release film 10 is thermally expanded before being supplied between the molds, a new thermal expansion due to contact with the mold surface can be reduced, and when the release film 10 is sucked and held on the mold surface. The wrinkles can be efficiently reduced by a simple method.
In addition, the present embodiment can reduce the amount of the release film to be delivered in one supply compared to the supply method shown in FIG. 2, and can greatly reduce the consumption of the release film, thereby reducing the cost. It is effective for.

Moreover, by providing the heating part 58, the wide range of a release film can be heated at once. As a result, only the preheated and thermally expanded release film in the required range can be supplied between the molds, and the generation of wrinkles when contacting the mold surface is uniformly reduced without being biased depending on the part. Can do.
Further, by providing the pulling roller 52a or the preheating roller 57 with a built-in heater, the release film can be heated uniformly and reliably in the width direction.
Further, by disposing one or both of the pulling roller 52a and the preheating roller 57 with a built-in heater and the heating unit 58 in combination, the release film is gradually heated to rapidly heat the release film. It is possible to prevent significant uneven deformation of the release film.
Conventionally, a release film having a thickness of 50 μm and a width of 180 mm and having a room temperature (about 20 ° C.) is fed between the molds heated to about 175 ° C. so as not to come into contact with the mold surface. After being heated, it was adsorbed and held on the mold surface.
In this embodiment, for example, a release film similar to the conventional one is heated and supplied up to about 110 ° C. by a heating mechanism before being supplied between the molds. Since the release film is preheated to about 110 ° C. and thermally expanded, the new thermal expansion due to contact with the mold surface can be reduced to half of the conventional one.
Thereby, the number of the slack absorption grooves 42 can be reduced to half of the conventional one. Furthermore, the allowable range of the linear expansion coefficient of the usable release film can be expanded to twice the conventional value.

As described above, according to this embodiment, it is possible to prevent the release film from wrinkling when it comes into contact with the mold surface, so that the number of slack absorbing grooves can be reduced, and the mold surface has a complicated shape. Can also handle molds. Furthermore, since wrinkles are unlikely to occur, a release film having a linear expansion coefficient larger than that of the conventional one can be used. Thereby, a multilayer release film having various functions such as a transfer function can be used, and the range of selection of the release film is expanded.
Furthermore, if the pulling rollers 52a and 52b are used, the release film is stretched in the width direction, and the wrinkles can be reliably removed before the release film contacts the mold surface.

While the present invention has been described in detail with reference to a preferred embodiment, the present invention is not limited to this embodiment, and it goes without saying that many modifications can be made without departing from the spirit of the invention. is there.
For example, in the above embodiment, three heating mechanisms are provided, but a resin mold apparatus provided with one or two of the three heating mechanisms may be used.
Moreover, in the said embodiment, although the upper mold surface was coat | covered with the release film, this invention is applicable also to the resin mold apparatus and resin mold method which coat | cover the lower mold surface with a release film. In this case, a release film supply mechanism G and a heating mechanism may be provided on the lower mold side.
The present invention is also applicable to a resin mold apparatus and a resin mold method in which a release film supply mechanism G and a heating mechanism are respectively provided on the upper and lower sides, and both upper and lower mold surfaces are covered with a release film. it can.

It is the schematic explaining the supply mechanism of the resin mold apparatus by this invention. It is the schematic explaining the supply method of a release film. It is sectional drawing which shows the structure of the metal mold | die of a press part. It is a top view which shows the state which has arrange | positioned the release film on the metal mold | die surface. It is sectional drawing which shows the state at the time of drawing a release film in a slack absorption groove | channel. It is a top view explaining the structure of the resin mold apparatus by this invention. It is the schematic which shows the structure of a tension roller.

Explanation of symbols

10 Release film 12 Molded product
20a Upper mold
20b Lower mold 43 Supply roller 44 Winding roller
52a, 52b Tension roller

Claims (5)

It has a supply roller around which the release film is wound and a take-up roller that takes up the release film drawn out from the supply roller, and is passed between the supply roller and the take-up roller and passes between the dies. In the resin mold apparatus that holds the release film supplied to the mold surface of the mold by suction and seals the resin by clamping the molded product via the release film,
A heating mechanism is provided to heat the release film before it is supplied between the molds.
A resin mold apparatus, wherein a release film having a length substantially equal to a length of the mold surface in the feed direction is fed from a supply roller, whereby a release film is newly supplied between the molds. The resin mold apparatus according to claim 1 , wherein the heating mechanism includes a heat source that heats the release film by heat radiation. The resin molding apparatus according to claim 1 , wherein the heating mechanism includes a heater built in the pulling roller. 2. The resin mold apparatus according to claim 1 , wherein the heating mechanism includes a preheating roller that heats the pulling roller, and heats the release film via the pulling roller. The release film is passed between the molds so as to pass between the molds between the supply roller around which the release films are wound and the take-up roller that takes up the release film drawn from the supply rollers. In the resin mold method of resin sealing by supplying and holding the supplied release film on the mold surface of the mold and clamping the molded product via the release film,
Heat the release film before supplying it between the molds,
A resin molding method characterized in that a release film is newly supplied between molds by feeding a release film having a length substantially equal to the length of the mold surface in the feeding direction from a supply roller.

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