JP2008001045A - Resin sealing device and resin sealing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a cycle time in a resin sealing device using a thermo-setting resin. <P>SOLUTION: The resin sealing device 100 sealing a molded article 150 with a thermo-setting resin 160 in the cavity 170 formed by superimposing an upper mold 110 on a lower mold 120 comprises a molding section 124 constituting the cavity 170 and a heat storing section 126 with a heater 127 in at least one of the upper mold 110, wherein the molding section 124 and the heat storing section 126 can come into contact with each other and be spaced apart from each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin sealing device and a resin sealing method for resin-sealing a semiconductor chip or the like using a thermosetting resin.

  Conventionally, a resin sealing device 2 shown in FIG. 4 is known (see Patent Document 1).

  The resin sealing device 2 includes an upper mold 12 and a lower mold 14 including a frame-shaped mold 16 and a compression mold (bottom mold) 18, and the upper mold 12 and the lower mold 18 can be combined. In the molding space (cavity) 46, the molded product 6 having the semiconductor chip 4 and the like is sealed with a thermosetting resin 8.

  Each mold in the resin sealing device 2 is provided with heaters 32, 34, and 36 for thermosetting the thermosetting resin.

  Thermosetting resin is a resin that undergoes polymerization to form a polymer network when heated and cannot be restored to its original state. For example, phenol resin, epoxy resin, melamine resin, urea Resins, unsaturated polyester resins, alkyd resins, and the like.

Japanese Patent Laid-Open No. 2005-305951

  The thermosetting resin requires some curing time until it is cured after receiving heat sufficient to cause a curing reaction. In the resin sealing device, the mold cannot be opened and the molded product cannot be taken out until the resin is cured to some extent. Therefore, the waiting time until the resin is cured dominates the cycle time of the resin sealing device. In particular, in the high fluidity resin that is preferably used with the recent high integration of semiconductor chips, the curing time of the resin itself is long, so that the cycle time of the apparatus is more prominent.

  In order to accelerate the curing of the thermosetting resin as soon as possible, for example, it is conceivable that the temperature of the mold is preliminarily heated to a temperature considerably higher than the curing temperature of the resin. However, if the temperature of the mold is set too high, the charged resin is immediately cured and the fluidity is hindered, so that the molded product cannot be uniformly sealed, and the recent high quality requirements have been met. I can't respond. In addition, there is a method in which the mold temperature is preheated to the temperature before the resin curing temperature and the mold temperature is further increased by a heater after the resin is charged. In this method, after the heater is heated, Since the mold is heated and the resin is heated for the first time by the heated mold, the timing of heating the heater and receiving the resin is delayed by the temperature rise of the mold. Since this timing delay directly affects the time until the resin is cured, there is a limit to shortening the cycle time of the resin sealing device.

  For example, if the mold is made thin and the heat capacity of the mold itself is made small in order to shorten the cycle time, the strength of the mold will be insufficient, and it will be difficult to incorporate a heater with the necessary heat generation amount, etc. On the other hand, if a heater with a larger calorific value is incorporated without changing the mold, the size of the apparatus is increased accordingly.

  The present invention has been made to solve these problems, and in a resin sealing device using a thermosetting resin, the cycle of the sealing device is ensured while ensuring sufficient fluidity immediately after the resin is charged. Its purpose is to reduce time.

  The present invention is a resin sealing device that seals a molded product with a thermosetting resin in a cavity formed by overlapping an upper mold and a lower mold, and the above-described mold is attached to at least one of the upper mold and the lower mold. The above-mentioned problems are solved by providing a molding part constituting the cavity and a heat storage part provided with a heater, and configuring the molding part and the heat storage part so as to be able to contact and separate.

  As a result, the temperature of the heat storage unit is maintained high by the heater in advance, and the heat stored in the heat storage unit is transmitted to the molding unit by bringing the heat storage unit into contact with the molding unit at a predetermined timing. It is possible to quickly heat the curable resin. That is, the heat storage section can be preheated to a temperature considerably higher than the curing temperature of the resin, and in this way, the curing of the resin is prevented from being accelerated (at a speed higher than intended). be able to.

  For example, if the heat storage part is formed to be relatively thick and then the molding part is made relatively thin, the heat capacity of the heat storage part can be made larger than the heat capacity of the molding part. When contacted, the temperature of the molded part can be quickly raised, and as a result, curing of the thermosetting resin can be promoted. In addition, since the heat capacity of the molded part itself can be reduced, the temperature of the molded part can be quickly lowered by separating the heat storage part from the molded part at a predetermined timing.

  Further, if an elastic body is interposed between the molding part and the heat storage part and the both are separated by the elastic body, the power of the device for opening and closing the mold (for example, a press device) can be increased. The contact / separation between the heat storage section and the molding section can be controlled at a predetermined timing by using the apparatus, and the apparatus can be realized with a simple configuration.

  In addition, if a cooling mechanism capable of cooling the molded part is provided, the temperature of the molded part can be more actively managed, and the cycle time (of the resin sealing device) can be further shortened. .

  For example, if the gap generated when the molded part and the heat storage part are separated from each other is configured as a cooling medium passage in the cooling mechanism, it is not necessary to incorporate the cooling mechanism into a member such as the molded part, and the space is effectively utilized. can do.

  In the present invention, at least one of the upper mold and the lower mold is provided with a molding part that constitutes a cavity and a heat storage part provided with a heater, and the article to be molded is placed in a cavity in which the upper mold and the lower mold can be stacked. Is a resin sealing method in which the thermosetting resin is sealed with a thermosetting resin, with the molding part and the heat storage part being separated from each other, and after the injection, A step of bringing the heat storage part into contact with the molded part at a predetermined timing; and a step of separating the heat storage part from the molded part at a predetermined timing after molding; It is also possible to grasp as a resin sealing method including the step of cooling the molded part, and similarly solves the above-mentioned problem.

  By applying the present invention, the cycle time of the resin sealing device can be shortened without impairing the fluidity of the resin immediately after being charged.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a side view showing a mold part of a resin sealing device 100 according to the present invention, in which the upper mold and the lower mold are separated from each other, and FIG. 2 is the upper mold and the lower mold. Is a state diagram before entering the compression process, and FIG. 3 is a diagram showing a state of the compression process.

  The resin sealing device 100 includes an upper mold 110 and a lower mold 120, and heats a molded product 150 on which a semiconductor chip or the like is mounted in a cavity 170 formed by combining the upper mold 110 and the lower mold 120. This is a device for sealing with a curable resin 160 by a compression molding method. In addition, although demonstrated as the resin sealing apparatus 100 using the compression molding method as an Example, this invention is not limited to this compression molding method, For example, it can apply also to the resin sealing apparatus by a transfer molding method. Is possible.

  The upper mold 110 and the lower mold 120 can be brought into contact with and separated from each other by a press mechanism (not shown) or the like.

  A molded product 150 is conveyed and supplied to the surface of the upper mold 110 (the lower mold 120 side surface) by a conveyance mechanism (not shown). The molded product 150 can be appropriately fixed to the surface of the upper mold 110 by suction means (not shown) provided on the upper mold 110.

  The lower mold 120 is configured to include a frame mold 122 and a bottom mold 129.

  The frame mold 122 is provided with a through hole 122A at a substantially central portion of the frame mold 122, and a bottom mold 129 described later is disposed through the through hole 122A.

  In the bottom mold 129, a heat storage unit 126 including a heater 127 is placed on the upper surface (the upper surface in FIG. 1) of the lower mold base 128, and the molding unit 124 that forms the cavity 170 on the upper surface side of the heat storage unit 126. Is arranged and configured. As shown in FIG. 1, the thickness T <b> 1 of the molding part 124 is configured to be thinner than the thickness T <b> 2 of the heat storage part 126, and the heat capacity thereof is set smaller than the heat capacity of the heat storage part 126. In addition, an elastic body 125 is disposed between the molding part 124 and the heat storage part 126. When no external force is applied to the molding part 124 or the heat storage part 126, the molding part 124 and the heat storage part 126 are stored. The portion 126 is configured such that a slight gap G is formed by the action of the elastic body 125. Various elastic bodies 125 can be used. For example, if a coil spring is used, an elastic body that is resistant to secular change can be formed. In addition, if heat-resistant rubber is used, a low-noise device can be realized, and the heat of the heat storage unit 126 is unintentionally transmitted through the interposed elastic body 125 while the heat storage unit 126 and the molding unit 124 are separated from each other. Therefore, it is possible to prevent the transmission to the forming part 124. As a result, the curing of the thermosetting resin 160 put into the cavity 170 is not unintentionally promoted.

  Further, a first press mechanism or the like (not shown) is connected to the lower mold base 128 so that the bottom mold 129 can freely move up and down with respect to the upper mold 110.

  The frame mold 122 is connected to a second press mechanism that can operate independently of the first press mechanism, and moves up and down independently of the bottom mold 129 (up and down movement with respect to the upper mold 110). It is possible.

  Next, the operation of the resin sealing device 100 will be described.

  When the molded product 150 is supplied to the surface of the upper mold 110 by a transport mechanism (not shown), the molded product 150 is sucked and fixed to the surface of the upper mold 110 by the suction mechanism. On the other hand, the thermosetting resin 160 is charged into the cavity 170 by a charging mechanism (not shown). In the drawing, the thermosetting resin 160 to be added is in the form of a sheet, but other resins such as tablets, granules, powders, and liquids can also be used.

  Next, the entire lower mold 120 begins to move toward the upper mold 110 by a press mechanism or the like connected to the lower mold base 128 and the frame mold 122. At this point, since there is a slight gap G (due to the action of the elastic body 125) between the molding part 124 and the heat storage part 126 constituting the cavity 170, the heat storage part 126 is thermoset by the heater 127. Even when the temperature is higher than the curing temperature of the curable resin 160, the curing of the thermosetting resin 160 is not accelerated at an unintended speed. Thereafter, when the frame mold 122 constituting the lower mold 120 comes into contact with the upper mold 110 by the action of a further pressing mechanism, the upper mold 110 is moved while the bottom mold 129 slides in the through hole 122A of the frame mold 122. Move to the side. At this time, the gap G between the molding part 124 and the heat storage part 126 moves while being held by the elastic body 125 (see FIG. 2).

  Thereafter, when the bottom mold 129 gradually moves to the upper mold 110 side, the injected thermosetting resin 160 comes into contact with the molded product adsorbed and fixed to the upper mold 110, and compression pressure is applied by a press mechanism or the like. The thermosetting resin 160 begins to seal (compression molding) the article 150 while being pressed (see FIG. 3). The elastic body 125 interposed between the molding part 124 and the heat storage part 126 is compressed by the sealing pressure (for example, 10 MPa / square cm) at this time, and the molding part 124 and the heat storage part 126 are brought into contact with each other. Allow. By this contact, the heat of the heat storage unit 126 in which heat is stored by the heater 127 is transmitted to the molding unit 124 side. Due to this heat transfer, the molded part 124 is heated and the thermosetting resin 160 itself is also heated, so that the curing of the thermosetting resin is promoted.

  In addition, since the thickness T1 of the molding unit 124 is smaller than the thickness T2 of the heat storage unit 126 and smaller than the heat capacity of the heat storage unit 126, the temperature of the molding unit 124 can be easily increased by the heat transmitted from the heat storage unit 126. Can do. As a result, the heat from the heat storage unit 126 is quickly transmitted to the thermosetting resin 160 through the molding unit 124. In addition, the temperature of the heat storage unit 126 is heated to a temperature equal to or higher than the curing temperature of the thermosetting resin 160 (before contacting the molding unit 124). The degree of this heating needs to be appropriately adjusted depending on the type of the molded product 150 to be sealed, the type of the thermosetting resin 160 to be used, and the like. For example, when the temperature of the molding unit 124 is heated to 200 ° C. to cause the resin to cure, the heat storage unit 126 is molded by setting the temperature of the heat storage unit 126 to about 210 to 220 ° C. in advance. After coming into contact with the portion 124, the temperature of the molding portion 124 can be quickly heated to 200 ° C. Moreover, even when the thickness of the molding part 124 is made thin in order to reduce the heat capacity as in this embodiment, the molding part 124 and the heat storage part 126 are in contact with each other in a plane, so that the molding part 124 is partly in the compression process. Moments do not act and no strength problems arise.

  Thereafter, at a timing when the predetermined time has elapsed and the thermosetting resin 160 is cured, the lower mold 120 is moved downward (lower side in FIGS. 1 to 3) by the action of a press mechanism or the like, and the mold is opened. At this time, the gap G is generated when the molded part 124 and the heat storage part 126 that are in contact with each other are separated by the presence of the elastic body 125. In this resin sealing device 100, since the molding part 124 and the heat storage part 126 are separated to reduce the heat capacity of the molding part 124, the temperature of the molding part 124 quickly decreases due to rapid heat dissipation. To do. That is, the temperature of the molding part 124 can be quickly lowered until the next sealing operation, and immediately after taking out the molded product after sealing, the thermosetting resin used for the next sealing is immediately stored in the cavity 170. Can be thrown into. As a result, also in this respect, it is possible to shorten the cycle time of the apparatus.

  In addition, a cooling mechanism for actively cooling the molding part 124 can be provided separately, and in this way, the temperature of the molding part 124 can be more actively controlled. At this time, the gap G generated between the molding part 124 and the heat storage part 126 is made to function as a cooling medium passage, for example, although not shown, air is passed from one side of the gap G to the other side at a predetermined timing. As a result, the molded portion 124 can be actively cooled. With such a configuration, it is not necessary to incorporate a cooling mechanism into a member such as a molding part, and space can be used effectively. Of course, it is also possible to cool using not only air but also fluid such as cooling water. In addition, it is good also as a structure which provides a cooling medium channel | path separately in shaping | molding part 124 itself.

  Thereafter, the resin-sealed molded product is taken out by the transport mechanism, and the process proceeds to the next sealing operation. Even after the molding unit 124 is cooled, the temperature of the heat storage unit 126 is kept constant by the heater 127 (a temperature higher than the temperature at which the thermosetting resin 160 is cured). It is possible to quickly transfer heat to the portion 124.

  In the resin sealing device 100, an elastic body 125 is interposed between the molding portion 124 and the heat storage portion 126, and a gap G between the molding portion 124 and the heat storage portion 126 is formed by the elastic body 125. Has been. With this configuration, in particular, a press mechanism (a press mechanism for opening and closing the mold) originally present in the resin sealing device is used as it is to bring the power source (the molding portion 124 and the heat storage portion 126 into contact). Power source), and the entire apparatus can be simply configured.

  As described above, in the resin sealing device 100, the lower mold is separated into the molding part that constitutes the cavity and the heat storage part that stores heat, and the molding part and the heat storage part are brought into contact / separated at a predetermined timing. By adopting such a configuration, it is possible to quickly supply heat to the thermosetting resin, and to reduce the time lag from the heat generation of the heater, which has been a problem in the past, until the resin receives heat. As a result, the cycle time of the resin sealing device itself can be greatly shortened.

  In the resin sealing device 100, the heater 127 is disposed and configured only in the heat storage unit 126. For example, the upper mold 110 and the frame mold 122 may include a heater. With such a configuration, the periphery of the cavity 170 can be warmed throughout, and the temperature management of the molding portion 124 can be performed more easily and accurately. That is, when the temperature of the surrounding mold (for example, the frame mold) is too low, for example, the heat applied to the molding portion 124 is diffused by heat conduction, and it becomes difficult to stabilize at a predetermined temperature at a predetermined timing. If the heaters are also arranged on the upper mold 110, the frame mold 122, etc., it is possible to prevent such a problem from occurring.

  In addition, it is not prohibited to incorporate a heater in the molding part itself. By incorporating a heater in the molding part, the temperature of the molding part is controlled and the heat storage part is brought into contact at a predetermined timing. Further, the cycle time of the apparatus can be shortened more actively. As described above, for example, when a heater is incorporated in the frame mold, the temperature of the molding part may be controlled using heat conducted from the frame mold.

  The present invention can be applied not only to a resin sealing apparatus using a compression molding method but also to a resin sealing apparatus using a transfer molding method.

It is a side view which shows the metal mold | die part of the resin sealing device concerning this invention, Comprising: The state figure which the upper mold | type and the lower mold | type have separated It is a side view which shows the metal mold | die part of the resin sealing device concerning this invention, Comprising: A state figure before an upper mold | type and a lower mold contact | abut and it enters into a compression process It is the side view which shows the metal mold | die part of the resin sealing device concerning this invention, Comprising: The figure which showed the state of the compression process Configuration diagram of resin sealing device described in Patent Document 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Resin sealing apparatus 110 ... Upper mold | type 120 ... Lower mold | type 122 ... Frame type | mold 122A ... Penetration part 124 ... Molding part 125 ... Elastic body 126 ... Heat storage part 127 ... Heater 128 ... Lower mold | type base 129 ... Bottom mold 150 ... To-be-molded Product 160 ... Thermosetting resin 170 ... Cavity (molding space)

Claims (7)

In a cavity formed by overlapping an upper mold and a lower mold, a resin sealing device that seals a molded product with a thermosetting resin,
At least one of the upper mold and the lower mold is provided with a molding part constituting the cavity and a heat storage part provided with a heater, and the molding part and the heat storage part can be brought into contact with and separated from each other. A resin sealing device. In claim 1,
The heat capacity of the said heat storage part is larger than the heat capacity of the said shaping | molding part. Resin sealing apparatus characterized by the above-mentioned. In claim 1 or 2,
An elastic body is interposed between the molding part and the heat storage part. In any one of Claims 1 thru | or 3,
A resin sealing device comprising a cooling mechanism capable of cooling the molded part. In claim 4,
A gap generated when the molded part and the heat storage part are separated from each other is a cooling medium passage in the cooling mechanism. At least one of the upper mold and the lower mold is provided with a molding part that constitutes a cavity and a heat storage part equipped with a heater, and the molded product is made into a thermosetting resin in a cavity where the upper mold and the lower mold can be overlapped. A resin sealing method for sealing,
In a state where the molded part and the heat storage part are separated from each other, the step of introducing the thermosetting resin into the cavity;
And a step of bringing the heat storage part into contact with the molded part at a predetermined timing after the charging. The process of claim 6, further comprising a step of separating the heat storage part from the molding part at a predetermined timing after molding.
And a step of cooling the molded part after the separation.

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