Resin encapsulation apparatus and resin encapsulation method

Abstract

To provide a resin sealing device and a resin sealing method, which are capable of preventing molding defects caused by a gradual decrease in a surface temperature of a sealing die when an automatic operation continues at a given cycle.SOLUTION: A resin sealing method according to the present invention is configured in that: a temperature of a sealing die 202 at which a resin R is appropriately thermally cured during sealing is defined as normal set temperature, and a temperature of the sealing die 202, which is set as a temperature higher than the normal set temperature by a predetermined temperature is defined as a switching set temperature; and during a unit process in which a workpiece W and the resin R are carried into the sealing die 202, sealed, and then carried out as a molded product Wp, a temperature of the sealing die 202 is controlled by changing the set temperature of at least one of an upper die 204 and a lower die 206 from the normal set temperature to the switching set temperature at a predetermined start timing, and a temperature of the sealing die 202 is controlled by changing the set temperature from the switching set temperature to the normal set temperature at a predetermined end timing.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a resin sealing device and a resin sealing method.

Background Art

[0002] As an example of a resin sealing device and a resin sealing method for sealing a work in which an electronic component is mounted on a base material with a sealing resin (hereinafter, may be simply referred to as "resin") and processing it into a molded product, those using a transfer molding method or a compression molding method are known.

[0003] The transfer molding method is a technique in which a pot for supplying a predetermined amount of resin is provided in two upper and lower sealing regions (cavities) provided in a sealing mold including an upper mold and a lower mold, and workpieces are respectively arranged at positions corresponding to the respective sealing regions, and the upper mold and the lower mold are clamped and the resin is poured from the pot into the cavity for resin sealing (see Patent Document 1: Japanese Patent Application Laid-Open No. 2020-102601). Further, the compression molding method is a technique in which a predetermined amount of resin is supplied to a sealing region (cavity) provided in a sealing mold including an upper mold and a lower mold, and a workpiece is arranged in the sealing region, and the upper mold and the lower mold are clamped for resin sealing. As an example, when using a sealing mold provided with a cavity in the upper mold, a technique of supplying resin all at once to the center position on the workpiece and molding is known. On the other hand, when using a sealing mold provided with a cavity in the lower mold, a technique of supplying a film covering the mold surface including the cavity and resin and molding is known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In conventional resin encapsulation equipment, the surface temperature of the encapsulation mold is typically controlled (adjusted) to be uniform between, for example, 100°C and 200°C, and the resin used for encapsulation is typically controlled to be below, for example, 30°C. Therefore, when the molding operation for resin encapsulation is continued in an automatic operation at a fixed cycle, the surface temperature of the encapsulation mold (especially the temperature around the resin containment area) gradually decreases due to the influence of the temperature of the resin contained in the encapsulation mold. This makes it impossible to secure the melting point temperature necessary for resin encapsulation, resulting in molding defects (insufficient resin curing, incomplete filling, etc.).

[0006] To address these challenges, Patent Document 1 discloses a resin encapsulation apparatus with a configuration that includes temperature sensors around the calblock and cavity, and employs processes such as acquiring temperature information before resin is placed in the encapsulation mold and before heating the encapsulation mold, thereby preventing a drop in the temperature of the encapsulation mold. However, this can lead to problems such as increased complexity of the apparatus structure and higher costs. Furthermore, the process of acquiring temperature information in advance is time-consuming and labor-intensive, which can lead to decreased production efficiency. [Means for solving the problem]

[0007] The present invention has been made in view of the above circumstances, and aims to provide a resin sealing apparatus and a resin sealing method that, with a simple configuration, can prevent the surface temperature of the sealing mold from gradually decreasing and causing molding defects, even when the molding operation for resin sealing is continued in an automatic operation at a fixed period.

[0008] The present invention solves the above problem by a solution described below as one embodiment.

[0009] The resin encapsulation method according to the present invention is a resin encapsulation method that processes a workpiece into a molded product by encapsulating it with resin using an encapsulation mold comprising an upper mold and a lower mold, wherein the temperature of the encapsulation mold, which is set to a temperature at which the resin is appropriately heat-cured during encapsulation, is set as the normal set temperature, and the temperature of the encapsulation mold, which is set to a temperature predeterminedly higher than the normal set temperature, is set as the switching set temperature, and during a unit process in which the workpiece and the resin are loaded into the encapsulation mold and encapsulated, and then the molded product is unloaded, the temperature of the encapsulation mold is controlled by changing the set temperature of at least one of the upper mold and the lower mold from the normal set temperature to the switching set temperature at a predetermined start timing, and by changing the set temperature of the encapsulation mold from the switching set temperature to the normal set temperature at a predetermined end timing. Furthermore, the termination timing is before the workpiece and resin are transferred to the sealing mold in the next unit process, and the normally set temperature is a temperature equal to or greater than the melting temperature of the resin. This is a requirement.

[0010] This method prevents the gradual decrease in the surface temperature of the sealing mold when the molding operation is performed automatically at regular intervals, without requiring complex equipment structures or complex implementation processes. Therefore, it becomes possible to ensure an appropriate melting point temperature in the sealing mold when performing resin sealing, thereby suppressing molding defects caused by insufficient temperature. In addition, it reduces the occurrence of abnormalities that could cause equipment shutdown, thus improving the operating rate.

[0011] Furthermore, it is preferable to set the start timing to the point in time when the resin is set in a predetermined position in the sealing mold. 。

[0012] Furthermore, it is preferable to set the predetermined temperature to a temperature selected from the range of 1°C to 20°C. This allows for optimal settings depending on the material and quantity of the resin, or the temperature decrease tendency of the sealing mold. Therefore, better molding quality can be maintained.

[0013] Furthermore, the switching setting temperature is configured such that the setting temperature in the upper mold is set as the first switching setting temperature, and the setting temperature in the lower mold is set as the second switching setting temperature, and it is preferable that the first switching setting temperature is set to a higher temperature than the second switching setting temperature. Furthermore, the start timing is configured such that the setting timing in the upper mold is set as the first start timing, and the setting timing in the lower mold is set as the second start timing, and the end timing is configured such that the setting timing in the upper mold is set as the first end timing, and the setting timing in the lower mold is set as the second end timing, and it is preferable that the time from the first start timing to the first end timing is set to be longer than the time from the second start timing to the second end timing. According to these configurations, it is possible to enhance the effect of suppressing temperature drop in the upper mold compared to the lower mold. Therefore, it is possible to suppress temperature drops in the upper mold, which are prone to large temperature drops during one cycle. Furthermore, it becomes possible to individually adjust the surface temperature of the sealing mold in both the upper and lower molds to a temperature more suitable for molding, thereby further improving molding quality.

[0014] Furthermore, the resin sealing apparatus according to the present invention is a resin sealing apparatus that processes a workpiece into a molded product by sealing it with resin using a sealing mold comprising an upper mold and a lower mold, and comprises a control unit that controls the temperature of the sealing mold, the control unit sets the temperature of the sealing mold to be set as the normal set temperature, which is set as the temperature at which the resin is appropriately heat-cured during sealing, and sets the temperature of the sealing mold to be set at a predetermined temperature higher than the normal set temperature, as a switching set temperature. During a unit process in which the workpiece and resin are loaded into the sealing mold and sealed, and then the molded product is discharged, the temperature of the sealing mold is controlled by changing the set temperature of at least one of the upper mold and the lower mold from the normal set temperature to the switching set temperature at a predetermined start timing, and then changing the set temperature back from the switching set temperature to the normal set temperature at a predetermined end timing. Furthermore, the termination timing is controlled to occur before the workpiece and resin are transferred to the sealing mold in the next unit process, and the normal set temperature is set to a temperature equal to or higher than the melting temperature of the resin. This is a requirement.

Advantages of the Invention

[0015] According to the present invention, with a simple structure, even when the molding operation for resin sealing is continued by automatic operation at a constant cycle, it is possible to prevent the surface temperature of the sealing mold from gradually decreasing and causing molding defects.

Brief Description of the Drawings

[0016] [Figure 1] It is a plan view showing an example of a resin sealing device according to an embodiment of the present invention. [Figure 2] It is a side view at the position of line II-II in FIG. 1. [Figure 3] It is a front sectional view showing an example of the sealing mold of the resin sealing device in FIG. 1. [Figure 4] It is a graph showing the temperature decrease tendency of the lower mold according to an embodiment of the present invention and a conventional embodiment. [Figure 5] It is a graph showing the temperature decrease tendency of the upper mold according to an embodiment of the present invention and a conventional embodiment.

Modes for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view (schematic view) showing an example of a sealing mold 202 according to an embodiment of the present invention and a resin sealing device 1 including the sealing mold 202. Further, FIG. 2 is a side view at the position of line II-II in FIG. 1 (some mechanisms are not shown). For the sake of convenience of explanation, in the drawings, the front-back, left-right, and up-down directions in the resin sealing device 1 may be described by arrows. Also, in all the drawings for explaining each embodiment, members having the same function are denoted by the same reference numerals, and repeated explanations thereof may be omitted.

[0018] The resin encapsulation device 1 according to this embodiment is a device that encapsulates a workpiece (molded product) W with resin using a sealing mold 202 including an upper mold 204 and a lower mold 206. Hereinafter, as the resin encapsulation device 1, a transfer molding method resin encapsulation device and method will be described by taking as an example a method in which the workpiece W is held by the lower mold 206, the cavity 208 (including a part of the mold surface 204a) provided in the upper mold 204 in a corresponding arrangement is covered with a release film (hereinafter sometimes simply referred to as "film") F, the clamping operation between the upper mold 204 and the lower mold 206 is performed, and the workpiece W is encapsulated with resin R. However, it is not limited thereto, and the cavity 208 may be provided only in the upper mold 204, or may be provided in both the lower mold 206 and the upper mold 204. Also, the film F is not essential.

[0019] First, the workpiece W to be molded has a configuration in which one or more electronic components Wb are mounted on a base material Wa in a predetermined arrangement. More specifically, examples of the base material Wa include plate-like members such as resin substrates, ceramic substrates, metal substrates, carrier plates, lead frames, and wafers formed in a rectangular shape, circular shape, etc. Examples of the electronic component Wb include semiconductor chips, MEMS chips, passive elements, heat dissipation plates, conductive members, spacers, and combinations thereof. However, it is not limited thereto.

[0020] Examples of methods for mounting the electronic component Wb on the base material Wa include mounting methods such as wire bonding mounting and flip chip mounting. Alternatively, in the case of a configuration in which the base material (glass or metal carrier plate) Wa is peeled off from the molded product Wp after resin encapsulation, there is also a method of attaching the electronic component Wb using a heat-peelable adhesive tape or an ultraviolet curable resin that cures by ultraviolet irradiation.

[0021] On the other hand, as an example of the resin R, a tablet-shaped (as an example, a columnar) thermosetting resin (for example, a filler-containing epoxy resin, etc.) is used. Note that the resin R is not limited to the above state, and may have a shape other than columnar, or may be a resin other than an epoxy-based thermosetting resin.

[0022] Furthermore, suitable examples of film F include film materials with excellent heat resistance, ease of peeling, flexibility, and stretchability, such as PTFE (polytetrafluoroethylene), ETFE (polytetrafluoroethylene polymer), PET, FEP, fluorine-impregnated glass cloth, polypropylene, and polyvinylidine chloride. In this embodiment, a roll-shaped film is used as film F. As another example, a configuration using strip-shaped film may also be used (not shown).

[0023] The above describes the case using a typical workpiece W and resin R, but there are also cases where the workpiece W is absent and the resin R is used alone to form a predetermined shape (in which case, this is referred to as a resin molding apparatus and method).

[0024] Next, an overview of the resin encapsulation apparatus 1 according to this embodiment will be described. As shown in Figure 1, the resin encapsulation apparatus 1 mainly comprises a supply unit 100A that primarily supplies the workpiece W to be encapsulated and the resin R, a press unit 100B that primarily processes the workpiece W into a molded product Wp by encapsulating it with resin, and a storage unit 100C that primarily stores the molded product Wp after resin encapsulation. Although the control unit 150 that controls each mechanism in each unit is located in the supply unit 100A, it may also be located in another unit.

[0025] Furthermore, the resin encapsulation apparatus 1 is equipped with a transport mechanism 100D that moves between each unit to transport the workpiece W, resin R, and molded product Wp. As an example, the transport mechanism 100D is equipped with an in-loader 122 that loads the workpiece W and resin R into the press unit 100B, an out-loader 124 that unloads the molded product Wp from the press unit 100B, and a guide rail 126 shared by the in-loader 122 and the out-loader 124. Note that the transport mechanism 100D is not limited to the above configuration, and may be configured to use known pickups or the like as appropriate (not shown). Also, instead of a configuration equipped with a loader, a configuration equipped with an articulated robot may be used (not shown).

[0026] Here, the inloader 122 receives the workpiece W and resin R from the supply unit 100A and transports them to the press unit 100B. As an example of the configuration of the inloader 122, there are two rows of workpiece holding sections 122A and 122B arranged side by side along the left-right direction, each capable of holding one workpiece W. In addition, a resin holding section 122C is provided between the two rows of workpiece holding sections 122A and 122B, capable of holding multiple (for example, four resins are given as an example, but it is not limited to this, and it may also be one) resins R along the front-back direction. Known holding mechanisms (for example, a configuration that grips with holding claws, a configuration that adsorbs with suction holes communicating with a suction device, etc.) are used in the workpiece holding sections 122A and 122B and the resin holding section 122C (not shown).

[0027] The in-loader 122 according to this embodiment is configured to move in the left-right and front-back directions to transport the workpiece W and resin R into the sealing mold 202 and place them in a predetermined position on the lower mold 206. However, it is not limited to this configuration, and a separate loader may be provided for transporting between units by moving in the left-right direction and for transporting into the sealing mold 202 by moving in the front-back direction (not shown).

[0028] Furthermore, the outloader 124 receives the molded product Wp (including unnecessary resin parts such as the calf and runner) from the press unit 100B and transports it to the storage unit 100C. As an example of the configuration of the outloader 124, there are molded product holding sections 124A and 124B arranged in two rows in the left-right direction, each capable of holding one molded product Wp. Known holding mechanisms (for example, a configuration that grips with holding claws, a configuration that uses suction with suction holes communicating with a suction device, etc.) are used in the molded product holding sections 124A and 124B (not shown).

[0029] The outloader 124 according to this embodiment is configured to move in the left-right and front-back directions to transport the molded product Wp out of the sealing mold 202 and place it on the molded product table 114. However, it is not limited to this configuration, and a separate loader may be provided that moves in the front-back direction to transport the product out of the sealing mold 202, and another loader that moves in the left-right direction to transport the product between units (not shown).

[0030] Furthermore, the resin encapsulation device 1 can be modified by changing the configuration of its units. For example, the configuration shown in Figure 1 is an example where two press units 100B are installed, but it is also possible to install only one press unit 100B, or three or more press units 100B, etc. It is also possible to install other units in addition (none of which are shown).

[0031] (Supply unit) Next, we will describe the supply unit 100A provided by the resin encapsulation device 1.

[0032] The supply unit 100A includes, for example, a workstocker 102 used to store workpieces W, and a worktable 104 on which the workpieces W are placed. The workstocker 102 uses a known stack magazine, slit magazine, etc., and is capable of storing multiple workpieces W at once. With this configuration, the workpieces W are removed from the workstocker 102 using a known pusher, etc. (not shown) and placed on the worktable 104 (for example, two workpieces W are placed side by side). Next, the workpieces W placed on the worktable 104 are held by the inloader 122 and transported to the press unit 100B.

[0033] Furthermore, the supply unit 100A (or any other unit) is equipped with a resin supply mechanism 140 that supplies resin R at a lateral position to the work table 104. For example, the resin supply mechanism 140 includes a supply section 142 that supplies resin R using a hopper, feeder, etc., and a transfer section 144 that has a transfer mechanism such as an elevator to hold multiple resins R supplied from the supply section 142 in a predetermined position. With this configuration, the multiple resins R held in the transfer section 144 are held by the in-loader 122 and transported to the press unit 100B.

[0034] (Press Unit) Next, we will describe the press unit 100B provided in the resin encapsulation device 1. Here, Figure 3 is a schematic front cross-sectional view of the encapsulation mold 202 of the resin encapsulation device 1.

[0035] The press unit 100B includes a press device 250 that clamps the workpiece W and seals it with resin by driving the sealing die 202, which will be described later, to open and close.

[0036] As shown in Figure 2, the press device 250 includes a sealing die 202 having an upper die 204 and a lower die 206 and disposed between a pair of platens 252 and 254, a plurality of connecting mechanisms 256 on which the pair of platens 252 and 254 are mounted, a drive source (e.g., an electric motor) 260 for moving (raising and lowering) the platen 254, and a drive transmission mechanism (e.g., a ball screw or a toggle link mechanism) 262. In this embodiment, the upper die 204 is assembled to the fixed platen 252, and the lower die 206 is assembled to the movable platen 254. However, the configuration is not limited to this, and the upper die 204 may be assembled to the movable platen and the lower die 206 to the fixed platen, or both the upper die 204 and the lower die 206 may be assembled to the movable platen (not shown).

[0037] Furthermore, the press unit 100B is equipped with a film supply mechanism 201 that transports (supplies) the roll-shaped film F into the sealing mold 202. As mentioned above, a configuration using strip-shaped film instead of roll-shaped film is also possible (not shown).

[0038] Next, the lower mold 206 of the sealing mold 202 will be described in detail. As shown in Figures 2 and 3, the lower mold 206 is constructed by assembling the lower mold mold base 212, the lower mold chase block 216, etc., and its upper surface is the mold surface 206a. As an example, the lower mold chase block 216 is fixed on the lower mold mold base 212, and the lower mold mold base 212 is fixed on the movable platen 254.

[0039] Here, the lower mold 206 is provided with multiple resin storage sections (in this embodiment, cylindrical pots 240 in which tablet-shaped resin R is stored) along the front-to-back direction, which serve as "predetermined positions" where the resin R is set (stored). (For example, four are given, but this is not limited to this, and there may be only one.) The pots 240 are formed as through holes that are continuous with the lower mold chase block 216 and the lower mold mold base 212. A plunger 242, which is pushed by a known transfer drive mechanism (not shown), is also disposed inside the pots 240. With this configuration, the plunger 242 is pushed, and the resin R inside the pots 240 is supplied into the cavity 208 (described later).

[0040] Furthermore, in this embodiment, a workpiece holding section 205 for holding one or more workpieces W is provided on the lower die chase block 216. More specifically, as shown in Figure 3, a set of workpiece holding sections 205 (first workpiece holding section 205A and second workpiece holding section 205B) is arranged in a predetermined set (one or more sets) in the front-to-back direction, sandwiching a predetermined number (one or more) of pots 240 in the left-to-right direction. As an example, this workpiece holding section 205 is equipped with a suction passage (not shown) that communicates with a suction device, and is configured to hold the workpiece W by suction. Alternatively, instead of, or in conjunction with, the configuration may be equipped with holding claws that grip the outer circumference of the workpiece W, or the workpiece W may simply be placed by inserting the hole of the workpiece W onto a pilot pin (not shown).

[0041] Furthermore, in this embodiment, a lower mold heating mechanism is provided to heat the lower mold 206 to a set temperature. This lower mold heating mechanism includes a lower mold heater 209, a temperature sensor (not shown), etc. (a tubular heater with a built-in temperature sensor may also be used), and the control unit 150 controls the heating so that the lower mold 206 reaches the set temperature. As an example, a known electric heating wire heater, sheath heater, etc., is used for the lower mold heater 209 and is arranged on the lower mold mold base 212. As a result, heat is conducted to the area around the workpiece holding section 205 and the resin storage section (pot 240) via the lower mold chase block 216, etc., and the workpiece W held in the workpiece holding section 205 and the resin R in the resin storage section (pot 240) can be heated to a set temperature (for example, 150°C to 200°C).

[0042] Next, the upper mold 204 of the sealing mold 202 will be described in detail. As shown in Figures 2 and 3, the upper mold 204 is constructed by assembling the upper mold base 210, the upper mold chase block 214, etc., and its lower surface is the mold surface 204a. As an example, the upper mold chase block 214 is fixed below the upper mold base 210, and the upper mold base 210 is fixed below the fixed platen 252.

[0043] Here, the upper mold 204 is provided with a cal block 244 on its lower surface, which has a cal 246 and (part of) a runner 248 drilled into it, at a position directly above the pot 240 of the lower mold 206 (here, referring to an area of ​​a predetermined width directly above it). A cavity 208 is also provided in which a predetermined part of the workpiece W (the part on which the electronic component Wb is mounted) is housed. Alternatively, the cal 246 and runner 248 in the upper mold 204 may be set to a "predetermined position (resin housing section)" where the resin R is housed (in this case, passed through or filled), and the control described later may be performed.

[0044] In this embodiment, the cavity 208 is arranged in a predetermined set (one or more sets) in the front-to-back direction, with a pair of cavities 208 (first cavity 208A and second cavity 208B) positioned to sandwich the calblock 244 in the left-to-right direction in a plan view, corresponding to the position where a pair of workpiece holding parts 205 (first workpiece holding part 205A and second workpiece holding part 205B) are arranged in a predetermined set (one or more sets) in the lower die 206.

[0045] Furthermore, in this embodiment, an upper mold heating mechanism is provided to heat the upper mold 204 to a set temperature. This upper mold heating mechanism includes an upper mold heater 207, a temperature sensor (not shown), etc. (a tubular heater with a built-in temperature sensor may also be used), and the control unit 150 controls the heating so that the upper mold 204 reaches the set temperature. As an example, a known electric heating wire heater, sheath heater, etc., is used for the upper mold heater 207 and is arranged on the upper mold mold base 210. As a result, heat is conducted around the cavity 208 and resin flow channels (cal 246, runner 248, etc.) via the upper mold chase block 214, etc., and the resin R in the cavity 208 and resin flow channels 246, 248 can be heated to a set temperature (for example, 150°C to 200°C).

[0046] Here, we will explain the temperature control of the sealing mold 202 performed by the control unit 150. In the following terms, the temperature of the sealing mold 202 set to the temperature at which the resin R is properly heat-cured during sealing (depending on the material and amount of resin R) is defined as the "normal set temperature." Furthermore, the temperature of the sealing mold 202 set to a predetermined temperature (described later) higher than the "normal set temperature" is defined as the "switching set temperature."

[0047] As a specific example of the above temperature control, the control unit 150 controls the temperature of the sealing mold 202 by changing the set temperature from the "normal set temperature" to the "switching set temperature" at a predetermined "start timing" during a unit process (1 cycle) in which the workpiece W and resin R are loaded into the sealing mold 202, sealed, and then discharged as a molded product Wp. Subsequently, at a predetermined "end timing", the control unit 150 controls the temperature of the sealing mold 202 by changing the set temperature from the "switching set temperature" to the "normal set temperature".

[0048] The "start timing" described above is, for example, set to the time (timing) when the resin R is set (contained) in the "predetermined position" of the sealing mold 202 (in this embodiment, the resin containment section (pot 240) of the lower mold 206). However, it is not limited to this, and instead of the above setting, or together with the above setting (i.e., separately), it may be set to the time (timing) when the resin R is contained (passed through or filled) in the resin containment section (cal 246, runner 248) of the upper mold 204.

[0049] Furthermore, the "completion timing" mentioned above is set, for example, to the point in time (timing) when the resin R reaches a predetermined thermally cured state (in this embodiment, the state after heating under pressure for a predetermined time). However, it is not limited to this.

[0050] Furthermore, the "predetermined temperature" mentioned above is set as a temperature selected from the range of 1°C to 20°C, for example. However, it is not limited to this range. The temperature is set appropriately depending on the material and quantity of the resin R, the size of the sealing mold 202, etc.

[0051] The configuration described above can solve the aforementioned problems. Specifically, when the molding operation for resin encapsulation is continued in an automatic operation at a fixed cycle, the surface temperature of the encapsulation mold 202 gradually decreases due to the influence of the temperature of the resin R being contained, making it impossible to secure the melting point temperature necessary for resin encapsulation, and thus solving the problem of molding defects (insufficient resin curing, incomplete filling, etc.).

[0052] Specifically, as described above, the system includes a configuration in which the temperature of the sealing mold 202 is controlled by changing the set temperature from the "normal set temperature" to the "switching set temperature" at the "start timing," and then controlled by changing the set temperature from the "switching set temperature" to the "normal set temperature" at a predetermined "end timing," and this process is repeated for each molding cycle. This makes it possible to prevent the surface temperature of the sealing mold 202 from gradually decreasing. Here, Figures 4 and 5 show the results of an experiment conducted by the inventors of the present invention to understand the temperature decrease trend when the molding cycle (1 cycle) is repeated at a fixed period. Figure 4 shows the results for the lower mold 206, and Figure 5 shows the results for the upper mold 204. In both figures, the solid line represents the result with the configuration of this embodiment, and the dashed line represents the result with the configuration of the conventional embodiment.

[0053] As clearly shown in the experimental results above, according to this embodiment, even when the molding operation is continued in automatic operation at a fixed cycle, it is possible to secure an appropriate melting point temperature corresponding to the resin R for resin sealing by the sealing mold 202, thereby suppressing molding defects due to insufficient temperature. Furthermore, since the occurrence of abnormalities that could cause the equipment to stop can be reduced, the operating rate can be improved. Moreover, regarding the application of this embodiment, the larger the amount of resin R used in a single sealing (molded product), the more effective this embodiment becomes.

[0054] Furthermore, compared to the apparatus exemplified in Patent Document 1 mentioned above, this embodiment does not require a temperature sensor to be provided on the upper chase block 214, thus simplifying the apparatus and reducing costs.

[0055] It should be noted that the above embodiment is merely an example. In another embodiment, the "start timing" in the upper mold 204 may be set as the "first start timing," and the "start timing" in the lower mold 206 may be set as the "second start timing," each at a different point in time (timing). Alternatively, the "end timing" in the upper mold 204 may be set as the "first end timing," and the "end timing" in the lower mold 206 may be set as the "second end timing," each at a different point in time (timing). As a specific example, a configuration in which the time from the "first start timing" to the "first end timing" is set to be longer than the time from the "second start timing" to the "second end timing" can be considered.

[0056] In yet another embodiment, the "switchable setting temperature" may be set to different temperatures, with the setting temperature in the upper mold 204 being the "first switchable setting temperature" and the setting temperature in the lower mold 206 being the "second switchable setting temperature". As a specific example, a configuration in which the "first switchable setting temperature" is set to a higher temperature than the "second switchable setting temperature" is conceivable.

[0057] Research by the inventors of this application has revealed that, for example, when a molding operation for resin sealing is continuously performed in an automatic operation at a fixed cycle using a configuration in which a cal block 244 having cals 246 and runner 248 is provided in the upper mold 204, a significant temperature drop may occur in the upper mold 204 during the molding cycle (1 cycle) compared with the lower mold 206 (see Figures 4 and 5). This problem can be solved by making it possible to suppress the temperature drop in the upper mold 204 more effectively than in the lower mold 206 in any of the above embodiments. Upon consideration, it is thought that after mold clamping, the resin (tablet) R comes into contact with the cals 246 of the upper mold 204 and melts, and is pressurized by the plunger 242, causing the temperature of the upper mold 204 to drop more than that of the lower mold 206 due to the flow of the resin R. Furthermore, it is possible to adjust the surface temperature of the sealing mold 202 in both the upper mold 204 and the lower mold 206 to a temperature more suitable for molding, thereby further improving the molding quality. Furthermore, in the case of large resin (tablets) R, if you want to put the resin R into the pot 240 and pressurize it with the plunger 242 after it has melted sufficiently, you can set the temperature of the lower mold 206 higher than that of the upper mold 204, or you can set the upper and lower molds to the same temperature.

[0058] Next, another embodiment relating to the configuration of the sealing mold 202 will be described. In the above embodiment, the cavity 208 was provided in the upper mold 204, but it may also be provided in the lower mold 206, or it may be provided in both the upper mold 204 and the lower mold 206. In this case, since the pot 240 is provided in the lower mold 206, a configuration in which a runner is connected from the cal 246 of the upper mold 204 to the lower mold 206 can be adopted. Alternatively, if the workpiece is a lead frame or the like, a configuration in which resin is passed vertically through a hole that penetrates the workpiece vertically can be adopted (neither of which is shown).

[0059] (Storage unit) Next, we will describe the storage unit 100C provided by the resin encapsulation device 1.

[0060] The storage unit 100C includes, as an example, a molded product table 114 on which molded products Wp are placed, a gate break section 116 for removing unwanted resin parts such as the cal portion, runner portion, and gate portion from the molded product Wp, and a molded product stocker 112 used for storing the molded product Wp from which the unwanted resin parts have been removed. The molded product stocker 112 uses a known stack magazine, slit magazine, etc., and is capable of storing multiple molded products Wp at once. With this configuration, molded products Wp (connected via unwanted resin parts) transported from the press unit 100B using an outloader 124, etc., are placed on the molded product table 114. Next, they are transferred to the gate break section 116 using a known pickup, etc. (not shown) to remove the unwanted resin parts, and then stored in the molded product stocker 112 using a known pusher, etc. (not shown).

[0061] (Resin encapsulation process) Next, the operation of performing resin sealing using the resin sealing apparatus 1 according to this embodiment (i.e., the resin sealing method according to this embodiment) will be described. Here, we will take as an example a configuration in which a single upper mold 204 is provided with multiple sets (or even just one set) of cavities 208, and a corresponding single lower mold 206 is provided with multiple sets (or even just one set) of workpiece holding sections 205, and workpieces W (for example, strip-shaped workpieces) are placed in the workpiece holding sections 205 to perform resin sealing all at once and obtain multiple molded products Wp simultaneously. However, the configuration is not limited to this.

[0062] As a preparation step, a heating step (upper mold heating step) is performed in which the upper mold 204 is heated by the upper mold heater 207 to a set temperature (for example, 150°C to 200°C). In addition, a heating step (lower mold heating step) is performed in which the lower mold 206 is heated by the lower mold heater 209 to a set temperature (for example, 150°C to 200°C). Furthermore, a film supply step (film supply step) is performed in which the film F is transported (fed out) by the film supply mechanism 201 and supplied to a predetermined position in the sealing mold 202 (a position between the upper mold 204 and the lower mold 206).

[0063] Next, a known pusher or the like (not shown) is used to unload the workpieces W one by one from the workpiece stocker 102 and place them on the upper surface of the work table 104 (a known pickup mechanism or the like may also be used in combination). Furthermore, a known feeder, elevator or the like (not shown) is used to unload the tablet-shaped resin R one by one from the supply unit 142 and hold multiple (for example, four) of the resin R at predetermined positions on the transfer unit 144.

[0064] Next, the inloader 122 is moved to directly above the worktable 104 (it may be waiting in the same position beforehand). At that position, the worktable 104 is raised (or the inloader 122 is lowered), and the workpieces W are held by the workpiece holding units 122A and 122B (in this embodiment, the workpiece holding units 122A and 122B each hold one workpiece W).

[0065] Next, the in-loader 122 is moved directly above the transfer section 144. At that position, the transfer section 144 is raised (or the in-loader 122 is lowered), and the resin R is held by the resin holding section 122C (in this embodiment, the resin holding section 122C holds four resins R).

[0066] Next, the inloader 122 transports multiple (two in this embodiment) workpieces W and multiple (four in this embodiment) resins R into the sealing mold 202 of the press unit 100B in a single process, and performs the steps of placing the workpieces W into each workpiece holding section 205 (workpiece holding sections 205A, 205B in this embodiment) of the lower mold 206, and storing the resins R into multiple (four in this embodiment) resin storage sections (pots 240) of the lower mold 206. During transport, a preheating step (preheating step) may be performed using a heater (not shown) provided on the inloader 122.

[0067] Next, the sealing mold 202 is closed, and the workpiece W is clamped between the upper mold 204 and the lower mold 206 to form a molded product Wp (resin sealing process).

[0068] In this embodiment, during a unit process (1 cycle) in which the workpiece W and resin R are loaded into the sealing mold 202, sealed, and then discharged as a molded product Wp, the temperature of the sealing mold 202 is controlled by changing the set temperature from the "normal set temperature" to the "switching set temperature" at a predetermined "start timing". Subsequently, the temperature of the sealing mold 202 is controlled by changing the set temperature from the "switching set temperature" to the "normal set temperature" at a predetermined "end timing". The settings for "normal set temperature" and "switching set temperature", as well as "start timing" and "end timing", are as described above and will not be repeated.

[0069] As described above, by heating and pressurizing the resin R over the workpiece W, the resin R heat-cures and resin sealing (compression molding) is performed to form the molded product Wp.

[0070] Next, the sealing mold 202 is opened, and the outloader 124 performs a process to remove multiple molded products Wp (including unnecessary resin parts such as the cal portion and runner portion, and connected via them) from the sealing mold 202 in a single step.

[0071] In parallel with (or afterward), the film supply mechanism 201 transports the film F, thereby performing a process to discharge the used film F.

[0072] Next, the outloader 124 performs the step of placing the molded product Wp (including the calf section, runner section, etc.) onto the molded product table 114 (a known pickup mechanism may also be used in combination). Next, the gate break section 116 performs the step of removing unnecessary resin parts such as the calf section and runner section from the molded product Wp. Next, a known pusher or the like (not shown) performs the step of loading the molded product Wp (with the unnecessary resin parts removed) one by one into the molded product stocker 112. Before these steps, a post-curing step of the molded product Wp may be performed.

[0073] The above describes the main operations of resin encapsulation using the resin encapsulation apparatus 1. However, the above process sequence is just one example, and the order can be changed or the operations performed in parallel as long as there are no obstacles. For example, in this embodiment, since the configuration includes two press units 100B, efficient molded product formation is possible by performing the above operations in parallel.

[0074] As described above, the resin encapsulation apparatus and resin encapsulation method according to the present invention make it possible to prevent the surface temperature of the encapsulation mold from gradually decreasing when the molding operation is continued in automatic operation at a fixed cycle, without requiring a complex apparatus structure or complex implementation process. Therefore, it is possible to ensure an appropriate melting point temperature in the encapsulation mold when performing resin encapsulation, thereby suppressing molding defects due to insufficient temperature. In addition, it is possible to reduce the occurrence of abnormalities that could cause the apparatus to stop, thereby improving the operating rate.

[0075] Furthermore, the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the present invention. Specifically, although the above embodiments were described using a transfer molding method as an example, the invention is not limited thereto, and can also be applied to a compression molding method. For example, in the case of a compression molding apparatus equipped with a sealing mold having a cavity in the lower mold, a configuration can be adopted in which the resin is set (contained) in the cavity directly or via a film. Therefore, the above embodiments can be applied with the cavity as the "predetermined position" where the resin is set. On the other hand, in the case of a compression molding apparatus equipped with a sealing mold having a cavity in the upper mold, as an example, a configuration can be adopted in which the workpiece is held in the workpiece holding part of the lower mold with the resin placed on it, and then the resin on the workpiece is set (contained) in the cavity directly or via a film by closing the mold. Therefore, the above embodiments can be applied with the workpiece holding part or the cavity as the "predetermined position" where the resin is set. Alternatively, as another example, a configuration can be adopted in which the resin placed on the resin loader is pressed and adhered to the bottom of the cavity, either directly or via a film, thereby setting (containing) it within the cavity. Therefore, the above embodiment can be applied to the cavity as a "predetermined position" where the resin is set. [Explanation of Symbols]

[0076] 1. Resin encapsulation device 202 Sealing mold 204 Upper mold 206 Lower mold R Sealing resin Double job

Claims

1. A resin encapsulation method for processing a workpiece into a molded product by encapsulating it with resin using an encapsulation die comprising an upper mold and a lower mold, The temperature of the sealing mold, which is set to a temperature at which the resin is properly heat-cured during sealing, is set as the normal setting temperature, and the temperature of the sealing mold, which is set to a predetermined temperature higher than the normal setting temperature, is set as the switching setting temperature. During a unit process in which the workpiece and the resin are loaded into the sealing mold and sealed, and then the molded product is discharged, the temperature of the sealing mold is controlled by changing the set temperature of at least one of the upper mold and the lower mold from the normal set temperature to the switching set temperature at a predetermined start timing, and by changing the set temperature from the switching set temperature to the normal set temperature at a predetermined end timing. The aforementioned termination timing is before the workpiece and the resin in the next unit process are transported to the sealing mold. The aforementioned normal setting temperature is a temperature equal to or greater than the melting temperature of the resin. A resin encapsulation method characterized by the following.

2. The start timing is set to the point in time when the resin is set in a predetermined position in the sealing mold. The resin encapsulation method according to claim 1, characterized by the above.

3. The predetermined temperature is set to a temperature selected from the range of 1°C to 20°C. The resin encapsulation method according to claim 1, characterized by the above.

4. The switching temperature is configured such that the temperature set in the upper mold is set as the first switching temperature, and the temperature set in the lower mold is set as the second switching temperature. The first switching setting temperature is set to a temperature higher than the second switching setting temperature. The resin encapsulation method according to claim 1, characterized by the above.

5. The aforementioned start timing is configured such that the setting timing in the upper mold is set as the first start timing, and the setting timing in the lower mold is set as the second start timing. The aforementioned termination timing is configured such that the setting timing in the upper mold is set as the first termination timing, and the setting timing in the lower mold is set as the second termination timing. The time from the first start timing to the first end timing is set to be longer than the time from the second start timing to the second end timing. The resin encapsulation method according to claim 1, characterized by the above.

6. A resin sealing apparatus that uses a sealing die comprising an upper mold and a lower mold to process a workpiece into a molded product by sealing it with resin, The system includes a control unit that controls the temperature of the sealing mold, The control unit, The temperature of the sealing mold, which is set to a temperature at which the resin is properly heat-cured during sealing, is set as the normal setting temperature, and the temperature of the sealing mold, which is set to a predetermined temperature higher than the normal setting temperature, is set as the switching setting temperature. During a unit process in which the workpiece and the resin are loaded into the sealing mold and sealed, and then the molded product is discharged, the temperature of the sealing mold is controlled by changing the set temperature of at least one of the upper mold and the lower mold from the normal set temperature to the switching set temperature at a predetermined start timing, and by changing the set temperature from the switching set temperature to the normal set temperature at a predetermined end timing. The termination timing is controlled to occur before the workpiece and resin are transported to the sealing mold in the next unit process. The aforementioned normal setting temperature is set to a temperature equal to or higher than the melting temperature of the resin. A resin encapsulation device characterized by the following.

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