Molding die, resin molding device, and method for manufacturing resin molded article

Abstract

Provided is a molding die capable of reducing the amount of resin used and improving moldability.　This molding die is used for transfer molding, and comprises an upper die, a lower die disposed below the upper die, and an intermediate die disposed between the upper die and the lower die. The molding die is formed with: a cavity which is formed from the upper surface of the lower die and the lower surface of the intermediate die, and has a shape that corresponds to a resin molded article; a runner portion which is formed from the upper surface of the intermediate die and the lower surface of the upper die, and guides a resin material to the upper part of the cavity; and a gate portion which is formed in the intermediate die and guides the resin material from the runner portion to the cavity, the upper surface of the intermediate die being formed with an intermediate-die groove which forms the runner portion. The present invention also provides a resin molding device and a method for manufacturing a resin molded article.

Description

Mold, resin molding device, and method for manufacturing resin molded product

[0001] The present invention relates to a molding die, a resin molding device, and a method for manufacturing a resin molded product.

[0002] Patent Document 1 discloses a molding die for top-gate transfer molding. In the technology described in Patent Document 1, the molding die is composed of an upper die, a lower die, and an intermediate die disposed between the upper and lower dies. A runner portion for guiding the resin material is formed in the upper die, and a cavity is formed between the lower die and the intermediate die. The intermediate die also has a gate portion for guiding the resin material from the runner portion to the cavity. By using a molding die configured in this manner, the resin material can be supplied from a direction perpendicular to the lead frame, which is the object to be molded.

[0003] JP 2009-196230 A

[0004] In the top-gate transfer molding mold described in Patent Document 1, the heights of the loader for loading the resin material and lead frame into the mold and the unloader for unloading the resin-encapsulated lead frame from the mold are fixed, making it difficult to change the thickness of the intermediate mold. Therefore, if a runner portion is formed only in the top mold as in Patent Document 1, the length of the gate portion formed in the intermediate mold becomes long, and the flow length (length of the flow path) of the resin material becomes relatively long. This leaves room for improvement in terms of the increased amount of resin required for resin molding.

[0005] Furthermore, in the molding die described in Patent Document 1, the flow length of the resin material is long, and therefore, the heat of the molding die maintained at a high temperature may cause the resin material flowing through the distribution channel to thermally harden, which may result in a decrease in moldability, leaving room for improvement.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and the problem it aims to solve is to provide a molding die, a resin molding device, and a method for manufacturing a resin molded product that are capable of reducing the amount of resin and improving moldability.

[0007] The problem that the present invention aims to solve is as described above, and in order to solve this problem, the molding die of the present invention is a molding die used for transfer molding, comprising an upper die, a lower die arranged below the upper die, and an intermediate die arranged between the upper die and the lower die, wherein the molding die is formed with a cavity formed by the upper surface of the lower die and the lower surface of the intermediate die and having a shape corresponding to the resin molded product, a runner portion formed by the upper surface of the intermediate die and the lower surface of the upper die and which guides resin material to above the cavity, and a gate portion formed in the intermediate die and which guides resin material from the runner portion to the cavity, and the upper surface of the intermediate die is formed with an intermediate die side groove portion which forms the runner portion.

[0008] A resin molding apparatus according to the present invention includes the molding die and a mold clamping mechanism capable of clamping the molding die.

[0009] In addition, the method for manufacturing a resin molded product according to the present invention is a method for manufacturing a resin molded product using the resin molding apparatus, and includes the steps of clamping the molding mold to mold resin, opening the molding mold to remove unnecessary resin parts held in the upper mold, and opening the molding mold to remove the resin molded product.

[0010] According to the present invention, it is possible to reduce the amount of resin and improve moldability.

[0011] 7 is a schematic plan view showing the overall configuration of the resin molding apparatus according to the first embodiment. FIG. 1 is a front cross-sectional view showing a molding mechanism according to the first embodiment. (a) A front view showing a holding pin. (b) A front cross-sectional view showing how the holding pin holds the unnecessary resin portion. (c) A front cross-sectional view showing how the holding pin releases the unnecessary resin portion. FIG. 1 is a front cross-sectional view showing a molding mechanism that forms a resin molded product and an unnecessary resin portion. FIG. 1 is a front cross-sectional view showing a molding mechanism in a state where the upper mold and the intermediate mold are separated. FIG. 2 is a front cross-sectional view showing a molding mechanism in a state where the lower mold and the intermediate mold are separated. (a) A front cross-sectional view showing a runner portion and a gate portion. (b) A plan view showing the intermediate mold. (a) A cross-sectional view taken along X1-X1 in FIG. 7. (b) A cross-sectional view taken along X2-X2 in FIG. 7. (a) A front cross-sectional view showing a runner portion and a gate portion according to a second embodiment. (b) A plan view showing the intermediate mold according to the second embodiment.

[0012] In the following explanation, the directions indicated by arrows U, D, L, R, F, and B in the figure will be defined as upward, downward, leftward, rightward, forward, and backward, respectively.

[0013] <Overall Configuration of Resin Molding Apparatus 1> First, the configuration of a resin molding apparatus 1 according to a first embodiment will be described with reference to Fig. 1. The resin molding apparatus 1 seals electronic elements such as semiconductor chips with resin to manufacture resin molded products. In particular, this embodiment illustrates a resin molding apparatus 1 that performs resin molding (transfer molding) using a transfer molding method.

[0014] The resin molding apparatus 1 includes, as its components, a supply module 10, a resin molding module 20, and an unloading module 30. Each component is detachable and replaceable with respect to the other components.

[0015] <Supply Module 10> The supply module 10 supplies lead frames 2, which are a type of substrate with chips mounted thereon, and resin tablets T to the resin molding module 20. In this embodiment, the lead frames 2 are used as an example of a substrate, but various other substrates (glass epoxy substrates, ceramic substrates, resin substrates, metal substrates, etc.) can also be used. The supply module 10 mainly includes a frame sending unit 11, a frame supply unit 13, a resin material supply mechanism 14, and a control unit 18.

[0016] The frame sending section 11 sends out the lead frames 2 that are not sealed with resin and are housed in an in-magazine unit (not shown) to the frame supplying section 13. The frame supplying section 13 receives the lead frames 2 from the frame sending section 11, aligns the received lead frames 2 appropriately, and passes them to the loader 17.

[0017] The resin material supply mechanism 14 supplies the resin tablets T to a loader 17 (described later). The resin material supply mechanism 14 can align a plurality of resin tablets T and deliver them to the loader 17.

[0018] The control unit 18 controls the operation of each module of the resin molding apparatus 1. The control unit 18 controls the operations of the supply module 10, the resin molding module 20, and the carry-out module 30. The control unit 18 can also be used to arbitrarily change (adjust) the operation of each module.

[0019] In this embodiment, an example is shown in which the control unit 18 is provided in the supply module 10, but the control unit 18 can also be provided in other modules. It is also possible to provide multiple control units 18. For example, it is possible to provide a control unit 18 for each module or device, and to control the operations of each module individually while linking them together.

[0020] <Resin molding module 20> The resin molding module 20 resin-seals the chips mounted on the lead frame 2. In this embodiment, two resin molding modules 20 are arranged side by side. The number of resin molding modules 20 may be one, or three or more. By using multiple resin molding modules 20 to resin-seal the lead frame 2 in parallel, the manufacturing efficiency of resin molded products can be improved. The resin molding module 20 mainly includes a molding mechanism 100.

[0021] The molding mechanism 100 mainly comprises molding dies (an upper die 110 , a lower die 120 , and an intermediate die 130 ) and a die clamping mechanism 160 .

[0022] The molding dies (upper die 110, lower die 120, and intermediate die 130) use molten resin material to resin-encapsulate the chip mounted on the lead frame 2. The molding dies include a plurality of dies arranged vertically, namely, the upper die 110, lower die 120, and intermediate die 130 (see FIG. 2, etc.).

[0023] The mold clamping mechanism 160 clamps and opens the molding dies (upper die 110, lower die 120, and intermediate die 130) by moving the lower die 120 up and down. The specific configuration of the molding mechanism 100 will be described later.

[0024] <Unloading module 30> The unloading module 30 receives and unloads the resin-sealed lead frame 2 from the resin molding module 20. The unloading module 30 mainly includes a substrate accommodating section 32. The substrate accommodating section 32 accommodates the resin-sealed lead frame 2.

[0025] <Loader 17> The supply module 10 and the resin molding module 20 are provided with a loader 17. The loader 17 transports the lead frames 2 and resin tablets T received from the frame supply unit 13 and the resin material supply mechanism 14 to the resin molding module 20. The loader 17 can move within the supply module 10 and the resin molding module 20 along rails (not shown).

[0026] <Unloader 31> The resin molding module 20 and the carry-out module 30 are provided with an unloader 31. The unloader 31 holds the resin-sealed lead frame 2 and carries it out to the substrate accommodating section 32. The unloader 31 can move within the resin molding module 20 and the carry-out module 30 along rails (not shown).

[0027] <Manufacturing Method of Resin Molded Product> The following describes a manufacturing method of a resin molded product using the resin molding apparatus 1 configured as described above. The control unit 18 controls the operation of each unit of the resin molding apparatus 1 to manufacture the resin molded product.

[0028] First, two lead frames 2 before resin sealing are sent out by the frame sending section 11 of the supply module 10 to the frame supply section 13. The frame supply section 13 aligns the two lead frames 2 received from the frame sending section 11.

[0029] Next, the loader 17 holds two lead frames 2 from the frame supply unit 13 and multiple resin tablets T from the resin material supply mechanism 14. The loader 17 transports the held lead frames 2 and resin tablets T to the lower mold 120 of the resin molding module 20. The loader 17 places the lead frames 2 on the lower mold 120 and places the resin tablets T in the pots 122a (see FIG. 2) of the lower mold 120. The resin tablets T are thermosetting resins. When the resin tablets T are heated, the temperature of the resin tablets T rises. As a result, the resin tablets T become a molten resin material once and then harden.

[0030] Next, the lower mold 120 is raised by the mold clamping mechanism 160, and the molding die is clamped. In this state, the resin tablet T contained in the pot 122a is heated, and the plunger 124 (described later) injects the molten resin material, filling the cavity of the molding die. After a certain time (cure time), the resin material hardens, and the electronic elements fixed to the lead frame 2 are resin-encapsulated, thereby obtaining a resin molded product (resin-encapsulated lead frame 2).

[0031] Next, the lower mold 120 is lowered by the mold clamping mechanism 160, and the molding mold is opened. Thereafter, the unloader 31 carries out the resin-sealed lead frame 2 from the resin molding module 20. Details of the method for carrying out the resin-molded product (resin-sealed lead frame 2) from the molding mold will be described later.

[0032] Next, the unloader 31 transfers the resin-sealed lead frame 2 to the carry-out module 30. The unloader 31 accommodates the resin-sealed lead frame 2 in the substrate accommodation section 32.

[0033] <Configuration of Forming Mechanism 100> Next, the configuration of the forming mechanism 100 will be described in more detail with reference to Figs. 1 to 4 .

[0034] The molding mechanism 100 shown in FIG. 2 mainly comprises an upper mold 110, a lower mold 120, an intermediate mold 130, a fixed platen 140, a movable platen 150, a mold clamping mechanism 160, and the like.

[0035] The upper mold 110 forms the upper portion of the mold. The upper mold 110 is fixed to the underside of a stationary platen 140, which is fixed to tie bars (not shown). This supports the upper mold 110 in an immovable state. Note that the member for fixing the stationary platen 140 is not limited to tie bars (not shown), and may be a plate-shaped hold frame. In this case, in FIG. 1 , one hold frame is disposed on the left side of the lower mold 120, and another hold frame is disposed on the right side of the lower mold 120. The upper mold 110 mainly comprises an upper mold block 111, a holding pin 112, etc.

[0036] The upper block 111 forms a cull portion and a runner portion between it and the intermediate block 130 to guide the resin material. The cull portion and the runner portion are passages through which the molten resin material flows. The upper block 111 is formed in a substantially rectangular parallelepiped shape. A protrusion 111a and an upper mold groove portion 111b are formed on the lower surface of the upper block 111.

[0037] The protruding portion 111a is a portion that protrudes downward from the lower surface of the upper die block 111. The protruding portion 111a is formed at a position that faces the pot 122a of the lower die 120 in the vertical direction.

[0038] The upper die groove 111b, together with the intermediate die groove 133 formed in the intermediate die 130, forms a runner for guiding the resin material. The upper die groove 111b is one embodiment of a runner according to the present invention. The upper die groove 111b is formed to extend horizontally from above the pot block 122 (pot 122a) of the lower die 120. The upper die groove 111b is formed to extend appropriately in a direction according to the shape of the resin molded product.

[0039] The retaining pin 112 holds the unnecessary resin portion UR (runner, gate, etc.) formed by resin molding against the upper mold 110. The retaining pin 112 is one embodiment of a retaining member according to the present invention. The retaining pin 112 is formed in a substantially cylindrical shape. The retaining pin 112 is arranged with its longitudinal direction facing up and down. The retaining pin 112 is arranged so as to penetrate the upper mold block 111 from top to bottom and to be movable up and down relative to the upper mold block 111. The upper end of the retaining pin 112 is connected to the mold clamping mechanism 160 via a connecting mechanism (not shown) and can be moved up and down by the power of the mold clamping mechanism 160. As shown in FIG. 3( a), a notch 112a is formed in the lower end of the retaining pin 112.

[0040] The cutout portion 112a is formed by cutting out a portion of the lower end of the holding pin 112. In the illustrated example, the cutout portion 112a is formed by cutting out the left portion of the lower end of the holding pin 112. The cutout portion 112a includes an inclined surface 112b that slopes leftward as it extends downward. This forms a portion at the lower end of the holding pin 112 whose width increases from side to side as it extends downward.

[0041] The lower end of the retaining pin 112 is positioned so as to be exposed to the upper die groove portion 111b. Specifically, when the retaining pin 112 is positioned in a raised position relative to the upper die block 111, the lower end surface of the retaining pin 112 is positioned so as to be flush with the upper surface of the upper die groove portion 111b (see FIG. 3(b)). When the retaining pin 112 is positioned in a lowered position relative to the upper die block 111, the lower end of the retaining pin 112 is positioned so as to protrude downward from the upper surface of the upper die groove portion 111b (see FIG. 3(c)). The retaining pin 112 is positioned at least directly above the gate portion 134 formed in the intermediate die 130. Note that the example shown in FIG. 2 illustrates an example in which the retaining pin 112 is positioned in a position other than directly above the gate portion 134. The gate portion 134 is a passage through which the molten resin material flows.

[0042] The lower mold 120 shown in Figure 2 forms the lower part of the mold. The lower mold 120 is fixed to the upper surface of the movable platen 150. This allows the lower mold 120 to move up and down as the movable platen 150 moves up and down. The lower mold 120 mainly includes a lower mold block 121, a pot block 122, a lower block 123, a plunger 124, an ejector pin 125, an ejector plate 126, a movable shaft 127, a spring 128, an ejector rod 129, etc.

[0043] The lower die block 121 forms a cavity between itself and the intermediate die 130. The lower die block 121 is formed in a roughly rectangular parallelepiped shape. Two lower die blocks 121 are arranged side by side on the left and right sides of the pot block 122. A concave lower die cavity portion 121a is formed on the upper surface of the lower die block 121.

[0044] The lower die cavity portion 121a is formed in a shape corresponding to the resin sealing portion R of the resin molded product (see FIG. 4, etc.) A plurality of lower die cavities 121a are formed so as to be aligned in the left-right direction and the front-rear direction.

[0045] The pot block 122 is a portion capable of accommodating the resin tablet T. The pot block 122 is formed in a substantially rectangular parallelepiped shape. The pot block 122 is disposed between the left and right lower mold blocks 121. A pot 122a is formed in the pot block 122 so as to penetrate the pot block 122 from top to bottom. The diameter of the pot 122a is formed to a size capable of accommodating the substantially cylindrical resin tablet T.

[0046] The lower block 123 holds the lower die block 121 and the pot block 122. The lower die block 121 and the lower part of the pot block 122 are fixed to the upper part of the lower block 123. The lower block 123 is formed with a first receiving portion 123a and a second receiving portion 123b.

[0047] The first accommodating portion 123a is a portion that accommodates the ejector plate 126 etc. The first accommodating portion 123a is formed below the lower die block 121 and the pot block 122.

[0048] The second receiving portion 123b is a portion that receives the spring 128, etc. The second receiving portion 123b is formed below the first receiving portion 123a. The second receiving portions 123b are formed near both left and right ends of the lower block 123.

[0049] The plunger 124 injects the resin tablet T contained in the pot 122a and supplies it to the aforementioned cavity. The plunger 124 is arranged so as to be movable up and down within the pot 122a. The plunger 124 can move up and down by the driving force of a plunger driving unit 124a provided below the plunger 124. The plunger driving unit 124a can be formed, for example, by a servo motor, an air cylinder, or the like.

[0050] The ejector pin 125 is used to release the resin-sealed lead frame 2 from the lower mold 120. The ejector pin 125 is formed in a substantially cylindrical shape. The ejector pin 125 is arranged with its longitudinal direction facing up and down. The ejector pin 125 is arranged so as to penetrate the lower mold block 121 from top to bottom and to be movable up and down relative to the lower mold block 121. The upper end of the ejector pin 125 is arranged so as to be exposed to the lower mold cavity portion 121a.

[0051] The ejector plate 126 connects the multiple ejector pins 125. The ejector plate 126 is formed in a flat plate shape. The ejector plate 126 is accommodated in the first accommodation portion 123a of the lower block 123. The ejector plate 126 connects the lower portions of the multiple ejector pins 125 provided in the lower block 121. The ejector plate 126 is provided to span the left and right lower block 121. For convenience, FIG. 2 illustrates the ejector plate 126 as being separated into left and right halves, but in reality, the ejector plate 126 is formed as a single unit. An opening is provided in the ejector plate 126 at a portion through which the plunger 124 and plunger drive portion 124a pass. The ejector plate 126 is supported by an appropriate guide member (not shown) so as to be movable up and down.

[0052] The movable shaft 127 is used to raise and lower the ejector plate 126. The movable shaft 127 passes vertically through the lower part of the lower block 123 (the partition wall between the first housing portion 123a and the second housing portion 123b) and is arranged so as to be movable vertically relative to the lower block 123. The upper part of the movable shaft 127 is connected to the ejector plate 126 via a connecting portion 127a.

[0053] The spring 128 applies a downward force to the movable shaft 127. The spring 128 is accommodated in the second accommodation portion 123b. The spring 128 can apply a downward force to a flange portion formed on the lower end portion of the movable shaft 127.

[0054] The ejector rod 129 is used to move the movable shaft 127 upward relative to the lower block 123. The ejector rod 129 is disposed below the lower block 123. More specifically, the ejector rods 129 are disposed below the second housing portions 123b formed in the lower block 123. The ejector rods 129 are appropriately fixed so as to be unable to move up and down. When the lower block 123 descends, the ejector rod 129 enters the second housing portion 123b and can push up the movable shaft 127 from below. When the movable shaft 127 is pushed up by the ejector rod 129, the ejector pin 125 rises relative to the lower mold 120.

[0055] The intermediate mold 130 forms the vertical center portion of the molding die. The intermediate mold 130 is disposed between the upper mold 110 and the lower mold 120 in the vertical direction. The intermediate mold 130 is formed in a substantially rectangular parallelepiped shape. The intermediate mold 130 has an opening 131, an intermediate mold cavity portion 132, an intermediate mold side groove portion 133, and a gate portion 134 formed therein.

[0056] The opening 131, together with the protrusion 111a formed on the upper mold 110, forms a cull portion for guiding the resin material. The opening 131 is formed so as to penetrate the intermediate mold 130 from top to bottom. The opening 131 is formed at a position that faces the pot 122a of the lower mold 120 and the protrusion 111a of the upper mold 110 from top to bottom. When the intermediate mold 130 is positioned so as to contact the lower surface of the upper mold 110, a predetermined gap is formed between the protrusion 111a of the upper mold 110 and the opening 131, thereby forming a cull portion for guiding the resin material.

[0057] The intermediate mold cavity portion 132 is formed on the lower surface of the intermediate mold 130. The intermediate mold cavity portion 132 is formed in a shape corresponding to the resin sealing portion R of the resin molded product (see FIG. 4, etc.). The intermediate mold cavity portion 132 is formed in a position facing the lower mold cavity portion 121a in the vertical direction. When the molding dies (upper mold 110, lower mold 120, and intermediate mold 130) are clamped, the lower mold cavity portion 121a and the intermediate mold cavity portion 132 form a cavity for resin molding.

[0058] The intermediate mold groove 133, together with the upper mold groove 111b formed in the upper mold 110, forms a runner for guiding the resin material. The intermediate mold groove 133 is one embodiment of a runner according to the present invention. The intermediate mold groove 133 is formed on the upper surface of the intermediate mold 130. The intermediate mold groove 133 is formed to extend horizontally from the opening 131 (above the pot 122a). The intermediate mold groove 133 is formed to extend appropriately in a direction according to the shape of the resin molded product. The intermediate mold groove 133 is formed to face the upper mold groove 111b in the vertical direction.

[0059] The gate portion 134 guides the resin material from the runner portion (the upper mold groove portion 111b and the intermediate mold groove portion 133) to the cavity (the lower mold cavity portion 121a and the intermediate mold cavity portion 132). The gate portion 134 is formed to extend from the cavity to the runner portion vertically above. The detailed shapes of the runner portion and the gate portion 134 will be described later.

[0060] The intermediate mold 130 can be held by either the upper mold 110 or the lower mold 120. For example, the upper mold 110 and the lower mold 120 are each provided with a holding claw (not shown) capable of holding the intermediate mold 130. By holding the intermediate mold 130 with the holding claws of either the upper mold 110 or the lower mold 120, the intermediate mold 130 can be held by the upper mold 110 or the lower mold 120. This allows the intermediate mold 130 to be held in a state where it is suspended from the upper mold 110 or placed on the lower mold 120 when the lower mold 120 is lowered.

[0061] The mold clamping mechanism 160 moves the movable platen 150 in the vertical direction to clamp and open the molding die. The mold clamping mechanism 160 is formed by a drive source such as a servo motor and an appropriate power transmission mechanism. The upper part of the mold clamping mechanism 160 is connected to the movable platen 150. By driving the mold clamping mechanism 160, the lower mold 120 can be moved (raised and lowered) in the vertical direction as desired via the movable platen 150. For example, the mold can be clamped by raising the lower mold 120 toward the upper mold 110 using the mold clamping mechanism 160. Furthermore, the mold can be opened by lowering the lower mold 120 in a direction away from the upper mold 110 using the mold clamping mechanism 160.

[0062] <Method for removing a resin molded product> Next, a method for removing a resin molded product from a molding die in the molding mechanism 100 configured as described above will be described with reference to Figures 2 to 6. Note that, for the sake of simplicity, some of the components of the molding mechanism 100 shown in Figure 2 are omitted from Figures 4 to 6 as appropriate.

[0063] As shown in Figure 2, the upper mold 110, lower mold 120, and intermediate mold 130 are clamped together, and the lead frame 2 before resin encapsulation is placed between the lower mold 120 and the intermediate mold 130. In this state, the resin tablet T contained in the pot 122a is melted. The molten resin material is pushed up by the plunger 124 and filled into the cavity through the cull portion, runner portion, and gate portion 134. After a certain period of time (cure time), the resin material hardens, encapsulating the electronic elements fixed to the lead frame 2, and a resin molded product (resin-encapsulated lead frame 2) (see Figure 4) can be obtained.

[0064] Furthermore, in the aforementioned cull portion, runner portion, and gate portion 134, as the resin material hardens, unnecessary resin portions (cull, runner, and gate) that do not become part of the product are formed. In this embodiment, these are collectively referred to as unnecessary resin portions UR. As shown in FIG. 3B, the unnecessary resin portions UR (runners) are hardened while entering the notches 112a of the retaining pins 112.

[0065] 5, the lower mold 120 is lowered, and the mold is opened. At this time, the intermediate mold 130 is held to the lower mold 120 by a holding claw (not shown). Therefore, the intermediate mold 130 is also lowered together with the lower mold 120, and the intermediate mold 130 and the upper mold 110 are separated.

[0066] Furthermore, since the unnecessary resin part UR has hardened while entering the notch 112a of the holding pin 112 (see FIG. 3B), the unnecessary resin part UR is hooked onto the holding pin 112 and held by the upper mold 110. Therefore, when the lower mold 120 and the intermediate mold 130 are lowered, the unnecessary resin part UR is held by the upper mold 110 and is pulled away from the intermediate mold 130. In this way, the unnecessary resin part UR (gate) is separated from the resin sealing part R formed on the lead frame 2 by resin-sealing the electronic element.

[0067] 2 pushes up the movable shaft 127. Therefore, in this state, the ejector pin 125 does not rise relative to the lower die block 121.

[0068] Next, the unloader 31 enters between the upper mold 110 and the intermediate mold 130 (below the unwanted resin part UR) and holds the unwanted resin part UR. At this time, as shown in FIG. 3( c), the holding pin 112 descends relative to the upper mold 110, and the lower end of the holding pin 112 (the part where the notch 112a is formed) protrudes downward from the upper surface of the upper mold groove portion 111b. When the lower end of the holding pin 112 protrudes, the unwanted resin part UR can be dropped by sliding down the inclined surface 112b of the holding pin 112, so that the unwanted resin part UR can be received by the unloader 31. Then, the unloader 31 retreats from the molding die, and the unwanted resin part UR is removed from the molding die. Note that once the unwanted resin part UR is removed, the holding pin 112 rises again relative to the upper mold 110.

[0069] Next, the lower mold 120 rises to a position where the intermediate mold 130 approaches the upper mold 110. In this state, the intermediate mold 130 is released from the holding claws of the lower mold 120, and the intermediate mold 130 is held by the holding claws of the upper mold 110.

[0070] 6, the lower mold 120 is lowered again, and the mold is opened. At this time, the intermediate mold 130 is held to the upper mold 110 by a holding claw (not shown). As a result, the intermediate mold 130 and the lower mold 120 are separated.

[0071] When the lower mold 120 descends a predetermined distance or more, the ejector rod 129 shown in FIG. 2 pushes up the movable shaft 127. This causes the ejector plate 126 to rise, and the ejector pins 125 to rise relative to the lower mold block 121. This causes the ejector pins 125 to protrude from the lower mold cavity portion 121a formed on the upper surface of the lower mold block 121. The ejector pins 125 protruding from the lower mold block 121 push up the resin sealing portion R formed on the lower surface of the lead frame 2. This causes the resin-sealed lead frame 2 to be released from the lower mold block 121.

[0072] Next, the unloader 31 enters between the intermediate mold 130 and the lower mold 120 (above the resin-sealed lead frame 2) and holds the lead frame 2. The unloader 31 then retreats from the molding die, thereby carrying the resin-sealed lead frame 2 out of the molding die. After the unloader 31 retreats from the molding die, the lower mold 120 rises. As the lower mold 120 rises, the ejector rod 129 shown in FIG. 2 separates from the movable shaft 127. The movable shaft 127 descends due to the force of the spring 128, and the ejector pin 125 also descends relative to the lower mold block 121.

[0073] <Shapes of Runner and Gate Portions> Next, the shapes of the runner and gate portions formed by the upper mold 110 and the intermediate mold 130 will be described in more detail with reference to FIGS.

[0074] When the molding dies are clamped, a runner is formed by the upper die groove 111b formed in the upper die 110 and the intermediate die groove 133 formed in the intermediate die 130, as described above. For simplicity of explanation, the illustration shows an example in which the runners (the upper die groove 111b and the intermediate die groove 133) are formed to extend to the left and right, but the shape of the runner is not particularly limited. For example, the runner may be formed so as to branch into multiple parts from the cull portion described above, or may be bent as appropriate depending on the arrangement of the resin molded product.

[0075] A gate portion 134 is formed in the middle of the runner portion (intermediate mold side groove portion 133). The gate portion 134 is formed to extend vertically so as to connect the intermediate mold side groove portion 133 and the intermediate mold cavity portion 132 formed below the intermediate mold side groove portion 133.

[0076] Here, in a molding die for top gate type transfer molding, the height of the loader 17 and unloader 31 is fixed (it is difficult to change the height), so it is difficult to change the thickness of the intermediate die 130 to shorten the length of the gate portion 134.

[0077] In this embodiment, as shown in FIG. 7 , a runner is formed using an intermediate mold groove 133 formed on the upper surface of the intermediate mold 130. This shortens the vertical distance L from the bottom of the runner to the cavity (intermediate mold cavity 132). This also shortens the vertical length of the gate 134. As a result, the volume of the unnecessary resin portion UR formed within the gate 134 is reduced, thereby reducing the amount of resin required for resin molding. Furthermore, shortening the length of the gate 134 shortens the flow length (length of the flow path) of the resin material. This makes it difficult for the temperature of the molten resin material to drop, improving moldability.

[0078] 8A, the depth D2 (vertical width) of the intermediate mold groove 133 is greater than the depth D1 (vertical width) of the upper mold groove 111b. This configuration effectively reduces the distance L (see FIG. 7A) from the intermediate mold groove 133 to the intermediate mold cavity 132. This effectively reduces the amount of resin required for resin molding.

[0079] 8(a), the intermediate mold groove portion 133 and the upper mold groove portion 111b, which is vertically opposed to the intermediate mold groove portion 133, are formed in a generally trapezoidal shape in a side cross-sectional view. In a side cross-sectional view, both side surfaces (front and rear side surfaces) of the intermediate mold groove portion 133 are inclined upward and away from each other. In other words, the intermediate mold groove portion 133 has a draft slope to make it easier to remove the cured resin from the intermediate mold groove portion 133. Like the intermediate mold groove portion 133, the upper mold groove portion 111b also has a draft slope.

[0080] The draft angle A2 of the intermediate mold groove portion 133 (the inclination angle of the side surface of the intermediate mold groove portion 133 with respect to the vertical direction) is formed to be larger than the draft angle A1 of the upper mold groove portion 111b facing the intermediate mold groove portion 133. This makes it easier to remove the hardened resin from the intermediate mold groove portion 133.

[0081] In this embodiment, as described above (see FIG. 5 ), the upper mold 110 is configured to hold the unwanted resin part UR when the upper mold 110 and the intermediate mold 130 are separated. Therefore, by making the draft angle A2 of the intermediate mold groove portion 133 larger than the draft angle A1 of the upper mold groove portion 111b, the adhesive force of the unwanted resin part UR to the intermediate mold 130 is reduced, and the unwanted resin part UR can be more reliably held by the upper mold 110. This prevents a portion of the unwanted resin part UR that has adhered to the intermediate mold 130 from remaining on the intermediate mold 130, which would result in a manufacturing defect.

[0082] In particular, in this embodiment, in order to reduce the amount of resin, as described above, the depth D2 of the intermediate mold groove portion 133 is formed to be deeper than the depth D1 of the upper mold groove portion 111b. This increases the contact area between the intermediate mold groove portion 133 and the unwanted resin portion UR, thereby increasing the adhesion force of the unwanted resin portion UR to the intermediate mold groove portion 133. However, by making the draft angle A2 of the intermediate mold groove portion 133 greater than the draft angle A1 of the upper mold groove portion 111b as described above, the increase in the adhesion force of the unwanted resin portion UR to the intermediate mold groove portion 133 can be suppressed. In other words, the unwanted resin portion UR can be more reliably held by the upper mold 110 while reducing the amount of resin.

[0083] 8(b), the gate 134 and the upper die groove 111b, which is opposed to the gate 134 in the vertical direction, are formed in a substantially trapezoidal shape in a side cross-sectional view. As in the example of FIG. 8(a), the gate 134 and the upper die groove 111b are provided with draft slopes.

[0084] The draft angle B2 of the gate portion 134 is formed to be larger than the draft angle B1 of the upper mold groove portion 111b facing the gate portion 134. This makes it easier to remove the resin that has hardened inside the gate portion 134. This allows the unnecessary resin portion UR to be more securely held by the upper mold 110 (see FIG. 5).

[0085] In particular, in this embodiment, in order to reduce the amount of resin as described above, the depth D2 of the intermediate mold groove portion 133 is formed to be deeper than the depth D1 of the upper mold groove portion 111b. However, by making the draft angle B2 of the gate portion 134 greater than the draft angle B1 of the upper mold groove portion 111b as described above, it is possible to suppress an increase in the adhesion force of the unnecessary resin portion UR to the gate portion 134. In other words, it is possible to more reliably hold the unnecessary resin portion UR in the upper mold 110 while reducing the amount of resin.

[0086] <Modification> Next, a modification of the forming die (second embodiment) will be described with reference to FIG.

[0087] In the molding die (upper die 110A and intermediate die 130A) according to the second embodiment shown in FIG. 9 , the retaining pin 112 is positioned between two adjacent gate portions 134. In the illustrated example, the retaining pin 112 is positioned midway between the two adjacent gate portions 134 in the direction (left-right direction) in which the runner portion (intermediate die side groove portion 133) extends. This configuration allows one retaining pin 112 to retain the unwanted resin portion UR that hardens in the two gate portions 134. This configuration allows the number of retaining pins 112 relative to the gate portions 134 to be reduced, thereby reducing parts costs and sliding resistance when the retaining pins 112 are operated.

[0088] 9B, when the retaining pin 112 is disposed between the gates 134 as described above, it is also possible to make the width of the runners (intermediate mold groove 133 and upper mold groove 111b) from the retaining pin 112 to the two adjacent gates 134 wider than the width of the runners in other areas. This configuration improves the rigidity of the unnecessary resin portion UR formed from the retaining pin 112 to the gates 134, and allows the retaining pin 112 to more reliably hold the unnecessary resin portion UR of the gates 134.

[0089] Furthermore, when the retaining pin 112 is disposed between the two gate portions 134 as described above, a recess 111c can be formed directly above the gate portion 134 instead of the retaining pin 112, as shown in FIG. 9A. The recess 111c is formed by recessing the upper surface of the upper mold groove portion 111b upward. The recess 111c can be formed, for example, in a quadrangular pyramid shape, a cone shape, or the like. By forming the recess 111c directly above the gate portion 134 in this manner, the contact area between the unwanted resin portion UR and the upper mold 110 increases, thereby increasing the adhesion of the unwanted resin portion UR to the upper mold 110. This allows the unwanted resin portion UR of the gate portion 134 to be more securely held in the upper mold 110.

[0090] Although each embodiment has been described above, the present invention is not limited to the above-described embodiments, and appropriate modifications are possible within the scope of the technical idea of ​​the invention described in the claims.

[0091] For example, the components (each module) of the resin molding apparatus 1 of the above embodiment are examples and can be added, changed, replaced, etc. as appropriate. Furthermore, the configurations and operations of the components (each module) used in the resin molding apparatus 1 of the above embodiment are examples and can be changed as appropriate.

[0092] In the above embodiment, an example was shown in which a groove (upper mold groove 111b) for forming a runner was formed on the lower surface of the upper mold 110, but the present invention is not limited to this. For example, it is also possible to form a groove for forming a runner only on the upper surface of the intermediate mold 130, and not form a groove on the lower surface of the upper mold 110.

[0093] In the above embodiment, the depth D2 of the intermediate mold groove 133 is greater than the depth D1 of the upper mold groove 111b (see FIG. 8 ), but the present invention is not limited to this. For example, the depth D2 of the intermediate mold groove 133 may be the same as the depth D1 of the upper mold groove 111b, or may be shallower than the depth D1 of the upper mold groove 111b.

[0094] In the above embodiment, the draft slope A2 of the intermediate groove 133 is larger than the draft slope A1 of the upper groove 111b (see FIG. 8 ), but the present invention is not limited to this. For example, the draft slope A2 of the intermediate groove 133 may be the same as or smaller than the draft slope A1 of the upper groove 111b.

[0095] In the above embodiment, the draft slope B2 of the gate 134 is larger than the draft slope B1 of the upper die groove 111b (see FIG. 8 ), but the present invention is not limited to this. For example, the draft slope B2 of the gate 134 may be the same as or smaller than the draft slope B1 of the upper die groove 111b.

[0096] In the above embodiment, the depth D2 of the intermediate groove 133 is greater than the depth D1 of the upper groove 111b, and the draft slope A2 of the intermediate groove 133 is greater than the draft slope A1 of the upper groove 111b, and the draft slope B2 of the gate 134 is greater than the draft slope B1 of the upper groove 111b. However, the present invention is not limited to this. For example, even if the depth D2 of the intermediate groove 133 is not greater than the depth D1 of the upper groove 111b, the draft slope A2 of the intermediate groove 133 can be greater than the draft slope A1 of the upper groove 111b, and the draft slope B2 of the gate 134 can be greater than the draft slope B1 of the upper groove 111b.

[0097] Furthermore, the retaining pins 112 illustrated in the above embodiment are merely examples, and the configuration is not particularly limited. The retaining pins 112 can be arbitrarily changed in shape, arrangement, number, etc., as long as they are capable of retaining the unwanted resin portion UR in the upper mold 110 and are capable of releasing the retention of the unwanted resin portion UR when the retaining pins 112 are lowered. For example, in the above embodiment, the notch portion 112a of the retaining pin 112 is formed by cutting out the left side of the lower end of the retaining pin 112, but the position of the notch portion 112a is not limited to this. For example, the notch portion 112a can be formed in any part of the retaining pin 112, such as the right side, the rear side, or the front side.

[0098] The configurations of the first and second embodiments described above can be combined as appropriate. For example, it is possible to configure the second embodiment so that the holding pins 112 are not located directly above some of the gate portions 134, and to arrange the holding pins 112 directly above other gate portions 134 as in the first embodiment, if necessary.

[0099] <Note> The molding die of a first aspect of the present disclosure is a molding die used for transfer molding, comprising an upper die 110, a lower die 120 arranged below the upper die 110, and an intermediate die 130 arranged between the upper die 110 and the lower die 120, wherein the molding die is formed with: a cavity formed by the upper surface of the lower die 120 and the lower surface of the intermediate die 130 and having a shape corresponding to a resin molded product, a runner portion formed by the upper surface of the intermediate die 130 and the lower surface of the upper die 110 and guiding resin material to above the cavity, and a gate portion 134 formed in the intermediate die 130 and guiding resin material from the runner portion to the cavity, wherein an intermediate die groove portion 133 forming the runner portion is formed on the upper surface of the intermediate die 130. The molding die of the first aspect of the present disclosure can reduce the amount of resin and improve moldability. That is, by forming the intermediate mold side groove portion 133, the length of the gate portion 134 can be shortened. This reduces the amount of resin required for molding. In addition, the flow length of the molten resin material can be shortened, improving moldability.

[0100] In the molding die for the second side surface according to the first side surface, an upper die groove portion 111b that forms the runner portion is formed on the lower surface of the upper die 110. The molding die for the second side surface of the present disclosure increases the adhesion force of the unnecessary resin portion UR to the upper die 110, and can prevent the unnecessary resin portion UR from remaining on the intermediate die 130 side when the die is opened.

[0101] In the molding die for the third side surface according to the second side surface, the depth D2 of the intermediate mold groove portion 133 is formed deeper than the depth D1 of the upper mold groove portion 111 b. According to the molding die for the third side surface of the present disclosure, the length of the gate portion 134 can be shortened.

[0102] In the molding die for the fourth side surface according to the third side surface, the draft angle A2 of the intermediate mold groove portion 133 is formed to be larger than the draft angle A1 of the upper mold groove portion 111 b. According to the molding die for the fourth side surface of the present disclosure, the unnecessary resin portion UR can be more reliably held in the upper mold 110.

[0103] In the molding die for the fifth side surface according to the third or fourth side surface, the draft angle B2 of the gate portion 134 is formed to be larger than the draft angle B1 of the upper mold groove portion 111 b. According to the molding die for the fifth side surface of the present disclosure, the unnecessary resin portion UR can be more reliably held in the upper mold 110.

[0104] In the molding die of the sixth side according to the first to fifth sides, the upper die 110 is disposed so as to be exposed to the runner portion and is provided with a holding member (holding pin 112) capable of hooking and holding the unwanted resin portion UR formed in the runner portion. According to the molding die of the sixth side of the present disclosure, the unwanted resin portion UR can be more reliably held in the upper die 110.

[0105] The resin molding apparatus 1 according to the seventh aspect of the present disclosure includes a molding die according to the first to sixth aspects, and a mold clamping mechanism 160 capable of clamping the molding die. The resin molding apparatus 1 according to the seventh aspect of the present disclosure can reduce the amount of resin and improve moldability.

[0106] A manufacturing method of a resin molded product according to an eighth aspect of the present disclosure is a manufacturing method of a resin molded product using the resin molding apparatus 1 described in the seventh aspect, and includes the steps of clamping the molding die to mold a resin, opening the molding die to carry out the unnecessary resin portion UR held by the upper die 110, and opening the molding die to carry out the resin molded product (resin-sealed lead frame 2). According to the resin molding apparatus 1 according to the eighth aspect of the present disclosure, it is possible to reduce the amount of resin and improve moldability.

[0107] REFERENCE SIGNS LIST 1 Resin molding device 110 Upper mold 111b Upper mold groove portion 112 Holding pin 120 Lower mold 130 Intermediate mold 133 Intermediate mold groove portion 134 Gate portion

Claims

1. A molding die used in transfer molding, comprising: an upper die; a lower die arranged below the upper die; and an intermediate die arranged between the upper die and the lower die, wherein the molding die has: a cavity formed by the upper surface of the lower die and the lower surface of the intermediate die, the cavity having a shape corresponding to the resin molded product; a runner portion formed by the upper surface of the intermediate die and the lower surface of the upper die, which guides resin material to above the cavity; and a gate portion formed in the intermediate die, which guides resin material from the runner portion to the cavity, wherein an intermediate die side groove portion which forms the runner portion is formed on the upper surface of the intermediate die.

2. The mold according to claim 1, wherein an upper mold groove portion that forms the runner portion is formed on the lower surface of the upper mold.

3. The mold according to claim 2, wherein the depth of the intermediate mold groove portion is formed deeper than the depth of the upper mold groove portion.

4. The mold according to claim 3, wherein the draft angle of the intermediate mold groove portion is greater than the draft angle of the upper mold groove portion.

5. A molding die according to claim 3 or claim 4, wherein the draft angle of the gate portion is formed to be larger than the draft angle of the upper die side groove portion.

6. A molding die according to any one of claims 1 to 5, wherein the upper die is arranged so as to be exposed to the runner portion and is provided with a holding member capable of hooking and holding the unnecessary resin portion formed in the runner portion.

7. A resin molding device comprising: the molding die according to any one of claims 1 to 6; and a mold clamping mechanism capable of clamping the molding die.

8. A method for manufacturing a resin molded product using the resin molding device described in claim 7, comprising the steps of: clamping the molding die to mold resin; opening the molding die to remove the unnecessary resin portion held in the upper die; and opening the molding die to remove the resin molded product.

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