Sealing mold and resin sealing device

Abstract

The present invention addresses the problem of providing a sealing mold and a resin sealing device capable of forming a molded underfill having higher accuracy. As the solution, a sealing mold (202) is provided with: a cavity (208) that serves as a sealing region for a sealing resin (R); a gate (248) that supplies the sealing resin (R) to the cavity (208); a workpiece holding part (205) that holds a workpiece (W); and an advance / retract member (220) that is provided in a state of having advanced into the cavity (208) toward the work holding part (205) and that advances into and retracts from the cavity (208) in response to a charging pressure of the sealing resin (R). The advancing / retracting member (220) has a first movable piece (222) at a portion on the gate (248) side, and the first movable piece (222), in a state of being separated from the surface of the workpiece (W) held by the workpiece holding part (205) when the mold is closed, is configured to narrow a flow path of the sealing resin (R) flowing in from the gate (248).

Description

Sealing Mold and Resin Sealing Device

[0005]

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

[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 substrate with a sealing resin (hereinafter sometimes simply referred to as "resin") and processing it into a molded product, a transfer molding method is known.

[0003] The transfer molding method is a technique in which a pot for supplying a predetermined amount of sealing resin is provided in a pair of cavities (sealing regions) provided in a sealing mold including an upper mold and a lower mold, a work is placed at a position corresponding to the cavity, clamped by the upper mold and the lower mold, and resin-sealed by an operation of pouring the sealing resin from the pot into the cavity.

[0004] As a molding die for transfer molding, a die capable of mold underfilling a work having a configuration in which an electronic component is flip-chip connected to a substrate with high precision is known (see Patent Document 1: Japanese Patent No. 6845903). The above-mentioned molding die includes a molding die body that holds a work in which an electronic component is disposed in a central region of a substrate and has a cavity having a rectangular shape in plan view into which a sealing resin is supplied. The molding die body includes a pot filled with the sealing resin, a gate provided on one side of the cavity and supplying the sealing resin toward the cavity, and a flow rate limiting mechanism that restricts only a side flow path of the flow path of the sealing resin flowing inside the cavity on both sides intersecting with the one side, where the electronic component is not disposed. According to this, the flow rate difference of the sealing resin between the central region where the electronic component exists and the sealing resin is difficult to flow, and the side flow path where the electronic component does not exist and the sealing resin is easy to flow is reduced, and the problem that the sealing resin wraps around from the side flow path to the central region and surrounds air (and thus voids are generated) can be prevented.

[0005] Japanese Patent No. 6845903

[0006] As shown in Figure 13, in transfer molding, the sealing resin, which is pumped from a pot (not shown) and passes through the runner 402, flows into the cavity 400 in an uneven, wavy state centered around the gate 404. As a result, the wavy resin flow (shown by dashed lines) can entrain air, sometimes causing molding defects such as voids. These molding defects were particularly noticeable when molding underfill workpieces in which electronic components Wb are flip-chip connected to a substrate Wa.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a sealing mold and resin sealing device that enable more precise mold underfilling.

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

[0009] An encapsulation mold according to one embodiment is an encapsulation mold for processing a workpiece on which electronic components are mounted on a base material into a molded product by encapsulating it with an encapsulation resin, comprising: a cavity which becomes the encapsulation region of the encapsulation resin; a gate which supplies the encapsulation resin to the cavity; a workpiece holding portion which holds the workpiece; and a retractable member which is provided in a state that extends into the cavity toward the workpiece holding portion and retracts from the cavity in response to the filling pressure of the encapsulation resin, wherein the retractable member has a first movable piece on the gate side portion, and the first movable piece is configured to narrow the flow path of the encapsulation resin flowing in from the gate when the mold is closed, while being separated from the surface of the workpiece held in the workpiece holding portion.

[0010] Furthermore, it is preferable that the sealing mold has an air vent on the opposite side of the gate across the cavity, and that the retractable member has a second movable piece on the air vent side.

[0011] Furthermore, it is preferable that the reciprocating member has third movable pieces on both sides parallel to the direction of resin flow.

[0012] Furthermore, it is preferable that the tip of the first movable piece is set to a position relatively higher than the tip of the third movable piece.

[0013] Furthermore, the resin sealing apparatus according to one embodiment is required to include a sealing mold described in any one of claims 1 to 4.

[0014] According to the sealing mold and resin sealing apparatus of the present invention, it is possible to achieve higher precision mold underfill.

[0015] Figure 1 is a plan view showing an example of a resin encapsulation apparatus according to an embodiment of the present invention. Figure 2 is a side view of the press apparatus of the resin encapsulation apparatus. Figure 3 is a front cross-sectional view of the encapsulation die of the resin encapsulation apparatus. Figure 4 is a side cross-sectional view of the encapsulation die of the resin encapsulation apparatus. Figure 5 is a bottom view of the upper die of the encapsulation die. Figure 6 is a schematic diagram for explaining the resin flow. Figure 7A is a front cross-sectional view illustrating a resin encapsulation method according to an embodiment of the present invention, and Figure 7B is a side cross-sectional view. Figure 8A is an explanatory diagram following Figure 7A, and Figure 8B is an explanatory diagram following Figure 7B. Figure 9A is an explanatory diagram following Figure 8A, and Figure 9B is an explanatory diagram following Figure 8B. Figure 10A is an explanatory diagram following Figure 9A, and Figure 10B is an explanatory diagram following Figure 9B. Figure 11A is an explanatory diagram following Figure 10A, and Figure 11B is an explanatory diagram following Figure 10B. Figure 12A is an explanatory diagram following Figure 11A, and Figure 12B is an explanatory diagram following Figure 11B. Figure 13 is a schematic diagram illustrating the resin flow in a conventional resin encapsulation device.

[0016] Embodiments of the present invention will be described in detail below with reference to the drawings. Figure 1 is a plan view (schematic diagram) showing an example of a resin encapsulation device 1 according to this embodiment. For convenience of explanation, arrows in the figure indicate the left-right direction (X direction), front-back direction (Y direction), and up-down direction (Z direction) of the resin encapsulation device 1. In addition, in all figures used to explain each embodiment, the same reference numerals are used for components having the same function, and repeated explanations may be omitted.

[0017] The resin sealing apparatus 1 according to this embodiment is a device that performs resin sealing of a workpiece (molded product) W using a sealing mold 202 comprising an upper mold 204 and a lower mold 206. Hereinafter, the resin sealing apparatus 1 will be described using a transfer molding method as an example, in which the workpiece W is held by a workpiece holding section 205 provided in the lower mold 206, and 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, and the upper mold 204 and lower mold 206 are clamped to seal the workpiece W with sealing resin R.

[0018] First, the workpiece W to be molded has a configuration in which electronic components Wb are mounted on a base material Wa. In this embodiment, we will explain using a workpiece W in which a plurality of electronic components Wb are arranged in a matrix (for example, three rows x three columns) in the central region of the surface of the base material Wa and are connected via bumps Wc using a flip-chip connection as an example (however, the embodiment is not limited to this configuration). Hereinafter, the outer peripheral region in which electronic components Wb are not mounted will be referred to as the "outer peripheral region" in relation to the "central region" described above. Examples of base material Wa include plate-shaped members such as resin substrates, ceramic substrates, metal substrates, carrier plates, lead frames, and wafers. Examples of electronic components Wb include semiconductor chips, MEMS chips, passive elements, heat sinks, conductive members, and spacers.

[0019] On the other hand, a tablet-type (e.g., cylindrical) thermosetting resin (e.g., an epoxy resin containing fillers) is preferably used as the sealing resin R. However, it is not limited to the above resin, and may be a powder resin, crushed resin, solid resin, liquid resin, or a combination of several of these, and may also be a resin other than an epoxy thermosetting resin.

[0020] Furthermore, as film F, a film material with excellent heat resistance, ease of peeling, flexibility, and stretchability (for example, PTFE (polytetrafluoroethylene), ETFE (polytetrafluoroethylene polymer), PET, FEP, fluorine-impregnated glass cloth, polypropylene, polyvinylidine chloride, etc.) is preferably used.

[0021] 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 for supplying workpieces W and encapsulating resin R, a press unit 100B for processing workpieces W into molded products Wp by encapsulating them with the encapsulating resin R, and a storage unit 100C for storing the molded products Wp. As an example, along the X direction in Figure 1, the supply unit 100A, press units 100B, 100B, and storage unit 100C are arranged in that order. However, the configuration is not limited to the above, and the equipment configuration within the units, the number of units (especially the number of press units 100B), the arrangement order of the units, etc. can be changed, and configurations with units other than those described above are also possible (none of which are shown).

[0022] Furthermore, the resin encapsulation apparatus 1 is provided with a linear guide rail 300 spanning between each unit, and a transport device (first loader) 302 for transporting the workpiece W and the encapsulation resin R, and a transport device (second loader) 304 for transporting the molded product Wp are provided to move along the guide rail 300 between predetermined units. However, the configuration is not limited to the above, and a configuration with a common (single) transport device (loader) for transporting the workpiece W, the encapsulation resin R, and the molded product Wp may also be provided (not shown). In addition, the transport device may be configured to include a robot hand or the like instead of a loader (not shown).

[0023] Furthermore, the resin encapsulation device 1 is provided with a control unit 150 that controls the operation of each mechanism in each unit. In this embodiment, the control unit 150 is located in the supply unit 100A, but it may also be located in other units.

[0024] (Supply Unit) The supply unit 100A includes a work supply mechanism 102, a work table 104, a resin supply mechanism 106, and a resin table 108. The work supply mechanism 102 supplies stocked workpieces W onto the work table 104, and a known stack magazine or slit magazine is used. As an example, two workpieces W are supplied onto the work table 104, but there may be one or more workpieces. The resin supply mechanism 106 supplies stocked sealing resin R onto the resin table 108, and a known hopper or feeder is used. As an example, three sealing resins R are supplied onto the resin table 108, but there may be one, two, or more than four workpieces. Note that the workpieces W and sealing resin R may be supplied to the same table (not shown).

[0025] The workpiece W supplied onto the worktable 104 and the sealing resin R supplied onto the resin table 108 are held by the first loader 302 and transported to the press unit 100B to be set in a predetermined position on the sealing mold 202. In this embodiment, the workpiece W is placed on the workpiece holding section 205 of the lower mold 206, and the sealing resin R is contained in the pot 240 of the lower mold 206.

[0026] As an example of the configuration of the first loader 302, workpiece holding sections 302A, 302A are provided, arranged in two parallel rows along the left-right direction, each capable of holding one workpiece W. Furthermore, a resin holding section 302B is provided between the workpiece holding sections 302A, 302A, capable of holding multiple (in this embodiment, three are given as an example, but not limited to this) sealing resins R along the front-rear direction. Note that known holding mechanisms (for example, configurations with holding claws for clamping, or configurations with suction holes communicating with a suction device for adsorption, etc.) are used for the workpiece holding sections 302A and the resin holding section 302B (not shown).

[0027] As a variation of the above conveying device, instead of the first loader 302 that moves in the X and Y directions, a separate conveying device (loader) that moves in the X direction to convey units between units and a separate conveying device (loader) that moves in the Y direction to load and set units into the lower mold 206 may be provided (not shown).

[0028] (Press Unit) The press unit 100B includes a sealing die 202 having a pair of dies that can be opened and closed (for example, a set of multiple die blocks, die plates, and other components made of alloy tool steel). It also includes a press device 250 that drives the sealing die 202 to open and close to seal the workpiece W with resin. As an example, the unit is configured to have one press device 250, but it may also be configured to have multiple units (not shown). Here, a side view (schematic diagram) of the press device 250 is shown in Figure 2.

[0029] The press device 250 is configured to include a pair of platens 254 and 256, a plurality of tie bars 252 on which the platens 254 and 256 are mounted, and a drive device for moving (raising and lowering) the platen 256. Specifically, the drive device is configured to include a drive source (e.g., an electric motor) 260 and a drive transmission mechanism (e.g., a ball screw) 262, etc. (however, it is not limited to this configuration). In this embodiment, the upper platen 254 in the vertical direction is set as a fixed platen (a platen fixed to the tie bar 252), and the lower platen 256 is set as a movable platen (a platen that moves in the axial direction (up and down direction) of the tie bar 252). However, it is not limited to this, and the top and bottom may be reversed, that is, the upper side may be set as a movable platen and the lower side as a fixed platen, or both the upper and lower sides may be set as movable platens (none of which are shown).

[0030] Furthermore, in this embodiment, a film supply mechanism 211 is provided for transporting (supplying) a roll-shaped film F into the sealing mold 202. Depending on the configuration of the workpiece W, the film F may be used in the form of strips instead of a roll.

[0031] Next, the sealing die 202 will be described. The sealing die 202 comprises an upper die 204 and a lower die 206 as a pair of dies disposed between the platens 254 and 256 in the press device 250. The upper die 204 is assembled to the upper platen 254 in the vertical direction, and the lower die 206 is assembled to the lower platen 256. In other words, the sealing die 202 is configured such that the upper die 204 and the lower die 206 move closer to and further apart from each other by driving a drive device to move the movable platen (in this embodiment, the lower platen 256) in the vertical direction, thereby closing and opening the die (the vertical direction (up and down direction) is the die opening and closing direction). Here, Figure 3 shows a front cross-sectional view of the sealing mold 202 (a cross-sectional view taken along line III-III in Figure 1, with the workpiece W and sealing resin R placed on it), and Figure 4 shows a side cross-sectional view of the sealing mold 202 (a cross-sectional view taken along line IV-IV in Figure 1, with the workpiece W placed on it). Also, Figure 5 shows a bottom view of the upper mold 204.

[0032] The lower mold 206 is provided with multiple cylindrical pots 240 (in this embodiment, three are given as an example, but it is not limited to this and may be one) along the front-to-back direction, each containing a sealing resin R. A plunger 242, driven by a known transfer mechanism (not shown), is inserted into the lower part of each pot 240, and the sealing resin R contained in the pot 240 is pushed by the plunger 242 and supplied into the cavity 208 (described later).

[0033] Furthermore, the lower mold 206 is provided with a workpiece holding section 205 for holding one or more workpieces W. Specifically, two workpiece holding sections 205A and 205B are provided in an arrangement that sandwiches the pot 240 in the left-right direction. The workpiece holding section 205 is provided with a suction passage (hole or groove, etc.) that communicates with a suction device (not shown). Specifically, one end of the suction passage is connected to the mold surface 206a of the lower mold 206, and the other end is connected to a suction device disposed outside the lower mold 206. This allows the suction device to be driven to suck the workpiece W from the suction passage, and the workpiece W to be held by suction on the mold surface 206a (in this case, the workpiece holding section 205). Instead of the above suction holding mechanism, or together with the suction holding mechanism, a configuration may be provided with holding claws that grip the outer circumference of the workpiece W (not shown). The shape and number of workpiece holding sections 205 provided on the lower mold 206 are appropriately set according to the shape and number of workpieces W.

[0034] Furthermore, the lower mold 206 is provided with a lower mold heating mechanism (not shown) that heats the lower mold 206 to a predetermined temperature (for example, 100°C to 300°C). The lower mold heating mechanism consists of a heater (for example, an electric heating wire heater), a temperature sensor, a power supply, etc., and the heating is controlled by the control unit 150. As an example, the heater is built into the lower mold 206 and is configured to heat the entire lower mold 206 and the sealing resin R contained in the pot 240.

[0035] The upper mold 204 is provided with a cal 246 and a runner 247 communicating with the cal 246, located directly above the pot 240 of the lower mold 206 (here, referring to a predetermined area of ​​a certain width directly above it). Furthermore, a cavity 208 is provided, communicating with the runner 247 and housing a predetermined portion of the workpiece W (the central area on which the electronic component Wb is mounted), which becomes the sealing area for the sealing resin R. The boundary between the runner 247 and the cavity 208 (boundary area) is referred to as the gate 248. Additionally, an air vent 249 is provided on the opposite side of the gate 248, across the cavity 208, for discharging air from within the cavity 208.

[0036] As cavities 208, cavities 208A and 208B are arranged on both sides in the left-right direction (or front-back direction) in a plan view, corresponding to the positions of the two workpiece holding portions 205A and 205B of the lower mold 206. These workpiece holding portions 205A and 205B and cavities 208A and 208B form a set of components that are resin-sealed by three pots 240 and their corresponding cals 246, runners 247, and gates 248.

[0037] Furthermore, the mold surface 204a of the upper mold 204 is provided with suction passages (holes, grooves, etc.) that communicate with a suction device (neither of which are shown), allowing the film F supplied from the film supply mechanism 211 to be adsorbed and held on the mold surface 204a, including the inner surface of the recess of the cavity 208.

[0038] Furthermore, the upper mold 204 is provided with an upper mold heating mechanism (not shown) that heats the upper mold 204 to a predetermined temperature (for example, 100°C to 300°C). The upper mold heating mechanism consists of a heater (for example, an electric heating wire heater), a temperature sensor, a power supply, etc., and the heating is controlled by the control unit 150. As an example, the heater is built into the upper mold 204 and is configured to heat the entire upper mold 204, as well as the molten sealing resin R that is filled in the cal 246, runner 247, gate 248, and cavity 208.

[0039] A characteristic feature of this embodiment is that the upper mold 204 is provided with a reciprocating member 220 that is configured to move back and forth (up and down) within the cavity 208. As shown in Figures 3 to 5, the reciprocating member 220 is arranged to surround the cavity piece 218 (arranged to surround the central region of the workpiece W held by the workpiece holding portion 205 of the lower mold 206), and is configured with a first movable piece 222 on the gate 248 side (upstream side of the resin flow), a second movable piece 224 on the air vent 249 side (downstream side of the resin flow), and third movable pieces 226, 226 on both sides parallel to the direction of the resin flow.

[0040] Specifically, each movable piece 222, 224, and 226 is attached to the lower surface of the base block 210 via biasing members (springs in this embodiment) 232 (232A, 232B, 232C) and pins 234 (234A, 234B, 234C) with its tip (bottom surface) 222a, 224a, and 226a extending (protruding) by a predetermined amount from the inner surface of the recess (mold surface 204a) of the cavity 208 toward the workpiece holding portion 205 of the lower mold 206. Here, the spring 232 is set to a spring force that can be compressed by the filling (molding) pressure of the sealing resin R. In other words, each movable piece 222, 224, and 226 is pushed (biased upward) by the sealing resin R from the tip ends 222a, 224a, and 226a as the sealing resin R fills the cavity 208, causing it to retract from within the cavity 208. To put it another way, each movable piece 222, 224, and 226 is retracted from within the cavity 208 by the filling pressure of the sealing resin R. Although a configuration (not shown) in which each movable piece 222, 224, and 226 is moved forward and backward by a mechanism using a drive source instead of the spring 232 (and pin 234) can also be adopted, the configuration using the spring 232 is preferred from the viewpoint of structural complexity and complicated drive control.

[0041] The first movable piece 222 is positioned such that, when the mold is closed, it is separated from the surface of the workpiece W (base material Wa) held by the workpiece holding portion 205 of the lower mold 206. As a result, as shown in Figure 6, by narrowing the flow path of the sealing resin R near the gate 248 (reducing the cross-sectional area of ​​the flow path), the aforementioned conventional problem of resin flow undulation is eliminated, and the resin flow (shown by a dashed line) can be straightened to a uniform state without bias. Therefore, air entrapment due to resin flow undulation can be prevented, and high-precision mold underfill can be achieved. In particular, when sealing resin R is supplied from multiple gates 248 as in this embodiment, the surrounding of air by waves generated from each gate 248 can be prevented, resulting in a more significant effect.

[0042] The second movable die 224 is provided so as to be in a state of being separated from the surface of the work W (base material Wa) held by the work holding portion 205 of the lower die 206 when the mold is closed. According to this, by narrowing the flow path of the sealing resin R at a position near the air vent 249, it is possible to prevent the problem that the resin flow wraps around from the outer peripheral region on the air vent 249 side to the central region and entraps air. In addition, since the air in the cavity 208 can be uniformly discharged from the air vent 249, the dummy cavity can be omitted.

[0043] Incidentally, the second movable die 224 may be provided so as to be in a state of abutting against the surface of the work W (base material Wa) held by the work holding portion 205 of the lower die 206 when the mold is closed (not shown). According to this, the air in the cavity 208 can be more efficiently discharged from the air vent 249.

[0044] The third movable die 226 is provided so as to be in a state of being separated from the surface of the work W (base material Wa) held by the work holding portion 205 of the lower die 206 when the mold is closed. According to this, by narrowing the flow path of the sealing resin R at a position in the outer peripheral region of the work W (excluding the gate 248 side and the air vent 249 side), the central region where the electronic component Wb exists and the sealing resin R is difficult to flow (particularly, the narrow portion between the base material Wa and the electronic component Wb) and the outer peripheral region where the electronic component Wb does not exist and the sealing resin R easily flows. The difference in the flow velocity of the resin flow can be reduced. Therefore, it is possible to prevent the problem that the sealing resin R wraps around from the outer peripheral region to the central region and entraps air.

[0045] The amount of extension of each movable piece 222, 224, 226 (tip portions 222a, 224a, 226a) (the distance between them and the surface of the workpiece W (base material Wa)) can be appropriately set according to the shape of the workpiece W and molded product Wp, the flow performance of the sealing resin R, etc. However, in order to ensure the filling of the sealing resin R, it is preferable that the tip portion 222a of the first movable piece 222 is set to a position relatively higher than the tip portion 226a of the third movable piece 226. In this embodiment, when the mold is closed, the tip portion 222a of the first movable piece 222 extends to the position of the electronic component Wb, and the tip portion 226a of the third movable piece 226 (and the tip portion 224a of the second movable piece 224) extends to the position of the narrow space between the base material Wa and the electronic component Wb. However, all movable pieces 222, 224, and 226 (tip portions 222a, 224a, and 226a) may be set to the same height or to different heights.

[0046] Furthermore, by adjusting the spring force of the springs 232 (232A, 232B, 232C), the timing at which each movable piece 222, 224, and 226 retracts from the cavity 208 can be arbitrarily set. For example, by making the spring force of spring 232A that biases the first movable piece 222 relatively weaker (or stronger) than the spring force of spring 232C that biases the second movable piece 224, the first movable piece 222 can be made to retract from the cavity 208 before (or after) the second movable piece 224.

[0047] In this embodiment, a configuration in which a first movable piece 222, a second movable piece 224, and a third movable piece 226 are provided as the retractable member 220 has been described as an example, but the second movable piece 224, the third movable piece 226, or both can be omitted. Furthermore, each movable piece 222, 224, and 226 may be divided into multiple parts, for example, the movable piece 222 may be divided into multiple (three) parts in an arrangement corresponding to the gate 248 (in this embodiment, three gates 248, 248, 248) (not shown).

[0048] (Storage Unit) The storage unit 100C includes a molded product table 122, a degating mechanism 124, and a molded product storage mechanism 126. A known stack magazine, slit magazine, or the like is used for the molded product storage mechanism 126.

[0049] The molded product Wp (in a state including unnecessary resin parts) molded by the press unit 100B is held by the second loader 304, conveyed to the storage unit 100C, and placed on the molded product table 122. Then, after the unnecessary resin parts are removed by the degating mechanism 124, it is stored in the molded product storage mechanism 126.

[0050] As a configuration example of the second loader 304, a molded product holding part 304A capable of holding the molded product Wp (in a state including unnecessary resin parts) is provided. Note that a known holding mechanism (for example, a configuration having holding claws for clamping or a configuration having suction holes communicating with a suction device for suction) is used for the molded product holding part 304A (not shown).

[0051] As a modified example of the above conveying device, instead of the second loader 304 that moves in the X and Y directions, a configuration may be provided that separately includes a conveying device (loader) that moves in the X direction to perform conveyance between units and a conveying device (loader) that moves in the Y direction to carry out unloading from the sealing mold 202 (not shown).

[0052] (Resin Sealing Operation) Next, the steps of the resin sealing method according to the present embodiment performed using the resin sealing device 1 will be described. Here, a configuration will be described as an example in which a pair of left and right cavities 208A and 208B are provided in the upper mold 204, and two workpieces W are arranged in parallel in the lower mold 206 and resin sealing is performed collectively to obtain a molded product Wp. However, the present invention is not limited to this configuration, and a configuration may be adopted in which one workpiece W is arranged or a plurality of workpieces W are arranged in parallel in a matrix for resin sealing. Here, FIGS. 7A to 12B are explanatory views of the resin sealing operation. FIGS. 7A, 8A, 9A, 10A, 11A, and 12A are shown as front cross-sectional views in the same direction as FIG. 3 (an enlarged view of the cavity 208A and its periphery), and FIGS. 7B, 8B, 9B, 10B, 11B, and 12B are shown as side cross-sectional views in the same direction as FIG. 4 (an enlarged view of the cavity 208A and its periphery).

[0053] First, as a preparation step, a heating step (upper mold heating step) is performed in which the upper mold 204 is heated to a predetermined temperature (for example, 100°C to 300°C) using the upper mold heating mechanism. Then, a heating step (lower mold heating step) is performed in which the lower mold 206 is heated to a predetermined temperature (for example, 100°C to 300°C) using the lower mold heating mechanism. Furthermore, a film supply step is performed in which a new film F is supplied by operating the film supply mechanism 211 and adsorbed so as to cover a predetermined area of ​​the mold surface 204a, including the inner surface of the cavity 208 in the upper mold 204.

[0054] The workpiece and resin supply process is carried out either before, during, or in parallel with the preparation process. Specifically, the workpiece W is taken from the workpiece supply mechanism 102 and placed on the worktable 104, while the sealing resin R is taken from the resin supply mechanism 106 and placed on the resin table 108.

[0055] Following the workpiece and resin supply process, a workpiece and resin pickup process is performed. Specifically, the first loader 302 is moved to a position directly above the worktable 104. Next, the worktable 104 is raised (or the first loader 302 is lowered), and the workpiece W is held by the workpiece holding section 302A, and the sealing resin R is held by the resin holding section 302B.

[0056] After the workpiece and resin pickup process, the workpiece and resin placement process is carried out. Specifically, the first loader 302 holding the workpiece W and the sealing resin R is moved into the sealing mold 202. Next, the workpiece W is held (placed) in the workpiece holding section 205 of the lower mold 206, and the sealing resin R is held (contained) in the pot 240 of the lower mold 206 (see Figures 7A and 7B). During transport, a process of preheating the workpiece W and sealing resin R using a heater (not shown) provided on the first loader 302 (preheating process) may be carried out.

[0057] After the workpiece and resin placement process, a mold closing process is performed to close the sealing mold 202. Specifically, the drive source 260 and the drive transmission mechanism 262 are activated to move the movable platen 256 upward, thereby moving the lower mold 206 toward the upper mold 204 (i.e., upward) to clamp the workpiece W (see Figures 8A and 8B). At this point, the movable pieces 222, 224, and 226 of the upper mold 204 (tip portions 222a, 224a, and 226a) advance (protrude) by a predetermined amount from the inner surface of the recess in the cavity 208 (mold surface 204a) toward the workpiece holding portion 205 of the lower mold 206, thereby narrowing the flow path of the sealing resin R (a position corresponding to the outer peripheral region of the workpiece W).

[0058] After the mold closing process, a resin sealing process is performed to seal the workpiece W with sealing resin R to process it into a molded product Wp. Specifically, by operating the transfer drive mechanism and pushing the plunger 242 toward the upper mold 204, the sealing resin R molten in the pot 240 is pressed against the cal 246 of the upper mold 204 and pumped toward the cavity 208 via the runner 247 and gate 248 which communicate with the cal 246. The sealing resin R that has passed through the gate 248 and flowed into the cavity 208 is first constricted by the first movable piece 222, and rectified into a flat state without waves, that is, a uniform state without bias (see Figures 9A and 9B). Then, the sealing resin R that has reached the central region of the workpiece W enters the narrow space between the base material Wa and the electronic component Wb, and the flow rate decreases, and the sealing resin R that has reached the outer peripheral region (excluding the gate 248 side) is constricted by the second movable piece 224 and the third movable piece 226, and the flow rate decreases. As a result, the difference in flow velocity of the sealing resin R between the central region and the outer region is reduced, and the sealing resin R is filled into the cavities 208A and 208B while preventing the sealing resin R from flowing back from the outer region to the central region (see Figures 10A and 10B). As the pumping of the sealing resin R continues, the movable pieces 222, 224, and 226 are moved out of the cavities 208A and 208B by the filling pressure of the sealing resin R (pushed by the sealing resin R), and the sealing resin R enters the narrowed flow path, filling the entire cavity 208A and 208B with the sealing resin R (see Figures 11A and 11B). Through the above resin sealing process, the sealing resin R heat-cures and the resin sealing (mold underfill) is completed.

[0059] After the resin sealing process, a mold opening process is performed to open the sealing mold 202. Specifically, the drive source 260 and the drive transmission mechanism 262 are driven to move the movable platen 256 downward, separating the lower mold 206 from the upper mold 204 (see Figures 12A and 12B).

[0060] After the mold opening process, the molded product unloading process is performed in which the second loader 304 unloads the molded product Wp (in this embodiment, including unnecessary resin parts such as the crust, runner, and gate, and in which two workpieces W are connected via these parts) from the sealing mold 202 and unloads it onto the molded product table 122. After the molded product unloading process, or in parallel therewith, the film supply mechanism 211 is activated to send the used film F out of the sealing mold 202 and feed a new film F into the sealing mold 202 and set it in place in a film supply process.

[0061] After the molded product unloading process, a degate process is performed in the degate mechanism 124 to remove unwanted resin parts such as the caliber, runner, and gate from the molded product Wp. Next, a molded product storage process is performed in which the molded products Wp (with the unwanted resin parts removed) are stored one by one in the molded product storage mechanism 126. Alternatively, a post-curing process for the molded products Wp may be performed before these processes.

[0062] The above outlines the main steps of the resin encapsulation method performed using the resin encapsulation apparatus 1. However, the above order of steps is merely an example, and the order can be changed or the steps performed in parallel as long as there are no obstacles.

[0063] As described above, the present invention provides a sealing mold and resin sealing apparatus that enable more precise mold underfilling.

Claims

1. A sealing mold for processing a workpiece on which electronic components are mounted on a base material into a molded product by sealing it with a sealing resin, comprising: a cavity which is the sealing region of the sealing resin; a gate which supplies the sealing resin to the cavity; a workpiece holding portion which holds the workpiece; and a retractable member which is provided in a state that extends into the cavity toward the workpiece holding portion and retracts from the cavity in response to the filling pressure of the sealing resin, wherein the retractable member has a first movable piece on the gate side portion, and the first movable piece is configured to narrow the flow path of the sealing resin flowing in from the gate when the mold is closed, while being separated from the surface of the workpiece held by the workpiece holding portion.

2. The sealing mold according to claim 1, wherein the sealing mold has an air vent on the opposite side of the gate across the cavity, and the retractable member has a second movable piece on the air vent side.

3. The sealing mold according to claim 2, characterized in that the reciprocating member has third movable pieces on both sides parallel to the direction of resin flow.

4. The sealing mold according to claim 3, characterized in that the tip of the first movable piece is set to a position relatively higher than the tip of the third movable piece.

5. A resin sealing apparatus characterized by comprising a sealing mold according to any one of claims 1 to 4.

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