Sealing resin for use in compression molding, and forming method and forming device thereof

Abstract

To provide a compression molding device and a sealing resin capable of realizing a compression molding method capable of preventing the occurrence of molding defects, and a method and device for forming the same.SOLUTION: A method for forming a sealing resin according to the present invention is a method for forming a sealing resin R to be used in compression molding of a workpiece W having a configuration in which an electronic component Wb is mounted on a substrate Wa, and includes a forming step of forming a frame-shaped or lattice-shaped sealing resin R having through holes Rh, the forming step includes a step of setting and forming the position and shape of the through hole Rh such that the electronic component Wb of the workpiece W is accommodated in the through hole Rh and the upper surfaces Wbf of the electronic component Wb is exposed.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present invention relates to a sealing resin used in compression molding, and a method and apparatus for forming the same. [Background technology]

[0002] 2. Description of the Related Art As an example of a resin sealing apparatus and a resin sealing method for sealing a workpiece having electronic components mounted on a substrate with a sealing resin and processing it into a molded product, a method using a compression molding method is known.

[0003] The compression molding method is a technology in which a predetermined amount of sealing resin is supplied to a sealing area (cavity) provided in a sealing mold comprising an upper mold and a lower mold, a workpiece is placed in the sealing area, and the upper mold and lower mold are clamped to seal the workpiece with resin. As an example, when a sealing mold having a cavity in the upper mold is used, a technology is known in which the sealing resin is supplied all at once to the center position on the workpiece and molded. On the other hand, when a sealing mold having a cavity in the lower mold is used, a technology is known in which a release film (hereinafter sometimes simply referred to as a "film") that covers the mold surface including the cavity and the sealing resin are supplied and molded (Patent Document 1: See JP 2019-145550 A). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-145550 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, when a strip-type wire-connected electronic component (semiconductor chip) is encapsulated with resin as a workpiece, the compression molding method in which a cavity is provided in the upper die has a problem that resin encapsulation is difficult because the wire portion of the workpiece held in the lower die comes into contact with the encapsulation resin previously supplied to the cavity or the encapsulation resin supplied onto the workpiece and deforms. Therefore, a compression molding method in which the workpiece is held in the upper die, a cavity is provided in the lower die, and encapsulation resin (granular resin, as an example) is supplied into the cavity has generally been adopted.

[0006] However, in a configuration in which a workpiece is held in the upper mold and a cavity is provided in the lower mold, when the workpiece is thin or large, there is a problem that it is difficult to hold the workpiece in the upper mold and it is likely to fall. In addition, although the sealing resin is usually supplied into the cavity of the lower mold through a film, when a thick molded product with a thickness (here, the thickness of the resin part after molding) of more than 1 mm is to be formed, the molding stroke becomes large, and there is a problem that the film is likely to be caught in the molded product, which is a molding defect. Furthermore, when a granular resin is used as the sealing resin, in addition to the problem that the film is likely to be caught in the molded product, dust is generated, and handling is difficult, there is a problem that it is difficult to supply (spray) the sealing resin evenly to the entire area in the cavity provided in the lower mold, and winding unevenness is likely to occur. In addition, there is a problem that the air contained in the gaps between the particles when the sealing resin is sprayed and the gas components due to degassing from the sealing resin when melted are not released and remain in the molded product, which is a molding defect. In particular, in the case of a workpiece in which electronic components are mounted by wire connections, there is a risk of wire flow (deformation or breakage of the wire) due to the flow of resin within the cavity during resin sealing.

[0007] On the other hand, when forming a molded product in which electronic components such as heat sinks are exposed, regardless of the arrangement of the cavities, it becomes difficult to prevent molding defects such as a situation in which a specific part of the electronic component, such as the top surface (i.e., the cooling surface) of a heat sink, is not exposed as designed. [Means for solving the problem]

[0008] The present invention has been made in consideration of the above circumstances, and aims to provide a sealing resin that is easy to handle and is particularly suitable for forming molded products in which the top surfaces of electronic components mounted on a workpiece are exposed, and that can realize a compression molding device and compression molding method that prevent molding defects caused by resin flow, uneven winding, residual gas, and dust generation during molding, and enable the formation of molded products with large thickness dimensions, as well as a molding method and molding device therefor.

[0009] The present invention solves the above problems by the solution means described below as one embodiment.

[0010] The sealing resin according to one embodiment is a sealing resin used for compression molding of a workpiece, and is required to be formed in a frame or lattice shape having through holes. For example, a workpiece having a configuration in which electronic components are mounted on a substrate is used as the workpiece. In this case, it is preferable that the workpiece is formed in a shape having through holes that accommodate the electronic components and expose the upper surface of the electronic components when placed on the substrate.

[0011] Moreover, a method for forming a sealing resin according to one embodiment is a method for forming a sealing resin used in compression molding of a workpiece having a configuration in which electronic components are mounted on a substrate, and includes a forming step of forming the sealing resin in a frame or lattice shape having through holes, and the forming step includes a step of setting and forming the positions and shapes of the through holes so that the electronic components of the workpiece are accommodated in the through holes and the top surfaces of the electronic components are exposed.

[0012] The forming step preferably includes a step of tableting a base resin to form the sealing resin. The base resin is preferably a powder resin. Effect of the Invention

[0013] By using the sealing resin according to the present invention, it is possible to realize a compression molding device and a compression molding method that can prevent molding defects caused by resin flow, uneven winding, residual gas, and dust generation during molding, in particular, prevention of molding defects in which the top surface of electronic components mounted on a work is not exposed, and formation of molded products with large thickness dimensions. In addition, handling is easier than granular resin, especially when supplying and setting. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a plan view showing an example of a compression molding device in which a sealing resin according to an embodiment of the present invention is used. [Diagram 2] 1A to 1C are explanatory diagrams illustrating an example of a compression molding method using a sealing resin according to an embodiment of the present invention. [Diagram 3] FIG. 3 is an explanatory diagram following FIG. 2. [Figure 4] 4A is an explanatory view following FIG. 3, and FIG. 4B is an explanatory view following FIG. 4A, both of which are enlarged views of the portion IV in FIG. [Diagram 5] FIG. 4B is an explanatory diagram following FIG. 4B. [Figure 6] FIG. 6 is an explanatory diagram following FIG. [Figure 7] 5A to 5C are explanatory diagrams illustrating another example of a compression molding method using a sealing resin according to an embodiment of the present invention. [Figure 8] FIG. 8 is an explanatory diagram following FIG. [Figure 9] FIG. 9 is an explanatory diagram following FIG. [Figure 10] 1 is a side view illustrating an example of an apparatus for forming a sealing resin according to an embodiment of the present invention. [Figure 11] FIG. 11 is a side cross-sectional view showing an example of a tableting die of the forming apparatus shown in FIG. [Figure 12] 5A to 5C are explanatory diagrams of a method for forming a sealing resin according to an embodiment of the present invention. [Figure 13] FIG. 13 is an explanatory diagram following FIG. 12. [Figure 14] FIG. 14 is an explanatory diagram following FIG. 13. [Figure 15]FIG. 2 is a perspective view illustrating an example of a sealing resin according to an embodiment of the present invention. [Figure 16] 1 is a perspective view showing an example of a workpiece to be resin-sealed with a sealing resin according to an embodiment of the present invention; [Figure 17] 1 is a perspective view showing an example of a molded product that is resin-sealed with a sealing resin according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] (Compression molding device and compression molding method) The sealing resin R according to the embodiment of the present invention is a sealing resin R used for compression molding of a workpiece W. First, an outline of a compression molding apparatus 1 and a compression molding method for resin sealing (compression molding) a workpiece W using the sealing resin R will be described. Here, FIG. 1 is a plan view (schematic view) showing an example of the compression molding apparatus 1.

[0016] The workpiece W to be sealed has a configuration in which electronic components Wb are mounted on a substrate Wa. More specifically, examples of the substrate Wa include plate-shaped members such as a resin substrate, a ceramic substrate, a metal substrate, a carrier plate, a lead frame, and a wafer. Examples of the electronic components Wb include a semiconductor chip, a MEMS chip, a passive element, a heat sink, a conductive member, and a spacer. The shape of the substrate Wa is a rectangular shape (striped shape), a square shape, a circular shape, and the like. The number of electronic components Wb mounted on one substrate Wa is set to one or more (for example, in a matrix shape, etc.).

[0017] Examples of methods for mounting the electronic components Wb on the substrate Wa include wire bonding mounting, flip chip mounting, etc. Alternatively, in the case of a configuration in which the substrate (glass or metal carrier plate) Wa is peeled off from the molded product Wp after resin sealing, there is also a method in which the electronic components Wb are attached using a thermally peelable adhesive tape or an ultraviolet-curable resin that is cured by exposure to ultraviolet light.

[0018] As examples of the film F, a film material having excellent heat resistance, peelability, flexibility, and extensibility, such as PTFE (polytetrafluoroethylene), ETFE (polytetrafluoroethylene polymer), PET, FEP, fluorine-impregnated glass cloth, polypropylene, polyvinylidine chloride, etc. are preferably used. The film F is also used when forming the sealing resin R in the forming device 100 described later.

[0019] As shown in Fig. 1, the compression molding apparatus 1 mainly comprises a supply unit 10A for supplying the workpiece W, a press unit 10B for sealing the workpiece W with resin and processing it into a molded product Wp, and a storage unit 10C for storing the molded product Wp. As an example, the supply unit 10A, the press unit 10B, and the storage unit 10C are arranged in this order along the X direction in Fig. 1. However, the above configuration is not limited to this, and the equipment configuration within the unit, the number of units (particularly the number of press units), the arrangement order of the units, and the like can be changed. Also, a configuration including units other than those described above (all not shown) is possible.

[0020] In addition, in the compression molding apparatus 1, a guide rail 20 is provided linearly across each unit, and a transport device (first loader) 22 for transporting the workpiece W and the sealing resin R, and a transport device (second loader) 24 for transporting the molded product Wp (which may be used to transport the sealing resin R) are provided so as to be movable between predetermined units along the guide rail 20. However, the configuration is not limited to the above, and a configuration may be provided with a common (single) transport device (loader) for transporting the workpiece W, the sealing resin R, and the molded product Wp (not shown). Also, the transport device may be configured to include a robot hand or the like instead of a loader.

[0021] In addition, in the compression molding apparatus 1, a control unit 30 that controls the operation of each mechanism in each unit is disposed in the supply unit 10A (it may be disposed in another unit).

[0022] The press unit 10B includes a pair of sealing dies that are opened and closed by a press device 250. As an example, the sealing dies may be configured such that a cavity is provided in an upper die (sealing die 202), or as another example, may be configured such that a cavity is provided in a lower die (sealing die 302). The press device 250 is also provided with a film supply unit 211 that supplies a film F for covering a die surface 204a (predetermined area) including the inner surface of the cavity 208 in the upper die 204. As an example, the film F is in a roll shape, but may also be in a rectangular shape.

[0023] As an example, steps of a compression molding method performed using a compression molding apparatus 1 equipped with a sealing mold 202 will be described with reference to Figs. 2 to 6. In this embodiment, an example will be described in which a molded product Wp is formed in which a predetermined portion (specifically, the upper surface (referring to the surface opposite to the substrate Wa side) of an electronic component Wb such as a heat sink, i.e., the cooling surface) Wbf of the heat sink is exposed. Note that, for simplicity of explanation, the electronic component Wb on the substrate Wa is treated as one component, but it may be composed of multiple laminated components.

[0024] First, a preparation step (sealing preparation step) is performed. Specifically, a step of adjusting and heating the upper mold 204 and the lower mold 206 to a predetermined temperature (for example, 100°C to 300°C) is performed. Also, a step of operating the film supply unit 211 to supply new film F and adsorb it to cover a predetermined area of ​​the mold surface 204a including the inner surface of the cavity 208 in the upper mold 204 is performed.

[0025] After the preparation step, a workpiece holding step is performed in which the workpiece W is held by the workpiece holding portion 205 of the lower die 206. Specifically, the workpiece W supplied from the supply magazine 12 is held by the first loader 22 and carried into the sealing die 202, and is held by the workpiece holding portion 205 of the lower plate 242 (die surface 206a) (see FIG. 2).

[0026] After the work holding step, a resin placing step is performed in which the sealing resin R is placed on the work W held by the work holding part 205 (see FIG. 3). Specifically, the sealing resin R formed in a sealing resin forming device (which may simply be referred to as a "forming device") 100 described later is held by a first loader 22 (or another conveying device may be used) and carried into the sealing mold 202, and placed on the work W held by the work holding part 205. When forming a molded product Wp in which the upper surface Wbf of the electronic component Wb is exposed, the work W and the sealing resin R are aligned with each other and placed so that the electronic component Wb is accommodated in a through hole Rh (described in detail later) of the sealing resin R.

[0027] Alternatively, as another example of the resin placing step, the sealing resin R formed in the forming apparatus 100 may be placed on the workpiece W before the above-described workpiece holding step. In this case, the workpiece holding step is a step of holding the workpiece W with the sealing resin R placed thereon in the workpiece holding section 205. That is, the first loader 22 holds the workpiece W with the sealing resin R placed thereon, carries it into the sealing die 202, and holds it in the workpiece holding section 205. This has the advantage of performing the workpiece W and the sealing resin R in the sealing die 202 at once, rather than separately.

[0028] Next, a resin sealing process is performed in which the workpiece W is sealed with sealing resin R and processed into a molded product Wp. Specifically, the sealing mold 202 is closed, and the cavity piece 226 is relatively lowered in the cavity 208 surrounded by the clamper 228 to perform a mold closing process in which the sealing resin R is heated and pressurized against the workpiece W.

[0029] When forming a molded product Wp in which the top surface Wbf of the electronic component Wb is exposed, the sealing mold 202 (upper die 204 in this case) preferably has the following configuration. Specifically, the cavity piece 226 is provided with a movable piece 236 that abuts against the entire top surface Wbf of the electronic component Wb and is vertically movable. The movable piece 236 is supported in a state in which it is biased toward the lower die 206 by a movable piece spring 234 via a pressing pin 232. As an example, the movable piece 236 is set to have an outer shape that is a predetermined dimension larger than the outer shape of the electronic component Wb in a plan view.

[0030] The mold closing process performed using the sealing die 202 having this configuration is as follows. Specifically, the upper mold 204 and the lower mold 206 are moved closer to each other. At this time, the clamper 228 first comes into contact with the base material Wa of the work W to clamp the work W (see FIG. 4A). Next (or at the same time), the movable piece 236 comes into contact with the upper surface Wbf of the electronic component Wb of the work W to cover the entire upper surface Wbf (see FIG. 4B). Next, the lower surface of the cavity piece 226 (the area where the movable piece 236 is not provided) comes into contact with the sealing resin R placed on the base material Wa of the work W, and further pressurizes it. Through this mold closing process, the sealing resin R is thermally cured to complete the resin sealing (compression molding) (see FIG. 5).

[0031] As a step following the mold closing step, the sealing mold 202 is opened and the molded product Wp is separated from the used film F to enable removal of the molded product Wp (see FIG. 6). In this embodiment, as described above, resin sealing is performed with the movable piece 236 covering the top surface Wbf (entire surface) of the electronic component Wb of the workpiece W, so that the molded product Wp is formed with the top surface Wbf (entire surface) exposed. As a modified example, it is also possible to set only a partial area as the exposed portion, rather than the entire top surface Wbf of the electronic component Wb (not shown).

[0032] Next, a molded product carrying-out process is performed in which the second loader 24 carries out the molded product Wp from inside the sealing die 202 and transports it to the storage unit 10C. As an example, the transported molded product Wp is stored in the storage magazine 14. In addition, after or in parallel with the molded product carrying-out process, a process is performed in which the film supply unit 211 is operated to send out the used film F from inside the sealing die 202 and send a new film F into the sealing die 202 and set it therein.

[0033] The above are the main steps of the compression molding method performed using the compression molding apparatus 1 when the sealing mold 202 is provided. However, the above order of steps is only an example, and the order of steps can be changed or steps can be performed in parallel as long as there is no problem.

[0034] As another example, steps of a compression molding method performed using a compression molding apparatus 1 equipped with a sealing mold 302 will be described with reference to Figs. 7 to 9. In this case, the press device 250 is provided with a film supply unit 311 that supplies a film F for covering a mold surface 306a (predetermined area) including the inner surface of a cavity 308 in a lower mold 306. Note that, as one example, the film F is in a roll shape, but it may also be in a rectangular shape.

[0035] First, a preparation step (sealing preparation step) is performed. Specifically, a step of adjusting and heating upper mold 304 and lower mold 306 to a predetermined temperature (for example, 100°C to 300°C) is performed. Also, a step of operating film supply unit 311 to supply new film F and adsorb it to cover a predetermined area of ​​mold surface 306a including the inner surface of cavity 308 in lower mold 306 is performed.

[0036] After the preparation step, a workpiece holding step is performed in which the workpiece W is held by the workpiece holding portion 305 of the upper die 304. Specifically, the workpiece W supplied from the supply magazine 12 is held by the first loader 22 and carried into the sealing die 302, and is held by the workpiece holding portion 305 of the upper plate 342 (die surface 304a).

[0037] After the workpiece holding step, a resin holding step is performed (it may be performed before or in parallel with the workpiece holding step). The resin holding step includes the following steps: The sealing resin R is held in the cavity 308 of the lower die 306 (see FIG. 7). Specifically, the sealing resin R formed in the forming device 100 is held by the first loader 22 (or another conveying device) and carried into the sealing die 302, and accommodated in the cavity 308 (specifically, placed on the upper surface of the cavity piece 326). When forming a molded product Wp in which the upper surface Wbf of the electronic component Wb is exposed, the workpiece W and the sealing resin R are aligned with each other and held so that the electronic component Wb is accommodated in the through hole Rh of the sealing resin R (details will be described later).

[0038] Next, a resin sealing process is performed in which the workpiece W is sealed with sealing resin R and processed into a molded product Wp. Specifically, the sealing mold 302 is closed, and the cavity piece 326 is relatively raised in the cavity 308 surrounded by the clamper 328 to perform the mold closing process in which the sealing resin R is heated and pressurized against the workpiece W. This thermally hardens the sealing resin R, completing the resin sealing (compression molding) (see FIG. 8).

[0039] In this example (when the sealing die 302 is provided), the cavity piece 326 of the lower die 306 may be provided with a movable piece 336, a pushing pin 332, and a movable piece spring 334 configured in the same manner as in the above example (when the sealing die 202 is provided). This allows the upper surface Wbf of the workpiece W (electronic component Wb) that comes into contact with the movable piece 236 to be formed as an exposed surface.

[0040] As a step following the mold closing step, a mold opening step is performed in which the sealing mold 302 is opened and the molded product Wp is separated from the used film F so that the molded product Wp can be removed (see FIG. 9). Next, a molded product carrying-out step is performed in which the second loader 24 carries the molded product Wp out of the sealing mold 302 and transports it to the storage unit 10C. As an example, the transported molded product Wp is stored in the storage magazine 14. In addition, after or in parallel with the molded product carrying-out step, a step is performed in which the film supply unit 311 is operated to send out the used film F from the sealing mold 302 and send a new film F into the sealing mold 302 and set it therein.

[0041] The above are the main steps of the compression molding method performed using the compression molding apparatus 1 when the sealing mold 302 is provided. However, the above order of steps is only an example, and the order of steps can be changed or steps can be performed in parallel as long as no problems occur.

[0042] (Sealing resin forming device) Next, a forming apparatus 100 for forming the sealing resin R used in the compression molding apparatus 1 and the compression molding method will be described with reference to Figs. 10 and 11. The forming apparatus 100 processes a base resin Rm to form the sealing resin R. Here, Fig. 10 is a side view (schematic view) showing an example of the forming apparatus 100. The forming apparatus 100 may be provided either inside or outside the compression molding apparatus 1.

[0043] In this embodiment, a thermosetting resin (for example, an epoxy resin containing a filler, but not limited thereto) is used as the base resin Rm and the sealing resin R formed from the base resin Rm. The sealing resin R is formed as a solid or semi-solid resin having a predetermined shape (details will be described later) that corresponds to the shape of the workpiece W. Usually, one piece constitutes the "whole" of the required amount of sealing (one time per workpiece W), but it may be configured so that several pieces (for example, about two or three pieces) are divided to constitute the "whole" of the required amount of sealing. In addition, the above-mentioned "semi-solid" does not mean a completely solid state, but a state in which it is melted to the so-called B stage. In addition, a powder resin (form) that is a thermosetting resin (property) is preferably used for the base resin Rm (details will be described later). However, it is not limited thereto, and a granular resin, a crushed resin, a solid resin, a liquid resin, or a resin that is a combination of a plurality of them may be used.

[0044] As shown in Fig. 10, the forming apparatus 100 is equipped with a tableting die 102 having a pair of dies that are opened and closed (for example, a combination of a plurality of die blocks, die plates, die pillars, and other members made of alloy tool steel). It also has a press device 150 that drives the tableting die 102 to open and close. It also has a control calculation unit 170 that controls the operation of each mechanism. Here, Fig. 11 is a side cross-sectional view (schematic diagram) showing an example of the tableting die 102.

[0045] As shown in FIG. 10, the press machine 150 includes a pair of platens 154, 156, a plurality of tie bars 152 on which the pair of platens 154, 156 are supported, and a drive device for moving (raising and lowering) the platen 156. Specifically, the drive device includes a drive source (e.g., an electric motor) 160 and a drive transmission mechanism (e.g., a ball screw or a toggle link mechanism) 162 (however, the present invention is not limited to this). In this embodiment, the platen 154 on the upper side in the vertical direction is set as a fixed platen (a platen fixed to the tie bars 152), and the platen 156 on the lower side is set as a movable platen (a platen slidably held by the tie bars 152 and raised and lowered). However, the present invention is not limited to this, and the platens may be set upside down, i.e., the upper side may be set as a movable platen and the lower side as a fixed platen, or both the upper side and the lower side may be set as movable platens (neither is shown).

[0046] On the other hand, as shown in Fig. 11, the tableting die 102 includes an upper die 104 on the upper side in the vertical direction and a lower die 106 on the lower side as a pair of dies disposed between the pair of platens 154, 156 in the press device 150. The upper die 104 is assembled to the upper platen (in this embodiment, the fixed platen 154), and the lower die 106 is assembled to the lower platen (in this embodiment, the movable platen 156). The upper die 104 and the lower die 106 approach and move away from each other to close and open the die (the vertical direction (up and down direction) is the die opening and closing direction). In the tableting die 102 according to this embodiment, the upper die 104 constitutes a so-called "punch die", and the lower die 106 constitutes a so-called "mortar die".

[0047] Next, the lower die 106 of the tableting die 102 will be described in detail. As shown in Fig. 11, the lower die 106 is equipped with a lower die chase 110, a cavity piece 126 held thereby, a clamper 128, etc. The lower die chase 110 is fixed to the upper surface of a support plate 114 via a support pillar 112. A cavity 108 is provided on the upper surface of the lower die 106 (the surface on the upper die 104 side). A predetermined amount of base resin Rm is accommodated in this cavity 108.

[0048] The lower die 106 according to the present embodiment has the following configuration for pressing a predetermined amount of base resin Rm contained in the cavity 108 to form (tablet) the sealing resin R having a predetermined shape corresponding to the shape of the workpiece W (details of the forming method will be described later). Specifically, a movable piece 136 that can abut against a tableting plate 142 of the upper die 104 described later and can move up and down is provided in the cavity piece 126 (within the area of ​​the cavity piece 126 in a plan view). The movable piece 136 is supported in a state in which it is biased toward the upper die 104 by a movable piece spring 134 via a pushing pin 132. As an example, the movable piece 136 is set to have an outer shape that is a predetermined dimension larger than the outer shape of the electronic component Wb in a plan view. In the lower mold 106 having the above-mentioned configuration, a predetermined amount of base resin Rm is accommodated in the concave portion 138 between the movable pieces 136 (it is also possible to first spray the base resin Rm over the entire cavity 108 including the upper surface of the movable piece 136, and then sweep it down with a squeegee or the like so that it is finally accommodated in the concave portion 138).

[0049] The clamper 128 is formed in an annular shape so as to surround the cavity piece 126, and is assembled to be movable up and down while being spaced apart (floating) from the upper surface of the support plate 114 via the pushing pin 122 and the clamper spring 124 (a biasing member exemplified by a coil spring, for example) (however, the assembly structure is not limited to this). The cavity piece 126 constitutes the inner part (bottom part) of the cavity 108, and the clamper 128 constitutes the side part of the cavity 108. The shape and number of cavities 108 provided in one lower mold 106 are set appropriately (one or multiple).

[0050] Here, the press device 150 is provided with a lower die film supplying section 111 that supplies a film F for covering the die surface 106a (predetermined area) including the inner surface of the cavity 108 in the lower die 106. Note that, as an example, the film F is in a roll shape, but it may also be in a rectangular shape.

[0051] Furthermore, the lower mold 106 is provided with suction paths (holes, grooves, etc.) (not shown) communicating with a suction device on the upper surface of the clamper 128, on the boundary between the clamper 128 and the cavity piece 126, etc. This allows the film F supplied from the lower mold film supply unit 111 to be adsorbed and held on the mold surface 106a including the inner surface of the cavity 108.

[0052] In this embodiment, a lower die heating mechanism (not shown) is provided to heat the lower die 106 to a predetermined temperature. This lower die heating mechanism includes a heater (e.g., an electric wire heater), a temperature sensor, a power source, etc., and heating is controlled by the control unit 30. As an example, the heater is built into the lower die chase 110 and is configured to apply heat to the entire lower die 106 and the base resin Rm contained in the cavity 108. At this time, the lower die 106 is heated to a predetermined temperature (e.g., 50°C to 80°C) at which the base resin Rm does not thermally cure (mainly cure).

[0053] Next, the upper die 104 of the tableting die 102 will be described in detail. As shown in FIG. 11, the upper die 104 is provided with a tableting plate 142 that presses a predetermined amount of base resin Rm contained in the cavity 108 of the lower die 106 to form (tablet) the sealing resin R having a predetermined shape corresponding to the shape of the workpiece W (details of the forming method will be described later). The tableting plate 142 is held (fixed) by the upper die chase 140. In this embodiment, a convex portion 144 that can abut against the movable piece 136 of the lower die 106 described above is provided on the lower surface (the surface on the lower die 106 side) of the tableting plate 142. As an example, the convex portion 144 is set so as to have an outer shape that can abut against the upper surfaces of all the movable pieces 136 and cover all the concave portions 138 in a plan view, and is erected at a predetermined height (set according to the formed thickness of the sealing resin R) on the lower surface of the tableting plate 142.

[0054] Here, the press device 150 is provided with an upper die film supplying section 113 that supplies a film F for covering the die surface 104a (predetermined area) of the upper die 104. Note that, as an example, the film F is in a roll shape, but it may also be in a rectangular shape.

[0055] Furthermore, the upper die 104 is provided with suction paths (holes, grooves, etc.) (not shown) communicating with a suction device on the tableting plate 142, etc. This allows the film F supplied from the upper die film supply unit 113 to be adsorbed and held on the die surface 104a.

[0056] In this embodiment, an upper die heating mechanism (not shown) is provided for heating the upper die 104 to a predetermined temperature. This upper die heating mechanism includes a heater (e.g., an electric wire heater), a temperature sensor, a power source, etc., and heating is controlled by the control unit 30. As an example, the heater is built into the upper die chase 140 and is configured to apply heat to the entire upper die 104. At this time, the upper die 104 is heated to a predetermined temperature (e.g., 50°C to 80°C) at which the base resin Rm held (contained) in the lower die 106 is not thermally cured (mainly cured).

[0057] (Method of forming sealing resin) Next, there will be described steps of the sealing resin forming method according to the present embodiment, which is carried out using the above-mentioned forming apparatus 100. Here, Fig. 12 to Fig. 14 are explanatory views of each step, and are illustrated as side cross-sectional views in the same direction as Fig. 11.

[0058] First, a preparation step (tabletting preparation step) is performed. The preparation step includes the following steps. A lower mold heating step is performed in which the lower mold 106 is adjusted to a predetermined temperature (a temperature at which the base resin Rm and the sealing resin R do not fully cure, for example, 50°C to 80°C) and heated by the lower mold heating mechanism. In addition, an upper mold heating step is performed in which the upper mold 104 is adjusted to a predetermined temperature (a temperature at which the base resin Rm and the sealing resin R do not fully cure, for example, 50°C to 80°C) and heated by the upper mold heating mechanism. In addition, a lower mold film supplying step is performed in which the lower mold film supplying unit 111 is operated to supply a new film F and adsorb it so as to cover a predetermined area of ​​the mold surface 106a including the inner surface of the cavity 108 in the lower mold 106. In addition, an upper mold film supplying step is performed in which the upper mold film supplying unit 113 is operated to supply a new film F and adsorb it so as to cover a predetermined area of ​​the mold surface 104a of the upper mold 104.

[0059] After the preparation step, a forming step is carried out in which the encapsulating resin R is formed into a "predetermined shape" (details will be described later). As an example, a tableting step is provided in which the base resin Rm is tableted to form, as the encapsulating resin R, a solid or semi-solid resin having a predetermined overall shape corresponding to the shape of the workpiece W. Note that, as another example of the forming step, a forming method other than tableting may be adopted.

[0060] Specifically, the above tableting step involves placing a "predetermined amount" (details to be described later) of base resin Rm in cavity 108 of lower die 106 using a dispenser or the like (not shown) (see FIG. 12). As described above, the base resin Rm is placed in recessed portion 138 between movable pieces 136 while being prevented from resting on the upper surface of each movable piece 136 (note that the base resin Rm may first be sprayed over the entire cavity 108 including the upper surface of each movable piece 136, and then swept off with a squeegee or the like, and finally placed in recessed portion 138).

[0061] Next, the press device 150 is operated to close the tableting die 102 that has been heated to the above-mentioned predetermined temperature (see FIG. 13). At this time, the cavity piece 126 rises relatively within the cavity 108, and the base resin Rm is tableted (sandwiched and pressurized) between the cavity piece 126 and the tableting plate 142.

[0062] More specifically, first, the clamper 128 and the tableting plate 142 (outer part than the convex part 144) come into contact with each other. Then (or at the same time), the upper surface of the movable piece 136 comes into contact with the lower surface of the convex part 144 of the tableting plate 142, so that the entire upper surface of the movable piece 136 is covered. Next, the base resin Rm is tableted (sandwiched and pressed) between the upper surface (region of the concave part 138) of the cavity piece 126 and the lower surface (region facing the concave part 138) of the convex part 144 of the tableting plate 142. This forms a solid or semi-solid sealing resin R that has a "predetermined shape" and is not yet thermoset (mainly cured). Specifically, the "predetermined shape" is a frame-like or lattice-like shape that is approximately plate-like and has through-holes Rh penetrating the plate surface. In this embodiment, the base resin Rm around the movable piece 136 of the lower die 106 (concave portion 138) is formed as the main body portion Ra of the sealing resin R by the above-mentioned forming process (tabletting process in this case), and the position of the movable piece 136 is formed as a through-hole Rh. Note that although the movable piece 136 is provided on the cavity piece 126, it may be provided on the tableting plate 142 (not shown).

[0063] An example of the configuration (shape) of the sealing resin R formed in the above process is shown in Fig. 15. Specifically, this is an example of a lattice-shaped sealing resin R in which a plurality of through holes Rh are arranged in a plate-shaped main body Ra (however, the present invention is not limited to this). The sealing resin R may be configured so that one piece of the sealing resin R constitutes the "whole" (in this case, lattice-shaped) amount required for sealing (one application per workpiece W), or may be configured so that a collection (connection) of a plurality of pieces (e.g., about two or three pieces) constitutes the "whole" (in this case, lattice-shaped) amount required for sealing.

[0064] The above-mentioned sealing resin R (see FIG. 15) can be suitably used in compression molding of a workpiece W (see FIG. 16) in which a heat sink or the like is mounted as an electronic component Wb on a base material Wa. Specifically, by using the above-mentioned sealing resin R, it is possible to reliably form a configuration in which the upper surface Wbf of the electronic component Wb (heat sink or the like) is exposed in a molded product Wp (see FIG. 17) after resin sealing (after compression molding).

[0065] Therefore, in the above-mentioned forming process, it is important to set the position and shape of the through hole Rh of the sealing resin R so that the electronic component Wb of the workpiece W to be sealed is accommodated in the through hole Rh and the upper surface Wbf of the electronic component Wb is exposed.

[0066] It is important that the above tableting step is carried out at a temperature at which the base resin Rm does not undergo thermal curing (full curing) (the lower die 106 and the upper die 104 are heated to a temperature at which the base resin Rm does not undergo thermal curing (full curing)) so that the encapsulating resin R formed can be thermally cured (full cured) in the subsequent resin encapsulating step (a step of the compression molding method). As described above, the "temperature at which the base resin Rm does not undergo thermal curing (full curing)" varies depending on the material of the base resin Rm, but is specifically about 50°C to 80°C (about 70°C in this embodiment).

[0067] Next, a resin amount setting step for setting the "predetermined amount" of the base resin Rm will be described. As an example of the resin amount setting step, for each workpiece W to be sealed, the number of electronic components Wb mounted on one substrate Wa (the number of mounted or missing components, and may further include measuring the height or weight of the electronic components Wb) is measured by a measuring mechanism or the like (not shown), and the total volume of the electronic components Wb is subtracted from the volume of the cavities 208, 308 of the sealing molds 202, 302 to calculate the amount of resin (in grams) required for resin sealing (compression molding), and set the "predetermined amount". Alternatively, as another example of the resin amount setting step, multiple types of fixed amounts corresponding to the types of workpieces W to be sealed are prepared, and the control calculation unit 170 or the operator selects one of the fixed amounts that is optimal according to the type of workpiece W to set the "predetermined amount". In the case of the fixed amount, it is important that the amount of resin is not insufficient during resin sealing (compression molding). Regardless of the setting, an appropriate amount of base resin Rm can be supplied according to the type of workpiece W. As a result, an appropriate amount of sealing resin R can be accurately formed for each workpiece W. This makes it possible to prevent molding defects caused by a shortage of the amount of resin required during resin sealing. It is also possible to prevent waste caused by supplying an amount of resin that is greater than necessary. In particular, when forming a molded product Wp on which an electronic component Wb, such as a heat sink, is mounted, it is possible to prevent molding defects in which a predetermined portion of the electronic component Wb, (for example, the upper surface, i.e., the cooling surface, of the heat sink) Wbf, is not exposed.

[0068] In addition, it is preferable to use a powder resin as the base resin Rm. This allows the "predetermined amount" of resin to be adjusted and supplied with extremely high accuracy compared to the case where a granular resin or a crushed resin is used. However, the base resin Rm is not limited to a powder resin.

[0069] After the tableting step, a mold opening step is performed in which the tableting mold 102 is opened and the sealing resin R and the used film F are separated to enable removal of the sealing resin R (see FIG. 14). In this embodiment, by providing the lower mold film supplying step and the upper mold film supplying step described above, the film F is disposed on both the mold surface 106a of the lower mold 106 and the mold surface 104a of the upper mold 104, so that the sealing resin R formed by tableting can be easily released and damage due to adhesion of the resin to the mold can be prevented.

[0070] After or in parallel with the mold opening process, the lower mold film supply unit 111 and the upper mold film supply unit 113 are operated to send out the used film F from within the tableting mold 102 and to send and set a new film F into the tableting mold 102, thereby carrying out a film supply process (lower mold film supply process, upper mold film supply process).

[0071] The above process order is merely an example, and the order of steps can be changed or steps can be performed in parallel as long as no problems occur.

[0072] As described above, the sealing resin according to the present invention can be suitably applied to a compression molding apparatus and a compression molding method having a cavity in either an upper mold or a lower mold.

[0073] In addition, by using the sealing resin according to the present invention, a compression molding apparatus and a compression molding method that have the following effects can be realized. Specifically, the compression molding apparatus and the compression molding method can prevent molding defects caused by resin flow, uneven winding, residual gas, and dust generation during molding. In particular, when a heat sink or the like is mounted as an electronic component, molding defects such as a predetermined portion of the electronic component (for example, the upper surface of the heat sink, i.e., the cooling surface) not being exposed in the molded product can be prevented. In addition, not only thin molded products (thickness dimension less than 1 mm) but also thick molded products (thickness dimension 1 mm or more) can be formed. Note that the upper limit of the thickness dimension depends on various setting conditions, but it is considered that it is possible to form a thickness dimension of up to about 10 mm. In addition, handling during supply and setting becomes easy.

[0074] The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the present invention. In particular, a heat sink is used as an example of an electronic component, but the present invention is not limited thereto. In addition, the entire top surface of an electronic component is used as an example of an exposed portion, but the present invention is not limited thereto. [Explanation of symbols]

[0075] 1. Compression molding equipment 100 Sealing resin forming device 102 Tablet pressing mold 138 Concave part 144 Convex part 202, 302 Sealing mold 236, 336 Movable piece Rm Base Resin R Sealing resin Ra Main unit Rh through hole Double work Wa base material Wb electronic components

Claims

1. A method for forming a sealing resin used in compression molding of a workpiece having a configuration in which an electronic component is mounted on a substrate, comprising the steps of: forming the sealing resin in a frame or lattice shape having through holes; The forming step includes a step of setting and forming a position and shape of the through hole so that the electronic component of the workpiece is housed in the through hole and an upper surface of the electronic component is exposed. A method for forming a sealing resin comprising the steps of:

2. The forming step includes a step of tableting a base resin to form the sealing resin.

2. The method for forming the sealing resin according to claim 1,

3. A powder resin is used as the base resin.

3. The method for forming a sealing resin according to claim 2, further comprising the steps of:

4. A forming apparatus for tableting a base resin to form an encapsulating resin to be used in compression molding of a workpiece, comprising: A tableting die is provided which accommodates the base resin and tablets the sealing resin into a frame-like or lattice-like shape having through holes corresponding to the shape of the workpiece. The sealing resin forming apparatus is characterized by the above.

5. A sealing resin used in compression molding of a workpiece, The frame or lattice shape is formed with through holes. The sealing resin is characterized by:

6. A sealing resin used in compression molding of a workpiece having a configuration in which an electronic component is mounted on a substrate, The electronic component is formed in a shape having a through hole that houses the electronic component when placed on the base material and exposes the top surface of the electronic component. The sealing resin is characterized by:

7. The plate is formed in a frame or lattice shape having the through holes. The sealing resin according to claim 6 .

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