Method for manufacturing a resin molded article

Abstract

The present invention suppresses generation of resin dregs at the time of resin molding, and is a resin molding product (P) manufacturing method for manufacturing a resin molding product (P) by resin sealing a molding object (W) using a plunger (51) to extrude resin material (J) housed in a groove (21) of a lower mold (2) into a mold cavity (31) of an upper mold (3), wherein in the resin molding product (P) manufacturing method, a covering body (7) that surrounds the resin material (J) while being open to a direction in which the resin material (J) is extruded is arranged between an inner surface of the groove (21) and the resin material (J), and the resin material (J) surrounded by the covering body (7) is extruded into the mold cavity (31) by the plunger (51).

Description

Technical Field

[0001] This invention relates to a method for manufacturing resin molded articles. Background Technology

[0002] As a resin molding method that uses resin material for resin molding, there is a method that uses a plunger to extrude resin material contained in a groove of a molding die into a cavity of the molding die, thereby sealing the molded object with resin.

[0003] Here, resin dust is generated during the transport or installation of the resin material contained in the tank. This resin dust not only adversely affects the sealing equipment but also requires cleaning. Therefore, as a method to prevent dust generated from the resin material, the resin particles shown in Patent Document 1 can be considered. These resin particles form a dust-proof film containing a paste or wax on their surface to suppress the generation of resin dust.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 11-291242 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, even when using resin materials as described above, resin residue adheres to the inner surface of the mold, causing contamination for subsequent resin molding and increasing the sliding resistance of the plunger, thus shortening the lifespan of the mold or plunger. Furthermore, when the resin material contained in the mold is extruded through the plunger, molten resin material can penetrate the inner surface of the mold and the sliding portion of the plunger, accumulating resin residue at the bottom of the plunger. Thus, resin residue refers to the residual residue (debris) that remains on the inner surface of the mold and the sliding portion of the plunger when the resin material is extruded from the mold cavity through the plunger, instead of being transferred out of the mold. To address this problem, reducing the distance between the inner surface of the mold and the sliding portion of the plunger can prevent resin material from penetrating the sliding portion; however, this increases the sliding resistance of the plunger, further shortening the lifespan of the mold or plunger.

[0009] Therefore, the present invention was made to solve the aforementioned problems, and its main objective is to suppress the generation of resin residue during resin molding.

[0010] Technical means to solve the problem

[0011] That is, the resin molding article manufacturing method of the present invention manufactures a resin molding article by using a plunger to extrude resin material contained in a groove of a molding die into a cavity of the molding die, thereby sealing the molded object with resin. The resin molding article manufacturing method is characterized in that a cover body surrounding the resin material is disposed between the inner surface of the groove and the resin material, while opening the direction in which the resin material is extruded, and the resin material surrounded by the cover body is extruded into the cavity by the plunger.

[0012] The effects of the invention

[0013] According to the present invention configured in this way, the generation of resin residue during resin molding can be suppressed. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view schematically illustrating the structure of a resin molding apparatus according to an embodiment of the present invention.

[0015] Figure 2 (a)~ Figure 2 (d) is a schematic diagram illustrating an example of a coating of resin material in the embodiment described above.

[0016] Figure 3 (a) to (c) in (1) Figure 3 (a) and (b) in (2) are schematic diagrams representing modified Example 1 and modified Example 2 of the coating that surrounds the resin material.

[0017] Figure 4 of (a), Figure 4 (b) is a schematic diagram representing a modified example 3 of a coating that surrounds the resin material.

[0018] Figure 5 of (a), Figure 5 (b) is a diagram illustrating a method for manufacturing a resin molded article according to the described embodiment.

[0019] Figure 6 (c) Figure 6 (d) is a diagram illustrating the method for manufacturing the resin molded article according to the embodiment.

[0020] Figure 7 of (e) Figure 7 (f) is a diagram illustrating the method for manufacturing the resin molded article according to the embodiment.

[0021] Figure 8 This is a graph showing the results of Experiment Example 1.

[0022] Figure 9 This is a graph showing the results of Experiment Example 2.

[0023] Figure 10 (a)~ Figure 10 Figure (e) shows various variations (a) to (e) of the tank and resin material.

[0024] Figure 11 (a)~ Figure 11 (c) shows (a) a perspective view, (b) a plan view, and (c) a cross-sectional view of a modified example of the groove and resin material.

[0025] Explanation of symbols

[0026] 2: Lower mold (forming mold)

[0027] 2H: Through hole

[0028] 3: Upper mold (forming mold)

[0029] 4: Lower mold retaining components

[0030] 5: Plunger Unit

[0031] 6: Drive mechanism

[0032] 7: Covered body

[0033] 7K: Cut

[0034] 20: Channel component

[0035] 21: Slot

[0036] 22: Installation Department

[0037] 31: Mold cavity

[0038] 32. J11: Rejection Tank Section

[0039] 33. J12: Flow channel section

[0040] 51: Plunger

[0041] 71: Segmentation

[0042] 100: Resin molding device

[0043] A, B: General resins

[0044] C: MUF resin

[0045] J: Resin materials

[0046] J1: Useless resin

[0047] L1: Width dimension

[0048] L2: Length dimension

[0049] P: Resin molded products

[0050] W: Shaped object

[0051] Wx: Electronic Components Detailed Implementation

[0052] Next, examples will be given to illustrate the invention in more detail. However, the invention is not limited to the following description.

[0053] As described above, the method for manufacturing resin molded articles of the present invention manufactures resin molded articles by using a plunger to extrude resin material housed in a groove of a molding die into a cavity of the molding die, thereby sealing the molded object with resin. The method for manufacturing resin molded articles is characterized in that a cover body surrounding the resin material is disposed between the inner surface of the groove and the resin material, while opening the direction in which the resin material is extruded, and the resin material surrounded by the cover body is extruded into the cavity by the plunger.

[0054] In the method for manufacturing the resin molded article, a cover is disposed between the inner surface of the tank and the resin material, thereby preventing the resin material from touching the inner surface of the tank and reducing resin residue adhering to the inner surface of the tank. Furthermore, since the resin material is surrounded by the cover, even with high-flow resins such as molded underfill (MUF) resin or clear resin, the molten resin material is less likely to penetrate into the inner surface of the tank and the sliding portion of the plunger, thus reducing resin residue generated by resin material penetrating into the sliding portion. Here, since the cover opens the direction in which the resin material is extruded, it does not hinder the plunger from extruding the resin material.

[0055] By reducing resin residue in this way, contamination of the next resin molding process can be reduced, thereby improving the quality of the resin-molded products. Furthermore, equipment malfunctions caused by resin residue can be prevented, and the frequency of cleaning operations can be reduced. Moreover, by using a coating, the design of reducing the distance between the inner surface of the tank and the plunger, as before, can be eliminated, preventing an increase in the sliding resistance of the plunger and thus extending the lifespan of both the tank and the plunger.

[0056] Ideally, as a specific embodiment of the coating, the coating is sheet-like and disposed in the groove in a state of being wound around the resin material. Wrapping the sheet-like coating around the resin material in this way simplifies the structure of the coating and reduces processing costs.

[0057] To prevent molten resin material from easily penetrating the inner surface of the tank and the sliding part of the plunger, it is ideal for the cover to be in close contact with the inner surface of the tank. By making such close contact with the inner surface of the tank, the cover covers the periphery of the front end face of the plunger, blocking the inner surface of the tank and the sliding part of the plunger, thus preventing molten resin material from easily penetrating the sliding part.

[0058] Ideally, the coating material should be in close contact with the inner surface of the tank via an internal pressure exerted by the resin material that has melted or softened within the tank. This internal pressure is generated either by the molten or softened resin material being pressed circumferentially by the plunger during injection, or by the molten or softened resin material being pressed circumferentially by the plunger and the ejector pool of the forming die. With this structure, it is not necessary for the coating material to be in close contact with the inner surface of the tank when it is placed in the tank, thus allowing for easy placement.

[0059] To prevent resin residue from adhering to the front end face of the plunger, it is ideal that the coating is also disposed within the groove between the resin material and the plunger.

[0060] In order to prevent the coating or its components from being introduced into the mold cavity along with the molten resin material, it is ideal that the coating is made of a material that does not melt or thermally decompose at the molding temperature.

[0061] Specifically, the covering material may be made of paper, resin, cellulose, woven fabric, nonwoven fabric, or a composite material containing at least two of these.

[0062] In order to facilitate the extrusion of the resin material surrounded by the cover into the mold cavity, it is ideal that the cover has a slit at the open end on the side where the resin material is extruded.

[0063] As a specific embodiment of the resin molding apparatus used in the resin molding method of the present invention, it is conceivable that the groove of the molding die has a shape with different longitudinal and transverse dimensions when viewed from above. In the case of the structure described above, it is ideal that the resin material contained in the groove has different longitudinal and transverse dimensions corresponding to the groove when viewed from above.

[0064] As a specific embodiment of the resin material, the resin material can be in the form of powder, liquid, or plate. Furthermore, the powder form of the resin material is not limited to particle size. Additionally, the liquid form of the resin material includes, for example, a high-viscosity resin material such as a paste, regardless of viscosity. Furthermore, the plate form of the resin material can be, for example, a resin material thicker than the coating.

[0065] Although the coating is extruded from the groove along with the molten resin material, it is not fed into the mold cavity of the molding die. Instead, it remains in the ejector box or runner of the molding die after resin molding. Therefore, the coating is discarded along with the resin remaining in the ejector box or runner after resin molding.

[0066] <An embodiment of the present invention>

[0067] Hereinafter, an embodiment of the resin molding apparatus of the present invention will be described with reference to the accompanying drawings. Furthermore, all the figures shown below are depicted schematically or with exaggerated representations for ease of understanding. The same reference numerals are used for the same constituent elements, and descriptions are appropriately omitted.

[0068] <Overall Structure of the Resin Molding Device>

[0069] The resin molding apparatus 100 of this embodiment performs resin molding on a molding object W to which electronic components Wx are mounted by using transfer molding of resin material J.

[0070] Here, the object to be molded, W, can be, for example, a metal substrate, a resin substrate, a glass substrate, a ceramic substrate, a circuit board, a semiconductor substrate, a wiring board, a lead frame, etc., regardless of whether wiring is present or not. Furthermore, the resin material J used for resin molding is, for example, a composite material containing a thermosetting resin, and the resin material J is, for example, a solid form in the shape of a small cylindrical tablet. Additionally, the electronic component Wx mounted on the upper surface of the object to be molded, is, for example, a bare chip or a chip sealed in resin.

[0071] Specifically, such as Figure 1 As shown, the resin molding apparatus 100 includes: one molding mold 2 (hereinafter, lower mold 2) having a groove 21 for receiving resin material J; another molding mold 3 (hereinafter, upper mold 3) disposed opposite to the lower mold 2 having a cavity 31 for injecting resin material J; and a mold closing mechanism (not shown) for closing the lower mold 2 and the upper mold 3. The lower mold 2 is disposed on a movable platen (not shown) that is raised and lowered by the mold closing mechanism via a lower mold holding member 4. The upper mold 3 is disposed on an upper fixed platen (not shown) via an upper mold holding member (not shown). Furthermore, the lower mold holding member 4 may have, for example, a heat plate or an insulating plate.

[0072] In the lower mold 2, for example, a plurality of grooves 21 are formed by openings on the upper surface (mold surface) of the lower mold 2. Each groove 21 includes a through hole 2H formed in the lower mold 2, which is formed by inserting a cylindrical groove member 20, for example, made of superhard alloy or steel, into the lower mold 2. The groove 21 has a shape corresponding to the shape of the resin material J. In this embodiment, the resin material J is cylindrical, therefore the groove 21 also has a correspondingly circular cross-sectional shape. Furthermore, a mounting portion 22 for mounting the molded object W is formed on the upper surface of the lower mold 2.

[0073] Furthermore, a cavity 31 is formed on the lower surface (mold surface) of the upper mold 3, which accommodates the electronic component Wx of the object to be molded, W, which is mounted on the mounting portion 22 of the lower mold 2. Additionally, on the lower surface of the upper mold 3, a recess, namely a ejector pool portion 32, is formed in the portion of the lower mold 2 facing the groove 21, and a flow channel portion 33 is formed connecting the ejector pool portion 32 and the cavity 31.

[0074] Furthermore, the resin molding apparatus 100 includes: a plunger unit 5 having a plurality of plungers 51 for extruding resin material J contained in a plurality of grooves 21 of the lower mold 2; and a drive mechanism 6 for moving the plunger unit 5 in such a way that the plungers 51 move forward and backward within the grooves 21.

[0075] The plunger unit 5 is located below the lower mold 2, and the plunger 51 is inserted into the through hole 2H of the lower mold 2. Furthermore, the upper surface of the plunger 51 forms the bottom surface of the groove 21 of the lower mold 2. In addition, the plunger 51 presses the resin material J, which is heated and melted in the groove 21, from the groove 21 toward the upper mold 3.

[0076] The drive mechanism 6 causes the plunger unit 5 to move relative to the lower die 2, thereby causing the plunger 51 to move forward and backward within the groove 21. In this embodiment, the drive mechanism 6 is located on the side opposite to the lower die 2 (below the plunger unit 5). Here, the drive mechanism 6 can be, for example, a drive mechanism combining a servo motor and a ball screw mechanism, or a drive mechanism combining a cylinder or hydraulic cylinder and a rod, etc.

[0077] Furthermore, if the plunger unit 5 is raised while the lower mold 2 and upper mold 3 are closed by the mold closing mechanism, the resin material J molten by the heat of the heater (not shown) included in the resin molding apparatus 100 is injected into the mold cavity 31. This seals the electronic component Wx of the molded object W housed within the mold cavity 31 with resin.

[0078] <Characteristics of the method for manufacturing resin molded articles>

[0079] Next, the characteristic parts of the method for manufacturing a resin molded article P using the resin molding apparatus 100 will be described.

[0080] like Figure 1 As shown, when resin material J is contained in groove 21 of lower mold 2, cover 7 is arranged between the inner surface of groove 21 and resin material J in such a way that resin material J does not contact the inner surface of groove 21.

[0081] The coating 7 surrounds the entire circumference of the resin material J within the groove 21 while allowing the resin material J to be extruded in an open direction. Specifically, the coating 7 does not cover the upper surface of the resin material J within the groove 21, but surrounds the entire circumference of the outer periphery of the resin material J.

[0082] The coating 7 is a consumable material discarded during each resin molding process. Examples of coatings made of materials such as paper, resin, cellulose, woven fabric, non-woven fabric, or composites thereof are possible. Furthermore, as composite materials, composites with a resin film, such as a heat-resistant film of less than 10 μm, laminated on paper; composites with resin coated on paper; resin materials impregnated with resin on paper; and composites made by mixing pulp and resin fibers and forming paper are all considered. These coatings 7 are made of materials that do not melt or thermally decompose at the molding temperature (e.g., around 170°C) used for resin sealing with resin material J.

[0083] Specifically, such as Figure 2 As shown, the coating 7 is, for example, a rectangular sheet, and is disposed in the groove 21 in a state of being rolled around the outer peripheral surface of the resin material J. Here, as... Figure 2 As shown in the (d) unfolded diagram, the width dimension L1 of the cover 7 is the axial dimension of the entire outer circumference of the resin material J, and the length dimension L2 of the cover 7 is the dimension that allows it to be wound around the outer circumference of the resin material J more than once. By winding the sheet-like cover 7 around the resin material J in this way, the structure of the cover 7 can be simplified, and the processing cost can be reduced. Furthermore, when the width dimension L1 of the cover 7 is smaller than the axial dimension of the resin material J, it is possible to consider winding the cover 7 in a spiral shape around the outer circumference of the resin material J. In addition, the cover 7 can also be cylindrical. When the cover 7 is cylindrical, it can be a shape with a uniform cross-section in the axial direction, or it can be a conical shape in the axial direction where the diameter decreases from one side to the other.

[0084] Furthermore, the thickness of the coating 7 is greater than the gap between the inner surface of the groove 21 and the plunger 51, and is configured such that the coating 7 itself does not intrude into the inner surface of the groove 21 or the sliding portion of the plunger 51. For example, the gap is 10 μm, and the thickness of the coating 7 is 50 μm.

[0085] Furthermore, the coating 7 is configured to be in close contact with the inner surface of the groove 21. Specifically, the coating 7 is configured to be in close contact with the inner surface of the groove 21 by the internal pressure applied by the resin material J that melts or softens within the groove 21. In this embodiment, the structure is configured such that the coating 7 is wound around the resin material J and is not constrained in the circumferential direction. As a result, the coating 7 can easily expand radially by the internal pressure applied by the self-melting or softening resin material J, thereby easily making close contact with the inner surface of the groove 21. In addition, the so-called internal pressure applied by the self-melting or softening resin material J mainly refers to the circumferential expansion caused by the molten or softened resin material J being pressed by the plunger 51 during the injection action using the plunger 51, or the circumferential expansion caused by the molten or softened resin material J being pressed by the plunger 51 and the ejector pool portion 32 of the upper mold 3.

[0086] By configuring the coating 7 to be in close contact with the inner surface of the groove 21, the coating 7 blocks the inner surface of the groove 21 and the sliding part of the plunger 51, thereby making it less likely for the molten resin material J to penetrate into the sliding part. In addition, since the coating 7 is in close contact with the inner surface of the groove 21 by the internal pressure applied by the resin material J that melts or softens within the groove 21, it is not necessary to make the coating 7 in close contact with the inner surface of the groove 21 when placing the coating 7 in the groove 21, and the coating 7 can be easily placed in the groove 21.

[0087] In addition, as a structure in which the covering body 7 and the inner surface of the groove 21 are in close contact, the following structure can also be considered: the covering body 7 is made into a sheet-like elastic member and rolled into a circle and placed in the groove 21, thereby using the restoring force of the elastic member to make close contact with the inner surface of the groove 21.

[0088] Alternatively, the coating 7 can be disposed within the groove 21 between the resin material J and the upper surface of the plunger 51. This further reduces the adhesion of resin residue to the plunger 51. In this case, it is possible to design the coating 7 to cover not only the outer peripheral surface of the resin material J, but also the bottom surface.

[0089] For example, the following structure could be considered: Figure 3 As shown in (1), multiple serrations are engraved on the lower edge of the rectangular sheet-shaped cover 7 to form a segment 71. The cover 7 is wound around the resin material J, and the segment 71 is bent inward, thereby covering not only the outer peripheral surface of the resin material J, but also the bottom surface. Alternatively, it can be configured such that no serrations are engraved on the lower edge, but the sheet is simply bent inward.

[0090] Alternatively, the following structure could be considered: Figure 3As shown in (2), it has a cylindrical shape (cup shape) with a bottom. When the cover body 7 is provided as a cylindrical shape with a bottom, it can be provided as a cylindrical shape with a uniform cross-sectional shape in the axial direction, or it can be provided as a conical shape with a diameter that decreases from one side to the other in the axial direction. In addition, the cover body 7 can also be a structure in which the component covering the outer peripheral surface of the resin material J and the component covering the bottom surface of the resin material J are separate components.

[0091] Furthermore, such as Figure 4 As shown, the coating 7 may also have a slit 7K formed at the open end (here, the upper end) on the side where the molten resin material J is extruded. The slit 7K is shaped in a way that does not impede the flow of the molten resin material J, as shown in the figure. Figure 4 As shown in (a), linear notches are engraved at the opening end of the covering 7, or as shown in... Figure 4 As shown in (b), triangular or arc-shaped notches are made. In addition, the shape of the cut at the opening end of the covered body 7 should be such that the molten resin material J can easily flow from the top end to the cavity 31.

[0092] In addition, such as Figure 1 As shown, in this embodiment, the cover 7 is integrally housed within the groove 21, but it can also be configured such that the upper end of the cover 7 extends out of the groove 21. In this case, it can also be configured such that a flange is formed at the upper end of the cover 7, and the flange covers the periphery of the opening of the groove 21. Through the flange, the molten resin material J can be prevented from easily penetrating into the inner surface of the groove 21 and the sliding portion of the plunger 51.

[0093] Next, the method of placing the coating 7 between the inner surface of the groove 21 and the resin material J will be described.

[0094] As a method of placing the cover 7 between the inner surface of the groove 21 and the resin material J, the following methods can be listed: (1) placing the cover 7 in the groove 21 before the resin material J is contained in the groove 21; (2) covering the resin material J with the cover 7 before the resin material J is contained in the groove 21, thereby placing the cover 7 in the groove 21.

[0095] In (1), as a structure for arranging the cover 7 in the trough 21, a structure in which the cover 7 is arranged in the trough 21 via a cover 7 conveying mechanism (not shown) can be considered. In (2), as a structure for arranging the cover 7 in the trough 21, the following structures can be considered: outside the resin molding apparatus, a device is prepared in advance to cover the cover 7 with resin material J by a person or machine, and the cover 7 is arranged in the trough 21 via a resin material conveying mechanism (not shown); or a covering mechanism is provided inside the resin molding apparatus, which covers the resin material J by wrapping the cover 7 around the resin material J, and the resin material J covered by the cover 7 by the covering mechanism is arranged in the trough 21 via a resin material conveying mechanism (not shown). In addition, a covering mechanism section can also be provided midway through the conveying process via the resin material conveying mechanism.

[0096] <Complete steps of the manufacturing method of resin molded article P>

[0097] First, such as Figure 5 As shown in (a), the resin material J and the cover body 7 are contained in the groove 21 of the lower mold 2 in the mold-open state. In addition, the molded object W is installed in the mounting part 22 of the lower mold 2.

[0098] Then, as Figure 5 As shown in (b), the upper mold 3 and the lower mold 2 are closed, and the object to be molded, W, is clamped between the upper mold 3 and the lower mold 2. At this time, the electronic component Wx of the object to be molded, W, is housed in the cavity 31 of the upper mold 3.

[0099] Then, the molten resin material J in the groove 21 is extruded through the plunger 51. Thus, as Figure 6 As shown in (c), the molten resin material J is introduced into the mold cavity 31 through the ejector pool section 32 and the flow channel section 33 of the upper mold 3. Here, when the cover body 7 is made of resin, it softens due to the heat from the heater included in the resin molding apparatus 100, making it less likely to obstruct the flow of the molten resin material J.

[0100] Then, as Figure 6 As shown in (d), molten resin material J is heated for the required time to harden, thereby forming a hardened resin. Thus, the electronic component Wx within the cavity 31 and its surrounding substrate are sealed within the hardened resin (sealing resin) which is shaped corresponding to the cavity 31.

[0101] Then, after the required hardening time, as... Figure 7As shown in (e), the upper mold 3 and lower mold 2 are opened, and the sealed substrate (resin molded article P) and the waste resin J1 are demolded together and transported as a single unit. Here, the waste resin J1 includes the resin remaining in the rejection pool section 32 (rejection pool section J11) and the resin remaining in the runner section 33 (runner J12). Afterwards, in other spaces away from the molding molds (upper mold 3 and lower mold 2), such as... Figure 7 As shown in (f), the useless resin J1 is removed from the resin molded article P and discarded. Here, after resin molding, the coating 7 remains in the scrap tank section 32 or the flow channel section 33, and is contained within the useless resin J1 (scraping tank section J11 or flow channel J12) remaining in the scrap tank section 32 and the flow channel section 33, and is discarded together with the useless resin J1.

[0102] <Experimental Example 1>

[0103] The resin residue adhering to the inner surface of the tank 21 and the plunger 51 was observed by one-time resin molding, with and without the use of the coating 7 made of various raw materials.

[0104] The shape of the covering 7 is set to cover the outer peripheral surface of the resin material J and the bottom surface of the resin material J. Figure 3 (1) shows the shape). Resin material J is an epoxy resin composition for semiconductor sealing (general resin A). In addition, as raw materials for the coating 7, copy paper, greaseproof paper, dust-free paper, polyethylene terephthalate (PET) film, polystyrene release film, and fluoropolymer (ethylene tetrafluoroethylene (ETFE)) film are used.

[0105] like Figure 8 As shown, without the coating 7, resin residue adheres severely to both the inner surface of the tank 21 and the plunger 51. On the other hand, compared to not using the coating 7, using the coating 7 reduces the amount of resin residue adhering to both the inner surface of the tank 21 and the plunger 51. In particular, resin residue is significantly reduced in greaseproof paper, PET film, release film, and ETFE film. Furthermore, considering bendability (processability) and cost, greaseproof paper, PET film, and release film are ideal.

[0106] <Experimental Example 2>

[0107] Resin residue on the inner surface of the groove 21 after continuous molding and resin residue accumulated at the bottom of the plunger 51 were observed with and without the use of the coating body 7 made from various raw materials. Furthermore, the resin residue accumulated at the bottom of the plunger 51 is generated by the sliding part of the groove 21 of the lower mold 2 and the plunger 51, falling through the lower opening of the through hole 2H of the lower mold 2. Additionally, the shape of the coating body 7 is designed to cover only the outer peripheral surface of the resin material J, without covering the bottom surface. Figure 2 (The shape shown).

[0108] When resin material J is set as an epoxy resin composition for semiconductor sealing (general resin A, general resin B), the state after 100 consecutive molding cycles was compared between the case of using an oil-resistant paper coating 7 and the case of not using a coating 7.

[0109] like Figure 9 As shown in the "General Resin" section on the left, compared to the case without the coating 7, both the case with the coating 7 and the case with the release film coating 7 show a reduction in resin residue adhering to the inner surface of the tank 21 and a reduction in resin residue accumulating at the bottom of the plunger 51. In particular, with the use of the release film coating 7, it is evident that in any general resin, there is almost no resin residue accumulating at the bottom of the plunger 51. Furthermore, a comparison was made of the amount of resin residue generated at the bottom of the plunger 51 (g / 100 times). The results showed that in general resin A, compared to the case without the coating 7, the amount of resin residue generated was reduced by 95.7% with the coating 7. Similarly, in general resin B, the amount of resin residue generated was reduced by 90.4%. Moreover, with the use of the release film coating 7, the amount of resin residue generated in any general resin was reduced to an immeasurable level. Based on these results, it can be seen that by covering the periphery of the upper surface of the plunger 51 with the coating 7, the inner surface of the groove 21 of the coating 7 is blocked from the sliding part of the plunger 51, and the molten resin material J does not easily penetrate into the sliding part.

[0110] Furthermore, when resin material J was set as the molding bottom fill (MUF) resin (MUF resin C), the results were compared after 75 consecutive molding cycles using an oil-resistant paper cover 7, an outer cover 7 using a release film, and an outer cover 7 without an outer cover 7.

[0111] like Figure 9As shown in the "MUF Resin" section on the right, compared to the case without the coating 7, the amount of resin residue adhering to the inner surface of the tank 21 is reduced when using the coating 7 with greaseproof paper and when using the coating 7 with release film. Furthermore, the amount of resin residue accumulating at the bottom of the plunger 51 is also reduced. In particular, when using the coating 7 with release film, almost no resin residue accumulates at the bottom of the plunger 51. In addition, a comparison was made of the amount of resin residue generated at the bottom of the plunger 51 (g / 75 times). The results showed that compared to the case without the coating 7, the amount of resin residue generated was reduced by 92.0% when using the coating 7 with greaseproof paper, and the amount of resin residue generated was reduced to an immeasurable level when using the coating 7 with release film. Based on these results, it can be seen that by covering the periphery of the upper surface of the plunger 51 with the coating 7, the inner surface of the groove 21 of the coating 7 is blocked from the sliding part of the plunger 51, and the molten resin material J does not easily penetrate into the sliding part.

[0112] <Effects of this implementation method>

[0113] According to the resin molding apparatus 100 of this embodiment, since a cover 7 surrounding the resin material J is disposed between the inner surface of the groove 21 and the resin material J, the resin material J is prevented from touching the inner surface of the groove 21, and the resin residue adhering to the inner surface of the groove 21 is reduced. Furthermore, since the resin material J is surrounded by the cover 7, even with highly flowable resins such as molding underfill (MUF) resin or transparent resin, the molten resin material J is less likely to penetrate into the inner surface of the groove 21 and the sliding portion of the plunger 51, thereby reducing resin residue generated by the resin material J penetrating into the sliding portion. Here, the cover 7 opens the direction in which the resin material J is extruded, thus not hindering the extrusion of the resin material J by the plunger 51.

[0114] By reducing resin residue in this way, contamination of the next resin molding process can be reduced, thereby improving the quality of the resin-molded product P. Furthermore, equipment malfunctions caused by resin residue can be prevented, and the frequency of cleaning operations can be reduced. Moreover, by using the coating 7, the design of reducing the distance between the inner surface of the groove 21 and the plunger 51, as before, is unnecessary, preventing an increase in the sliding resistance of the plunger 51, thus extending the lifespan of both the groove 21 and the plunger 51.

[0115] <Other variations and implementations>

[0116] Furthermore, the present invention is not limited to the embodiments described herein.

[0117] For example, in the embodiment described, the groove is formed in the lower mold and the cavity is formed in the upper mold, but the groove or cavity may also be formed in either forming mold.

[0118] Furthermore, the groove and plunger are not limited to a circular cross-section; for example, they can also be other shapes such as a rectangular cross-section. For instance, they can be like... Figure 10 (a)~ Figure 10 As shown in (e), the groove 21 is configured to have different longitudinal and transverse dimensions when viewed from above (shapes with different longitudinal and transverse dimensions in a cross-sectional shape orthogonal to the sliding direction of the plunger 51). In this case, the resin material J has different longitudinal and transverse dimensions corresponding to the groove 21 when viewed from above. Furthermore, the plunger 51 has a shape corresponding to each groove 21. Additionally, in Figure 10 In the diagram, the covering 7 is not shown, but it is disposed in the groove 21, for example, in a state of being wound around the resin material J.

[0119] Specifically, Figure 10 When viewed from above, groove 21 of (a) has a rectangular shape with different longitudinal and transverse dimensions, and resin material J has a rectangular shape with different longitudinal and transverse dimensions corresponding to groove 21 when viewed from above. Figure 10 (b) The groove 21 has a rectangular shape with different dimensions in the horizontal and vertical directions when viewed from above, and the corners are formed into an R shape. The resin material J has a rectangular shape with different dimensions in the horizontal and vertical directions corresponding to the groove 21 when viewed from above, and the corners are formed into an R shape. Figure 10 When viewed from above, groove 21 of (c) has an elongated oval shape with different longitudinal and transverse dimensions, and resin material J has an elongated oval shape with different longitudinal and transverse dimensions corresponding to groove 21 when viewed from above. Figure 10 (d) refers to a plurality of grooves 21 arranged in a row, each groove 21 having a rectangular shape with different longitudinal and transverse dimensions when viewed from above. In addition, the resin material J is, for example, a granular resin material that has a rectangular shape with different longitudinal and transverse dimensions corresponding to each groove 21 when viewed from above. Figure 10 When viewed from above, the groove 21 of (e) is a long and narrow rectangular shape with different longitudinal and transverse dimensions, and the resin material J is a plate with different longitudinal and transverse dimensions corresponding to the groove 21 when viewed from above.

[0120] Furthermore, such as Figure 11 As shown, the resin receiving space formed by the groove 21 and the plunger 51 can also be shallow, and the resin material J can be received in a planar manner within the groove 21. Here, the resin material J to be received can be in powder, liquid, or plate form. In the case of powder or liquid resin material J, it is difficult to wrap the cover body 7 around the resin material, or it is difficult to wrap the resin material J with a small thickness in the case of plate-shaped resin material J. Therefore, it is advisable to pre-position the cover body 7 in the groove 21. Here, in order not to hinder the extrusion of the resin material J, the cover body 7 is configured not to protrude from the upper opening of the groove 21 (see reference). Figure 11 (c) Furthermore, the covering 7 may be a structure having a bottom when disposed in the groove 21, or it may be a structure without a bottom.

[0121] Furthermore, the resin molding apparatus is not limited to a multi-plunger configuration; it may also have a single plunger. In this case, the plunger unit becomes a structure with only one plunger.

[0122] Furthermore, a pair of forming molds is not limited to an upper mold and a lower mold, but can also be other forming molds that can be used for transfer molding (e.g., a top gate type forming mold with an intermediate plate).

[0123] In addition, of course, the present invention is not limited to the described embodiments, and various modifications can be made without departing from its spirit.

[0124] Industrial availability

[0125] According to the present invention, the generation of resin residue during resin molding can be suppressed.

Claims

1. A method for manufacturing a resin molded article, comprising extruding resin material contained in a groove of a molding die into a cavity of the molding die using a plunger, thereby sealing the molded object with resin to manufacture the resin molded article, wherein in the method for manufacturing the resin molded article, Before the resin material is received in the tank, a sheet-like covering is wound around the resin material, the covering being unconstrained in the circumferential direction of the resin material to cover it. The resin material covered by the coating is contained in the tank. The resin material covered by the coating is extruded into the mold cavity through the plunger. The thickness of the coating is greater than the distance between the inner surface of the groove and the plunger. It is in close contact with the inner surface of the groove by the internal pressure applied by the resin material that is molten or softened in the groove. The coating blocks the sliding part between the inner surface of the groove and the plunger.

2. The method for manufacturing a resin molded article according to claim 1, wherein the cover is also disposed in the groove between the resin material and the plunger.

3. The method for manufacturing a resin molded article according to claim 1, wherein the coating is made of a material that does not melt or thermally decompose at the molding temperature.

4. The method for manufacturing a resin molded article according to claim 1, wherein the coating is made of paper, resin, cellulose, woven fabric, nonwoven fabric, or a composite material comprising at least two of these.

5. The method for manufacturing a resin molded article according to claim 1, wherein the cover has a slit formed at the open end on the side where the resin material is extruded.

6. The method for manufacturing a resin molded article according to claim 1, wherein the groove of the molding die is not circular when viewed from above. The resin material contained in the groove has a non-circular shape when viewed from above, corresponding to the groove.

7. The method for manufacturing a resin molded article according to claim 1, wherein the groove of the molding die has a shape with different longitudinal and transverse dimensions when viewed from above. The resin material contained in the tank has different longitudinal and transverse dimensions relative to the tank when viewed from above.

8. The method for manufacturing a resin molded article according to any one of claims 1 to 7, wherein the coating remains in the scrap pool or runner of the molding die after resin molding, and is discarded together with the resin remaining in the scrap pool or runner.

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