JP2713059C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component or an electronic device for preventing electromagnetic interference (EMI).
The present invention relates to a method for manufacturing a housing including a box or a lid for storing electronic components or electronic devices in order to protect the electronic components or electronic devices from being protected. 2. Description of the Related Art Conventionally, electronic components and electronic devices are housed in a cabinet (housing) made of metal, which has served as an electromagnetic wave shield. With advances in technology, miniaturization of parts and devices has progressed, and with the expansion of demand, plastic molded products with good productivity and low cost have been adopted as casings, and the EMI problem has surfaced. As a method of EMI shielding of a molded product having a plastic housing, various conventional techniques have been adopted. As one of the methods, after forming the housing, a method of applying a paint using a conductive material such as silver or copper as a filler to the housing, a method of melting a conductive material such as silver or copper and spraying the housing with high-pressure air, A vacuum evaporation method of evaporating a low-boiling point metal (for example, aluminum) in a vacuum to form a thin film on the housing surface, a method of applying an electroless plating of nickel or the like to a housing formed of a highly adhesive resin such as an ABS resin, A method of molding a housing using a molding material containing a conductive filler such as carbon or aluminum flake, or a composite material obtained by laminating a vinyl chloride (PVC) or polyester film on a film of aluminum, copper, etc. There is a way to attach. [0003] Also, various methods have been proposed for integrally molding a metal shield material with a resin. FIG. 6A is a housing for digital electronic equipment disclosed in Japanese Patent Application Laid-Open No. 61-22915, 217 ′ is a resin, 215 ′ is a wire mesh, FIG. 6B is a schematic sectional view of a mold showing a molding state, and 211 is An upper mold, 212 is a lower mold, 213 is a resin gate provided on the lower mold 212, 215 is a box-shaped preformed metal net for electromagnetic reflection and cutoff, and is placed on the lower mold. 217 is supplied, the upper die is opened, pressurized and cooled to complete the molding. FIG. 7A shows an electronic device disclosed in Japanese Utility Model Application Laid-Open No. 63-201391, in which reference numeral 71 denotes a metal chassis in which electronic components, electronic circuits, and the like are provided. Reference numeral 73 denotes a cover. As shown in FIG. An electronic circuit card 72 is housed inside the chassis 71, and a wire mesh 74 is formed integrally with the plastic as shown in FIGS. 7C to 7E to expose the wire mesh 74 around the cover 73. When the wire 73 is attached to the chassis 71, the wire mesh 74 and the chassis 71 are electrically connected. However, this publication does not describe a method of manufacturing the cover. [0005] Other than the above, there are Japanese Utility Model Application Laid-Open No. Sho 59-18496 and Japanese Patent Application Laid-Open No. Sho 58-115894 as methods for preforming an electromagnetic wave shielding material in advance and inserting it during molding. [0006] After forming a conventional housing, a conductive coating is formed on the upper surface of the housing by applying a conductive paint as a shielding material, spraying a conductive material, vacuum deposition, and resin plating. This method is expensive and has problems of peeling of the film. In addition, the method of molding a housing using a molding material mixed with a conductive material has a problem that the conductive filler is not uniformly dispersed inside the molded product and the shielding effect is not good. The method disclosed in Japanese Patent Application Laid-Open No. 61-22915 requires the preform of the wire mesh, and has a problem that the number of steps is increased. The method disclosed in Japanese Utility Model Laid-Open No. 63-201391 is expensive in terms of cost because one of the housings is made of metal. The present invention has been made in order to solve such a problem, and since a shielding material can be integrally formed with a resin without performing a preform, a housing having an electromagnetic wave shielding function that is inexpensive and has good workability. An object is to obtain a method for manufacturing a housing. According to a first aspect of the present invention, there is provided a method of manufacturing a housing comprising a box or a lid for housing electronic components or electronic devices, wherein the housing is formed over substantially the entire surface of the housing. After that, the electromagnetic shielding member is exposed from the edge of the housing, and has an area enough to expose the electromagnetic shielding member, a flexible thin wire mesh, or a flat plate obtained by cutting the electromagnetic shielding member made of a metal foil plate having a plurality of small holes. a step of setting to face the stationary mold in a state, and causing the movable mold to deform the electromagnetic wave shielding member while allowed mold closing in the direction of the fixed mold, the formed shape resin material immediately after the start closing the mold Injecting into the space formed by the fixed mold and the movable mold, and allowing a part of the molding resin material to permeate the movable mold from the wire mesh or the plurality of small holes of the electromagnetic wave shielding member, The electromagnetic wave shielding member with pressurized moved to a final stroke mold closing a serial movable mold comprises the step of solidifying Shi fit to the shape of the box or lid. In the first invention, the deformation of the electromagnetic wave shield member by closing the mold in the first invention omits the preform of the electromagnetic wave shield member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a perspective view showing a housing including a box and a lid for storing an electronic component or an electronic device (not shown) according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a box of a housing, which may be a box using the present invention or a metal box such as an aluminum die-cast. Reference numeral 2 denotes a housing lid using the present invention. FIG. 2 is a partial sectional view of FIG.
An electromagnetic wave shielding member 21 made of a highly flexible metal foil plate such as a wire mesh made of a 60 μm copper wire or a copper foil plate having a plurality of small holes is arranged.
An exposed portion 21a and a bent portion 21b of the electromagnetic wave shielding member 21 are provided at an edge of the lid 2. Further, the ventilation port 2 having only the electromagnetic wave shielding member 21 left in a part of the lid 2
2 is provided at the same time as molding. When the present invention is used for a box, the electromagnetic wave shielding member 11 is also arranged inside the box 1, and the exposed portion 11 is also provided at the edge of the box 1 as well as the lid.
a and a bent portion 11b, and the bent portion 11b
They are connected by a washer 14 and a nut 15. Since the lid 2 is attached to the box by a method (not shown), the exposed portion 11a of the electromagnetic wave shielding member 11 of the box and the exposed portion 21a of the lid 2 make electrical contact. When a metal box such as an aluminum die-cast is used for the box, the exposed portion 21a of the lid 2 comes into electrical contact with the metal box by attaching the lid of the present invention to the metal box. FIG. 3 is a perspective view of the box or lid immediately after molding. FIG. 4 is a partial sectional view of FIG. The electromagnetic wave shielding member 11 or 21 is positioned so as to substantially contact the intersection between the inner bottom surface or the inner top plate portion 41 and the inner side wall 42 of the box 1 or the lid 2, and contacts the outer side wall 43 at the edge 44 of the box or the lid. Are located in Next, a method for manufacturing the housing shown in FIG. 3 will be described. Generally, when a box or lid housing is manufactured by resin molding, a mold is used. The mold consists of an upper mold (cavity in this case) and a lower mold (core in this case), and heats and softens and melts the molding material, which is then combined with the upper and lower molds. , Pressurized and solidified, the mold is opened, and the molded product is removed from the mold. In FIG. 3, the upper die is described as a cavity and the lower die is described as a core. However, the upper die may be a core and the lower die may be a cavity. FIG. 5 illustrates a method of forming a housing according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view of a mold for molding the housing of the present invention with a mold. In a state where the upper mold 51 and the lower mold 52 are opened, the electromagnetic wave shielding member 54 in the state of a flat plate that has just been cut is subjected to the lower mold. A robot or the like (not shown) mounts on a core 52 at a preset position (FIG. 5A). The electromagnetic wave shielding member 54 is in the form of a wire mesh made of copper wire or the like having a diameter of 30 to 60 μm or a flat plate obtained by cutting a copper foil plate having a plurality of small holes, and is very flexible. I do. In FIG. 5, the upper mold 51 is positioned in the direction of the top, the lower mold 52 is positioned in the direction of the ground, and the upper mold 51 is represented as being up and down. However, the upper mold 51 and the lower mold 52 are arranged in the horizontal direction, When the upper mold 51 moves in the horizontal direction, the electromagnetic wave shielding member 54 may be suspended by a robot or the like (not shown), and the robot hand may be moved together with the movement of the upper mold 51. Next, the upper mold 51 is moved in the direction of the lower mold 52 by a command from a control device (not shown) (referred to as mold closing). The mold closing speed is set at about 50% as compared with ordinary injection molding. On the other hand, the gate 53 provided on the lower mold 52 is opened, and the softened and melted molding material is injected. As the upper mold 51 descends, the electromagnetic wave shielding member 54 is pressed by the end face of the upper mold 51 and hits a corner of the lower mold 52, and is deformed into a spherical shape. With this force, the electromagnetic wave shielding member 54 near the gate 53 rises from the core of the lower mold 52 (FIG. 5B).
The injection speed is set so low that the molding material does not scatter. Further, the melting temperature of the molding material is appropriately set according to the type of the molding material. The molding material injected from the gate 53 also penetrates through the hole provided in the shield member 12 to the upper mold 51 side. As the mold is closed, the electromagnetic wave shielding member 54 tends to be shifted toward the lower mold 52 due to the pressure of the molding material, and is not exposed to the outside of the housing and does not impair the design of the housing. At the final stroke of closing the mold, the electromagnetic wave shielding member 54 is taken out of the space of the casing formed by the cavity and the core from the gap where the outer periphery of the cavity and the outer periphery of the core are in contact (FIG. 5c). After closing the mold, after an appropriate solidification time, open the upper mold 51 and remove the molded product from the lower mold 5.
2 (FIG. 5d). Although the mold closing speed has been described as one speed, a normal speed may be set up to the middle of the mold closing stroke, and the subsequent speed may be set to about 50% of the normal speed. In addition, the injection of the molding material has been described as being started in the middle of closing the mold. However, if the thickness of the housing can be made relatively thick, after closing the upper mold to the final stroke, the molding material is injected. Is also good. As a molding material, polypropylene (PP) which is a general-purpose thermoplastic resin is used.
, ABS, polycarbonate (PC), polyphenylene oxide (PPO), polyamide (PA), PA / PPO alloy which is an engineering plastic, and PC / PBT (polybutylene terephthalate). Further, the present invention can be applied to a thermosetting resin such as a phenol resin, an epoxy resin, or a polyurethane resin. As described above, according to the first aspect of the present invention, since the electromagnetic wave shielding member is cut into a flat plate and is not subjected to preform but directly enters the resin molding step, the number of processing steps is reduced. Thus, an inexpensive housing for housing electronic components or electronic devices can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a housing including a box and a lid for storing an electronic component or an electronic device according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view of FIG. FIG. 3 is a perspective view of the housing of the present invention after molding. FIG. 4 is a partial cross-sectional view of FIG. FIG. 5 is a schematic cross-sectional view of a mold for molding the housing of the present invention. FIG. 6 is a cross-sectional view schematically illustrating a conventional case and a mold. FIG. 7 is a perspective view and a cross-sectional view illustrating a housing of another conventional electronic device. [Description of Signs] 1 Box 2 Lid 11, 11a, 11b, 21, 21a, 21b, 54 Electromagnetic shielding member 12 Ground wire 13 Bolt 14 Washer 15 Nut 22 Ventilation hole 41 Bottom surface of housing 42 Inner side wall of housing 43 Housing Outer side walls 51, 211 Upper mold 52, 212 Lower mold 53, 213 Gate 72 Electronic circuit card 73 Cover 74, 74a, 215, 215 'Wire mesh 75a, 75b, 217, 217' Molding resin

Claims (1)

Claims: 1. A method of manufacturing a housing comprising a box or a lid formed of a resin for housing an electronic component or an electronic device, comprising the steps of: disposing the housing or the cover over substantially the entire surface of the housing; A fixed metal plate in a state where the electromagnetic wave shielding member made of a flexible thin metal net or a metal foil plate having a plurality of small holes is cut as it is, having an area enough to expose the electromagnetic wave shielding member from the edge. a step of setting to face the mold, and causing the movable mold to deform the electromagnetic wave shielding member while allowed mold closing in the direction of the fixed mold, the fixed mold and formed shape resin material immediately after the start closing the mold And injecting into a space formed by the movable mold, and allowing a part of the molding resin material to penetrate into the movable mold through a wire mesh or a plurality of small holes of the electromagnetic wave shielding member. A step of moving the movable mold to the final stroke, closing the mold, moving the mold to the final stroke, applying pressure, and adapting the electromagnetic wave shielding member to the shape of the box or lid and solidifying the electromagnetic shielding member. A method of manufacturing a housing.