JP2004363450A - Electromagnetic wave shield casing and method of producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing an electromagnetic wave shield casing where infiltration of water from external environment is prevented surely. <P>SOLUTION: In a first molding process, the back surface of an insertion material 4 is supported by a surface 108 formed by a metallic mold 10B. Thus, when resin for first molding is poured into the recess 100 of a metallic mold 10A, the insertion material 4 is never deformed. By first molding, an outer wall 6 having a projecting part 6a projecting on the side of an inner wall and a cavity 6b opposing a through hole 41a is formed. In a second molding process, when resin for second molding is poured into the recess 104 of a metallic mold 11B, the resin flows into the cavity 6b from the through hole 41a. Since the insertion material 4 is supported by the outer wall 6 in the case of second molding, the insertion material 4 is never deformed due to pouring of the resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic wave shielding housing formed by a member in which an electronic device or the like is housed and a shield material is insert-molded, and a method of manufacturing the same.
[0002]
[Prior art]
Conventionally, when housing an electronic device such as a semiconductor module in a housing, a shield housing is used as a housing in consideration of prevention of leakage of electromagnetic waves generated by the electronic device to the outside and prevention of invasion of electromagnetic waves from the outside. May be used. In a shield case, a shield member is used on a case wall in order to prevent intrusion of electromagnetic waves into the case and emission of electromagnetic waves to the outside of the case. For example, there is known a shield housing in which a net-shaped shield material is insert-molded inside a resin material for a housing wall (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP 2002-134977 A
[Problems to be solved by the invention]
By the way, when the above-mentioned housing wall is insert-molded, the molding is performed in the following steps. First, a mesh-shaped shield material is set in an injection molding die, and thereafter, a molding resin is injection molded in the die. At the time of this molding, the net-like shield material may be deformed by the injection pressure of the resin or the like, and the shield material may be exposed on the surface of the resin molded member that is the housing wall. When the shielding material is exposed on the surface of the resin molded member, water or the like may enter the housing from the external environment through the boundary surface between the shielding material and the resin portion. If water enters the inside of the housing, the life of the electronic device in the housing may be shortened.
[0005]
An object of the present invention is to provide an electromagnetic wave shielding housing capable of more reliably preventing water from entering from an external environment, and a method of manufacturing the same.
[0006]
[Means for Solving the Problems]
In the method for manufacturing an electromagnetic wave shielding casing according to the first aspect of the present invention, both front and back surfaces of the electromagnetic wave shielding material are molded with resin by two types of molding steps, a primary molding step and a secondary molding step. In the primary molding step, one surface of the electromagnetic wave shielding material is always held by the holding member during the molding. In the secondary molding, the first resin layer molded in the primary molding step is already formed on the other surface of the electromagnetic wave shielding material. Therefore, at the time of primary and secondary molding, the electromagnetic wave shielding material is held by either the holding member or the first resin layer, and deformation of the electromagnetic wave shielding material at the time of molding can be prevented.
According to a third aspect of the present invention, in the electromagnetic wave shielding case formed by the method for manufacturing an electromagnetic wave shielding case according to the second aspect, at least one of the first projecting portion and the second projecting portion has a part thereof. The diameter is larger than the diameter of the through hole. Thereby, the bond between the first resin layer and the second resin layer becomes stronger.
[0007]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, deformation | transformation of the electromagnetic wave shielding material at the time of shaping | molding can be prevented, and an electromagnetic wave shielding material does not appear on the surface of a housing | casing. Therefore, it is possible to avoid a situation in which water enters from the external environment via the joint surface between the electromagnetic wave shielding material and the resin.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing an embodiment of an electromagnetic wave shielding housing according to the present invention, in which a part of a side wall portion 1 is shown in a broken section. The shield housing shown in FIG. 1 has a side wall 1 and a cover 2, and the cover 2 and the side wall 1, and the side wall 1 and the cooling unit 3 are fixed by screws or the like. The cooling unit 3 is formed of an aluminum-based or copper-based metal having excellent thermal conductivity, and an electronic device (not shown) is provided on the cooling unit 3. For example, electronic components that generate a large amount of heat, such as power modules, are surface-mounted on the cooling unit 3.
[0009]
The shield housing shown in FIG. 1 is used, for example, as a housing of a power conversion device mounted on a vehicle or the like, and is provided in an engine room or the like. Therefore, it is easily affected by moisture such as rainwater and the temperature of the engine, and the shield housing is required to have a sealing property and a heat insulating property against moisture and environmental temperature in addition to the electromagnetic wave shielding property. Although the seal between the cover 2, the side wall 1 and the cooling unit 3 is not shown, the seal is performed using an O-ring, a gasket or the like. At this time, the cover 2, the side wall portion 1 and the cooling portion 3 are sufficiently brought into contact with each other to secure magnetic shielding properties and thermal conductivity. Further, a conductive material may be used for the O-ring and the gasket.
[0010]
As described above, the cooling unit 3 functions as a heat sink for cooling the electronic device. In the case of the liquid cooling specification, a water channel for circulating a cooling liquid such as an ethylene glycol aqueous solution is provided inside or on the lower surface of the cooling unit 3. In the case of the air cooling specification, cooling fins and the like are formed on the lower surface of the cooling unit 3. The side wall portion 1 is formed by insert-molding an insert material 4 functioning as a shield material inside a resin material. That is, the side wall 1 has an inner wall 5 and an outer wall 6 made of resin with the insert material 4 interposed therebetween. Details of the side wall 1 will be described later.
[0011]
In the example shown in FIG. 1, the insert material 4 is formed of a metal plate having a plurality of through holes 41 formed therein. The plurality of through holes 41 are formed so as to be evenly distributed over the entire surface of the insert material 4. As the metal plate used for the insert material 4 functioning as an electromagnetic shield, there are various types such as aluminum, copper, brass, and steel plate, and in consideration of the need for high heat transfer performance, for example, 200 W / m. -It is preferable to use an aluminum-based or copper-based material having a thermal conductivity of about K.
[0012]
By using a metal material having such a thermal conductivity for the insert 4, heat in the housing can be efficiently transported to the cooling unit 3 via the insert 4, and the heat of the electronic device disposed in the housing can be improved. Cooling efficiency can be improved. Although the heat transfer performance is slightly inferior, punched metal or wire mesh, or honeycomb or expanded metal can also be used as the insert material 4.
[0013]
As the resin used for the inner wall 5 and the outer wall 6 of the shielded housing, the electronic components housed inside the housing are often high heat-generating components, and the housing itself requires a cooling action. Resins having relatively excellent heat resistance such as PA (polyamide), PBT (polybutylene terephthalate), and PPS (polyphenylene sulfide) are preferred. Further, a resin having a low thermal conductivity is used for the resin of the outer wall 6 so as to block heat from entering the inside of the housing from the outside, and heat generated inside the housing is radiated through the insert material 4. As described above, it is preferable to use a resin having a high thermal conductivity for the resin of the inner wall 5. For example, the outer wall 6 is made of PPS containing an elastomer (thermal conductivity: about 0.2 W / mK), and the inner wall 5 is made of glass-reinforced PPS (thermal conductivity: about 0.3 W / mK).
[0014]
Although the cover 2 is formed by pressing a metal plate, the cover 2 may be formed by inserting an insert material with a resin as in the case of the side wall portion 1. The insert material 4 of the side wall portion 1 is in electrical contact with the metal cover 2 and the cooling portion 3, so that the inside of the housing is electromagnetically shielded.
[0015]
2A and 2B are diagrams showing a detailed structure of the side wall portion 1, and FIG. 2A is a diagram showing a part of the outer surface of the side wall portion 1, that is, a part on the side of the outer wall 6, and FIG. It is a II sectional view. In FIG. 2B, the resin member on the right side of the insert 4 forms the inner wall 5, and the resin member on the left side of the insert 4 forms the outer wall 6. Folds 42 and 43 are formed at the upper end and the lower end of the insert 4 so that the insert 4 can be kept in sufficient contact with the cover 2 and the cooling unit 3.
[0016]
The through hole 41 formed in the insert material 4 is divided into two types of holes 41a and 41b. A part of the resin member forming the inner wall 5 projects to the left of the insert 4 through the hole 41a, and a part of the resin member forming the outer wall 6 forms the insert 4 through the hole 41b of the insert 4. It protrudes to the right. The protrusion 5a projecting from the hole 41a and fitting into the outer wall 6 penetrates the outer wall 6 from the inside to the outside, and the tip of the protrusion 5a is exposed on the surface of the outer wall 6 as shown in FIG. ing. On the other hand, the protrusion 6a projecting from the hole 41b and fitting into the inner wall 5 penetrates the inner wall 5 from the outside to the inside.
[0017]
The protrusions 5a and 6a are formed in a columnar shape, and their diameter d1 is set larger than the diameter d2 of the holes 41a and 41b. That is, the protruding portions 5a and 6a extend to the outside of the columnar region whose bottom surface is the cross section of the holes 41a and 41b. As a result, the inner wall 5 and the outer wall 6 are firmly connected to each other by the protrusions 5a and 6a with the insert member 4 interposed therebetween, thereby preventing the inner wall 5 and the outer wall 6 as resin members from peeling off from the insert member 4 as a metal member. ing.
[0018]
In the example shown in FIG. 2, the protruding portion 5a has a cylindrical shape. However, even if the protruding portion 5a is linearly expanded from the hole 41a, the protruding portion 5a having the shape of a truncated cone is connected to the outer wall 6. The inner wall 5 and the outer wall 6 are mutually connected.
[0019]
FIG. 3 is a view for explaining a molding process of the side wall portion 1. In the present embodiment, molding is performed in two stages, primary and secondary. FIG. 3A shows a primary molding operation, FIG. 3B shows a primary molded product of the side wall portion 1, and FIG. 3C shows a secondary molding operation. First, as shown in FIG. 3A, the insert material 4 is mounted on the primary molding dies 10A and 10B to perform primary molding.
[0020]
The mold 10A has a concave portion 100 for forming the outer wall 6, and a columnar convex portion 101 for forming a region into which the protruding portion 5a fits. On the other hand, a cylindrical concave portion 102 for forming the protruding portion 6a of the outer wall 6 is formed in the mold 10B. The diameter of each of the convex portion 101 and the concave portion 102 is set to be equal to the diameter d1 of the protruding portions 5a and 6a shown in FIG. The convex portions 101 are formed at positions facing the holes 41a of the insert material 4, and the concave portions 102 are formed at positions facing the holes 41b of the insert material 4, respectively.
[0021]
When the primary molding resin is injected into the recess 100 of the mold 10A, the inside of the recess 100 is filled with the resin without any gap, and the resin in the recess 100 flows into the recess 102 of the mold 10B through the hole 41b, and the recess 102 is formed. Meet. At this time, since the back surface of the insert 4 is supported by the surface 108 of the mold 10B, the insert 4 is not deformed by the pressure of the injected primary molding resin. When the molds 10A and 10B are removed after the resin is solidified, a primary molded product of the side wall portion 1 composed of the insert material 4 and the outer wall 6 as shown in FIG.
[0022]
A columnar protrusion 6a made of a primary molding resin is formed in the hole 41b of the insert material 4, and a columnar cavity 6b is formed in a portion of the outer wall 6 facing the hole 41a. The diameter of the protrusion 6a and the cavity 6b is d1, which is larger than the diameter d2 of the holes 41a and 41b (see FIG. 2B). Therefore, even in the state of FIG. 3B, the insert material 4 does not come off from the outer wall 6, and the secondary molding operation is easily performed.
[0023]
Next, as shown in FIG. 3C, the primary molded product of the side wall portion 1 is mounted on secondary molding dies 11A and 11B to perform secondary molding. The outer wall 6 of the primary molded product is housed in the recess 103 of the mold 11A. A concave portion 104 for forming the inner wall 5 is formed in the mold 11B, and the protruding portion 6a is housed in the concave portion 104. When the secondary molding resin is injected into the concave portion 104 of the mold 11B, the inside of the concave portion 104 is filled with the secondary molding resin without any gap. Further, the resin in the concave portion 104 flows into the columnar cavity 6b of the outer wall 6 through the hole 41a, and the cavity 6b is filled with the secondary molding resin. The secondary molding resin may be the same as or different from the primary molding resin. When the molds 11A and 11B are removed after the resin for secondary molding is solidified, the side wall portion 1 composed of the inner wall 5, the insert material 4 and the outer wall 6 as shown in FIG. 1 is obtained.
[0024]
In the above-described embodiment, the metal plate on which the plurality of through holes 41a and 41b are formed is used as the insert material 4, but a mesh member such as a wire mesh may be used as the insert material. FIG. 4 is a view for explaining a forming method when the metal mesh 14a is used as the insert material 14, and (a) to (c) show the procedure. The insert member 14 includes a metal mesh 14a and end members 14b provided at both upper and lower ends of the metal mesh 14a. For the metal mesh 14a and the end member 14b, an aluminum material or a copper material having excellent thermal conductivity is used as in the case of the insert material 4 described above. The end member 14b is provided to make sufficient electrical and thermal contact between the metal mesh 14a and the cover 2 and the cooling unit 3, and is fixed to the mesh 14a by brazing, crimping, or the like.
[0025]
As shown in FIG. 4A, when the insert material 14 is used, the same primary molding dies 10A and 10B as those in FIG. 3 are used. At this time, the mesh 14a is disposed so as to be in close contact with the flat surface 105 formed on the mold 10A. Each diameter d1 of the cylindrical convex portion 101 of the mold 10A and the concave portion 102 of the mold 10B is set to be larger than the gap (hole diameter) of the mesh 14a. When the primary molding resin is injected into the concave portion 100 of the mold 10A, the concave portion 100 is filled with the resin without any gap. Furthermore, when the primary molding resin passes through the gap of the mesh 14a, the inside of the concave portion 102 of the mold 10B is filled with the primary molding resin. Except for the region where the convex portion 101 faces, the gap of the mesh 14a is filled with the primary molding resin.
[0026]
When the dies 10A and 10B are removed after the primary molding resin has solidified, a primary molded product of the side wall portion 1 as shown in FIG. 4B is obtained. In the case where the above-described insert material 4 is used, the primary molding resin that has passed through the hole 41b forms a columnar protrusion 6a having a diameter d1 larger than the diameter d2 of the hole 41b. Therefore, the protrusion 6a is narrowed at the hole 41b (see FIG. 3B). On the other hand, when the insert material 14 is used, since the primary molding resin fills the concave portion 102 so as to seep out from the gap of the mesh 14a, the projecting portion 6a does not form the constricted portion as described above, and the mesh 14a Is formed so as to rise with a diameter d1. As a result, the mesh 14a and the primary molding resin are securely fixed.
[0027]
Next, as shown in FIG. 4C, the primary molded product of the side wall portion 1 is mounted on secondary molding dies 11A and 11B to perform secondary molding. When the secondary molding resin is injected into the concave portion 104 of the mold 11B, the inside of the concave portion 104 is completely filled with the secondary molding resin without any gap, and the secondary molding resin passes through the gap of the mesh 14a and forms a circle of the outer wall 6. It flows into the columnar cavity 6b. As a result, the side wall 1 having the inner wall 5, the insert material 14, and the outer wall 6 is formed. When the mesh 14a is used like the insert member 14, the resin is filled at the bases of the protrusions 5a and 6a so as to fill the gaps of the mesh 14a, so that the inner wall 5 and the outer wall 6 are fixed to the insert material 14. Is reliably performed, and the inner wall 5 and the outer wall 6 do not peel off from the insert material 14.
[0028]
By the way, when a metal mesh or the like is used as an insert material in a conventional shield housing, a mesh is arranged near a center position of a mold, and an inner wall and an outer wall are formed by one resin injection. I have. For this reason, the mesh may be deformed by the flow of the resin when the resin is injected, and the mesh may reach the vicinity of the wall surface as shown in FIG. In such a case, moisture or the like may enter the inside of the housing via the contact surface between the mesh and the resin member.
[0029]
However, in the present embodiment, as shown in FIGS. 3 and 4, the mesh 14a is disposed so as to be in close contact with the flat surface 105 of the mold 10B in the primary molding step, and is provided on the inner surface of the outer wall 6 in the secondary molding step. It is fixed. Therefore, the mesh 14a is not deformed when the resin is pressed into the mold, and is reliably disposed between the inner wall 5 and the outer wall 6.
[0030]
[First Modification]
FIG. 5 is a view showing a first modification of the above-described electromagnetic wave shielding housing, and is a view showing a cross section of the side wall portion 1 as in FIG. 2B. In the side wall portion 1 shown in FIG. 5, the shapes of the protruding portions 50a and 60a of the inner wall 5 and the outer wall 6 are different from those of the side wall portion 1 shown in FIG. 2B, and the other portions are the same. The projections 50a and 60a form stepped columnar projections in which two cylindrical bodies having different diameters are stacked. In the case of the protrusion 50a, the diameter of the tip portion is d3, and the diameter d4 of the root portion is smaller than d3. On the other hand, in the case of the protruding portion 60a, the diameter d4 of the tip portion is smaller than the diameter d3 of the root portion, contrary to the protruding portion 50a, in consideration of removal from the mold.
[0031]
FIG. 6 is a view showing a molding step. First, as shown in FIG. 6A, the insert material 4 is mounted on the primary molding dies 12A and 12B. A concave portion 105 for forming the outer wall 6 is formed in the mold 12A. In the concave portion 105, a convex portion 106 for forming the projecting portion 50a of the inner wall 5 is formed at a position facing the through hole 41a of the insert material 4. On the other hand, in the mold 12B, concave portions 107 for forming the protruding portions 60a of the outer wall 6 are formed at positions facing the through holes 41b of the insert material 4, respectively.
[0032]
FIG. 6B shows a primary molded product of the side wall portion 1, which is obtained by injecting a primary molding resin into the dies 12A and 12B of FIG. 6A. A cavity 6c is formed at a position of the outer wall 6 facing the through hole 41a, and a protrusion 60a is formed at the through hole 41b so as to project toward the inner wall side (the right side in the drawing) of the insert material 4.
[0033]
FIG. 6C is a diagram showing a secondary molding step, in which secondary molding is performed using the same dies 11A and 11B as in FIG. 3C. When the primary molded product of FIG. 6B is mounted on the dies 11A and 11B and the resin for secondary molding is injected into the concave portion 104 of the die 11B, the resin is inserted into the cavity 6c of the outer wall 6 through the through hole 41a of the insert material 4. The resin for secondary molding flows. As a result, the side wall 1 as shown in FIG. 5 is formed.
[0034]
In the side wall portion 1 shown in FIG. 5, the portions of the protruding portions 50a and 60a are joint portions where the inner wall 5 and the outer wall 6 are in direct contact. In the side wall portion 1, a step is provided in each of the protruding portions 50 a and 60 a, so that the joining area at the joining portion is further increased, so that the connection between the inner wall 5 and the outer wall 6 is further ensured. Further, with respect to the intrusion of moisture when a gap is formed in the joint surface, the penetration path becomes longer than that in the case of FIG. Note that the level difference between the protruding portions 50a and 60a is not limited to one, and may be two or more. The protruding portions 50a and 60a may have a truncated cone shape to increase the joint area and the approach path.
[0035]
[Second Modification]
In the side wall portion 1 shown in FIGS. 5 and 2 described above, the distal end surfaces of the protruding portions 50a, 5a are exposed on the surface of the outer wall 6, and the distal end surfaces of the protruding portions 60a, 6a are exposed on the surface of the inner wall 5. As shown in FIGS. 7 (a) and 7 (b), the protrusions of the protrusions 50a, 60a, 5a and 6a may be reduced so as not to be exposed on the surface.
[0036]
[Third Modification]
FIG. 8A is a cross-sectional view showing a third modification of the shield housing, in which the protrusions 50a and 60a of the first modification are modified. In the first modification, the protruding portions 50a, 60a are stepped columnar protruding portions having a step. However, in the third modification shown in FIG. 8A, a large diameter portion having a diameter d4 of each protruding portion 50a, 60a. Extending portions 54 and 64 extending in the direction of the small diameter portions 53 and 63 are formed on 51 and 61. In the example shown in FIG. 8A, the extension portions 54 and 64 are formed in a ring shape so as to surround the small diameter portions 51 and 61 having the diameter d3. As a result, the extension portions 54 and 64 and the small diameter portions 51 and 61 are formed. Ring-shaped depressions (gap) 52, 62 are formed between the outer peripheral surface and the peripheral surface. The primary molding resin forming the outer wall 6 enters the recess 52, and the secondary molding resin forming the inner wall 5 enters the recess 62.
[0037]
FIG. 8B is an enlarged view of a portion of the protruding portion 60a, and is a diagram illustrating the function of the protruding portion 60a. When the secondary molding resin forming the inner wall 5 shrinks during solidification, the inner wall 5 shrinks at the protruding portion 60a away from the protruding portion 60a as indicated by an arrow 20. However, in the third modified example, since the ring-shaped portion 55 that is a part of the inner wall 5 is fitted into the recess 62 of the large-diameter portion 61, the ring-shaped portion 55 is connected to the extension portion 64 outside the recess 62. Interference prevents the inner wall 5 from contracting in the direction of the arrow 20. Then, due to the contraction of the resin forming the inner wall 5, a surface pressure is generated at the joint surface between the ring-shaped portion 55 and the extension portion 64, and the joining strength between the protruding portion 60 a of the outer wall 6 and the inner wall 5 increases.
[0038]
On the other hand, in the portion of the protruding portion 50a, the extension portion 54 of the protruding portion 50a contracts toward the center of the large diameter portion 51 when the resin for secondary molding is solidified, and the outer wall resin member in the recess 52 is It works to prevent contraction. As a result, the joining strength between the extension portion 54 of the protrusion 50a and the outer wall 6 increases. By forming the extending portions 54 and 64 on the large diameter portions 51 and 61 of the protruding portions 50a and 60a in this manner, the bonding strength between the inner wall 5 and the outer wall 6 can be improved.
[0039]
Further, since the shrinkage of the inner wall 5 and the protruding portion 50a during solidification is suppressed, gaps are less likely to be generated in the joint surface between the inner wall 5 and the protruding portion 60a and the joint surface between the outer wall 6 and the protruding portion 50a. Improvement can be achieved. In the example shown in FIG. 8, the extension portions 54 and 64 are formed on both the protruding portions 50a and 60a. However, sufficient joint strength can be obtained even if the extension portions are formed on only one of them.
[0040]
Since the above-described improvement in bonding strength is caused by the contraction of the secondary molding resin during solidification, the resin having a higher shrinkage rate than the primary molding resin constituting the outer wall 6 is used as the secondary molding resin constituting the inner wall 5. By using the material, the bonding strength can be further improved. Furthermore, by using a resin material having a low Young's modulus as the secondary molding resin, the dispersion of pressure in the joint at the time of shrinkage is improved, and the reliability of the joint can be increased.
[0041]
For example, a glass-reinforced PPS having a linear expansion coefficient of about 1.5 × 10 ⁻⁵ / ° C., a Young's modulus of about 2.5 × 10 ¹⁰ Pa, and a thermal conductivity of about 0.3 W / mK as a primary molding resin. As the secondary molding resin, an elastomer-containing PPS having a linear expansion coefficient of about 3.0 × 10 ⁻⁵ / ° C., a Young's modulus of about 5.7 × 10 ⁹ Pa, and a thermal conductivity of about 0.2 W / mK is used. Used. By selecting the resin material in this manner, it is possible to avoid compromising the compatibility of the resin at the joint portion, and it is possible to make the difference in the characteristics of the two resins small depending on the environment in which they are used.
[0042]
In the correspondence between the embodiment described above and the elements of the claims, the insert 4 is an electromagnetic wave shielding material, the mold 10B is a holding member, the outer wall 6 is a first resin layer, and the inner wall 5 is a second resin. Layer, the through hole 41b is the first through hole, the through hole 41a is the second through hole, the protrusion 6a is the first protrusion, the protrusion 5a is the second protrusion, and the large diameter portion 51, 61 constitutes a first columnar body, and the small diameter portions 53 and 63 respectively constitute a second columnar body.
[0043]
In the above-described embodiment, the through holes 41a and 41b are described as being circular. However, the present invention is not limited to the circular shape and can be applied to holes having various shapes. The protruding portions 5a and 6a are not limited to the columnar shape, and various shapes are possible. Further, the present invention is not limited to the above-described embodiment at all, as long as the features of the present invention are not impaired.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of an electromagnetic wave shielding housing according to the present invention.
FIGS. 2A and 2B are diagrams showing a detailed structure of a side wall portion 1, in which FIG. 2A is a diagram showing a part of an outer surface of the side wall portion 1, and FIG. 2B is a cross-sectional view taken along line II-II of FIG.
FIGS. 3A to 3C are diagrams illustrating a molding process of the side wall portion 1, and FIGS.
FIG. 4 is a view for explaining a forming step when a metal mesh 14a is used as an insert material 14, and (a) to (c) show the procedure.
FIG. 5 is a diagram showing a first modification of the electromagnetic wave shielding housing.
FIG. 6 is a view for explaining a molding step in a first modified example, and (a) to (c) show the procedure.
FIGS. 7A and 7B are diagrams showing a second modification, in which FIG. 7A is a diagram showing protrusions 50a and 60a, and FIG. 7B is a diagram showing protrusions 5a and 6a.
FIGS. 8A and 8B are diagrams showing a third modification, in which FIG. 8A is a cross-sectional view of a side wall portion 1 and FIG. 8B is an enlarged view of a protruding portion 60a.
FIG. 9 is a diagram showing a comparative example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Side wall part 2 Cover 3 Cooling part 4, 14 Insert material 5 Inner wall 5a, 6a, 50a, 60a Projection part 6 Outer wall 6b, 6c Cavity 10A, 10B, 12A, 12B Primary molding die 11A, 11B Secondary molding metal Dies 41, 41a, 41b Through holes 51, 61 Large diameter portions 53, 63 Small diameter portions 54, 64 Extension portions

Claims (9)

In a method of manufacturing an electromagnetic wave shielding casing in which both front and back surfaces of an electromagnetic wave shielding material are molded with resin,
A primary molding step of molding a first resin layer made of a first resin on the other surface of the electromagnetic wave shielding material while holding one surface of the electromagnetic wave shielding material at a predetermined position with a holding member;
A second molding step of molding a second resin layer made of a second resin on one surface of the electromagnetic wave shielding material after the primary molding step. The method for manufacturing an electromagnetic wave shielding casing according to claim 1,
The electromagnetic wave shielding material has a first through hole and a second through hole,
In the primary molding step, the first resin is projected toward the one surface side through the first through hole to form a first projection connected to the first resin layer, and Forming a communication hole or cavity communicating with the through hole of the first resin layer;
In the secondary molding step, the second resin layer is molded so as to include the first protrusion, and the second resin is caused to flow into the communication hole or the cavity through the second through hole. Forming a second protruding portion connected to the second resin layer by using the method. An electromagnetic wave shielding case formed by the method for manufacturing an electromagnetic wave shielding case according to claim 2,
A part of at least one of the first protrusion and the second protrusion has a diameter larger than a diameter of the through hole. The electromagnetic wave shielding casing according to claim 3,
At least one of the first projection and the second projection is a stepped columnar projection in which a first columnar body and a second columnar body, which are two columnar bodies having different cross-sectional areas, are overlapped. Electromagnetic wave shielding case. The electromagnetic wave shielding casing according to claim 4,
The extending portion extending from the first columnar body having a large cross-sectional area toward the second columnar body having a small cross-sectional area, and facing the peripheral surface of the second columnar body with a gap provided between the first columnar body and the first columnar body, An electromagnetic wave shielding housing formed in a columnar body. The electromagnetic wave shielding casing according to claim 5,
An electromagnetic wave shielding casing, wherein the linear expansion coefficient of the second resin is larger than the linear expansion coefficient of the first resin. The electromagnetic wave shielding casing according to claim 6,
The Young's modulus of the second resin is higher than the Young's modulus of the first resin. The electromagnetic wave shielding casing according to any one of claims 3 to 7,
An electromagnetic wave shielding case, wherein the thermal conductivity of the shielding material is higher than the thermal conductivity of the first and second resins. The electromagnetic wave shielding casing according to any one of claims 3 to 8,
The casing outer wall of the electromagnetic wave shielding casing is constituted by the first resin layer, and the casing inner wall is constituted by the second resin layer, and the thermal conductivity of the first resin is reduced by the thermal conductivity of the second resin. An electromagnetic wave shielding housing characterized in that the conductivity is smaller than the conductivity.

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