Shielding case, electronic component unit, and assembly method for electronic component unit

Abstract

To improve shield performance in a structure in which objects to be shielded provided on an attachment target member are covered with a shield case.SOLUTION: An electronic component unit 10 comprises a substrate 1 and a shield case 3 fixed to the substrate 1. The shield case 3 has a storage part 31 that covers objects to be shielded 2 mounted on the substrate 1, a plurality of fixation parts 32 fixed to the substrate 1, a groove 33 that is continuously provided along an outer periphery of the storage part 31 and opens toward the substrate 1, and a single inlet 34 for injecting a conductive resin 4 into the groove 33. In the electronic component unit 10, the conductive resin 4 injected into the groove 33 fills a gap between the substrate 1 and the shield case 3.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a shielding structure in which an object to be shielded is covered with a shielding case. [Background technology]

[0002] 2. Description of the Related Art A shielding structure is known in which noise is blocked by covering a component (a shielding target) provided on a mounting member such as a substrate with a shielding case (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-39012 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned prior art, there is a problem in that a gap may occur between the attached member and the shielding case, and this gap may result in a decrease in shielding performance.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to improve the shielding performance in a structure in which a shielding target provided on a mounting member is covered with a shield case. [Means for solving the problem]

[0006] The shielding case of the present invention is a shielding case that is fixed to a workpiece, and has a box-shaped storage section that covers the shielding target provided on the workpiece, a fixing section that is fixed to the workpiece, a groove that is provided continuously along the outer periphery of the storage section and opens toward the workpiece, and a single injection port for injecting conductive resin into the groove, and is characterized in that a surface is formed within the groove that extends from the inner surface that constitutes the groove toward the space into which the conductive resin is filled and in a direction that goes all the way around the groove. The shielding case of the present invention is a shielding case that is fixed to a workpiece, and has a box-shaped storage section that covers a shielding target provided on the workpiece, a fixing section that is fixed to the workpiece, a groove that is provided continuously along the outer periphery of the storage section and opens toward the workpiece, and a single injection port for injecting conductive resin into the groove, and is characterized in that the groove has multiple convex portions that protrude outward from the inside of the storage section, the multiple convex portions are arranged at intervals in a direction around the groove, and each convex portion has a surface that extends outward from the inside of the storage section and in a direction around the groove.

[0007] The electronic component unit of the present invention is characterized in that the shielding target provided on the mounting member is covered by the shielding case, and the gap between the mounting member and the shielding case is sealed by the conductive resin injected into the groove.

[0008] The method for assembling an electronic component unit of the present invention is characterized in that, after fixing the fixed portion of the shielding case to the mounting member, conductive resin is injected into the groove from the injection port to seal the gap between the mounting member and the shielding case. [Effects of the Invention]

[0009] According to the present invention, the gap between the attached member and the shielding case is filled with the conductive resin injected into the groove, thereby improving the shielding performance. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of an electronic component unit equipped with a shield case according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3] FIG. 3 is an enlarged view of part B in FIG. 2. [Figure 4] This is a view of only the shielding case of Figure 1, viewed upside down. [Figure 5] FIG. 5 is an enlarged view of part C in FIG. [Figure 6] 6 is a diagram showing a state in which the fixing portion of FIG. 5 is fixed to a substrate. [Figure 7] 6 is a diagram showing a modified example of the protrusion in FIG. 5. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] A "shield case" and an "electronic component unit" according to one embodiment of the present invention will be described with reference to FIGS.

[0012] The electronic component unit 10 shown in Fig. 1 includes a printed circuit board 1 (corresponding to a "receiving member") on which multiple electronic components are mounted, and a shielding case 3 fixed to the board 1. The shielding case 3 covers a shielding target 2 (shown in Fig. 2), which is a group of multiple electronic components mounted on the board 1, thereby blocking noise generated from the shielding target 2. Furthermore, in this electronic component unit 10, the gap between the board 1 and the shielding case 3 is sealed by a conductive resin 4 (shown in Figs. 2 and 3) injected into a groove 33 in the shielding case 3.

[0013] The substrate 1 has a conductive layer, a shielding target 2 made up of various electronic components, and through holes 11 through which fixing parts 32 (described later) pass. The circuit pattern formed on the substrate 1 is insulated from the shielding case 3 and the conductive resin 4 by being covered with an insulating resin such as solder resist.

[0014] Shielding case 3 is made of an electromagnetic wave suppression resin mixed with magnetic filler, etc. As shown in Fig. 4, shielding case 3 has a box-shaped housing portion 31 that covers the shielding target 2, a plurality of fixing portions 32 that are fixed to substrate 1, a groove 33 formed along the outer periphery of shielding case 3, a single injection port 34, and a plurality of protrusions 35 provided within groove 33.

[0015] The multiple fixing portions 32 are provided on the outer periphery of the shielding case 3 so as to protrude toward the substrate 1. Each fixing portion 32 has only a shaft portion 32a before the shielding case 3 is fixed to the substrate 1, and a head portion 32b is formed when the shielding case 3 is fixed to the substrate 1, as shown in FIGS. 4 and 5 . The shaft portion 32a is formed so that it protrudes from the through hole 11 of the substrate 1 when inserted through the through hole 11 before the shielding case 3 is fixed to the substrate 1, i.e., is longer than the thickness of the substrate 1. The head portion 32b is formed so as to be larger than the diameter of the through hole 11. The shaft portion 32a of each fixing portion 32 is inserted into the corresponding through hole 11 of the substrate 1, and the tip of the shaft portion 32a that penetrates through the back side of the substrate 1 is welded (crimped) using ultrasound, heat, or the like, thereby forming the head portion 32b and fixing the shielding case 3 to the substrate 1. Note that in FIGS. 4 and 5 , the substrate 1 is not shown after the shielding case 3 is fixed to the substrate 1. FIG. 6 is a view of the fixing portion 32 after the substrate is fixed, as seen from the back side of the substrate 1.

[0016] Groove 33 is provided continuously along the outer periphery of shield case 3 and opens on the side of substrate 1. That is, groove 33 is provided along the entire outer periphery of housing portion 31.

[0017] The injection port 34 is used to inject the conductive resin 4 into the groove 33, and also functions as a hole for discharging air when the conductive resin 4 is injected. As shown in Fig. 4, the injection port 34 is provided near a corner of the housing portion 31 and on an extension of the linearly extending portion of the groove 33. Therefore, the conductive resin 4 injected from the injection port 34 flows in one direction toward the linearly extending portion of the groove 33, as shown by arrow D1, and then flows in the directions of arrows D2, D3, D4, and D5 to spread around the entire circumference of the groove 33.

[0018] The conductive resin 4 is conductive and can be used as a noise countermeasure, and is, for example, liquid when injected and hardens over time.

[0019] The plurality of protrusions 35 are arranged at intervals in a direction going around the groove 33. The "direction going around the groove 33" refers to the directions of the arrows D1, D2, D3, D4, and D5 described above. The "direction going around the groove 33" is determined by the direction from the injection port 34 described above toward the linearly extending portion of the groove 33 (the direction of the arrow D1). In this example, each protrusion 35 protrudes from the inside of the storage section 31 toward the outside within the groove 33.

[0020] 5, each protrusion 35 has a first surface 35a, a second surface 35b continuous with the first surface 35a, and a third surface 35c continuous with the second surface 35b. The first surface 35a extends from the inner surface 33a of the groove 33 closer to the housing portion 31 toward the outside of the housing portion 31 (i.e., toward the inner surface 33b of the groove 33 away from the housing portion 31) and extends in a direction that circles around the groove 33. The second surface 35b is approximately parallel to the inner surface 33a of the groove 33 closer to the housing portion 31. The third surface 35c extends from the second surface 35b toward the inner surface 33a of the groove 33 closer to the housing portion 31 and extends in the opposite direction to the direction that circles around the groove 33.

[0021] That is, a plurality of first surfaces 35a are formed in groove 33, extending from inner surface 33a constituting groove 33 toward the space filled with conductive resin 4 and in a direction that circles around groove 33. These first surfaces 35a restrict the flow of conductive resin 4 injected into groove 33 to one direction and direct it toward the outside of accommodating section 31. Furthermore, third surface 35c restricts the backflow of conductive resin 4, which flows in one direction within groove 33 in the directions of arrows D1, D2, D3, D4, and D5, thereby enabling smooth filling.

[0022] The electronic component unit 10 is assembled as follows. First, each fixing portion 32 of the shielding case 3 is inserted into each through-hole 11 of the substrate 1, and the tip of each fixing portion 32 is crimped (welded) with heat or ultrasonic waves to fix the shielding case 3 to the substrate 1. Thereafter, conductive resin 4 is injected into the grooves 33 through the injection port 34, and the conductive resin 4 is cured to seal the gap between the substrate 1 and the shielding case 3. The electronic component unit 10 is assembled through these steps.

[0023] In the electronic component unit 10, the conductive resin 4 injected into the groove 33 seals the gap between the substrate 1 and the shielding case 3, preventing noise leakage from this gap and improving shielding performance. Furthermore, the configuration of the single injection port 34 and multiple protrusions 35 allows the conductive resin 4 to flow smoothly in one direction within the groove 33, which also ensures that air within the groove 33 escapes in one direction. This makes it easy to confirm that the conductive resin 4 has spread throughout the entire groove 33, resulting in the production of a high-quality product. Furthermore, the operation of filling the groove 33 with the conductive resin 4 can be easily performed. Furthermore, the formation of multiple protrusions 35 on the inner surface 33a of the groove 33 near the housing portion 31 allows the conductive resin 4 to be filled into the groove 33 without seeping out toward the shielding target 2.

[0024] The above-described protrusions 35 may be modified as shown in protrusions 135 in FIG. 7. In FIG. 7, the same components as those in FIG. 5 are denoted by the same reference numerals, and their description will be omitted. Each protrusion 135 has a first surface 35a, a second surface 35b continuous with the first surface 35a, and a third surface 135c continuous with the second surface 35b. The third surface 135c extends perpendicularly from the second surface 35b toward the inner surface 33a of the groove 33 closer to the housing portion 31.

[0025] Although the above-described protrusion 35 is formed to extend from the inner surface 33a toward the outside of the accommodating portion 31, it may be provided on any of the surfaces constituting the groove 33. That is, it may be provided so as to extend from the surface constituting the groove 33 toward the space to be filled with the conductive resin 4 and to regulate the injection direction of the conductive resin 4 in a direction that goes around the groove 33. In either case, it is sufficient that a surface (first surface 35a) is formed in the groove 33, extending from the inner surface (33a or 33b) constituting the groove 33 toward the space to be filled with the conductive resin 4 and in a direction that goes around the groove 33. Note that providing a protrusion on the inner surface 33a can further prevent the conductive resin 4 from seeping into the accommodating portion 31.

[0026] The above-described embodiment merely shows a typical form of the present invention, and the present invention is not limited to this embodiment. In other words, the present invention can be implemented with various modifications within the scope of the gist of the present invention. As long as such modifications still include the configuration of the present invention, they are of course included in the scope of the present invention. [Explanation of symbols]

[0027] 1. Board (mounting component) 2 Shielded 3,103 Shield Case 4. Conductive resin 10 Electronic Components Unit 31 Storage unit 32 Fixed part 33 Groove 34 Inlet 35,135 convex part

Claims

1. A shield case fixed to a mounting member, a box-shaped receiving portion that covers a shielding target provided on the mounting member; a fixing portion fixed to the workpiece; a groove provided continuously along the outer periphery of the accommodating portion and opening toward the attached member; a single injection port for injecting a conductive resin into the groove; A surface is formed in the groove, extending from the inner surface of the groove toward the space filled with the conductive resin and in a direction that goes around the groove. A shielding case characterized by:

2. A shield case fixed to a mounting member, a box-shaped receiving portion that covers a shielding target provided on the mounting member; a fixing portion fixed to the workpiece; a groove provided continuously along the outer periphery of the accommodating portion and opening toward the attached member; a single injection port for injecting a conductive resin into the groove; A plurality of protrusions protruding from the inside of the accommodating portion toward the outside are provided in the groove, the plurality of protrusions are arranged at intervals in a direction surrounding the groove, Each protrusion has a surface that extends outward from the inside of the accommodating portion and extends in a direction that goes around the groove. A shielding case characterized by:

3. A plurality of protrusions protruding from the inside of the accommodating section toward the outside are provided in the groove, the plurality of protrusions are arranged at intervals in a direction surrounding the groove, Each protrusion has a surface that extends outward from the inside of the accommodating portion and extends in a direction that goes around the groove.

2. The shield case according to claim 1.

4. A shielding target provided on a workpiece is covered by the shield case according to any one of claims 1 to 3, and the gap between the workpiece and the shield case is filled by the conductive resin injected into the groove. An electronic component unit characterized by:

5. 5. A method for assembling an electronic component unit according to claim 4, comprising the steps of: After the fixing portion of the shield case is fixed to the workpiece, conductive resin is injected into the groove through the injection port to close the gap between the workpiece and the shield case.

1. A method for assembling an electronic component unit comprising:

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