Electronic device

Abstract

To provide an electronic device with improved design freedom.SOLUTION: An electronic device includes a wiring board on which ground wiring is printed, a conductive heat sink facing the wiring board, a fixing member that fixes a positional relationship between the wiring board and the heat sink, and an elastic member that is provided at a position different from the position of the fixing member, at least a portion of which is conductive, and electrically connects the ground wiring and the heat sink.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to electronic devices. [Background technology]

[0002] In recent years, electronic devices have been developed as disclosed in the following Patent Document 1. Such electronic devices include a wiring board, a conductive heat sink, a fixing member, and a conductive spring member. A semiconductor device is mounted on the wiring board, and a ground wiring is printed on the wiring board.

[0003] The heat sink dissipates heat generated by the semiconductor device to the outside of the electronic device. The fixing member fixes the wiring board and the heat sink. The spring member is wound around the fixing member and electrically connects the heat sink and the ground wiring. The reason for electrically connecting the heat sink and the ground wiring in this manner is to prevent unwanted radiation or static electricity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-155166 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology disclosed in the above Patent Document 1, a spring member is wound around a fixing member. Therefore, the position of electrical connection between the heat sink and the ground wiring is limited to the position of the fixing part that fixes the heat sink and the wiring board. As a result, it becomes necessary to provide a through hole in the wiring board at the position of electrical connection between the heat sink and the ground wiring. Therefore, the degree of freedom in designing the wiring board, or the degree of freedom in the position of electrical connection between the heat sink and the ground wiring as a countermeasure against unwanted radiation or static electricity, is reduced. In other words, the degree of freedom in designing the electronic device is reduced.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide an electronic device with improved design freedom. [Means for solving the problem]

[0007] The electronic device of the present disclosure comprises a wiring board on which ground wiring is printed, a conductive heat sink facing the wiring board, a fixing member that fixes the positional relationship between the wiring board and the heat sink, and an elastic member that is provided at a position different from the position of the fixing member, at least a portion of which is conductive, and electrically connects the ground wiring and the heat sink. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of an electronic device according to a first embodiment. [Diagram 2] FIG. 11 is a cross-sectional view of an electronic device according to a second embodiment. [Diagram 3] FIG. 11 is a cross-sectional view of an electronic device according to a third embodiment. [Figure 4] FIG. 11 is a perspective view of an elastic member of an electronic device according to a third embodiment. [Diagram 5] FIG. 11 is a cross-sectional view of an electronic device according to a fourth embodiment. [Figure 6] FIG. 13 is a perspective view of an elastic member of an electronic device according to a fourth embodiment. [Figure 7] FIG. 13 is a cross-sectional view of an electronic device according to a fifth embodiment. [Figure 8] 13 is a front view of an elastic member of the electronic device according to the sixth embodiment. FIG. [Figure 9] 13 is a plan view of an elastic member of an electronic device according to a sixth embodiment. FIG. [Figure 10] 13A to 13C are views showing a process of inserting an elastic member of the electronic device according to the sixth embodiment into a through hole of the heat sink. [Figure 11] FIG. 13 is a cross-sectional view of an electronic device according to a sixth embodiment. [Figure 12] FIG. 23 is a front view of an elastic member of the electronic device according to the seventh embodiment. [Figure 13] 13 is a plan view of an elastic member of an electronic device according to a seventh embodiment. FIG. [Figure 14] 13A to 13C are views showing a process of inserting the elastic member of the electronic device according to the seventh embodiment into the through-hole of the heat sink. [Figure 15] FIG. 13 is a cross-sectional view of an electronic device according to a seventh embodiment. [Figure 16] FIG. 23 is a front view of an elastic member of the electronic device according to the eighth embodiment. [Figure 17] 13 is a plan view of an elastic member of an electronic device according to an eighth embodiment. FIG. [Figure 18] 13A to 13C are views showing a process of inserting the elastic member of the electronic device according to the eighth embodiment into the through hole of the heat sink. [Figure 19] FIG. 13 is a cross-sectional view of an electronic device according to an eighth embodiment. [Figure 20] FIG. 13 is a front view of an elastic member of the electronic device according to the ninth embodiment. [Figure 21] 13 is a plan view of an elastic member of an electronic device according to a ninth embodiment. FIG. [Figure 22] 13A to 13C are views showing a process of inserting the elastic member of the electronic device according to the ninth embodiment into the through hole of the heat sink. [Diagram 23] FIG. 13 is a cross-sectional view of an electronic device according to a ninth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an electronic device according to an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will not be repeated.

[0010] (Embodiment 1) FIG. 1 is a cross-sectional view of an electronic device 10 according to the first embodiment.

[0011] As shown in FIG. 1, the electronic device 10 includes a wiring board 1, a heat sink 2, a fixing member 3, an elastic member 4, and a push pin 5.

[0012] Heat sources (not shown) such as semiconductor devices and electronic components are mounted on the wiring board 1. Circuit wiring (not shown) electrically connected to the semiconductor devices and electronic components is printed on the wiring board 1. The base material of the wiring board 1 is an insulating substrate such as resin. Circuit wiring formed of a conductive film made of copper, silver, or the like is printed on the surface of the insulating substrate.

[0013] A ground wiring 1a is also printed on the wiring board 1. The ground wiring 1a constitutes a part of the circuit line and is electrically connected to the semiconductor device, electronic components, etc. Therefore, the ground wiring 1a is used to fix the potential of the semiconductor device and electronic components. The ground wiring 1a is a part of the circuit wiring called a GND pattern, and is formed of a conductive film such as copper or silver.

[0014] The heat sink 2 is disposed so as to face the wiring board 1. The heat sink 2 is made of a metal such as aluminum, and therefore has a superior heat dissipation property to the wiring board 1. The heat sink 2 is electrically conductive.

[0015] Therefore, the heat sink 2 has both a function of releasing heat generated by the semiconductor device and the electronic components to the external space, and a function of fixing the electric potential of the semiconductor device, the electronic components, etc. The heat sink 2 has a through hole 2a.

[0016] The fixing member 3 fixes the positional relationship between the wiring board 1 and the heat sink 2. The fixing member 3 maintains a constant distance between the wiring board 1 and the heat sink 2. The fixing member 3 is a push pin. The fixing member 3 is made of resin and therefore has insulating properties.

[0017] The elastic member 4 is provided at a position different from the position of the fixed member 3. In the present embodiment, the elastic member 4 is a helical spring. The elastic member 4 is made of metal and has appropriate elasticity and conductivity.

[0018] The elastic member 4 is provided in a compressed state between the head 5a of the push pin 5 and the heat sink 2. The elastic member 4 is in contact with both the head 5a of the push pin 5 and the heat sink 2. The push pin 5 is made of metal and is therefore conductive. The elastic member 4 is conductive and therefore electrically connects the ground wiring 1a and the heat sink 2 via the head 5a. However, as long as at least a part of the elastic member 4 is conductive, the entire elastic member 4 does not need to be conductive.

[0019] The push pin 5 is inserted into the through hole 2a. The push pin 5 has a head 5a. The head 5a of the push pin 5 is in contact with the ground wiring 1a. The elastic member 4 is wound around the shaft of the push pin 5.

[0020] According to the electronic device 10 of the present embodiment as described above, the electrical conduction path consisting of the conductive ground wiring 1a, the head 5a of the conductive push pin 5, the conductive elastic member 4, and the conductive heat sink 2 is provided at a position different from the position of the fixing member 3. Therefore, the position of the electrical connection between the heat sink 2 and the ground wiring 1a is not limited to the position of the fixing member 3. As a result, the degree of freedom in designing the wiring board 1 and the degree of freedom in the position of the electrical connection between the heat sink 2 and the ground wiring 1a as a countermeasure against unwanted radiation or static electricity are improved. Therefore, the degree of freedom in designing the electronic device 10 is improved.

[0021] Furthermore, in the electronic device 10 of this embodiment, the wiring board 1 does not have a through hole at the position of the ground wiring 1a, which increases the degree of freedom in designing the ground wiring 1a on the wiring board 1.

[0022] The heat sink 2 also has a through hole 2a. The push pin 5 is inserted into the through hole 2a. The push pin 5 is made of metal and therefore conductive. The elastic member 4 is provided between the head 5a of the push pin 5 and the heat sink 2.

[0023] As described above, the elastic member 4 presses the head 5a against the ground wiring 1a. The elastic member 4 is in contact with both the head 5a and the heat sink 2. Therefore, the heat sink 2 and the ground wiring 1a are electrically connected via the head 5a and the elastic member 4.

[0024] According to the electronic device 10 of the present embodiment, simply by opening the through-hole 2a at an arbitrary position on the heat sink 2, the elastic member 4 can be provided together with the push pin 5 between the heat sink 2 and the ground wiring 1a.

[0025] (Embodiment 2) The electronic device 10 of the second embodiment will be described with reference to Fig. 2. Note that the following description will not repeat the same points as those of the electronic device 10 of the first embodiment. The electronic device 10 of the present embodiment differs from the electronic device 10 of the first embodiment in the following points.

[0026] Fig. 2 is a cross-sectional view of electronic device 10 according to embodiment 2. Although fixing member 3 is not depicted in Fig. 2, electronic device 10 according to the present embodiment also has fixing member 3 for fixing the positional relationship between wiring board 1 and heat sink 2, similar to embodiment 1.

[0027] 2, the push pin 5 has a disk-shaped head 5a and a shaft portion extending from one surface of the head 5a. The push pin 5 has a protrusion 5a1 protruding from the head 5a in the opposite direction to the shaft portion.

[0028] The protrusion 5a1 has a width (diameter) smaller than the width (diameter) of the head 5a. The protrusion 5a1 is pressed against the ground wiring 1a by an elastic member 4 that presses the head 5a. The shaft portion, head 5a, and protrusion 5a1 that constitute the push pin 5 are all formed of conductive materials. In this embodiment, the heat sink 2 and the ground wiring 1a are electrically connected via the head 5a, the protrusion 5a1, and the elastic member 4.

[0029] In this embodiment, since the protrusion 5a1 is smaller than the width of the head 5a, the width of the ground wiring 1a that the protrusion 5a1 contacts can be made smaller than when the entire head 5a contacts the ground wiring 1a. As a result, the degree of freedom in designing the wiring printed on the wiring board 1 can be improved.

[0030] (Embodiment 3) The electronic device 10 of the third embodiment will be described with reference to Figures 3 and 4. Note that the following description will not repeat the same points as those of the electronic device 10 of the first or second embodiment. The electronic device 10 of the present embodiment differs from the electronic device 10 of the first or second embodiment in the following points.

[0031] Fig. 3 is a cross-sectional view of electronic device 10 of embodiment 3. Fig. 4 is a perspective view of elastic member 4 of electronic device 10 of embodiment 3. Although fixing member 3 is not depicted in Figs. 3 and 4, electronic device 10 of the present embodiment also has fixing member 3 that fixes the positional relationship between wiring board 1 and heat sink 2, similar to embodiment 1.

[0032] 3 and 4, the heat sink 2 has a through hole 2a. The push pin 5 is inserted into the through hole 2a. However, the push pin 5 in this embodiment is made of resin and is therefore not conductive. In other words, the push pin 5 is insulating. The elastic member 4 is provided between the wiring board 1 and the heat sink 2.

[0033] In the electronic device 10 of this embodiment, the tip of the insulating push pin 5 presses the conductive elastic member 4 against the ground wiring 1a. Note that, although the push pin 5 is made of insulating resin in this embodiment, it may be made of conductive metal.

[0034] The conductive elastic member 4 is in contact with the conductive heat sink 2. The elastic member 4 is fixed to the tip of the push pin 5 by adhesive 6 or a pin (not shown), etc. In the present embodiment, the elastic member 4 is also conductive, so that the heat sink 2 and the ground wiring 1a are electrically connected via the elastic member 4.

[0035] The electronic device 10 of this embodiment also improves the degree of freedom in designing the wiring printed on the wiring board 1. The electronic device 10 of this embodiment also improves the degree of freedom in the position of the electrical connection between the heat sink 2 and the ground wiring 1a as a countermeasure against unwanted radiation or static electricity. Therefore, the present embodiment also improves the degree of freedom in designing the electronic device 10.

[0036] The conductive elastic member 4 contacts the conductive heat sink 2 on both sides of the push pin 5. This reduces the risk that the elastic member 4 will no longer contact the heat sink 2. This reduces the risk that the electrical path consisting of the ground wiring 1a, the conductive elastic member 4, and the conductive heat sink 2 will be physically disconnected.

[0037] The elastic member 4 of this embodiment has a bilaterally symmetrical shape. Specifically, the elastic member 4 is formed into a V-shape or a U-shape by bending a leaf spring. Therefore, the elastic member 4 can be easily manufactured. Also, the area of ​​the contact surface between the heat sink 2 and the elastic member 4 can be increased.

[0038] (Embodiment 4) An electronic device 10 according to the fourth embodiment will be described with reference to Figures 5 and 6. Note that, in the following, description of the same points as those of the electronic devices 10 according to the first to third embodiments will not be repeated. The electronic device 10 according to the present embodiment differs from the electronic devices 10 according to the first to third embodiments in the following points.

[0039] Fig. 5 is a cross-sectional view of electronic device 10 of embodiment 4. Fig. 6 is a perspective view of elastic member 4 of electronic device 10 of embodiment 4. Although fixing member 3 is not depicted in Figs. 5 and 6, electronic device 10 of the present embodiment also has fixing member 3 that fixes the positional relationship between wiring board 1 and heat sink 2, similar to embodiment 1.

[0040] 5 and 6, the elastic member 4 of the electronic device 10 of the present embodiment differs only in shape from the elastic member 4 of the electronic device 10 of the third embodiment shown in Figures 3 and 4. The electronic device 10 of the present embodiment also improves the degree of freedom in designing the wiring printed on the wiring board 1.

[0041] The elastic member 4 of this embodiment has an elastic member through hole 4th. The push pin 5 is made of insulating resin in this embodiment as well. Although the push pin 5 is made of insulating resin in this embodiment, it may be made of conductive metal. The push pin 5 is inserted into the elastic member through hole 4th. Therefore, the elastic member 4 of this embodiment is less likely to come off the push pin 5 than the elastic member 4 of embodiment 3.

[0042] (Embodiment 5) An electronic device 10 according to the fifth embodiment will be described with reference to Fig. 7. Note that, in the following, description of the same points as those of the electronic devices 10 according to the first to fourth embodiments will not be repeated. The electronic device 10 according to the present embodiment differs from the electronic devices 10 according to the first to fourth embodiments in the following points.

[0043] FIG. 7 is a cross-sectional view of an electronic device 10 according to the fifth embodiment.

[0044] 7, the heat sink 2 has a through hole 2a. The push pin 5 is inserted into the through hole 2a. In this embodiment, the push pin 5 is made of resin and is therefore not conductive. In other words, the push pin 5 has insulating properties.

[0045] However, a conductive film 5b is applied to the surface of the push pin 5. The conductive film 5b is metal plating. In other words, the surface of the push pin 5 is made up of the conductive film 5b. Therefore, the surface of the push pin 5 has conductivity.

[0046] The conductive heat sink 2 and the ground wiring 1a are electrically connected via a conductive film 5b. Note that the electronic device 10 of the present embodiment does not have the elastic member 4 described in the above embodiments 1 to 4.

[0047] Electronic device 10 of this embodiment also makes it possible to improve the degree of freedom in designing the wiring printed on wiring board 1.

[0048] The push pin 5 of this embodiment has a slit 5c. The portions of the push pin 5 on both sides of the slit 5c are thinner than the other portions of the push pin 5 on both sides of the slit 5c, and are therefore more flexible. Therefore, the push pin 5 of this embodiment functions as an elastic member.

[0049] Therefore, the push pin 5 as an elastic member presses the conductive film 5b against both the ground wiring 1a and the heat sink 2. Therefore, the electronic device 10 of this embodiment can maintain a good electrical connection between the ground wiring 1a and the heat sink 2 even if it does not have the elastic member 4 described in the first to fourth embodiments. However, the push pin 5 may function as an elastic member by a structure other than the slit 5c.

[0050] (Embodiment 6) Electronic device 10 of embodiment 6 will be described with reference to Figures 8 to 11. Note that, in the following, description of the same points as electronic device 10 of embodiments 1 to 5 will not be repeated. Electronic device 10 of the present embodiment differs from electronic device 10 of embodiments 1 to 5 in the following points.

[0051] 8 and 9, the elastic member 4 of this embodiment has a coil-shaped spring portion 4a and a hook-shaped fixing structure 4b for fixing the spring portion 4a between the wiring board 1 and the heat sink 2. In this embodiment as well, the elastic member 4 is conductive. The elastic member 4 of this embodiment is made by shaping a metal wire, and can be manufactured at low cost.

[0052] As shown in FIG. 10, the two hook-shaped tips of the fixing structure 4b are inserted into one of the through holes 2a of the heat sink 2. As a result, the fixing structure 4b is caught in the through hole 2a, and the elastic member 4 does not come out of the through hole 2a. Thereafter, as shown in FIG. 11, the tip of the spring portion 4a is brought into contact with the ground wiring 1a on the wiring board 1. As a result, the ground wiring 1a of the wiring board 1 and the heat sink 2 are electrically connected via the elastic member 4. Although the fixing member 3 is not shown in FIG. 11, the electronic device 10 of this embodiment also has a fixing member 3 that fixes the positional relationship between the wiring board 1 and the heat sink 2, as in the first embodiment.

[0053] The elastic member 4 of the electronic device 10 of this embodiment includes a spring portion 4a provided between the ground wiring 1a and the heat sink 2, and a fixing structure 4b that is provided integrally with the spring portion 4a and is inserted into the through hole 2a of the heat sink 2 to fix the elastic member 4 to the heat sink 2. In the electronic device 10 of this embodiment, too, an electrical conduction path consisting of the conductive ground wiring 1a, the elastic member 4, and the conductive heat sink 2 is provided at a position different from the position of the fixing member 3. Therefore, the position of the electrical connection between the heat sink 2 and the ground wiring 1a is not limited to the position of the fixing member 3. Therefore, the electronic device 10 of this embodiment also has an improved degree of freedom in design, similar to the electronic devices 10 of the first to fifth embodiments.

[0054] (Embodiment 7) The electronic device 10 of the seventh embodiment will be described with reference to Figures 12 to 15. Note that, in the following, description of the same points as those of the electronic devices 10 of the first to sixth embodiments will not be repeated. The electronic device 10 of the present embodiment differs from the electronic devices 10 of the first to sixth embodiments in the following points.

[0055] 12 to 15, electronic device 10 of the present embodiment differs from electronic device 10 of embodiment 6 only in that fixing structures 4b of elastic member 4 are located at separate positions and through holes 2a of heat sink 2 are made up of first through hole portion 2a1 and second through hole portion 2a2. In the present embodiment, two hook-shaped tips of fixing structure 4b are inserted into first through hole portion 2a1 and second through hole portion 2a2, respectively, so that elastic member 4 and heat sink 2 are fixed more firmly.

[0056] In the present embodiment as well, the elastic member 4 is made by shaping a metal wire, and therefore can be manufactured at low cost. Although the fixing member 3 is not depicted in Fig. 15, the electronic device 10 of the present embodiment also has the fixing member 3 that fixes the positional relationship between the wiring board 1 and the heat sink 2, similar to the first embodiment. The electronic device 10 of the present embodiment as described above improves the degree of freedom in designing the electronic device 10, similar to the electronic devices 10 of the first to sixth embodiments.

[0057] (Embodiment 8) 16 to 19, electronic device 10 of embodiment 8 will be described. Note that, in the following, description of the same points as electronic device 10 of embodiments 1 to 7 will not be repeated. Electronic device 10 of the present embodiment differs from electronic device 10 of embodiments 1 to 7 in the following points.

[0058] 16 and 17, the electronic device 10 of this embodiment differs from the electronic device 10 of the sixth or seventh embodiment only in that the fixing structure 4b of the elastic member 4 has a coil structure. The fixing structure 4b of this embodiment is composed of a coil portion having a diameter smaller than the diameter of the through hole 2a of the heat sink 2 and a coil portion having a diameter larger than the diameter of the through hole 2a, so that it is possible to prevent the elastic member 4 from shifting in position and falling off. In this embodiment, as shown in FIG. 18, the spring portion 4a is screwed into the through hole 2a while rotating the elastic member 4 around the central axis of the spring portion 4a.

[0059] 19, by bringing the ground wiring 1a into contact with the tip of the spring portion 4a, the spring portion 4a is positioned between the wiring board 1 and the heat sink 2. Although the fixing member 3 is not depicted in FIG. 19, the electronic device 10 of this embodiment also has a fixing member 3 that fixes the positional relationship between the wiring board 1 and the heat sink 2, similar to the first embodiment. The electronic device 10 of this embodiment also improves the freedom of design of the electronic device 10, similar to the electronic devices 10 of the first to seventh embodiments.

[0060] (Embodiment 9) 20 to 23, electronic device 10 of embodiment 9 will be described. Note that, in the following, description of the same points as electronic device 10 of embodiments 1 to 8 will not be repeated. Electronic device 10 of the present embodiment differs from electronic device 10 of embodiments 1 to 8 in the following points.

[0061] 20 to 23, electronic device 10 of the present embodiment differs from electronic device 10 of embodiment 6 only in the shape of fixing structure 4b of elastic member 4. Although fixing member 3 is not depicted in FIG. 23, electronic device 10 of the present embodiment also has fixing member 3 that fixes the positional relationship between wiring board 1 and heat sink 2, similar to embodiment 1. Electronic device 10 of the present embodiment as described above improves the design freedom of electronic device 10, similar to electronic devices 10 of embodiments 1 to 8. [Explanation of symbols]

[0062] 1. Wiring board 1a ground wire 2 Heat sink 2a Through hole 3 Fixing material 4 Elastic member 4a Spring part 4b Fixing structure 4th Elastic member through hole 5 Pushpin 5a Head 5a1 protrusion 5b Conductive film 5c Slit 10 Electronic equipment

Claims

1. A wiring board on which a ground wiring is printed; a conductive heat sink facing the wiring board; a fixing member that fixes a positional relationship between the wiring board and the heat sink; and an elastic member provided at a position different from the position of the fixing member, at least a portion of which is conductive, and electrically connecting the ground wiring and the heat sink. electronic equipment.

2. The electronic device according to claim 1 , wherein the wiring board does not have a through hole at the position of the ground wiring.

3. The heat sink has a through hole, A conductive push pin is inserted into the through hole, the elastic member is provided between the head of the push pin and the heat sink, and presses the head against the ground wiring and is in contact with the heat sink; the heat sink and the ground wiring are electrically connected via the head and the elastic member.

2. The electronic device of claim 1.

4. the push pin has a conductive protrusion extending from the head and having a width smaller than a width of the head; The projection is pressed against the ground wiring by the elastic member, the heat sink and the ground wiring are electrically connected via the protrusion, the head, and the elastic member.

4. The electronic device of claim 3.

5. The heat sink has a through hole, Further comprising a push pin inserted into the through hole, the elastic member is provided between the wiring board and the heat sink, is pressed against the ground wiring by the push pin, and is in contact with the heat sink; The heat sink and the ground wiring are electrically connected via the elastic member.

2. The electronic device of claim 1.

6. The elastic member is in contact with the heat sink on both sides of the push pin.

6. The electronic device of claim 5.

7. The elastic member has an elastic member through hole, The push pin is inserted into the through hole and the elastic member through hole.

6. The electronic device of claim 5.

8. The heat sink has a through hole, the elastic member is a push pin inserted into the through hole, a surface of the push pin is formed of the conductive film having electrical conductivity; the heat sink and the ground wiring are electrically connected via the conductive film.

2. The electronic device of claim 1.

9. The push pin has a slit that allows the push pin to function as the elastic member.

9. The electronic device of claim 8.

10. The elastic member is a spring portion provided between the ground wiring and the heat sink; The electronic device according to claim 1 , further comprising: a fixing structure provided integrally with the spring portion, the fixing structure being inserted into a through hole of the heat sink to fix the elastic member to the heat sink.

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