JP6624949B2 - Electronics - Google Patents

Description

  The present invention relates to a conductive structure for electrically connecting members such as a sheet metal to prevent static electricity or EMI (Electro Magnetic Interface), an electronic device including the conductive structure, and a method of manufacturing the conductive structure.

2. Description of the Related Art Conventionally, there is an electronic device in which electronic components are housed in a housing configured by combining sheet metal members. In such electronic devices, in order to reduce the influence of static electricity or electromagnetic waves on electronic components in the housing, the sheet metal members are combined in a state where they are conductive and grounded.
Further, since the sheet metal member may be placed in a rust-prone state depending on the usage environment of the electronic device, an electrically insulating film is often formed on the surface layer as a measure against rust.
When such a coating is formed, simply contacting the sheet metal members tends to cause poor conduction, and grounding may not be performed.

On the other hand, for example, a bonding structure of a sheet metal component described in Patent Document 1 is such that a conductive member is disposed between sheet metal components having an electrically insulating film formed on a surface layer, and in this state, the sheet metal component is placed. Is pressed out from the back side of the bonding surface by pressing to make the bonding surface side convex.
In the protrusions formed on the bonding surface side, the coating near the apex is cracked by the force applied by the punching, and the underlying metal is exposed. When the exposed metal contacts the conductive member, conduction between the sheet metal parts is ensured via the conductive member.

JP 2007-73758 A

In the connection structure described in Patent Literature 1, the coating near the apex of the protrusion is stretched by the force applied by the punching to cause cracks.
However, the underlying metal is exposed only between cracks in the coating near the apex of the protrusion.
As described above, since the amount of exposed metal at the protrusions is small, there is a problem that there is a high possibility that an amount of exposure that satisfies a required conduction state cannot be obtained by measures against static electricity or EMI.

  An object of the present invention is to solve the above-described problems, and to provide a conductive structure, an electronic device, and a manufacturing method that can sufficiently secure conduction of a member having an insulating coating.

An electronic device according to the present invention includes a first member having a first metal base covered with an insulating first coating, and a first member having a first metal protruding from the first member and covered with the first coating. And a first protruding surface portion having a first outer peripheral surface exposing a first metal base, which follows the entire outer periphery of the flat surface portion and the first flat surface portion, and is arranged so as to cover and contact the first outer peripheral surface. It comprises a conductive member and a second member that is electrically connected to the first member via the conductive member.

According to the present invention, since the metal base is exposed from the outer peripheral surface of the protruding surface provided on the first member, the metal base is exposed from the crack of the coating at the apex portion of the protrusion as in the related art. The amount of exposure is large, and the amount of exposure can be adjusted according to the amount of projection of the flat portion.
As a result, it is possible to sufficiently secure conduction between the member having the insulating coating and the conductive member, and it is possible to improve measures against static electricity or EMI.

FIG. 1A is a front view showing an electronic device having a conduction structure according to Embodiment 1 of the present invention. FIG. 1B is an enlarged cross-sectional view showing a cross section of the electronic device of FIG. 1A taken along line AA. FIG. 2A is a cross-sectional view illustrating the conduction structure according to the first embodiment. FIG. 2B is a cross-sectional view illustrating another example of the conduction structure according to Embodiment 1. FIG. 3A is a perspective view showing a sheet metal member and a conductive member that constitute the conduction structure according to the first embodiment. FIG. 3B is a sectional arrow view showing a cross section of the sheet metal member and the conductive member of FIG. 3A taken along line BB. FIG. 4A is a perspective view illustrating a sheet metal member included in the conduction structure according to Embodiment 1. FIG. 4B is a sectional arrow view showing a section of the sheet metal member of FIG. 4A taken along line CC. FIG. 4 is a diagram illustrating an outline of a method for manufacturing a conductive structure according to the first embodiment; FIG. 6A is a front view showing an example of a sheet metal member constituting a conduction structure according to Embodiment 2 of the present invention. FIG. 6B is a perspective view showing the sheet metal member of FIG. 6A. FIG. 7A is a front view showing another example of the sheet metal member forming the conduction structure according to Embodiment 2. FIG. FIG. 7B is a perspective view showing the sheet metal member of FIG. 7A. FIG. 8A is a front view showing still another example of the sheet metal member forming the conductive structure according to Embodiment 2. FIG. FIG. 8B is a perspective view showing the sheet metal member of FIG. 8A.

Embodiment 1 FIG.
FIG. 1A is a front view showing an electronic device 1 including a conduction structure according to Embodiment 1 of the present invention. FIG. 1B is an enlarged cross-sectional view showing a cross section of the electronic device 1 of FIG. 1A taken along line AA.
The electronic device 1 is, for example, a vehicle-mounted electronic device such as a car navigation device, and includes a liquid crystal panel 2 and a housing 3. As shown in FIG. 1A, the liquid crystal panel 2 is a component exposed from one surface of the housing 3 to the outside, and static electricity generated outside is easily transmitted to an internal circuit board.

  For example, as shown in FIG. 1B, the liquid crystal panel 2 may have a liquid crystal unit 2A held by a chassis 4B and a circuit board (not shown) attached to the chassis 4B. A protective plate 2B is mounted on the display surface side of the liquid crystal unit 2A, and the protective plate 2B is mounted on the front side of the housing 3. With this configuration, static electricity generated in the protection plate 2B or the housing 3 may be transmitted from the sheet metal chassis 4B to the circuit board through a gap between the protection plate 2B and the housing 3.

On the other hand, conventionally, the chassis 4A is kept at the ground potential, and the chassis 4A and the chassis 4B are electrically connected to each other through a conductive member, thereby preventing static electricity from being transmitted to the circuit board. Structure is adopted.
However, as described above, a sheet metal chassis often has an electrically insulating film formed on the surface layer by plating or the like as a measure against rust.
In this case, if the conductive members are merely sandwiched between the chassis, the conduction between the chassis and the conductive members is insufficient, and the chassis may not be sufficiently electrically connected.

On the other hand, the conductive structure according to the present invention includes a protruding surface portion having a flat portion protruding from the chassis by half blanking or the like and an outer peripheral surface on which the underlying sheet metal member is exposed. The conductive member is arranged to be in contact with the underlying sheet metal member exposed from the outer peripheral surface.
In this manner, by exposing the base sheet metal member from the outer peripheral surface of the protruding surface portion, the base sheet metal member is exposed from cracks in the coating at the apexes of the protrusions, as in the joint structure described in Patent Document 1. As compared with the configuration, a larger amount of exposure can be obtained in each stage. Also, by changing the amount of protrusion of the flat portion, the amount of exposure of the underlying sheet metal member can be adjusted.

  FIG. 2A is a cross-sectional view showing the conduction structure according to Embodiment 1, and shows a structure in which protruding surface portions 4A-4 are provided only in chassis 4A. In this structure, for example, a chassis without an electrically insulating coating is used as the chassis 4B. FIG. 2B is a cross-sectional view showing another example of the conduction structure according to Embodiment 1, showing a structure in which a protruding portion 4A-4 is provided on chassis 4A and a protruding portion 4C-4 is provided on chassis 4C. I have.

In FIG. 2A, a chassis 4A is a component that embodies the first member of the present invention, and is a member in which a sheet metal member 4A-1 is covered with coatings 4A-2 and 4A-3 having electrical insulation. . That is, the electrically insulating film 4A-2 is formed on one surface layer of the sheet metal member 4A-1, and the film 4A-3 is formed on the other surface layer.
The protruding surface portion 4A-4 is formed in a state where the flat portion 4A-5 protrudes from a part of the chassis 4A, and the underlying sheet metal member 4A-1 is exposed from the outer peripheral surface 4A-6 of the flat portion 4A-5. ing.

The conductive member 5 is a member disposed in contact with the base exposed from the outer peripheral surface 4A-6 of the flat portion 4A-5, and is made of, for example, a conductive and sponge-like soft member. .
Specifically, a sponge member covered with a thin sheet of metal mesh such as stainless steel can be used. When the conductive member 5 configured as described above is sandwiched between the chassis 4A and the chassis 4B, the protruding surface portion 4A-4 is sunk as shown in FIG. Contact exposed substrate.
For example, when the height dimension of the conductive member 5 before being sandwiched between the chassis 4A and the chassis 4B is 5 mm, the chassis 4A and the chassis 4B sandwich the conductive member 5 and the height of the conductive member 5 Compress until the size in the direction becomes about 2.5 mm. As a result, the protruding surface portion 4A-4 sinks into the conductive member 5, and the base exposed from the outer peripheral surface 4A-6 and the conductive member 5 reliably contact.

In FIG. 2B, a chassis 4C is a component that embodies the second member of the present invention, and is a member in which a sheet metal member 4C-1 is covered with coatings 4C-2 and 4C-3 having electrical insulating properties. . That is, the coating 4C-2 is formed on the surface layer on one side of the sheet metal member 4C-1, and the coating 4C-3 is formed on the surface layer on the other side.
Note that the chassis 4C may be a sheet metal chassis that holds the liquid crystal unit 2A, like the chassis 4B illustrated in FIG. 1B.

Like the chassis 4A, the protruding surface portion 4C-4 is formed in a state where the flat portion 4C-5 protrudes from a part of the chassis 4C, and the underlying sheet metal member 4C-1 is exposed from the outer peripheral surface 4C-6. .
As shown in FIG. 2B, the conductive member 5 is also arranged in contact with the base exposed from the outer peripheral surface 4C-6, so that the chassis 4C conducts with the chassis 4A via the conductive member 5.

FIG. 3A is a perspective view showing a sheet metal member and a conductive member constituting the conductive structure according to the first embodiment, and shows chassis 4A and conductive member 5 arranged on chassis 4A. FIG. 3B is a sectional arrow view showing a cross section of the chassis 4A and the conductive member 5 of FIG. 3A taken along the line BB.
FIG. 4A is a perspective view showing a sheet metal member constituting the conductive structure according to Embodiment 1, and shows a chassis 4A provided with a protruding surface 4A-4. FIG. 4B is a sectional arrow view showing a cross section of the chassis 4A of FIG. 4A taken along the line CC.

Conventionally, there is a structure for electrically connecting chassis to each other via a conductive member, and the conductive member has been attached to the chassis using an adhesive or a double-sided adhesive tape.
In this structure, if the adhesive or the double-sided pressure-sensitive adhesive tape is electrically insulating, it may be a factor that hinders the electrical connection between the chassis and the conductive member.

On the other hand, as shown in FIGS. 4A and 4B, the protruding surface portion 4A-4 of the present invention has a structure in which only the flat portion 4A-5 protrudes from the chassis 4A. It is covered with a coating 4A-2 formed on the surface layer of the chassis 4A.
However, as shown in FIGS. 3A and 3B, conduction between the chassis 4A and the conductive member 5 is ensured by the conductive member 5 being in contact with the base exposed from the outer peripheral surface 4A-6.
Therefore, the conductive member 5 is attached to the chassis 4A by an electrically insulating adhesive or a double-sided adhesive tape disposed on the coating 4A-2 of the plane portion 4A-5.
By doing so, the conductive member 5 can be attached to the chassis 4A without interrupting the conduction between the chassis 4A and the conductive member 5.
Although FIG. 4A shows a case where two protruding portions 4A-4 are provided, one or three or more protruding portions 4A-4 may be provided.

FIG. 5 is a diagram showing an outline of a method of manufacturing the conductive structure according to the first embodiment. 2 shows a section taken along the line.
First, the chassis 4A is placed on a die 6 having a hole having a diameter similar to that of the plane portion 4A-5.
Next, a punch 7 having a diameter slightly larger than the plane portion 4A-5 is pushed into the die 6 along the direction of arrow D from the surface of the chassis 4A opposite to the die 6.
The protruding surface portion 4A-4 is formed by performing a so-called half-punching process in which the pressing of the punch 7 is stopped before the flat portion 4A-5 completely comes out of the chassis 4A.

The sheet metal member 4A-1 is exposed from the outer peripheral surface 4A-6 when the coating 4A-2 of the outer peripheral surface 4A-6 is sheared by the die 6 when the punch 7 is pressed.
When the pushing amount of the punch 7 is E1, the height E2 of the outer peripheral surface 4A-6 has the same size as E1. Therefore, by adjusting the pushing amount of the punch 7, the amount of the sheet metal member 4A-1 exposed from the outer peripheral surface 4A-6 can be adjusted.
For example, when the punch 7 is further pushed into the position shown by the broken line in FIG. 5, the flat portion 4A-5 further projects, and the exposure amount of the sheet metal member 4A-1 also increases.
In addition, although the case where the projecting surface portion 4A-4 is formed by the half blanking process is shown, the projecting surface portion 4C-4 shown in FIG. 2B may be formed by the half blanking process. Also in this case, the same effect as when the protruding surface portion 4A-4 is formed by half blanking can be obtained.

As described above, in the conduction structure according to Embodiment 1, the chassis 4A has the sheet metal member 4A-1 covered with the insulating coating 4A-2. The protruding surface portion 4A-4 has a flat surface portion 4A-5 protruding from the chassis 4A and covered with the coating 4A-2, and an outer peripheral surface 4A-6 from which the underlying sheet metal member 4A-1 is exposed. The conductive member 5 is disposed in contact with the underlying sheet metal member 4A-1 exposed from the outer peripheral surface 4A-6.
As described above, the base metal member 4A-1 is exposed from the outer peripheral surface 4A-6 of the protruding surface portion 4A-4 provided on the chassis 4A, so that the base metal can be removed from cracks in the coating at the apexes of the protrusions as in the related art. The amount of exposure is larger than the structure to be exposed, and the amount of exposure can be adjusted according to the amount of projection of the flat portion. As a result, sufficient conduction between the chassis 4A having the insulating coating 4A-2 and the conductive member 5 can be ensured, and the effect of countermeasures against static electricity or EMI in the electronic device 1 having this conduction structure can be obtained. Can be improved.

The conductive structure according to the first embodiment includes a chassis 4C in which the sheet metal member 4C-1 is covered with an insulating coating 4C-2, and a flat portion 4C protruding from the chassis 4C and covered with the coating 4C-2. -5 and a projecting surface 4C-4 having an outer peripheral surface 4C-6 from which the underlying sheet metal member 4C-1 is exposed. The chassis 4C is electrically connected to the chassis 4A via the conductive member 5 disposed in contact with the base sheet metal member 4C-1 exposed from the outer peripheral surface 4C-6.
In the first embodiment, the flat portion 4A-5 and the flat portion 4C-5 are circular, and the protruding portions 4A-4 and 4C-4 are cylindrical.
Even with such a configuration, it is possible to sufficiently secure conduction between the chassis 4A and the chassis 4C via the conductive member 5.

Furthermore, in the method of manufacturing the conduction structure according to the first embodiment, the flat surface portion 4A-5 or the flat surface portion 4C-5 is partially punched to form the protruding surface portion 4A-4 or the protruding surface portion 4C-4.
By doing so, the protruding surface portion 4A-4 can be easily formed. Further, by adjusting the pushing amount of the punch 7, the amount of exposure of the sheet metal member 4A-1 from the outer peripheral surface 4A-6 can be adjusted. Thereby, conduction between the chassis 4A and the conductive member 5 can be adjusted, and the effect of measures against static electricity or EMI in the electronic device 1 having this conduction structure can be improved.

Embodiment 2 FIG.
In the first embodiment, the amount by which the sheet metal member 4A-1 or the sheet metal member 4C-1 is exposed is adjusted by the amount of protrusion of the flat part 4A-5 or the flat part 4C-5. A structure in which the amount by which the underlying sheet metal member is exposed in the shape will be described.
FIG. 6A is a front view showing an example of a sheet metal member constituting a conduction structure according to Embodiment 2 of the present invention, and shows a structure in which a protruding surface 4A-7 is provided on a chassis 4A. FIG. 6B is a perspective view showing the chassis 4A of FIG. 6A.

As shown in FIG. 6A, the flat part 4A-8 has a star shape, and the protruding surface part 4A-7 has a star-shaped polygonal pillar shape as shown in FIG. 6B. With such a configuration, the base metal member is exposed from the outer peripheral surface 4A-9 of the flat portion 4A-8.
The conductive member 5 shown in the first embodiment is arranged in contact with the underlying sheet metal member exposed from the outer peripheral surface 4A-9, so that sufficient conduction between the chassis 4A and the conductive member 5 is ensured. be able to. As a result, the effect of countermeasures against static electricity or EMI in the electronic device 1 having the conductive structure can be improved.

FIG. 7A is a front view showing another example of the sheet metal member constituting the conductive structure according to Embodiment 2, and shows a structure in which a protruding surface portion 4A-10 is provided on a chassis 4A. FIG. 7B is a perspective view showing the chassis 4A of FIG. 7A.
As shown in FIG. 7A, the flat portion 4A-11 has a quadrangular shape, and the protruding surface portion 4A-10 has a quadrangular prism shape having a quadrangular end face as shown in FIG. 7B. With such a configuration, the base metal member is exposed from the outer peripheral surface 4A-12 of the flat portion 4A-11.
Since conductive member 5 shown in the first embodiment is arranged in contact with the underlying sheet metal member exposed from outer peripheral surface 4A-12, conduction between chassis 4A and conductive member 5 is sufficiently ensured. be able to. As a result, the effect of countermeasures against static electricity or EMI in the electronic device 1 having the conductive structure can be improved.

FIG. 8A is a front view showing still another example of the sheet metal member constituting the conductive structure according to Embodiment 2, and shows a structure in which a protruding surface portion 4A-13 is provided on a chassis 4A. FIG. 8B is a perspective view showing the chassis 4A of FIG. 8A.
As shown in FIG. 8A, the flat surface portion 4A-14 has a triangular shape, and the protruding surface portion 4A-13 has a triangular prism shape with a triangular end surface as shown in FIG. 8B. With such a configuration, the underlying sheet metal member is exposed from the outer peripheral surface 4A-15 of the flat portion 4A-14.
The conductive member 5 described in the first embodiment is arranged in contact with the underlying sheet metal member exposed from the outer peripheral surface 4A-15, so that sufficient conduction between the chassis 4A and the conductive member 5 is ensured. be able to. As a result, the effect of countermeasures against static electricity or EMI in the electronic device 1 having the conductive structure can be improved.

As described above, in the conduction structure according to the second embodiment, the flat portions 4A-8, 4A-11, and 4A-14 are polygonal, and the protruding portions 4A-7, 4A-10, and 4A-13 are polygonal columns. Shape. With this configuration, the amount of exposure is larger than in the conventional structure in which the underlying metal is exposed from the apex portion of the protrusion, and the amount of exposure depends on the shape of the plane portions 4A-8, 4A-11, and 4A-14. You can also adjust the amount of exposure.
Therefore, the conduction between the chassis 4A having the insulating coating 4A-2 and the conductive member 5 can be sufficiently ensured, and the effect of countermeasures against static electricity or EMI in an electronic device having this conduction structure can be improved. be able to.

In the case where both the protruding portions 4A-4 and the protruding portions 4C-4 are formed, the shapes of the flat portions of these protruding portions may be the same or different.
Further, when a plurality of protruding portions are provided for one conductive member as shown in FIG. 4A, the shape or size of the flat portion of the protruding portion may be changed.
Furthermore, by combining Embodiment 1 and Embodiment 2, the shape of the flat portion and the amount of protrusion may be changed to adjust the amount by which the underlying sheet metal member is exposed from the outer peripheral surface.
Furthermore, although the case has been described where the conductive member 5 is formed of a conductive and sponge-like soft member, the conductive member 5 may be formed of a hard member having a hole into which the protruding surface is fitted.
That is, the conductive member may have any configuration as long as the conductive member can be in contact with the outer peripheral surface of the flat portion when disposed on the chassis.

  In the present invention, within the scope of the invention, any combination of the embodiments can be freely combined, or any of the constituent elements of each of the embodiments can be modified, or any of the constituent elements can be omitted in each of the embodiments. .

  DESCRIPTION OF SYMBOLS 1 Electronic device, 2 liquid crystal panel, 2A liquid crystal part, 2B protective plate, 3 housing, 4A, 4B, 4C chassis, 4A-1, 4C-1 sheet metal member, 4A-2, 4A-3, 4C-2, 4C -3 Coating, 4A-4, 4A-7, 4A-10, 4A-13, 4C-4 Projection, 4A-5, 4A-8, 4A-11, 4A-14, 4C-5 Planar, 4A- 6, 4A-9, 4A-12, 4A-15 Outer peripheral surface, 5 conductive members, 6 dies, 7 punches.

Claims (6)

A first member in which a base of a first metal is covered with an insulating first coating;
A first flat portion protruding from the first member and covered with the first coating, and a first outer peripheral surface exposing the first metal base following the entire outer periphery of the first flat portion; A first projection,
And the conductive member to be placed in contact over said first outer peripheral surface,
A second member that conducts with the first member via the conductive member;
An electronic device comprising: It said second member, the base of the second metal is covered with a second coating of insulation, the second flat portion and said first covered with projecting the second coating from the second member a second protruding surface portion having a second outer peripheral surface of the second metal base following the entire outer periphery of the second plane portion is exposed,
Said second member, electrons according to claim 1, characterized in that conduction with the first outer peripheral surface through the conductive members to be placed in contact over said second outer circumferential surface machine. The electronic device according to claim 1, wherein the first protruding portion has a cylindrical shape or a polygonal shape . The electronic device according to claim 2, wherein the second protruding portion has a cylindrical shape or a polygonal pillar shape . The electronic device according to claim 1, wherein the conductive member is compressible. The said conductive member was attached to the said 1st member via the adhesive agent provided on the said 1st coating of the said 1st plane part, or the double-sided adhesive tape, The said 1st member. The electronic device according to any one of claims 1 to 5.

Images