CN213213961U

CN213213961U - Multilayer combined type PCB circuit board

Info

Publication number: CN213213961U
Application number: CN202022616293.XU
Authority: CN
Inventors: 徐康; 黄明星
Original assignee: Hangzhou Linan Kangyi Electronic Co Ltd
Current assignee: Hangzhou Linan Kangyi Electronic Co Ltd
Priority date: 2020-11-12
Filing date: 2020-11-12
Publication date: 2021-05-14
Anticipated expiration: 2030-11-12

Abstract

The utility model provides a multilayer combined type PCB circuit board belongs to circuit board technical field. The multilayer composite PCB circuit board comprises a first substrate mechanism, a second substrate mechanism and a third substrate mechanism, wherein a first bolt penetrates through the first PCB board in a sliding mode, and a first spring is sleeved on the outer surface of the first bolt. The utility model discloses a first spring housing, first bolt, first PCB board, second screw thread post, the second spring, the second bolt, the second PCB board, third screw thread post, the third spring, the fourth spring, the third bolt, the fourth bolt, the fifth spring, the fifth bolt, the third PCB board, the second screw thread post, the sixth spring, the effect of sixth bolt and fourth PCB board, thereby the purpose of difficult damage circuit board has been reached, make the too pine that the screw can not be twisted through the spring during the fix with screw or too tight, make the difficult damage of multilayer PCB circuit board, improve the life of multilayer PCB circuit board.

Description

Multilayer combined type PCB circuit board

Technical Field

The utility model relates to a circuit board field particularly, relates to a multilayer combined type PCB circuit board.

Background

The PCB circuit board is also called as a printed circuit board, is a provider of electrical connection of electronic components, the design of the PCB circuit board is mainly a layout design, the main advantage of the adopted circuit board is that the errors of wiring and assembly are greatly reduced, the automation level and the production labor rate are improved, in order to increase the area capable of wiring, a printed circuit board with a double-sided inner layer and two single-sided outer layers or two double-sided inner layers and two single-sided outer layers is used, the printed circuit board which is alternately arranged together by a positioning system and an insulating binding material and is interconnected by conductive patterns according to the design requirement becomes a four-layer or six-layer printed circuit board, also called as a multilayer PCB circuit board, while the existing multilayer composite PCB circuit board is easy to damage when being installed, the existing mounting and fixing of the multilayer PCB circuit board generally adopts a screw fixing mode, and the multilayer PCB circuit board is easy to damage when being screwed too tightly, when the PCB is too loose, the PCB is easy to shake, and the service life of the multilayer PCB is influenced.

SUMMERY OF THE UTILITY MODEL

In order to make up for above not enough, the utility model provides a multilayer combined type PCB circuit board aims at improving the problem of damaging the circuit board easily when installing.

The utility model discloses a realize like this:

the utility model provides a multilayer combined type PCB circuit board, including first base plate mechanism, second base plate mechanism and third base plate mechanism.

The first substrate mechanism comprises a heat dissipation assembly, a connecting assembly, a first bolt, a first spring, a second bolt and a second spring, the first substrate mechanism comprises a first PCB and a second PCB, the connecting assembly comprises a third bolt, a third spring, a first threaded column, a fourth bolt and a fourth spring, the first bolt penetrates through the first PCB in a sliding manner, the first spring is sleeved on the outer surface of the first bolt, the third bolt penetrates through the first PCB in a sliding manner, the third spring is sleeved on the outer surface of the third bolt, the third bolt is in threaded connection with the first threaded column, the fourth bolt penetrates through the second PCB in a sliding manner, the fourth spring is sleeved on the outer surface of the fourth bolt, the fourth bolt is in threaded connection with the first threaded column, and the second bolt penetrates through the second PCB in a sliding manner, the second spring is sleeved on the outer surface of the second bolt, the second substrate mechanism comprises a third PCB, a fifth bolt, a fifth spring and a second threaded column, the fifth bolt penetrates through the third PCB in a sliding mode, the fifth spring is sleeved on the outer surface of the fifth bolt, the fifth bolt is in threaded connection with the second threaded column, the first bolt is in threaded connection with the second threaded column, the third substrate mechanism comprises a fourth PCB, a sixth bolt, a sixth spring and a third threaded column, the sixth bolt penetrates through the fourth PCB in a sliding mode, the sixth spring is sleeved on the outer surface of the sixth bolt, the sixth bolt is in threaded connection with the third threaded column, and the third threaded column is in threaded connection with the second bolt.

In an embodiment of the present invention, the heat dissipation assembly further includes a first heat conduction pad, a first copper plate and a second heat conduction pad, the first heat conduction pad both sides are connected to the first copper plate and the first PCB plate, the second heat conduction pad both sides are connected to the first copper plate and the second PCB plate.

The utility model discloses an in multilayer combined type PCB circuit board embodiment, coupling assembling still includes first gasket and second gasket, first gasket with the second gasket install respectively in first screw thread post both sides, first gasket with first PCB board one side contact, the second gasket with second PCB board one side contact.

In an embodiment of the present invention, the second substrate mechanism further includes a second copper sheet and a third thermal pad, the fifth bolt slidably penetrates through the second copper sheet, and two sides of the third thermal pad are connected to the second copper sheet and the third PCB.

In an embodiment of the present invention, the third substrate mechanism further includes a third copper sheet and a fourth thermal pad, the sixth bolt slidably penetrates through the third copper sheet, and the fourth thermal pad is connected to the third copper sheet and the fourth PCB.

The utility model discloses an in the embodiment of multilayer combined type PCB circuit board, first through-hole has been seted up to first PCB inboard surface, first bolt with first through-hole clearance fit, the second through-hole has been seted up to first PCB inboard surface, the third bolt slide run through in the second through-hole.

In the embodiment of the present invention, the second through hole is formed on the inner surface of the second PCB, and the second through hole is in clearance fit with the second bolt.

In the embodiment of the present invention, a fourth through hole is formed on the inner surface of the second PCB, and the fourth bolt is slidably inserted into the fourth through hole.

In the embodiment of the present invention, the third through hole is formed on the inner surface of the third PCB, and the fifth bolt is in clearance fit with the fifth through hole.

In the embodiment of the present invention, a sixth through hole is opened on the inner surface of the fourth PCB, and the sixth bolt slidably penetrates through the sixth through hole.

The utility model has the advantages that: the utility model provides a multilayer combined type PCB circuit board that obtains through above-mentioned design, when using, cover first spring on first bolt, insert first bolt in the first through-hole on the first PCB board, and screw up second screw thread post screw thread on first bolt, again cover second spring on the second bolt surface, and insert the second bolt in the third through-hole on the second PCB board, and screw up the third screw thread post screw thread on the second bolt, again respectively cover third spring and fourth spring on third bolt and fourth bolt surface, and make third bolt and fourth bolt insert respectively in second through-hole and the fourth through-hole on first PCB board and the second PCB board, and make first screw thread post and third bolt and fourth bolt screw thread, can fix first PCB board and second PCB board together this moment, third spring and fourth spring make first PCB board and second PCB board have elasticity, then, a fifth spring is sleeved on the outer surface of the fifth bolt, the fifth bolt sequentially penetrates through the second copper sheet and the third PCB and is in threaded connection with the second threaded column, at the moment, the third PCB can be fixed on the first PCB and the second PCB, the fifth spring can enable the third PCB and the first PCB to have elasticity, finally, a sixth spring is sleeved on the sixth bolt, the sixth bolt sequentially penetrates through the third copper sheet and the fourth PCB and is screwed on the third threaded column, at the moment, the fourth PCB can be placed and fixed on the second PCB, the sixth spring can enable the fourth PCB and the second PCB to have elasticity, the first PCB, the second PCB, the third PCB and the fourth PCB are tightly connected, and meanwhile, the screw cannot be screwed too tightly or too loosely, so that the purpose of damaging the circuit board is achieved, the screw cannot be screwed too loosely or too tightly screwed by the spring when the screw is fixed, the multilayer PCB is not easy to damage, and the service life of the multilayer PCB is prolonged.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a multilayer composite PCB circuit board according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a first substrate mechanism according to an embodiment of the present invention;

fig. 3 is a schematic structural view of a heat dissipation assembly according to an embodiment of the present invention;

fig. 4 is a schematic structural view of a connection assembly according to an embodiment of the present invention;

fig. 5 is a schematic structural view of a second substrate mechanism according to an embodiment of the present invention;

fig. 6 is a schematic structural view of a third substrate mechanism according to an embodiment of the present invention.

In the figure: 10-a first substrate mechanism; 110-a heat sink assembly; 111-a first PCB board; 112-a second PCB board; 113-a first thermally conductive pad; 114-a first copper plate; 115-a second thermally conductive pad; 116-a first via; 117-second via; 118-a third via; 119-a fourth via; 120-a connecting assembly; 121-a third bolt; 122-a third spring; 123-a first shim; 124-a first threaded post; 125-a second gasket; 126-fourth bolt; 127-a fourth spring; 130-a first bolt; 140-a first spring; 150-a second bolt; 160-a second spring; 20-a second substrate mechanism; 210-a third PCB board; 220-a fifth bolt; 230-a fifth spring; 240-a second copper sheet; 250-a third thermally conductive pad; 260-a second threaded post; 270-a fifth via; 30-a third substrate mechanism; 310-a fourth PCB board; 320-sixth bolt; 330-sixth spring; 340-a third copper sheet; 350-a fourth thermally conductive pad; 360-a third threaded post; 370-sixth via.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the drawings of the embodiments of the present invention are combined to clearly and completely describe the technical solutions of the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

Examples

Referring to fig. 1, the present invention provides a multi-layer composite PCB, which includes a first substrate mechanism 10, a second substrate mechanism 20 and a third substrate mechanism 30.

The second substrate mechanism 20 is screwed above the first substrate mechanism 10, the third substrate mechanism 30 is screwed below the first substrate mechanism 10, and the first substrate mechanism 10, the second substrate mechanism 20 and the third substrate mechanism 30 are used for forming a multilayer composite PCB.

Referring to fig. 1, 2, 3, and 4, the first substrate mechanism 10 includes a heat sink 110, a connecting member 120, a first bolt 130, a first spring 140, a second bolt 150, and a second spring 160, the first substrate mechanism 10 includes a first PCB 111 and a second PCB 112, the connecting member 120 includes a third bolt 121, a third spring 122, a first threaded post 124, a fourth bolt 126, and a fourth spring 127, the first bolt 130 slidably penetrates the first PCB 111, the first spring 140 is sleeved on an outer surface of the first bolt 130, the third bolt 121 slidably penetrates the first PCB 111, the third spring 122 is sleeved on an outer surface of the third bolt 121, the third bolt 121 is threadedly connected to the first threaded post 124, the fourth bolt 126 slidably penetrates the second PCB 112, the fourth spring 127 is sleeved on an outer surface of the fourth bolt 126, the fourth bolt 126 is threadedly connected to the first threaded post 124, the second bolt 150 slidably penetrates the second PCB 112, the second spring 160 is sleeved on the outer surface of the second bolt 150, the first spring 140 is used for enabling the first bolt 130 and the first PCB 111 to have elasticity, the second spring 160 is used for enabling the second bolt 150 and the second PCB 112 to have elasticity, the third spring 122 is used for enabling the third bolt 121 and the first PCB 111 to have elasticity, the fourth spring 127 is used for enabling the fourth bolt 126 and the second PCB 112 to have elasticity, and the first threaded column 124 is used for connecting the third bolt 121 and the fourth bolt 126, so that the first PCB 111 and the second PCB 112 are fixed together.

In some specific embodiments, the heat dissipation assembly 110 further includes a first thermal pad 113, a first copper plate 114, and a second thermal pad 115, two sides of the first thermal pad 113 are connected to the first copper plate 114 and the first PCB 111, two sides of the second thermal pad 115 are connected to the first copper plate 114 and the second PCB 112, the connection assembly 120 further includes a first gasket 123 and a second gasket 125, the first gasket 123 and the second gasket 125 are respectively installed on two sides of the first threaded post 124, the first gasket 123 contacts one side of the first PCB 111, the second gasket 125 contacts one side of the second PCB 112, the first through hole 116 is opened on the inner surface of the first PCB 111, the first bolt 130 is in clearance fit with the first through hole 116, the second through hole 117 is opened on the inner surface of the first PCB 111, the third bolt 121 slidably penetrates through the second through hole 117, the third through hole 118 is opened on the inner surface of the second PCB 112, the third through hole 118 is in clearance fit with the second bolt 150, a fourth through hole 119 is formed in the inner surface of the second PCB 112, a fourth bolt 126 penetrates through the fourth through hole 119 in a sliding manner, the first heat conduction pad 113 and the second heat conduction pad 115 are used for transferring heat generated by electronic components on the first PCB 111 and the second PCB 112 during operation to the first copper plate 114 to dissipate heat of the PCB, and the first gasket 123 and the second gasket 125 are used for protecting the connection between the first threaded column 124 and the first PCB 111 and the second PCB 112.

Referring to fig. 1, 2, 3 and 5, the second substrate mechanism 20 includes a third PCB 210, a fifth bolt 220, a fifth spring 230 and a second threaded post 260, the fifth bolt 220 slidably penetrates through the third PCB 210, the fifth spring 230 is sleeved on an outer surface of the fifth bolt 220, the fifth bolt 220 is in threaded connection with the second threaded post 260, the first bolt 130 is in threaded connection with the second threaded post 260, the second threaded post 260 is used for fixing the fifth bolt 220 and the first bolt 130 together, so that the third PCB 210 is fixed on the first PCB 111, and the fifth spring 230 is used for providing elasticity between the fifth bolt 220 and the third PCB 210.

In some specific embodiments, the second substrate mechanism 20 further includes a second copper sheet 240 and a third thermal pad 250, the fifth bolt 220 slidably penetrates through the second copper sheet 240, two sides of the third thermal pad 250 are connected to the second copper sheet 240 and the third PCB 210, a fifth through hole 270 is formed in the inner surface of the third PCB 210, the fifth bolt 220 is in clearance fit with the fifth through hole 270, and the third thermal pad 250 is used for transferring heat generated by electronic components on the third PCB 210 during operation to the second copper sheet 240 to dissipate heat of the third PCB 210.

Referring to fig. 1, 2, 3 and 6, the third substrate mechanism 30 includes a fourth PCB 310, a sixth bolt 320, a sixth spring 330 and a third threaded post 360, the sixth bolt 320 slidably penetrates through the fourth PCB 310, the sixth spring 330 is sleeved on the outer surface of the sixth bolt 320, the sixth bolt 320 is in threaded connection with the third threaded post 360, the third threaded post 360 is in threaded connection with the second bolt 150, the third threaded post 360 is used for fixing the sixth bolt 320 and the second bolt 150 together, so that the fourth PCB 310 is fixed on the second PCB 112, and the sixth spring 330 is used for providing elasticity between the fifth bolt 220 and the third PCB 210.

In some specific embodiments, the third substrate mechanism 30 further includes a third copper sheet 340 and a fourth thermal pad 350, the sixth bolt 320 slidably penetrates through the third copper sheet 340, two sides of the fourth thermal pad 350 are connected to the third copper sheet 340 and the fourth PCB 310, a sixth through hole 370 is formed in the inner surface of the fourth PCB 310, the sixth bolt 320 slidably penetrates through the sixth through hole 370, and the fourth thermal pad 350 is configured to transfer heat generated by electronic components on the fourth PCB 310 during operation to the third copper sheet 340 to dissipate heat of the fourth PCB 310.

The working principle of the multilayer composite PCB circuit board is as follows: in use, the first spring 140 is fitted over the first bolt 130, the first bolt 130 is inserted into the first through hole 116 of the first PCB 111, the second threaded post 260 is screwed onto the first bolt 130, the second spring 160 is fitted over the outer surface of the second bolt 150, the second bolt 150 is inserted into the third through hole 118 of the second PCB 112, the third threaded post 360 is screwed onto the second bolt 150, the third spring 122 and the fourth spring 127 are fitted over the outer surfaces of the third bolt 121 and the fourth bolt 126, respectively, the third bolt 121 and the fourth bolt 126 are inserted into the second through hole 117 and the fourth through hole 119 of the first PCB 111 and the second PCB 112, respectively, and the first threaded post 124 is screwed onto the third bolt 121 and the fourth bolt 126, respectively, at which time the first PCB 111 and the second PCB 112 are fixed together, and the third spring 122 and the fourth spring 127 provide elasticity between the first PCB 111 and the second PCB 112, then, the fifth spring 230 is sleeved on the outer surface of the fifth bolt 220, the fifth bolt 220 sequentially passes through the second copper sheet 240 and the third PCB 210 and is in threaded connection with the second threaded post 260, at this time, the third PCB 210 can be fixed on the first PCB 111 and the second PCB 112, the fifth spring 230 can enable the third PCB 210 and the first PCB 111 to have elasticity, finally, the sixth spring 330 is sleeved on the sixth bolt 320, the sixth bolt 320 sequentially passes through the third copper sheet 340 and the fourth PCB 310 and is screwed on the third threaded post 360, at this time, the fourth PCB 310 can be placed and fixed on the second PCB 112, the sixth spring 330 can enable the fourth PCB 310 and the second PCB 112 to have elasticity, the screws of the first PCB 111, the second PCB 112, the third PCB 210 and the fourth PCB 310 are tightly connected and cannot be screwed or loosened, and the purpose of not being damaged easily is achieved, when the screw is fixed, the screw cannot be screwed too loosely or too tightly through the spring, so that the multilayer PCB is not easy to damage, and the service life of the multilayer PCB is prolonged.

It should be noted that the specific model specifications of the first PCB 111, the second PCB 112, the third PCB 210, and the fourth PCB 310 need to be determined by type selection according to the actual specification of the device, and the specific type selection calculation method adopts the prior art, so detailed description is omitted.

The power supply of the first PCB 111, the second PCB 112, the third PCB 210 and the fourth PCB 310 and the principle thereof will be apparent to those skilled in the art and will not be described in detail herein.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-layer composite PCB circuit board is characterized by comprising

A first substrate mechanism (10), the first substrate mechanism (10) including a heat sink assembly (110), a connection assembly (120), a first bolt (130), a first spring (140), a second bolt (150), and a second spring (160), the first substrate mechanism (10) including a first PCB (111) and a second PCB (112), the connection assembly (120) including a third bolt (121), a third spring (122), a first threaded post (124), a fourth bolt (126), and a fourth spring (127), the first bolt (130) slidably penetrating the first PCB (111), the first spring (140) sleeved on an outer surface of the first bolt (130), the third bolt (121) slidably penetrating the first PCB (111), the third spring (122) sleeved on an outer surface of the third bolt (121), the third bolt (121) threadedly connected to the first threaded post (124), the fourth bolt (126) penetrates through the second PCB (112) in a sliding mode, the fourth spring (127) is sleeved on the outer surface of the fourth bolt (126), the fourth bolt (126) is in threaded connection with the first threaded column (124), the second bolt (150) penetrates through the second PCB (112) in a sliding mode, and the second spring (160) is sleeved on the outer surface of the second bolt (150);

the second substrate mechanism (20), the second substrate mechanism (20) includes a third PCB (210), a fifth bolt (220), a fifth spring (230) and a second threaded column (260), the fifth bolt (220) slidably penetrates through the third PCB (210), the fifth spring (230) is sleeved on the outer surface of the fifth bolt (220), the fifth bolt (220) is in threaded connection with the second threaded column (260), and the first bolt (130) is in threaded connection with the second threaded column (260);

a third substrate mechanism (30), the third substrate mechanism (30) includes a fourth PCB (310), a sixth bolt (320), a sixth spring (330) and a third threaded post (360), the sixth bolt (320) slides and runs through the fourth PCB (310), the sixth spring (330) is sleeved on the outer surface of the sixth bolt (320), the sixth bolt (320) is in threaded connection with the third threaded post (360), and the third threaded post (360) is in threaded connection with the second bolt (150).

2. The PCB of claim 1, wherein the heat sink assembly (110) further comprises a first thermal pad (113), a first copper plate (114) and a second thermal pad (115), wherein the first thermal pad (113) is connected to the first copper plate (114) and the first PCB (111) at two sides, and the second thermal pad (115) is connected to the first copper plate (114) and the second PCB (112) at two sides.

3. The PCB of claim 1, wherein the connecting assembly (120) further comprises a first gasket (123) and a second gasket (125), the first gasket (123) and the second gasket (125) are respectively mounted on two sides of the first threaded post (124), the first gasket (123) contacts with one side of the first PCB (111), and the second gasket (125) contacts with one side of the second PCB (112).

4. The PCB of claim 1, wherein the second substrate mechanism (20) further comprises a second copper sheet (240) and a third thermal pad (250), the fifth bolt (220) slidably penetrates through the second copper sheet (240), and both sides of the third thermal pad (250) are connected to the second copper sheet (240) and the third PCB (210).

5. The PCB of claim 1, wherein the third substrate mechanism (30) further comprises a third copper sheet (340) and a fourth thermal pad (350), the sixth bolt (320) slidably penetrates through the third copper sheet (340), and both sides of the fourth thermal pad (350) are connected to the third copper sheet (340) and the fourth PCB (310).

6. The PCB of claim 1, wherein the first PCB (111) has a first hole (116) formed therein, the first bolt (130) is in clearance fit with the first hole (116), the first PCB (111) has a second hole (117) formed therein, and the third bolt (121) slidably penetrates the second hole (117).

7. The PCB of claim 1, wherein a third hole (118) is defined in an inner surface of the second PCB (112), and the third hole (118) is in clearance fit with the second bolt (150).

8. The PCB of claim 1, wherein a fourth hole (119) is defined in an inner surface of the second PCB (112), and the fourth bolt (126) slidably penetrates the fourth hole (119).

9. The PCB of claim 1, wherein a fifth hole (270) is defined in an inner surface of the third PCB (210), and the fifth bolt (220) is in clearance fit with the fifth hole (270).

10. The PCB of claim 1, wherein a sixth through hole (370) is formed on an inner surface of the fourth PCB (310), and the sixth bolt (320) slidably penetrates through the sixth through hole (370).