CN210202171U

CN210202171U - Multilayer PCB structure with uniform plate thickness

Info

Publication number: CN210202171U
Application number: CN201920468420.0U
Authority: CN
Inventors: Xiangfu Zeng; 曾祥福; Dehai He; 何德海; Siquan Shen; 沈思泉
Original assignee: Chien Electronics (daya Bay) Co Ltd
Current assignee: Chien Electronics (daya Bay) Co Ltd
Priority date: 2019-04-09
Filing date: 2019-04-09
Publication date: 2020-03-27
Anticipated expiration: 2029-04-09

Abstract

The utility model relates to a thick even multilayer PCB structure of board belongs to the PCB field, and it includes the core that a plurality of overlaps set up, is provided with the PP piece between each core, the core includes the ground plane, the edge on ground plane is provided with the technology limit, the technology edge is provided with the extension the guiding gutter on technology limit, the guiding gutter slope sets up. The utility model discloses thickness is even.

Description

Multilayer PCB structure with uniform plate thickness

Technical Field

The utility model relates to a PCB field, in particular to thick even multilayer PCB structure of board.

Background

The multilayer PCB is formed by bonding one or more PP sheets among layers, the PP sheets belong to a semi-cured state before lamination, the components of the PP sheets mainly comprise glass fiber cloth and epoxy resin, the resin is changed into a liquid state after the temperature reaches the melting point of the resin during lamination, and the resin can flow to fill the blank positions among circuits on the inner core plate under certain pressure, and cavities cannot appear, so that the balance is kept.

The ground layer of the PCB inner core board is often a large copper surface, the resin demand is not much, the process edge design is basically full-spread copper, the protruding structure of the process edge design can block vertical flowing, a large amount of resin which is excessive in the process of lamination can not be discharged, and the thickness of the laminated board of the multilayer PCB is uneven.

SUMMERY OF THE UTILITY MODEL

Therefore, a multilayer PCB structure with uniform board thickness is needed to be provided, which includes a plurality of core boards overlapped with each other, a PP sheet is disposed between the core boards, the core boards include a ground layer, a process edge is disposed at an edge of the ground layer, a diversion trench extending out of the process edge is disposed on the process edge, and the diversion trench is disposed in an inclined manner.

The utility model discloses mainly to multilayer PCB's inlayer ground plane, the ground plane is big copper face and its technology limit is the multilayer PCB on the technology limit of the copper-clad entirely of four sides.

The utility model discloses when the pressfitting, the temperature of pressfitting reaches behind the melting point of PP piece, the PP piece can enter into the molten state, then the PP piece of molten state can flow under the effect of the pressure of pressfitting in-process and go to fill the ground plane and rather than the blank position between the circuit on the adjacent core, and because the ground plane of multilayer PCB is big copper face, the demand of resin is not many, therefore, the PP piece of unnecessary molten state can spill over multilayer PCB through the guiding gutter on the technology edge during pressfitting, thereby can guarantee that the PP piece of molten state distributes evenly between ground plane and rather than adjacent core, guarantee that the thickness of multilayer PCB after the pressfitting is even.

Preferably, the included angle between the diversion trench and one center line of the ground layer is 40-50 °.

The flow guide grooves are obliquely arranged relative to the grounding layer, so that the PP sheet in a molten state is hindered to flow out of the multilayer PCB to a certain extent when flowing out of the multilayer PCB through the flow guide grooves, the PP sheet in the molten state slowly flows out of the space between two adjacent core boards, the phenomenon that the PP sheet in the molten state is not filled in the space between the grounding layer and the core board adjacent to the grounding layer and is discharged out of the multilayer PCB is avoided, and the uniformity of the thickness of the laminated multilayer PCB is ensured.

Further, an included angle between the diversion trench and one center line of the ground layer is 45 °.

Further, the width of guiding gutter is 2 mm.

Through a large number of experiments, the width of the flow guide groove is 2mm, and the included angle between the flow guide groove and the central line of the grounding layer is 45 degrees, so that redundant PP sheets in a molten state can be slowly discharged out of the multilayer PCB during pressing, and the gap between the grounding layer and two adjacent core boards can be uniformly filled in the process; the flow guide groove penetrates through the process edge, and the two ends of the flow guide groove extend out of the process edge.

Further, the guiding gutter is disposed on the process edge on the wide side of the ground layer.

The flow guide grooves are positioned on two opposite wide sides of the grounding layer, so that when the grounding layer is pressed, the PP sheet in a molten state can be filled in a gap between the grounding layer and the core board adjacent to the grounding layer.

Further, the number of the diversion trenches on the process side on the wide side of the ground layer is 4.

The principle and effect of the present invention will be further explained by combining the above technical solutions:

Drawings

Fig. 1 is a schematic structural diagram of a multilayer PCB structure with uniform plate thickness according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a ground plane according to an embodiment of the present invention.

Description of reference numerals:

1-multilayer PCB, 11-core board, 111-ground layer, 112-process edge, 1121-diversion trench, and 12-PP sheet.

Detailed Description

To facilitate understanding of those skilled in the art, the present invention will be described in further detail with reference to the accompanying drawings and examples:

as shown in fig. 1-2, a multilayer PCB structure with uniform board thickness includes a plurality of core boards 11 arranged in an overlapping manner, PP pieces 12 are disposed between the core boards 11, each core board 11 includes a ground layer 111, a process edge 112 is disposed at an edge of the ground layer 111, a guide groove 1121 extending out of the process edge 112 is disposed on the process edge 112, and the guide groove 1121 is disposed in an inclined manner.

The utility model discloses mainly to multilayer PCB 1's inlayer ground plane 111, ground plane 111 is big copper face and its technology limit 112 is the multilayer PCB1 of the technology limit 112 of the whole copper-clad of four sides.

The utility model discloses when the pressfitting, the temperature of pressfitting reaches behind PP piece 12's the melting point, PP piece 12 can enter into the molten state, then the PP piece 12 of molten state can flow under the effect of the pressure of pressfitting in-process and go to fill the blank position between the circuit on ground plane 111 and rather than adjacent core 11, and because multilayer PCB 1's ground plane 111 is big copper face, the demand of resin is not many, therefore, unnecessary molten state's PP piece 12 can spill over multilayer PCB1 through guiding gutter 1121 on technology limit 112 during the pressfitting, thereby can guarantee that molten state's PP piece 12 distributes evenly between ground plane 111 and rather than adjacent core 11, guarantee that the thickness of multilayer PCB1 after the pressfitting is even.

In one embodiment, an included angle between the guiding trench 1121 and one of the center lines of the ground layer 111 is 40-50 °.

The guiding grooves 1121 are obliquely arranged relative to the ground layer 111, so that the molten PP sheet 12 is hindered to flow out of the multi-layer PCB1 through the guiding grooves 1121, the molten PP sheet 12 slowly flows out between two adjacent core boards 11, the molten PP sheet 12 is prevented from being discharged out of the multi-layer PCB1 without filling the gap between the ground layer 111 and the core board 11 adjacent to the ground layer, and the uniformity of the thickness of the laminated multi-layer PCB1 is ensured.

In one embodiment, an angle between the guiding trench 1121 and one of the center lines of the ground layer 111 is 45 °.

In one embodiment, the width of the guiding gutter 1121 is 2 mm.

Through a large number of experiments, it is verified that the width of the guiding groove 1121 is 2mm, and the included angle between the guiding groove 1121 and the center line of the grounding layer 111 is 45 degrees, so that the excessive PP sheets 12 in a molten state can be slowly discharged out of the multi-layer PCB1 during lamination, and in the process, the gap between the grounding layer 111 and two adjacent core boards 11 can be uniformly filled; the guiding groove 1121 penetrates through the process edge 112, and two ends of the guiding groove extend out of the process edge 112.

In one embodiment, the guiding trench 1121 is disposed on the process edge 112 located on the wide side of the ground layer 111.

The guiding grooves 1121 are located on two opposite wide sides of the ground layer 111, and can ensure that the PP sheet 12 in a molten state can fill the gap between the ground layer 111 and the adjacent core board 11 when being pressed together.

In one embodiment, the number of the guiding trenches 1121 on the process side 112 on the wide side of the ground layer 111 is 4.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A multilayer PCB structure with uniform plate thickness comprises a plurality of core plates which are arranged in an overlapped mode, and PP (polypropylene) sheets are arranged between the core plates.

2. The multi-layer PCB structure of claim 1, wherein the angle between the guiding groove and one of the center lines of the ground layer is 40-50 °.

3. The multilayer PCB structure of claim 2, wherein the angle between the guiding groove and one of the center lines of the ground layer is 45 °.

4. The multilayer PCB structure of uniform plate thickness of claim 2 or 3, wherein the width of the flow guide groove is 2 mm.

5. The multilayer PCB structure of uniform board thickness as claimed in claim 2 or 3, wherein the guiding gutter is provided on a process edge on a wide side of the ground layer.

6. The multilayer PCB structure of claim 5, wherein the number of the flow guide grooves on the process side on the wide side of the ground layer is 4.