CN216873458U

CN216873458U - Improve thick homogeneity of thick copper sheet board prestack structure and PCB board

Info

Publication number: CN216873458U
Application number: CN202220429154.2U
Authority: CN
Inventors: 盛从学; 何静安; 龙能水; 陈定康; 吴鹏; 章恒; 杨子璐
Original assignee: Pi Semiconductor Nantong Co ltd
Current assignee: Pi Semiconductor Nantong Co ltd
Priority date: 2022-03-01
Filing date: 2022-03-01
Publication date: 2022-07-01
Anticipated expiration: 2032-03-01

Abstract

The utility model provides a pre-stacking structure for improving the thickness uniformity of a thick copper plate, which comprises two outer copper foils on the outermost side, two outer PP layers arranged on the inner sides of the two outer copper foils, two thick copper core plates arranged on the inner sides of the two outer PP layers and an inner PP layer arranged between the two thick copper core plates, wherein each thick copper core plate comprises a substrate and thick copper plates arranged on two sides of the substrate, each thick copper plate comprises a copper area and a copper-free area, the copper area is formed by a plurality of round copper beans, the copper area is larger than 60% of the sum of the areas of the copper area and the copper-free area, and the copper area is larger than the sum of the areas of the copper area and the copper-free area. The application has solved current inner base plate 6OZ copper thick warp with PP, copper foil pressfitting back, whole board thickness inhomogeneous, have the pressfitting hole unusual scheduling problem, the thick homogeneity of board and medium thickness homogeneity have effectively been improved to the prestack structure of this application.

Description

Improve thick homogeneity of thick copper sheet board prestack structure and PCB board

Technical Field

The utility model particularly relates to a pre-stacked structure for improving the thickness uniformity of a thick copper plate and a PCB.

Background

With the rapid development of the electronic information age, designers increasingly demand Printed Circuit Boards (PCBs) such as power boards of high-power and high-current servers, which require high heat resistance, high heat dissipation, and other characteristics, and therefore, the power boards are preferably designed as thick copper plates. Due to the characteristic that the copper thickness of the thick copper plate is more than or equal to 3OZ, a plurality of processing difficulties exist in the processing and production process of the PCB, particularly the pressing process. For example, the thickness uniformity of the existing thick copper plate product is poor after lamination, and the phenomenon of glue shortage exists in a vacant region.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a pre-stack structure and a PCB for improving the thickness uniformity of a thick copper plate aiming at the defects of the prior art.

On one hand, the utility model provides a pre-stacked structure for improving the thickness uniformity of a thick copper plate, which comprises two outer copper foils on the outermost side, two outer layers PP arranged on the inner sides of the two outer copper foils, two thick copper core plates arranged on the inner sides of the two outer layers PP and an inner layer PP arranged between the two thick copper core plates, wherein the thick copper core plates comprise a substrate and thick copper plates arranged on two sides of the substrate, each thick copper plate comprises a copper area and a copper-free area, the copper area is formed by a plurality of round copper beans, the copper area is larger than 60% of the sum of the areas of the copper area and the copper-free area, and the copper area is formed by the copper area and the copper-free area.

In some embodiments, the outer copper foil has a thickness of 3OZ and the thick copper core has a thickness of 6 OZ.

In some embodiments, the outer layer PP comprises three layers of PP, wherein one layer of PP is PP106 and the other two layers of PP are PP 1080.

In some embodiments, the inner layer PP comprises five layers of PP, wherein three layers of PP are PP1080 and the other two layers of PP are PP 1080.

In another aspect, the present invention provides a PCB board manufactured by the above pre-stacked structure.

Has the advantages that:

the application has solved current inner base plate 6OZ copper thick warp with PP, copper foil pressfitting back, whole board thickness inhomogeneous, have the pressfitting hole unusual scheduling problem, the thick homogeneity of board and medium thickness homogeneity have effectively been improved to the prestack structure of this application.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a pre-stack structure according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a comparative pre-stack structure according to the present invention;

FIG. 3 is a schematic structural diagram of a thick copper core board according to an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a pair of scaled thick copper core plates according to the present invention;

FIG. 5 is a table summarizing board thickness data for 3 different positions (A, B, C) of a comparative PCB board according to the present invention;

FIG. 6 is a table showing thickness data of 3 different positions (A, B, C) of the PCB according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.

Referring to fig. 1, a preferred embodiment of the present invention is shown:

the pre-stacking structure comprises the following components in sequence from top to bottom: a copper foil 11 with a thickness of 3OZ (1OZ ≈ 35um), a PP (prepreg) with a 1-layer model number 106, a PP 12 with a 2-layer model number 1080, a thick copper core 13 with a thickness of 6OZ, a PP with a 3-layer model number 106, a PP 14 with a 2-layer model number 1080, a thick copper core 15 with a thickness of 6OZ, a PP with a 1-layer model number 106, a PP 16 with a 2-layer model number 1080, and a copper foil 17 with a thickness of 3 OZ;

as shown in fig. 3, the thick copper core plate includes a PP substrate, and thick copper plates disposed on both sides of the PP substrate, the thick copper plates are composed of copper-containing regions and copper-free regions, the copper-containing regions are formed by a plurality of round copper beams, the area of the copper-containing regions is 0.65 square meter, the total area of the copper-containing regions and the copper-free regions is 1 square meter, and the area of the copper-containing regions is 65% of the total area.

The manufacturing process of the PCB comprises the following steps: 2 thick copper core plates of 6OZ are manufactured, namely, the substrate is subjected to inner lamination film laminating, exposure, development and etching to obtain a graph required by a customer, the substrate with the image is subjected to brown oxidation and then is pressed with PP and copper foil, and kraft paper, a steel plate, copper foil, PP106 + PP1080 × 2, the thick copper core plates of 6OZ, PP106 + PP1080 × 2, copper foil, the steel plate and the kraft paper are sequentially placed from bottom to top during pressing.

Comparative example:

the pre-stacking structure (as shown in fig. 2) comprises, in order from top to bottom: a copper foil 21 with a thickness of 3OZ, a PP 22 with a 3-layer model 106, a thick copper core plate 23 with a thickness of 6OZ, a PP 24 with a 4-layer model 106, a thick copper core plate 25 with a thickness of 6OZ, a PP 26 with a 3-layer model 106 and a copper foil 27 with a thickness of 3 OZ; as shown in fig. 4, the thick copper core plate includes a PP substrate, and thick copper plates disposed on two sides of the PP substrate, where the thick copper plates are all copper surfaces.

The manufacturing process of the PCB comprises the following steps: 2 sheets of 6OZ thick copper core boards are manufactured, namely, the base boards are subjected to inner laminating film pressing, exposure, development and etching to obtain patterns required by customers, the base boards with the patterns are browned and then are pressed with PP and copper foils, and kraft paper, steel plates, copper foils, thick copper core boards of PP 106X 3 and 6OZ, thick copper core boards of PP 106X 4 and 6OZ, PP 106X 3, copper foils, steel plates and kraft paper are sequentially placed from bottom to top during pressing.

The PCB panels of the comparative example and example, the panel thicknesses were measured at different 3 positions (a, B, C), and the data are as follows in fig. 5 and 6: (Unit: mil, 1mil ═ 0.0254mm)

From the data of the comparative PCB panel of fig. 5, it can be seen that:

the sheet thickness was between 58.32mil and 75.35mil with a difference of 17.03mil, i.e., 0.432mm, and the standard deviation of the actual thickness at the three A/B/C positions was 8.64 mil.

From the data for the PCB board of the embodiment of fig. 6, it can be seen that:

the thickness of the whole board is 66.86mil to 69.72mil, and the difference is 2.86mil (0.0726 mm); the plate thickness range difference is reduced from 0.432mm to 0.0726mm, which is improved by 80%.

To sum up: aiming at the design of a thick copper plate with 6OZ copper thickness as an inner layer, a lot of original data of customers are large copper surface designs (figure 4), the designs lead to the phenomenon of glue shortage of a vacant copper-free area in the pressing process due to large glue flow difference of a circuit or a bonding pad dense area and the vacant copper-free area in the pressing process, the medium thickness is not even (the thickness difference of the whole plate is 0.2mm), the problems of copper skin delamination, plate explosion and the like are seriously caused, and the safety and the performance of a product are seriously influenced;

the embodiment of the application optimizes the large copper surface into the copper bean interval arrangement on the basis of not influencing the functionality and the reliability of a client product, ensures that the area of the copper bean is equivalent to more than 60 percent (figure 4) of the area of the original large copper surface, and simultaneously uses 1080+106 types of PP combination on the basis of meeting the medium thickness for improving the uniformity of the medium thickness.

The data also can prove that the design of the embodiment of the application can effectively improve the uniformity of the plate thickness and the dielectric thickness.

The above-mentioned embodiments are further described in detail for the purpose of illustrating the utility model, and it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not to be construed as limiting the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides an improve thick copper sheet thick homogeneity's prestack structure which characterized in that, includes two outer copper foils in the outside, sets up two outer PP in two outer copper foils inboards, sets up two thick copper core boards in two outer PP inboards and sets up the inlayer PP between two thick copper core boards, thick copper core board include the base plate and set up in the thick copper sheet of base plate both sides, thick copper board has the copper district and except having the copper district to constitute by a plurality of circular copper beans, the area that has the copper district is greater than there is 60% of copper district and no copper district area sum.

2. The pre-laminated structure for improving the thickness uniformity of a thick copper plate as claimed in claim 1, wherein the thickness of the outer copper foil is 3OZ and the thickness of the thick copper core plate is 6 OZ.

3. The pre-laminated structure for improving the thickness uniformity of a thick copper plate as claimed in claim 1, wherein the outer layer of PP comprises three layers of PP, wherein one layer of PP is PP106 and the other two layers of PP are PP 1080.

4. The pre-laminated structure for improving the thickness uniformity of a thick copper plate as claimed in claim 1, wherein the inner layer PP comprises five layers of PP, wherein three layers of PP are made of PP1080, and the other two layers of PP are made of PP 1080.

5. A PCB board comprising the pre-stacked structure of any one of claims 1 to 4.