Method for improving the uniformity of the hot melt thickness of a PCB

Abstract

The embodiment of the application discloses a method for improving the thickness uniformity of a PCB (Printed Circuit Board), which comprises the following steps: preparing a substrate and a prepreg to be fused, alternately and overlappingly placing the substrate and the prepreg to obtain a PCB to be fused, arranging a hot-melt block between the substrate and the prepreg of the PCB to be fused, the hot-melt block having a copper grid structure, placing the PCB to be fused with the hot-melt block arranged thereon on a processing platform of a hot-melt machine, starting the hot-melt machine, heating the hot-melt block, and pressing the PCB to be fused to obtain a fused PCB. The hot-melt block with the copper grid structure is arranged between the substrate and the prepreg of the PCB to be fused, and then the PCB to be fused is heated and pressed, so that the hot-melt block area is uniformly heated, and then the thickness of the produced PCB is uniform, and it is not easy to form wrinkles, and the probability of the PCB being scrapped is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PCB printed circuit board production, and particularly relates to a method for improving the thickness uniformity of PCB hot melting. BACKGROUND

[0002] In the pressing production process of a to-be-fused printed circuit board (PCB), a prepreg and a substrate are placed together to form a to-be-fused PCB, and a hot melting block is arranged at the edge of the PCB. A hot melting machine is in contact with the surface of the hot melting block through a hot melting clamp and a heating sheet. The hot melting block is heated to make the prepreg gel and fuse with the substrate. During the heating process, the heat is repeatedly transferred between the prepreg and the substrate due to the heat accumulation of the substrate, which increases the flow of the prepreg or causes temperature instability, resulting in uneven heating in the hot melting block area, uneven thickness, and a height difference in this area. The flowability of the prepreg at the edge of the PCB is poor during pressing, which causes wrinkles and increases the probability of PCB scrap. SUMMARY

[0003] Therefore, it is necessary to provide a method for improving the thickness uniformity of PCB hot melting to solve the above problems. The method is used to design a hot melting block to achieve the purpose of uniform thickness of PCB hot melting.

[0004] A method for improving the thickness uniformity of PCB hot melting, the method comprising:

[0005] preparing a to-be-fused substrate and a prepreg, the substrate and the prepreg being alternately and overlapped to obtain a to-be-fused PCB;

[0006] arranging a hot melting block between the substrate and the prepreg of the to-be-fused PCB, the hot melting block having a copper grid structure;

[0007] placing the to-be-fused PCB with the arranged hot melting block on a processing platform of a hot melting machine;

[0008] turning on the hot melting machine to heat the hot melting block and press the to-be-fused PCB to obtain a fused PCB.

[0009] Optionally, the copper grid structure is embedded in one surface of the hot melting block, and the surface with the copper grid structure is in contact with the substrate when the hot melting block is placed.

[0010] Optionally, the hot melting machine comprises a hot melting clamp and a heating sheet, and the hot melting clamp and the heating sheet are in contact with the back surface of the surface with the copper grid structure of the hot melting block when the hot melting machine heats the hot melting block.

[0011] Optionally, a preset number of the hot melt blocks are arranged between the substrate and the prepreg of each layer, and the hot melt blocks are located at the edge of the substrate and the prepreg.

[0012] Optionally, one of the substrate and one of the prepreg are overlapped to form one board layer structure, the number of the board layers is even, and the number of the board layers is greater than 6.

[0013] Optionally, when the number of the board layers is 6, the hot melt blocks are arranged between the substrate and the prepreg of the third board layer and between the substrate and the prepreg of the fourth board layer.

[0014] Optionally, when the number of the board layers is 8, the hot melt blocks are arranged between the substrate and the prepreg of the third board layer, between the substrate and the prepreg of the fourth board layer, between the substrate and the prepreg of the fifth board layer and between the substrate and the prepreg of the sixth board layer.

[0015] Optionally, when the number of the board layers is 10, the hot melt blocks are arranged between the substrate and the prepreg of the third board layer, between the substrate and the prepreg of the fifth board layer, between the substrate and the prepreg of the sixth board layer, between the substrate and the prepreg of the seventh board layer and between the substrate and the prepreg of the eighth board layer.

[0016] Optionally, when the number of the board layers is 12, the hot melt blocks are arranged between the substrate and the prepreg of the third board layer, between the substrate and the prepreg of the fifth board layer, between the substrate and the prepreg of the sixth board layer, between the substrate and the prepreg of the seventh board layer, between the substrate and the prepreg of the eighth board layer and between the substrate and the prepreg of the tenth board layer.

[0017] Optionally, when the number of the board layers is 14, the hot melt blocks are arranged between the substrate and the prepreg of the third board layer, between the substrate and the prepreg of the fifth board layer, between the substrate and the prepreg of the sixth board layer, between the substrate and the prepreg of the seventh board layer, between the substrate and the prepreg of the eighth board layer, between the substrate and the prepreg of the tenth board layer and between the substrate and the prepreg of the twelfth board layer.

[0018] By adopting the embodiment of the present application, the following beneficial effects are achieved:

[0019] The method for improving the thickness uniformity of the PCB board hot melting provided by the application comprises the following steps: preparing a substrate to be fused and a prepreg, alternately and overlappingly placing the substrate and the prepreg to obtain a PCB board to be fused, arranging a hot melting block with a copper grid structure between the substrate and the prepreg of the PCB board to be fused, placing the PCB board to be fused with the hot melting block arranged therein on a processing platform of a hot melting machine, starting the hot melting machine, heating the hot melting block, and pressing the PCB board to be fused to obtain a fused PCB board. The hot melting block with the copper grid structure is arranged between the substrate and the prepreg of the PCB board to be fused, and then the PCB board to be fused is heated and pressed, so that the hot melting block area is uniformly heated, and then the thickness of the produced PCB board is uniform, and it is not easy to form a wrinkle, and the probability of the PCB board being scrapped is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0021] Among them:

[0022] Figure 1 It is a flowchart of the method for improving the thickness uniformity of the PCB board hot melting in an embodiment.

[0023] Figure 2 It is a placement schematic diagram of the prepreg and the hot melting block without overlapping the substrate in an embodiment. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] As shown in the flowchart of the method for improving the thickness uniformity of the PCB board hot melting in an embodiment, the method comprises the following steps: Figure 1

[0026] Step 101, preparing a substrate to be fused and a prepreg, alternately and overlappingly placing the substrate and the prepreg to obtain a PCB board to be fused;

[0027] ​In the embodiment of the present application, one substrate and one prepreg are placed in an overlapping manner to form a board layer structure, the number of board layers of the board layer structure is set to be even, and the number of board layers is greater than 6. The substrate is a basic material for manufacturing a PCB. In general, the substrate is a copper-clad laminate, and a single-sided or double-sided printed board is manufactured by selectively performing hole processing, chemical copper plating, electroplating copper, etching and other processes on the substrate material-copper-clad laminate to obtain a required circuit pattern. Another type of multilayer printed board is manufactured by alternately laminating and bonding conductive pattern layers and prepregs together to form 3 or more conductive pattern layers for interconnection between layers, which has the functions of conduction, insulation and support. The performance, quality, processability, manufacturing cost and manufacturing level of the printed board are largely dependent on the substrate material. Generally, the substrate material for printed boards can be divided into two categories: rigid substrate material and flexible substrate material. An important variety of rigid substrate material is copper-clad plate, which is made by using reinforcing materials, immersing them in resin glue, drying, cutting, laminating into a blank, then covering copper foil, using steel plate as a mold, and processing by high temperature and high pressure in a hot press. The prepreg is a treated fiberglass cloth, which is impregnated with resin glue and then heat treated to make the resin enter the B stage to form a sheet material. It is one of the main materials in multilayer board production.

[0028] In step 102, a hot melt block is arranged between the substrate and the prepreg of the PCB to be fused, and the hot melt block has a copper grid structure.

[0029] In the embodiment of the present application, the copper grid structure is embedded in one surface of the hot melt block, and when the hot melt block is placed, the surface with the copper grid structure is in contact with the substrate. In the embodiment of the present application, a predetermined number of hot melt blocks are arranged between each layer of substrate and prepreg, and the hot melt blocks are located at the edge of the substrate and the prepreg. In the embodiment of the present application, 8 hot melt blocks are arranged at the long edge of the substrate and the prepreg, and every two hot melt blocks are arranged near the four corners of the substrate and the prepreg.

[0030] In the embodiments of the present application, the number of board layers of the hot melt block is set as follows: when the number of board layers is 6, the hot melt block is arranged between the substrate and the prepreg of the third board layer and between the substrate and the prepreg of the fourth board layer; when the number of board layers is 8, the hot melt block is arranged between the substrate and the prepreg of the third board layer, between the substrate and the prepreg of the fourth board layer, between the substrate and the prepreg of the fifth board layer, and between the substrate and the prepreg of the sixth board layer; when the number of board layers is 10, the hot melt block is arranged between the substrate and the prepreg of the third board layer, between the substrate and the prepreg of the fifth board layer, between the substrate and the prepreg of the sixth board layer, between the substrate and the prepreg of the seventh board layer, and between the substrate and the prepreg of the eighth board layer; when the number of board layers is 12, the hot melt block is arranged between the substrate and the prepreg of the third board layer, between the substrate and the prepreg of the fifth board layer, between the substrate and the prepreg of the sixth board layer, between the substrate and the prepreg of the seventh board layer, between the substrate and the prepreg of the eighth board layer, and between the substrate and the prepreg of the tenth board layer; when the number of board layers is 14, the hot melt block is arranged between the substrate and the prepreg of the third board layer, between the substrate and the prepreg of the fifth board layer, between the substrate and the prepreg of the sixth board layer, between the substrate and the prepreg of the seventh board layer, between the substrate and the prepreg of the eighth board layer, between the substrate and the prepreg of the tenth board layer, and between the substrate and the prepreg of the twelfth board layer.

[0031] In step 103, the PCB to be fused with the hot melt block is placed on the processing platform of the hot melt machine.

[0032] In step 104, the hot melt machine is turned on to heat the hot melt block and press the PCB to be fused to obtain a fused PCB.

[0033] In the embodiments of the present application, the hot melt machine includes a hot melt chuck and a heating sheet. When the hot melt machine heats the hot melt block, the hot melt chuck and the heating sheet are in contact with the back surface of the surface with the copper grid structure of the hot melt block.

[0034] In the embodiment of the present application, a method for improving the thickness uniformity of a PCB board during hot melting includes: preparing a substrate and a prepreg to be fused, the substrate and the prepreg are alternately and overlappedly placed to obtain a PCB board to be fused, a hot melting block is arranged between the substrate and the prepreg of the PCB board to be fused, the hot melting block has a copper grid structure, the PCB board to be fused with the hot melting block arranged is placed on a processing platform of a hot melting machine, the hot melting machine is started, the hot melting block is heated, and the PCB board to be fused is pressed to obtain a fused PCB board. By arranging the hot melting block with the copper grid structure between the substrate and the prepreg of the PCB board to be fused, and arranging the hot melting block according to different numbers of board layers, the hot melting block area is uniformly heated, and the thickness of the produced PCB board is uniform, wrinkles are not easily formed, and the probability of PCB board scrapping is reduced.

[0035] For better understanding of the technical solutions in the embodiments of the present application, please refer to Figure 2 , which is a placement schematic view of the prepreg and the hot melting block without the substrate in one embodiment.

[0036] In the embodiment of the present application, 201 is a hot melting block, 203 is a copper grid structure embedded on one surface of the hot melting block 201, 202 is a prepreg, and eight hot melting blocks 201 with the copper grid structure 203 are arranged at positions close to four corners of long edge edges of the prepreg 202 respectively, further, the substrate is overlapped and placed on the structure shown in Figure 2 , the substrate and the prepreg form a board layer structure, and the surface of the hot melting block 201 with the copper grid structure 203 is in contact with the substrate.

[0037] In the embodiment of the present application, a method for improving the thickness uniformity of a PCB board during hot melting includes: preparing a substrate and a prepreg to be fused, the substrate and the prepreg are alternately and overlappedly placed to obtain a PCB board to be fused, a hot melting block is arranged between the substrate and the prepreg of the PCB board to be fused, the hot melting block has a copper grid structure, the hot melting block with the copper grid structure is arranged between the substrate and the prepreg of the PCB board to be fused, the hot melting block is heated, and the PCB board to be fused is pressed to obtain a fused PCB board. By arranging the hot melting block with the copper grid structure between the substrate and the prepreg of the PCB board to be fused, and arranging the hot melting block according to different numbers of board layers, the hot melting block area is uniformly heated, and the thickness of the produced PCB board is uniform, wrinkles are not easily formed, and the probability of PCB board scrapping is reduced.

[0038] Any combination of the technical features in the above embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, any combination of the technical features is deemed to be within the scope of the present disclosure as long as there is no inconsistency.

[0039] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for improving the uniformity of hot melt thickness on a PCB board, characterized in that, The method includes: Prepare a substrate and a prepreg to be fused, and place the substrate and the prepreg alternately to obtain a PCB board to be fused; A hot melt block is placed between the substrate and the prepreg of the PCB board to be fused, and the hot melt block has a copper mesh structure; The PCB board to be fused, with the hot melt block already set, is placed on the processing platform of the hot melt machine; Turn on the hot melt machine, heat the hot melt block, and press the PCB board to be fused together to obtain the fused PCB board; The copper mesh structure is embedded in one surface of the hot melt block, and the surface with the copper mesh structure is in contact with the substrate when the hot melt block is placed.

2. The method for improving the uniformity of hot melt thickness on a PCB board according to claim 1, characterized in that, The hot melt machine includes a hot melt chuck and a heating plate. When the hot melt machine heats the hot melt block, the hot melt chuck and the heating plate contact the back side of the surface of the hot melt block that has a copper grid structure.

3. The method for improving the uniformity of hot melt thickness on a PCB board according to claim 1, characterized in that, A predetermined number of hot melt blocks are disposed between each substrate and the prepreg, and the hot melt blocks are located at the edges of the substrate and the prepreg.

4. The method for improving the uniformity of hot melt thickness on a PCB board according to claim 1, characterized in that, A layered structure is formed by overlapping a substrate and a prepreg, wherein the number of layers is set to an even number and the number of layers is greater than 6.

5. The method for improving the uniformity of PCB board hot melt thickness according to claim 4, characterized in that, When the number of layers is 6, the hot melt block is disposed between the substrate and the prepreg in the 3rd layer and between the substrate and the prepreg in the 4th layer.

6. The method for improving the uniformity of hot melt thickness on a PCB board according to claim 4, characterized in that, When the number of layers is 8, the hot melt block is disposed between the substrate and the prepreg in the 3rd layer, between the substrate and the prepreg in the 4th layer, between the substrate and the prepreg in the 5th layer, and between the substrate and the prepreg in the 6th layer.

7. The method for improving the uniformity of hot melt thickness on a PCB board according to claim 4, characterized in that, When the number of layers is 10, the hot melt block is disposed between the substrate and the prepreg in the 3rd layer, between the substrate and the prepreg in the 5th layer, between the substrate and the prepreg in the 6th layer, between the substrate and the prepreg in the 7th layer, and between the substrate and the prepreg in the 8th layer.

8. The method for improving the uniformity of hot melt thickness on a PCB board according to claim 4, characterized in that, When the number of layers is 12, the hot melt block is disposed between the substrate and the prepreg in the 3rd layer, between the substrate and the prepreg in the 5th layer, between the substrate and the prepreg in the 6th layer, between the substrate and the prepreg in the 7th layer, between the substrate and the prepreg in the 8th layer, and between the substrate and the prepreg in the 10th layer.

9. The method for improving the uniformity of hot melt thickness on a PCB board according to claim 4, characterized in that, When the number of layers is 14, the hot melt block is disposed between the substrate and the prepreg in the 3rd layer, between the substrate and the prepreg in the 5th layer, between the substrate and the prepreg in the 6th layer, between the substrate and the prepreg in the 7th layer, between the substrate and the prepreg in the 8th layer, between the substrate and the prepreg in the 10th layer, and between the substrate and the prepreg in the 12th layer.

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