CN110972387B

CN110972387B - Printed circuit board and method for manufacturing the same

Info

Publication number: CN110972387B
Application number: CN201811137947.1A
Authority: CN
Inventors: 李秉谚; 陈博政; 邓自强; 王赞钦; 石汉青; 吕政明
Original assignee: Tripod Wuxi Electronic Co Ltd
Current assignee: Tripod Wuxi Electronic Co Ltd
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2022-10-21
Anticipated expiration: 2038-09-28
Also published as: CN110972387A

Abstract

The invention discloses a printed circuit board and a manufacturing method thereof, wherein the manufacturing method of the printed circuit board comprises the steps of providing a circuit board base material which is provided with a plurality of radiating through holes, processing a containing hole on the radiating through holes of the circuit board base material, electroplating an electroplated layer on the bottom surface and the side wall of the containing hole, forming a solder mask layer on the surface of the circuit board base material, and removing the electroplated layer on the side wall of the containing hole.

Description

Printed circuit board and method for manufacturing the same

Technical Field

The present invention relates to a printed circuit board and a method for manufacturing the same, and more particularly, to a printed circuit board having a heat dissipation function and a method for manufacturing the same.

Background

At present, electronic products are developed toward high performance, high frequency, high speed, light weight, and thin, and various electronic related components are also developed toward multi-function, high speed, multi-power, and small volume. Under the condition that the functions of the electronic product are more and more, the consumed power is more and more, so that the electronic product generates much heat energy during operation, thereby increasing the temperature of the electronic product.

Printed Circuit Boards (PCBs) also face thermal control problems. Printed circuit boards are composed of substrate material connected within conductive insulating material between components and are not themselves good conductors of heat. Therefore, in order to reduce the reliability problem of the electronic product caused by the over-high temperature, a thermal via (thermal vias) is usually introduced into the circuit board to increase the heat dissipation rate.

The copper block embedded in the circuit board is also one of the methods for increasing the heat dissipation rate of the circuit board, and for a copper block with a diameter of 1.95 mm, about 372 heat dissipation through holes are needed to achieve the same heat dissipation effect, but in terms of cost, the heat dissipation method introducing the heat dissipation through holes is relatively low in cost.

However, the method for manufacturing the circuit board with the copper block embedded therein may not be suitable for the method for manufacturing the circuit board with the copper block embedded therein to achieve the requirement of heat dissipation due to the relationship between the stacking structure and the size of the embedded chip component. Therefore, it is desirable for circuit board manufacturers to provide sufficient heat dissipation capability on a limited number of circuit boards.

Disclosure of Invention

Embodiments of the present invention relate to a printed circuit board with heat dissipation function and a method for manufacturing the same.

In some embodiments of the present invention, a method for manufacturing a printed circuit board includes providing a circuit board substrate having a plurality of heat dissipating through holes, processing a receiving hole on the heat dissipating through holes of the circuit board substrate, electroplating an electroplated layer on a bottom surface and sidewalls of the receiving hole, forming a solder mask on a surface of the circuit board substrate, and removing the electroplated layer on the sidewalls of the receiving hole.

In some embodiments of the present invention, in the above-mentioned manufacturing method, removing the plating layer on the sidewall of the accommodating hole further includes removing a portion of the plating layer on the bottom surface of the accommodating hole to form a planarized surface.

In some embodiments of the present invention, the above-mentioned manufacturing method further comprises forming a groove around the planarized surface.

In some embodiments of the present invention, in the above manufacturing method, the processing of the receiving hole is blind-drilling the receiving hole at a fixed depth.

In some embodiments of the present invention, in the above manufacturing method, the removing of the plating layer on the sidewall of the accommodating hole is performed by blind-tapping the plating layer on the sidewall of the accommodating hole at a fixed depth.

In some embodiments of the present invention, in the above-described manufacturing method, the plating layer is a full plate plating layer.

In some embodiments of the present invention, the manufacturing method further includes filling a heat conducting material in the heat dissipation through holes.

In another embodiment of the present invention, a printed circuit board includes a circuit board substrate, a receiving hole, an electroplated layer and a solder mask layer. The circuit board substrate is provided with a plurality of heat dissipation through holes. The accommodating holes are formed on the heat dissipation through holes of the circuit board substrate. The electroplated layer is formed on a bottom surface of the accommodating hole, and the bottom surface is provided with a flattened surface for stably supporting an electronic element. The solder mask is formed on the surface of the circuit board substrate.

In some embodiments of the present invention, in the printed circuit board, the planarized surface is formed by a fixed-depth blind-drilling machining.

In some embodiments, the printed circuit board further includes a groove formed around the planarization surface.

In view of the above, the printed circuit board and the method for manufacturing the same according to the present invention can achieve a good heat dissipation effect by processing a receiving hole, electroplating an electroplating layer, forming a solder mask layer, and removing a portion of the sidewall and the bottom of the electroplating layer, so that the surface of the formed planarization electroplating layer can stably support electronic components, thereby enhancing the performance of electronic products.

The foregoing is merely illustrative of the problems to be solved, solutions to problems, and effects thereof, and the specific details of the present invention are set forth in the following description and the related drawings.

Drawings

Fig. 1 is a flowchart of a method for manufacturing a printed circuit board according to an embodiment of the present invention.

Fig. 2A to 2D are schematic cross-sectional views illustrating steps of a method for manufacturing a printed circuit board according to an embodiment of the invention.

Description of the symbols

100: method for manufacturing printed circuit board

110. 120, 130, 140, 150, 160: step (ii) of

200: circuit board

210: circuit board base material

212: first inner layer wiring

214: second inner layer wiring

220: heat radiation through hole

230: containing hole

230b: bottom surface

230s: side wall

240: electroplated coating

250: welding-proof layer

260: planarizing a surface

270: groove

Detailed Description

The following detailed description of the embodiments, taken in conjunction with the accompanying drawings, serve to better understand aspects of the present disclosure. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be shown for clarity. Like numbers refer to like elements. It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Thus, a first element discussed below could be termed a second element without departing from the teachings of the present concepts. As used in this disclosure, the term "and/or" includes any and all combinations of one or more of the associated listed items. Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Refer to fig. 1. Fig. 1 is a flow chart of a method 100 for manufacturing a printed circuit board according to an embodiment of the invention. Additional operations are provided before, during, and after the printed circuit board manufacturing method 100, and some of the operations described may be replaced, eliminated, or rearranged to achieve additional implementations of the method without departing from the scope of the invention. The printed circuit board manufacturing method 100 is described below in conjunction with fig. 2A through 2D. Fig. 2A to 2D are schematic cross-sectional views illustrating steps of a method for manufacturing a circuit board 200 according to an embodiment of the invention.

In step 110, referring to fig. 2A, the printed circuit board manufacturing method 100 provides a circuit board substrate 210 in the circuit board 200, wherein the circuit board substrate 210 has a plurality of thermal vias (thermal vias) 220. In some embodiments, the circuit board substrate 210 includes a plurality of inner traces and a plurality of resin insulation layers. The size of the heat dissipation through-hole 220 is not limited in the present invention, and in some embodiments, the diameter of the heat dissipation through-hole 220 is in a range of about 0.15 mm to about 0.4 mm. In some embodiments, the heat dissipation via 220 may be formed by laser machining. In some embodiments, solder resist or a heat dissipation paste made of a material such as copper paste, solder paste, etc. may be filled into the inner side of the heat dissipation through hole 220 according to actual heat dissipation requirements, so as to enhance the heat dissipation performance of the circuit board 200.

In step 120, referring to fig. 2B, the pcb manufacturing method 100 processes a cavity 230 on the heat dissipation via 220 of the pcb substrate 210. Specifically, in step 120, a portion of the circuit board substrate 210 and the heat dissipating through hole therein is processed to form a receiving hole 230. In the present embodiment, the depth of the accommodating hole 230 can be adjusted according to the actual requirement of the designer. That is, the receiving holes 230 may be machined to any position of the circuit board substrate 210 to match the size of the subsequently placed components. For example, in the present embodiment, the receiving hole 230 can be processed to the middle between the first inner layer trace 212 and the second inner layer trace 214. That is to say, the accommodating hole 230 has a bottom surface 230b located at the middle position between the first inner layer trace 212 and the second inner layer trace 214, but the present invention is not limited thereto, and the accommodating hole 230 may be processed to include any position of the first inner layer trace 212, the second inner layer trace 214, and the like, or any position between any two inner layer traces according to the requirement of the actual device size, without departing from the protection scope of the present invention.

In some embodiments, the method of processing the receiving hole 230 may be performed by a fixed-depth blind-fishing machine, so as to adjust the depth of the receiving hole 230 according to actual requirements, and the receiving hole 230 processed by the fixed-depth blind-fishing machine has flatness and dimensional accuracy, so as to meet the requirements of subsequent component placement. For example, the receiving hole 230 may be processed using a depth setting function of a forming machine (routing machine).

In step 130, referring to fig. 2C, the method 100 for manufacturing a printed circuit board electroplates a plating layer 240 on the bottom surface 230b and the sidewall 230s of the receiving hole 230, wherein the thickness of the plating layer 240 may be determined according to the actual requirements of the designer. In some embodiments, the plating layer 240 is performed by full plating (panel plating), and the entire surface of the circuit board substrate 210 is subjected to full plating. That is, the plating layer 240 is formed on the surface of the circuit board base 210 in addition to the bottom surface 230b and the sidewall 230s of the receiving hole 230. In some embodiments, the material of the plating layer 240 may include copper (Cu), aluminum (Al), nickel (Ni), gold (Cu), or a combination thereof. In some embodiments, the plating layer 240 may be a metal conductive sheet formed of a conductive metal.

In step 140, with continued reference to fig. 2C, the pcb manufacturing method 100 forms a solder mask 250 on the surface of the pcb substrate 210. In some embodiments, the solder mask layer 250 is formed on the plating layer 240 on the surface of the circuit board substrate 210. Specifically, the plating layer 240 on the surface of the circuit board substrate 210 is covered by the solder mask layer 250. In some embodiments, the solder mask 250 may be a photosensitive, heat sensitive or combination thereof material, for example, the solder mask 250 may be a green paint, such as an ultraviolet type green paint or a thermosetting type green paint. In some embodiments, the method of forming the solder mask layer 250 may be coating.

In step 150, and referring to fig. 2D, the printed circuit board manufacturing method 100 removes the plating layer 240 on the sidewall 230s of the accommodating hole 230, thereby providing appropriate insulation. In some embodiments, the method of removing the plating layer 240 on the sidewall 230s of the receiving hole 230 may be performed by a fixed-depth blind-fishing machine. For example, the plating layer 240 on the sidewall 230s of the receiving hole 230 may be removed using a depth setting function of a molding machine. When machining is performed using a molding machine, the front end of the milling cutter, after contacting the surface of the plated layer 240, is fed back to the circuit, stopping at the depth, and starting to remove the plated layer 240 on the side wall 230s of the housing hole 230. In some embodiments, the milling cutter of the molding machine used in step 120 is different in size from the milling cutter of the molding machine used in step 150 based on the need to perform machining, for example, the milling cutter of the molding machine used in step 120 is larger in size than the milling cutter of the molding machine used in step 150, or a plurality of milling cutters of different sizes are used in step 120 or step 150, respectively.

In step 160, with continued reference to fig. 2D, the pcb manufacturing method 100 forms a recess 270. Specifically, removing the plating layer 240 on the sidewalls 230s of the receiving hole 230 further includes removing a portion of the depth of the plating layer 240 above the bottom surface 230b of the receiving hole 230 to form a planarized surface 260. When processing is performed to remove the plating layer 240 on the sidewall 230s of the receiving hole 230, a groove 270 is further formed around the planarized surface 260. Specifically, a portion of the plating layer 240 on the bottom surface 230b of the receiving hole 230 is removed by machining, and the planarized surface 260 is formed to stably support an electronic component. That is, the planarized surface 260 is a machined planarized electroplated surface, wherein in some embodiments the machining is performed by fixed depth blind scooping. In addition, the groove 270 can effectively prevent the electronic component from interfering, so that the electronic component can be more smoothly disposed on the planarization surface 260, and the receiving hole 230 can be processed according to the size requirement of the actual electronic component, so that the electronic component can be correctly mounted in the circuit board 200.

Although the present invention describes the disclosed printed circuit board fabrication method as a series of steps, it should be understood that the order of the steps shown should not be construed in a limiting sense. In addition, not all illustrated steps may be required to implement a particular aspect or embodiment of the invention. Furthermore, one or more steps of the present invention may be performed in one or more separate steps and/or stages.

In summary, the printed circuit board and the method for manufacturing the same according to the present invention can achieve a good heat dissipation effect by processing a receiving hole, electroplating an electroplating layer, forming a solder mask layer, and removing a portion of the sidewall and the bottom of the electroplating layer, so that the formed planarized electroplating layer surface can stably and accurately support electronic components, thereby improving the performance of electronic products.

While the invention has been described in conjunction with the embodiments described above, it is not intended to limit the invention, and various modifications and alterations may be made without departing from the spirit and scope of the invention, which is to be determined by the following claims.

Claims

1. A method of manufacturing a printed circuit board, comprising:

providing a circuit board base material, wherein the circuit board base material is provided with a plurality of heat dissipation through holes;

processing accommodating holes on the heat dissipation through holes of the circuit board substrate;

electroplating layer on the bottom and side walls of the containing hole;

forming a solder mask layer on the surface of the circuit board substrate; and

removing the plating layer on the sidewall of the accommodating hole,

wherein the removing the plating layer on the sidewall of the receiving hole further comprises removing a portion of the plating layer on the bottom surface of the receiving hole to form a planarized surface.

2. The manufacturing method according to claim 1, further comprising:

around the planarized surface, a groove is formed.

3. The method of claim 1, wherein the receiving hole is formed by blind drilling the receiving hole at a constant depth.

4. The method according to claim 1, wherein the removing the plating layer on the sidewall of the receiving hole is performed by blind-fishing the plating layer on the sidewall of the receiving hole at a constant depth.

5. The method of claim 1, wherein plating the electroplated layer is plating the electroplated layer in full plate.

6. The manufacturing method according to claim 1, further comprising:

and filling heat-conducting materials in the heat-dissipation through holes.

7. A printed circuit board made by the method of claim 1, comprising:

the circuit board substrate is provided with a plurality of heat dissipation through holes;

the accommodating holes are formed on the heat dissipation through holes of the circuit board substrate;

the electroplated layer is formed on the bottom surface of the accommodating hole and is provided with a flattened surface for stably supporting the electronic element; and

the solder mask layer is formed on the surface of the circuit board substrate.

8. The printed circuit board of claim 7, wherein the planarized surface is formed by fixed depth blind machining.

9. The printed circuit board of claim 8, further comprising:

a groove formed around the planarization surface.