Manufacturing method of metalized half-hole PCB and PCB

Abstract

The invention discloses a manufacturing method of a PCB (printed circuit board) with a metalized half hole, which relates to the technical field of PCBs, and comprises the following steps: carrying out hole metallization processing on a drilled PCB; the metal holes of the PCB are filled with protective slurry, and the protective slurry is solidified; metalized half-hole processing is carried out on the edge of the PCB; removing the protective slurry in the metal hole of the PCB; before metallized half hole machining, a metal hole is filled with protective slurry, the protective slurry is solidified, the metal hole is filled and leveled up by the protective slurry, and the metal hole is filled with solid-state formed protective slurry, so that when edge metallized half hole milling is carried out, due to the fact that the metal hole has supporting and balancing functions of the protective slurry under the action force of a milling worker, the edge of the edge metallized half hole is not prone to deformation. Therefore, when a milling worker cuts, the metal hole is not prone to deformation, and metal on the inner wall of the hole can be prevented from being pulled and falling off under the strong acting force of the milling worker due to the fact that the metal is buried in the protective slurry.

Description

Technical Field

[0001] The invention relates to the technical field of PCB boards, and in particular to a manufacturing method of a PCB board with a metallized half hole and a PCB board. Background Art

[0002] At present, the development speed of electronic information technology is getting faster and faster, and various electronic products as product ends are also rapidly developing in the direction of miniaturization and multi-function. Therefore, as one of the core of electronic products, PCB boards need to achieve reliable connection between PCB boards in many application scenarios, and the connection distance is short. Therefore, the design of many PCBs introduces the function of metallized half holes. Through the metallized half hole, the PCB can be effectively connected to the PCB port, or connected to the chassis shell to improve the grounding effect and improve the heat dissipation effect.

[0003] At present, the conventional method of making PCB half-holes is as follows: after the PCB drilling process, electroplating is performed to achieve metallization of the half-hole; then exposure and development are performed, and the outer layer graphics are produced using positive or negative film processes, followed by processes such as solder mask and text. During the shape processing, the metallized half-hole is milled out using a milling machine. This method is a mature method in the industry and has been widely used.

[0004] However, although the above method has no problem for the ordinary half-hole metallization process, for some special structure plates, such as irregular half-holes, large half-hole diameters, etc., during the final shape processing, the half-hole lacks support and is prone to cause the hole wall to deform, or cause the metal on the half-hole wall to be torn and pulled off. Therefore, the traditional method can no longer meet the processing requirements of such plates. Summary of the invention

[0005] The purpose of the present invention is to provide a method for manufacturing a PCB board with a metallized half hole and a PCB board, so as to solve the following technical problems:

[0006] How to prevent the metal holes of PCB from being deformed and damaged during the etching of the board surface.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] In a first aspect, the present invention discloses a method for manufacturing a PCB board with a metallized half hole, comprising the following steps:

[0009] S1: Perform hole metallization on the drilled PCB board;

[0010] S2: Filling the metal holes of the PCB with protective paste and curing the protective paste;

[0011] S3: Perform metallization half-hole processing on the edge of the PCB board;

[0012] S4: Remove the protective paste in the metal holes of the PCB board.

[0013] In a further scheme of the present invention: after step S1 is completed, an aluminum sheet and a FR-4 board of the same size as the PCB board are taken, and holes corresponding to the metal holes on the PCB board are opened on the aluminum sheet and the FR-4 board respectively, and then the FR-4 board, the PCB board, and the aluminum sheet are stacked and fixed in sequence from bottom to top.

[0014] In a further embodiment of the present invention, the thickness of the aluminum sheet is 0.1 mm, and the thickness of the FR-4 board is 0.2 mm.

[0015] In a further embodiment of the present invention: in step S2, the protective slurry is prepared by adding calcium hydroxide into water and mixing evenly to obtain the protective slurry, and the concentration of the calcium hydroxide is 1.5-2.5 g / mL.

[0016] In a further embodiment of the present invention: in step S2, the protective slurry is filled into the metal hole by silk screen printing.

[0017] In a further embodiment of the present invention, in step S2, the method for curing the protective paste is as follows: placing the PCB board with the protective paste in the metal holes in an oven filled with CO2 and baking at 75-85°C for 25-35 minutes.

[0018] In a further solution of the present invention: in step S3, metallized half-hole processing is performed on the edge of the PCB board by milling, and half of the hole on the edge of the PCB board is removed to obtain a metallized half-hole.

[0019] In a further embodiment of the present invention, in step S4, the protective slurry is removed by:

[0020] Place the PCB in water and use ultrasonic waves for 8-12 minutes to loosen the protective slurry in the metal holes. Then soak the PCB in a 4-6% dilute hydrochloric acid solution for 8-12 minutes, then use high-pressure water to wash away the residual protective slurry in the holes. Finally, wash and dry the PCB.

[0021] In a second aspect, the present invention further discloses a PCB board, which is processed by the manufacturing method of the PCB board with metallized half holes as described above.

[0022] Furthermore, the PCB board is a double-sided board or a multi-layer board.

[0023] Beneficial effects of the present invention:

[0024] Before the metallized half-hole processing is performed, the present invention fills the metal hole with protective slurry and solidifies the protective slurry, so that the metal hole is filled with the protective slurry and the metal hole is filled with the solid-formed protective slurry. Therefore, when the edge of the metallized half-hole is milled, under the force of the milling work, since the metal hole has the support and balance of the protective slurry, the metal hole is not easy to deform during milling. The metal on the inner wall of the hole is buried in the protective slurry and can also be prevented from being pulled off under the strong force of the milling work. At the same time, the raw materials of the protective slurry used are cheap and easily available materials, so the processing cost will not be increased. The operation of the process of filling and removing the protective slurry is also very simple, the production process is simple, and the one-time qualified rate of the product and the production efficiency can be greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] Figure 1 It is a process flow chart of the method for manufacturing a PCB board with metallized half holes of the present invention.

[0027] Figure 2 It is a schematic diagram of a metallized half hole of a PCB board prepared by a method for manufacturing a PCB board in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1 As shown, the present invention discloses a method for manufacturing a PCB board with a metallized half hole, comprising the following steps:

[0030] Step 1: Take a PCB board with a length of 8 cm, a width of 5 cm, and a thickness of 0.2 cm, and perform hole metallization copper plating after mechanical drilling. The processing process adopts the conventional hole metallization copper plating process in the prior art, which will not be described here; take a 0.1 mm aluminum sheet and a 0.2 mm FR-4 board with the same size as the PCB board, and open holes corresponding to the metal holes on the PCB board on the aluminum sheet and the FR-4 board respectively, and then stack and fix the FR-4 board, PCB board, and aluminum sheet in order from bottom to top by hot pressing;

[0031] It should be noted that there is no specific limitation on the size of the PCB board, and in other embodiments, any desired size may be adopted.

[0032] Step 2: Fill the metal holes of the PCB board with protective paste and solidify the protective paste. The specific steps are as follows:

[0033] a. Preparation of protective slurry

[0034] Pour 200 mL of pure water into a beaker, then pour 400 g of sodium hydroxide powder into the pure water, and stir evenly with a glass rod to obtain a protective slurry;

[0035] b. Filling protective slurry

[0036] Use the screen printing equipment to place the PCB board under the screen printing mesh, pour the protective paste on the screen printing mesh, and use a scraper to scrape the protective paste so that the protective paste penetrates the screen printing mesh into the metal holes and fills the metal holes;

[0037] c. Curing protective slurry

[0038] Place the PCB in a CO2-filled oven and bake at 80°C for 30 minutes to solidify the protective paste;

[0039] Step 3: Use a milling cutter to remove half of the metal hole on the edge of the PCB board to obtain a metallized half hole.

[0040] Step 4: Take the PCB out of the oven and place it in an ultrasonic cleaner for 10 minutes to loosen the protective paste in the metal holes. Then soak the PCB in a 5% dilute hydrochloric acid solution for 10 minutes, then take it out and use high-pressure water to rinse off the residual protective paste in the holes. Finally, wash the PCB in water and dry it with a hair dryer.

[0041] See also Figure 2 , the metallized half hole of the prepared PCB board was observed, and it can be seen that the metallized half hole did not deform, and the metal on the hole wall was evenly attached without pulling and falling off.

[0042] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, and a specific direction structure and operation, and therefore, cannot be understood as a limitation on the present invention. In addition, "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for manufacturing a PCB board with a metallized half hole, characterized in that: The following steps are involved: S1: Perform hole metallization on the drilled PCB board; S2: Filling the metal holes of the PCB with protective paste and curing the protective paste; S3: Perform metallization half-hole processing on the edge of the PCB board; S4: Remove the protective paste in the metal holes of the PCB board.

2. The method for manufacturing a PCB board with a metallized half hole according to claim 1, characterized in that: After step S1 is completed, take an aluminum sheet and a FR-4 board of the same size as the PCB board, and open holes on the aluminum sheet and the FR-4 board corresponding to the metal holes on the PCB board, and then stack and fix the FR-4 board, PCB board, and aluminum sheet in order from bottom to top.

3. The method for manufacturing a PCB board with a metallized half hole according to claim 2, characterized in that: The thickness of the aluminum sheet is 0.1 mm, and the thickness of the FR-4 board is 0.2 mm.

4. The method for manufacturing a PCB board with a metallized half hole according to claim 1, characterized in that: In step S2, the protective slurry is prepared by adding calcium hydroxide into water and mixing the mixture evenly to obtain the protective slurry, wherein the concentration of the calcium hydroxide is 1.5-2.5 g / mL.

5. The method for manufacturing a PCB board with a metallized half hole according to claim 4, characterized in that: In step S2, the protective slurry is filled into the metal hole by silk screen printing.

6. The method for manufacturing a PCB board with a metallized half hole according to claim 4, characterized in that: In step S2, the method for curing the protective paste is: placing the PCB board with the protective paste filled in the metal hole in an oven filled with CO2 and baking it at 75-85°C for 25-35 minutes.

7. The method for manufacturing a PCB board with a metallized half hole according to claim 1, characterized in that: In step S3, metallized half-hole processing is performed on the edge of the PCB board by milling, and half of the hole on the edge of the PCB board is removed to obtain a metallized half-hole.

8. The method for manufacturing a PCB board with a metallized half hole according to claim 1, characterized in that: In step S4, the protective slurry is removed by: Place the PCB in water and use ultrasonic waves for 8-12 minutes to loosen the protective slurry in the metal holes. Then soak the PCB in a 4-6% dilute hydrochloric acid solution for 8-12 minutes, then use high-pressure water to wash away the residual protective slurry in the holes. Finally, wash and dry the PCB.

9. A PCB board, characterized in that: The method is obtained by processing the PCB board with metallized half holes according to any one of claims 1 to 8.

10. The PCB board according to claim 9, characterized in that: The PCB board is a double-sided board or a multi-layer board.

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