A method for manufacturing a circuit board

Abstract

The application discloses a manufacturing method of a circuit board, comprising the following steps: S1, die cutting, taking a copper foil and a carrier film, attaching the copper foil on the carrier film, and cutting out a circuit; S2, transferring, taking a base layer, adhering the die-cut carrier film to the base layer, putting the combination of the base layer and the carrier film into a pressing machine for pressing, combining the circuit with the base layer, tearing off the carrier film, and leaving the base layer with the attached circuit; S3, printing a solder pad, printing conductive ink on a solder pad connecting position by printing to form the solder pad; S4, screen printing, screen printing ink on one side of the base layer with the circuit, leaving a first opening window at the position of the solder pad during screen printing, so that the solder pad can be exposed from the first opening window; S5, gold plating, performing gold plating treatment on the solder pad; S6, re-printing, re-printing the solder pad after gold plating with ink; and S7, laser windowing, performing laser windowing treatment on the ink at the position of the solder pad, so that a second opening window is formed at the position of the solder pad, and the second opening window reaches a predetermined size.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit board manufacturing, and particularly relates to a circuit board manufacturing method. BACKGROUND

[0002] Circuit boards are commonly used in various types of electrical appliances, for example, the keyboard of a notebook computer needs to use a circuit board, and the keyboard circuit board of the notebook computer is manufactured by using a soft base layer as a carrier.

[0003] In the past, the circuit board of a notebook computer and the like mainly relies on traditional copper foil development etching to manufacture a circuit, and this manufacturing method has many steps and low efficiency, and it is difficult to etch the copper foil on the soft base layer on the circuit board. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a circuit board manufacturing method, which can reduce manufacturing difficulty and improve production efficiency.

[0005] The circuit board manufacturing method according to an embodiment of the present application comprises:

[0006] S1, die cutting, taking a copper foil and a carrier film, attaching the copper foil to the carrier film, and placing the combination of the copper foil and the carrier film into a die cutting machine for die cutting, in the process of die cutting, a circuit is cut out, the circuit has a pad connection position, and then the waste copper after die cutting is removed, so that the circuit is retained on the carrier film;

[0007] S2, transferring, taking a base layer, laminating the carrier film after die cutting and the base layer, and making the circuit on the carrier film contact the base layer, then placing the combination of the base layer and the carrier film into a pressing machine for pressing, so that the circuit is combined with the base layer, and the carrier film is torn off, leaving the base layer with the attached circuit;

[0008] S3, printing a pad, printing conductive ink on the pad connection position by printing to form a pad;

[0009] S4, screen printing, screen printing ink on one side of the base layer with the circuit, leaving a first opening window at the position of the pad during screen printing, so that the pad can be exposed from the first opening window;

[0010] S5, gold plating, gold plating treatment is performed on the pad;

[0011] S6, re-printing, re-printing the pad after gold plating with ink;

[0012] S7, laser windowing, laser windowing treatment is performed on the ink at the position of the pad, so that a second opening window is formed at the position of the pad, and the second opening window reaches a predetermined size.

[0013] According to the method for manufacturing a circuit board, the circuit is cut out and transferred to the base layer by die cutting, the manufacturing process is simplified, no chemical reaction etching is involved, the operation is more convenient, the influence of environmental factors is small, and the production efficiency is improved; the die cutting avoids cutting out the solder pad, instead, the solder pad is formed by printing, the influence of die cutting precision is reduced, the combination of die cutting and printing enables the solder pad to be suitable for manufacturing in various scenarios, ensures the smooth formation of the solder pad, and gold plating on the solder pad can improve the ability of the solder pad to withstand the welding thrust and improve the conductivity, reduce the influence of resistance in the conductive ink, among the two times of silk printing ink, the first time of silk printing is to cover the area except the solder pad, leave the area where the solder pad is located to facilitate gold plating and other operations on the solder pad, and reinforce the solder pad, and the reprinted ink is prepared for subsequent laser opening, the laser windowing precision is higher than that of silk printing, and laser windowing can enable the solder pad to be adapted to products.

[0014] According to some embodiments of the present application, in the S3 step, the conductive ink is printed on the solder pad connection position by silk printing to form the solder pad, and the silk printing method can make a template in advance and is suitable for batch production.

[0015] According to some embodiments of the present application, the base layer is a black PET film, in the S4 step and the S6 step, the ink is white solder mask ink, the black PET film reduces light transmission, and the white solder mask ink improves light reflection, so that the LED lamp welded on the solder pad can achieve the predetermined illumination effect.

[0016] According to some embodiments of the present application, in the S1 step, the die cutting adopts a cylindrical die cutting knife roller, a shovel base block is arranged on the die cutting knife roller, and the shovel base block is used to shovel the copper foil at the solder pad connection position after die cutting, so that the solder pad connection position of the circuit is prevented from being lifted or torn when the waste copper foil is wound during the die cutting of the circuit, and the quality of the circuit is ensured.

[0017] According to some embodiments of the present application, in the S1 step, the carrier film (200) is an adhesive film, which is convenient for sticking the copper foil and positioning the copper foil.

[0018] According to some embodiments of the present application, in the S1 step, the waste material is removed by a sticking roller to stick the lifted waste copper foil, and the waste copper foil is stuck away with the rotation of the sticking roller, leaving the circuit layer on the carrier film. The sticking roller is simple, convenient to implement and operate.

[0019] According to some embodiments of the present application, in the S1 step, the thickness of the base layer is between 50 μm and 100 μm, and the thickness of the copper foil is between 6 μm and 10 μm.

[0020] According to some embodiments of the present application, in the S2 step, the pressing is performed by hot pressing.

[0021] According to some embodiments of the present application, in the S3 step, the conductive ink is conductive copper paste or conductive silver paste.

[0022] According to some embodiments of the present application, in the S5 step, the soldering pad is plated with hard gold.

[0023] Additional aspects and advantages of the present application will be made apparent from the following description, which, taken in conjunction with the accompanying drawings, that will further illustrate the principles and practical implementation of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or additional aspects and advantages of the present application will become apparent and be more readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 A schematic diagram of a copper foil adhered to a carrier film according to an embodiment of the present application;

[0026] Figure 2 A schematic diagram of a circuit on a carrier film after removal of scrap copper according to an embodiment of the present application;

[0027] Figure 3 A schematic diagram of a first window left by a transfer circuit according to an embodiment of the present application;

[0028] Figure 4 A schematic diagram of a first window left by a transfer circuit according to an embodiment of the present application;

[0029] Figure 5 A schematic diagram of a second window left by a transfer circuit according to an embodiment of the present application;

[0030] Figure 6 A schematic diagram of a die cutter roller according to an embodiment of the present application;

[0031] Figure 7 A schematic diagram of a die cutter roller according to an embodiment of the present application;

[0032] Copper foil 100, soldering pad connection site 110, die cutter roller 120, shovel base 121, adhesive roller 130;

[0033] Carrier film 200, base layer 300, soldering pad 400, first window 500, second window 600. DETAILED DESCRIPTION

[0034] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only, for the purpose of explaining the present application, and should not be understood as a limitation of the present application.

[0035] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0036] In the description of the present application, the meaning of several is one or more, the meaning of multiple is two and more than two, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If it is described as first, second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated.

[0037] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0038] Referring to Figures 1 to 7 According to the manufacturing method of the circuit board of the embodiment of the present application, the following steps are included: S1, die cutting, taking a copper foil 100 and a carrier film 200, attaching the copper foil 100 on the carrier film 200, and putting the combination of the copper foil 100 and the carrier film 200 into a die cutting machine for die cutting. In the process of die cutting, the circuit is cut out, and the circuit has a pad connection site 110. Then, the waste copper after die cutting is removed, and the circuit is left on the carrier film 200;

[0039] S2, transfer, taking a base layer 300, laminating the die-cut carrier film 200 with the base layer 300, and making the circuit on the carrier film 200 contact the base layer 300. Then, the combination of the base layer 300 and the carrier film 200 is put into a pressing machine for pressing, so that the circuit is combined with the base layer 300. The carrier film 200 is torn off, and the base layer 300 with the circuit attached is left;

[0040] S3, printing a pad 400, the conductive ink is printed on the pad connection site 110 by printing to form the pad 400;

[0041] S4, silk screen printing, silk screen printing ink on the side of the base layer 300 with the circuit, leaving a first window 500 at the position of the solder pad 400 when silk screen printing, so that the solder pad 400 can be exposed from the first window 500;

[0042] S5, gold plating, gold plating treatment is performed on the solder pad 400;

[0043] S6, back printing, back printing ink on the solder pad 400 after gold plating;

[0044] S7, laser windowing, laser windowing treatment is performed on the ink at the position of the solder pad 400, so that a second window 600 is formed at the position of the solder pad 400, and the second window 600 reaches a predetermined size.

[0045] It should be understood that the circuit is cut out and transferred to the base layer by die cutting, the manufacturing process is simplified, there is no chemical reaction etching involved, the operation is more convenient, the environmental factors have less influence, and the production efficiency is improved; When die cutting, the solder pad 400 is formed by printing instead of being cut out, which reduces the influence of die cutting precision. Die cutting is directly operated by a die cutting roller, and the circuit is made by removing material, which is greatly affected by precision. The die cutting roller itself is pressed against the copper foil to cut it off. When the cutter starts, the copper foil is easily lifted, especially the fine circuit structure such as the copper foil at the solder pad connection position, which is easily torn after being lifted, affecting product quality, and even causing waste. Therefore, the printing solder pad method is more practical for production and can avoid the problem of insufficient die cutting precision. When producing a notebook computer keyboard circuit board, high precision is required. Most of the circuit is made by die cutting, and the solder pad is printed. The combination of the two is better.

[0046] The combination of die cutting and printing enables the solder pad 400 to be adapted to various scenarios for smooth formation at the solder pad 400, and gold plating on the solder pad 400 can improve the solder pad's 400 ability to withstand welding force and improve conductivity, reduce the influence of resistance in conductive ink. Among the two times of silk screen printing ink, the first silk screen printing is to cover the area except the solder pad 400 to leave the area where the solder pad 400 is located to facilitate gold plating and other operations on the solder pad 400, and to reinforce the solder pad. The back printing ink is prepared for subsequent laser opening. The precision of laser windowing is higher than that of silk screen windowing. Laser windowing can adapt the solder pad to the product. It can be understood that the solder pad on the notebook computer keyboard circuit board is very small, with a length and width of 0-0.1 mm. At this time, laser windowing can achieve better precision. After plating hard gold, the carrying capacity and resistance of the solder pad are increased, which is suitable for laser windowing. By controlling the depth of laser windowing, the process can ensure that the solder pad is not damaged and the windowing is successful.

[0047] In some embodiments, in the step S3, the conductive ink is printed on the pad connection site 110 by silk screen printing, which can make a template in advance and is suitable for mass production. It can be understood that the digital inkjet printing can also be used to make the pad 400.

[0048] In some embodiments, the base layer 300 is a black PET film, and the ink is white solder mask ink in the steps S4 and S6. The black PET film reduces light transmission, and the white solder mask ink improves light reflection, so that the LED lamp welded on the pad 400 can achieve the predetermined illumination effect.

[0049] In some embodiments, in the step S1, the die cutting uses a cylindrical die cutting roller 120, and the die cutting roller 120 is provided with a shovel base 121 for shoveling the copper foil at the pad connection site 110 after die cutting. In this way, the pad connection site of the circuit can be prevented from being lifted or torn when the waste copper foil is wound during the die cutting process, thereby ensuring the quality of the circuit. It should be noted that when the die cutting roller 120 rolls on the surface of the copper foil, the shovel base 121 can shovel the waste copper foil at the pad connection site 110.

[0050] In some embodiments, in the step S1, the carrier film 200 is a film with adhesion, which is convenient for sticking the copper foil and positioning the copper foil. It can be understood that the carrier film 200 includes a micro-adhesive film with adhesion smaller than the combination of the copper foil and the base layer. After pressing, the micro-adhesive film can be easily removed.

[0051] In some embodiments, in the step S1, the waste removal uses a sticky roller 130 to stick the lifted waste copper foil, and the waste copper foil is stuck away as the sticky roller 130 rotates, leaving the circuit layer on the carrier film 200. The sticky roller 130 is simple, easy to implement and operate.

[0052] In some embodiments, in the step S1, the thickness of the base layer 300 is between 50 μm and 100 μm, and the thickness of the copper foil 100 is between 6 μm and 10 μm.

[0053] In some embodiments, in the step S2, the pressing is performed by hot pressing.

[0054] In some embodiments, in the step S3, the conductive ink is conductive copper paste or conductive silver paste.

[0055] In some embodiments, in the step S5, the pad 400 is subjected to hard gold plating treatment.

[0056] The embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A method of manufacturing a wiring board, characterized by, The application relates to a method for manufacturing a circuit board, comprising the following steps: S1, die cutting, taking a copper foil (100) and a carrier film (200), attaching the copper foil (100) to the carrier film (200), putting the combination of the copper foil (100) and the carrier film (200) into a die cutting machine for die cutting, cutting out a circuit in the process of die cutting, the circuit having a pad connecting position (110), then removing the waste copper after die cutting, and leaving the circuit on the carrier film (200); S2, transferring, taking a base layer (300), bonding the carrier film (200) after die cutting to the base layer (300), and making the circuit on the carrier film (200) contact the base layer (300), then putting the combination of the base layer (300) and the carrier film (200) into a pressing machine for pressing, combining the circuit with the base layer (300), and tearing off the carrier film (200) to leave the base layer (300) with the attached circuit; S3, printing a pad (400), printing conductive ink on the pad connecting position (110) by printing to form the pad (400); S4, silk printing, silk printing ink on one side of the base layer (300) with the circuit, leaving a first window (500) at the position of the pad (400) during silk printing, so that the pad (400) can be exposed from the first window (500); S5, gold plating, gold plating treatment on the pad (400); S6, re-printing, re-printing the pad (400) after gold plating with ink; S7, laser windowing, laser windowing treatment on the ink at the position of the pad (400), forming a second window (600) at the position of the pad (400), and the second window (600) reaching a predetermined size; In the S1 step, the carrier film (200) adopts a film with adhesion, and in the S1 step, the waste material is removed by using an adhesive roller (130) to stick up the waste copper foil, and the waste copper foil is stuck away with the rotation of the adhesive roller (130), and the circuit layer is left on the carrier film (200).

2. The method of manufacturing a circuit board according to claim 1, wherein: In the S3 step, conductive ink is printed on the pad connecting position (110) by silk printing to form the pad (400).

3. The method of claim 1, wherein: The base layer (300) adopts a black PET film, and in the S4 step and the S6 step, the ink adopts white solder resist ink.

4. The method of manufacturing a circuit board according to claim 1, wherein: In the S1 step, a cylindrical die cutting knife roller (120) is adopted for die cutting, and a shovel base block (121) is arranged on the die cutting knife roller (120), and the shovel base block (121) is used for shoveling up the copper foil at the pad connecting position (110) after die cutting.

5. The method of claim 1, wherein: In the S1 step, the thickness of the base layer (300) is between 50 mu m and 100 mu m, and the thickness of the copper foil (100) is between 6 mu m and 10 mu m.

6. The method of manufacturing a circuit board of claim 1, wherein: In the S2 step, hot pressing is adopted for pressing.

7. The method for manufacturing a circuit board according to claim 1, wherein: In the S3 step, the conductive ink adopts conductive copper paste or conductive silver paste.

8. The method of manufacturing a circuit board of claim 1, wherein: In the S5 step, hard gold plating treatment is performed on the pad (400).

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