Manufacturing method of circuit board

Abstract

The invention discloses a manufacturing method of a circuit board, which comprises the following steps: S1, die cutting: taking a copper foil and a carrier film, attaching the copper foil to the carrier film, and cutting out a circuit; s2, transferring, taking a base layer, fitting the die-cut carrier film with the base layer, putting a 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 attached with the circuit; s3, printing a bonding pad, and printing conductive ink on the bonding pad connection position in a printing mode to form the bonding pad; s4, silk-screen printing: silk-screen printing ink on the surface, with the circuit, of the base layer, and reserving a first window at the position of the bonding pad during silk-screen printing, so that the bonding pad can be exposed from the first window; s5, gold plating: carrying out gold plating treatment on the bonding pad; s6, printing back: printing ink back on the gold-plated bonding pad; and S7, performing laser windowing, namely performing laser windowing treatment on the ink at the position of the bonding pad, so that a second windowing is formed at the position of the bonding pad, and the second windowing reaches a preset size.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board manufacturing, and in particular to a method for manufacturing a circuit board. Background Art

[0002] Circuit boards are commonly used in various electrical appliances. For example, laptop keyboards require circuit boards. Laptop keyboard circuit boards are made using a soft base layer as a carrier.

[0003] In the past, circuit boards such as notebooks mainly relied on traditional copper foil development and etching to make circuits. This production method has many steps and low efficiency, and it is difficult to etch the copper foil on the soft base layer of the circuit board. Summary of the invention

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

[0005] A method for manufacturing a circuit board according to an embodiment of the present invention includes:

[0006] S1, die-cutting, taking copper foil and carrier film, attaching the copper foil to the carrier film, putting the combination of the copper foil and the carrier film into a die-cutting machine for die-cutting, cutting out the circuit in the die-cutting process, the circuit having a pad connection position, and then removing the waste copper after die-cutting, so that the circuit remains on the carrier film;

[0007] S2, transfer, take the base layer, attach the die-cut carrier film to the base layer, and make the circuit on the carrier film contact the base layer, then put the combination of the base layer and the carrier film into a press machine for pressing, so that the circuit is combined with the base layer, tear off the carrier film, and leave the base layer with the circuit attached;

[0008] S3, printing pads, printing conductive ink at the pad connection position to form pads;

[0009] S4, silk screen printing, printing ink on the side of the substrate with the circuit, leaving a first window at the location of the pad during silk screen printing, so that the pad can be exposed from the first window;

[0010] S5, gold plating, performing gold plating on the pad;

[0011] S6, back-printing, back-printing ink on the gold-plated pad;

[0012] S7, laser windowing, performing laser windowing processing on the ink at the pad position to form a second window at the pad position, and the second window reaches a predetermined size.

[0013] A method for manufacturing a circuit board according to an embodiment of the present invention has at least the following beneficial effects: the circuit is cut out and transferred to the base layer by pressing by die cutting, the manufacturing process is simplified, and no chemical reaction etching is involved, the operation is simpler, the impact of environmental factors is small, and the production efficiency is improved; when die cutting, the pad is avoided from being cut out, and the pad is formed by printing instead, reducing the impact of die cutting accuracy; the combination of die cutting and printing enables the pad to adapt to a variety of production scenarios, ensuring the smooth formation of the pad, and gold plating on the pad can improve the ability of the pad to withstand welding thrust, and improve conductivity, reducing the impact of resistance in conductive ink; in the two silk-screen ink printings, the first silk-screen printing is to cover the area except the pad, leaving the area where the pad is located to facilitate gold plating and other operations on the pad, and strengthen the pad, and the back-printing ink is to prepare for subsequent laser opening, the laser window opening accuracy is higher than the silk-screen window opening, and the use of laser window opening can make the pad adaptable to the product.

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

[0015] According to some embodiments of the present invention, the base layer adopts a black PET film, and in the step S4 and the step S6, the ink adopts white solder resist ink. The black PET film reduces light transmittance, and the white solder resist ink increases reflection, so that the LED lamp soldered on the pad can achieve a predetermined lighting effect.

[0016] According to some embodiments of the present invention, in the S1 step, a cylindrical die-cutting roller is used for die-cutting, and a shovel base block is provided on the die-cutting roller. The shovel base block is used to shovel up the copper foil at the pad connection position after die-cutting. In this way, in the process of die-cutting the circuit, it is possible to prevent the waste copper foil from being lifted up or torn at the pad connection position of the circuit when it is rolled up, thereby ensuring the quality of the circuit.

[0017] According to some embodiments of the present invention, in the step S1, the carrier film (200) is a sticky film to facilitate sticking to the copper foil and achieve positioning of the copper foil.

[0018] According to some embodiments of the present invention, in the step S1, the waste material is removed by using a sticky roller to stick the raised waste copper foil. As the sticky roller rotates, the waste copper foil is stuck away, leaving the circuit layer on the carrier film. The sticky roller method is simple and easy to implement and operate.

[0019] According to some embodiments of the present invention, in the step S1, 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 invention, in the step S2, the pressing is performed by hot pressing.

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

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

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following 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 invention;

[0026] Figure 2 A schematic diagram of a circuit on a carrier film after waste copper is removed according to an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of leaving a first window after printing solder resist ink on a transfer circuit according to an embodiment of the present invention;

[0028] Figure 4 A schematic diagram of reprinting solder resist ink at a first window according to an embodiment of the present invention;

[0029] Figure 5 It is a schematic diagram of opening a second window on the reprinted solder resist ink according to an embodiment of the present invention;

[0030] Figure 6 Schematic diagram of die-cutting copper foil by die-cutting roller according to an embodiment of the present invention;

[0031] Figure 7 It is a schematic diagram of the sticking roller sticking away the waste copper foil according to an embodiment of the present invention.

[0032] Copper foil 100, pad connection position 110, die-cutting knife roller 120, shovel base block 121, adhesive roller 130;

[0033] The carrier film 200 , the base layer 300 , the pad 400 , the first window 500 , and the second window 600 . DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In the description of the present invention, "several" means one or more, "more" means two or more, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0037] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0038] Reference Figures 1 to 7 According to an embodiment of the present invention, a method for manufacturing a circuit board comprises 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 die cutting process, the circuit having a pad connection position 110, and then removing the waste copper after die cutting, so that the circuit remains on the carrier film 200;

[0039] S2, transfer, take the base layer 300, attach the die-cut carrier film 200 to the base layer 300, and make the circuit on the carrier film 200 contact the base layer 300, then put the combination of the base layer 300 and the carrier film 200 into a press machine for pressing, so that the circuit is combined with the base layer 300, tear off the carrier film 200, and leave the base layer 300 with the circuit attached;

[0040] S3, printing the pad 400, printing the conductive ink on the pad connection position 110 to form the pad 400;

[0041] S4, silk screen printing, silk screen printing ink is applied to the side of the substrate 300 with the circuit, and a first window 500 is left at the location of the pad 400 during silk screen printing, so that the pad 400 can be exposed from the first window 500;

[0042] S5, gold plating, performing gold plating on the pad 400;

[0043] S6, back-printing, back-printing the gold-plated pad 400 with ink;

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

[0045] It should be understood that the circuit is cut out and pressed onto the base layer by die-cutting, which simplifies the manufacturing process and does not involve chemical etching, making the operation easier and less affected by environmental factors, thereby improving production efficiency. Avoid cutting out the pad 400 during die-cutting, and instead print the pad 400 to reduce the impact of die-cutting accuracy. Die-cutting is performed directly with a die-cutting roller, and the circuit is produced by removing materials, which is greatly affected by accuracy. The die-cutting roller itself presses the copper foil to cut, and the copper foil is easily lifted when the knife is lifted, especially for fine circuit structures. For example, the copper foil at the pad connection position is easily torn after being lifted, affecting product quality and even causing waste. Therefore, the printed pad method is more suitable for actual production and can avoid the problem of insufficient die-cutting accuracy. When producing keyboard circuit boards for laptops, higher accuracy requirements are required. Die-cutting is used for large parts of the circuit and printing is used for small parts such as pads, and the combination of the two is better.

[0046] The combination of die-cutting and printing enables the pad 400 to adapt to a variety of production scenarios, ensuring the smooth forming of the pad 400, and gold plating on the pad 400 can improve the ability of the pad 400 to withstand the welding thrust, and improve the conductivity, and reduce the influence of the resistance in the conductive ink. In the two silk-screen ink printings, the first silk-screen printing is to cover the area except the pad 400, leaving the area where the pad 400 is located for convenient gold plating and other operations on the pad 400 to strengthen the pad, and the back-printed ink is to prepare for the subsequent laser opening. The accuracy of laser window opening is higher than that of silk-screen window opening. The use of laser window opening can make the pad adapt to the product. It is understandable that the pad on the keyboard circuit board of the laptop is very small, with a length and width of 0-0.1mm. At this time, better accuracy can be achieved by laser window opening, and after hard gold plating, the load-bearing capacity and bearing capacity of the pad are increased, which is suitable for laser window opening. The depth is controlled by laser window opening to meet the process of not damaging the pad and ensuring successful window opening.

[0047] In some embodiments, in step S3, conductive ink is printed on the pad connection position 110 by silk screen printing to form the pad 400. The silk screen printing method can make a template in advance and is suitable for mass production. It is understandable that the pad 400 can also be made by digital printing.

[0048] In some embodiments, the base layer 300 uses a black PET film, and in steps S4 and S6, the ink uses white solder resist ink. The black PET film reduces light transmittance, and the white solder resist ink increases reflection, so that the LED lamp soldered on the pad 400 can achieve a predetermined lighting effect.

[0049] In some embodiments, in step S1, die cutting uses a cylindrical die cutting roller 120, and a shovel base block 121 is provided on the die cutting roller 120. The shovel base block 121 is used to shovel up the copper foil at the pad connection position 110 after die cutting. This method can prevent the waste copper foil from being carried up or torn when the waste copper foil is rolled up during the die cutting process, thereby ensuring the quality of the circuit. It should be noted that when the die cutting roller 120 rolls over the surface of the copper foil, the shovel base block 121 can shovel up the waste copper foil at the pad connection position 110.

[0050] In some embodiments, in step S1, the carrier film 200 uses a sticky film to facilitate sticking to the copper foil and positioning the copper foil. It can be understood that the carrier film 200 includes a micro-sticky film, and the stickiness is less than the combination of the copper foil and the base layer, so that the micro-sticky film can be easily torn off after lamination.

[0051] In some embodiments, in step S1, the waste is removed by using a sticky roller 130 to stick the raised waste copper foil. As the sticky roller 130 rotates, the waste copper foil is stuck away, leaving the circuit layer on the carrier film 200. The sticky roller 130 is simple to implement and operate.

[0052] In some embodiments, in 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 step S2, the pressing is performed by heat pressing.

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

[0055] In some embodiments, in step S5 , the pad 400 is plated with hard gold.

[0056] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for manufacturing a circuit board, characterized in that: include: S1, die-cutting, taking a copper foil (100) and a carrier film (200), attaching the copper foil (100) to the carrier film (200), placing the assembly of the copper foil (100) and the carrier film (200) into a die-cutting machine for die-cutting, cutting out a circuit during the die-cutting process, the circuit having a pad connection position (110), and then removing the waste copper after die-cutting, so that the circuit remains on the carrier film (200); S2, transfer, take the base layer (300), attach the die-cut carrier film (200) to the base layer (300), and make the circuit on the carrier film (200) contact the base layer (300), then put the combination of the base layer (300) and the carrier film (200) into a press machine for pressing, so that the circuit is combined with the base layer (300), and tear off the carrier film (200), leaving the base layer (300) with the circuit attached; S3, printing the pad (400), printing a conductive ink on the pad connection position (110) to form the pad (400); S4, silk screen printing, applying silk screen ink on the side of the base layer (300) having the circuit, and leaving a first window (500) at the location of the pad (400) during silk screen printing, so that the pad (400) can be exposed from the first window (500); S5, gold plating, performing gold plating on the pad (400); S6, back-printing, back-printing ink on the gold-plated pad (400); S7, laser windowing, performing laser windowing processing on the ink at the position of the pad (400), so that a second window (600) is formed at the position of the pad (400), and the second window (600) reaches a predetermined size.

2. The method for manufacturing a circuit board according to claim 1, characterized in that: In the step S3, conductive ink is printed on the pad connection position (110) by silk-screen printing to form the pad (400).

3. The method for manufacturing a circuit board according to claim 1, characterized in that: The base layer (300) is a black PET film, and in the step S4 and the step S6, the ink is a white solder resist ink.

4. The method for manufacturing a circuit board according to claim 1, characterized in that: In the step S1, a cylindrical die-cutting roller (120) is used for die-cutting. A shovel block (121) is provided on the die-cutting roller (120). The shovel block (121) is used to shovel up the copper foil at the pad connection position (110) after die-cutting.

5. The method for manufacturing a circuit board according to claim 1, characterized in that: In the step S1, the carrier film (200) is a sticky film.

6. A method for manufacturing a circuit board according to claim 5, characterized in that: In the step S1, the waste material is removed by using a sticking roller (130) to stick the raised waste copper foil. As the sticking roller (130) rotates, the waste copper foil is stuck away, leaving the circuit layer on the carrier film (200).

7. The method for manufacturing a circuit board according to claim 1, characterized in that: 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.

8. The method for manufacturing a circuit board according to claim 1, characterized in that: In the step S2, the pressing is performed by hot pressing.

9. The method for manufacturing a circuit board according to claim 1, characterized in that: In the step S3, the conductive ink uses conductive copper paste or conductive silver paste.

10. The method for manufacturing a circuit board according to claim 1, characterized in that: In the step S5, the pad (400) is plated with hard gold.

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