Laser beam removal process for solder resist on substrate

Abstract

To provide a removing process method by a laser beam of a solder resist on a substrate.SOLUTION: A method contains: a step of providing a substrate provided to a pad onto a front surface; a step of covering a front surface of a substrate and a solder pad with a solder resist layer having a mask part onto a surface opposite to the substrate and a removing part in a place that is opposite to a solder pad; a step of reading a QR code (R) of a member number of the substrate by an image capture module; a step of automatically reading a circuit pattern corresponded to the member number of the substrate to a laser device; an operation step of performing removal by the laser beam so as to follow the circuit pattern in sequentially; a step of forming the solder resist to a hollowed part; a step of imaging a processing figure of the substrate by the image capture module; a step of projecting whether or not the processing figure surface is matched to the circuit pattern; and a step of terminating the processing operation of the substrate if it is matched.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a substrate, and more particularly to a solder resist processing method for a solder resist of a substrate using laser light. [Background technology]

[0002] Usually, the solder resist process for circuit boards involves applying a photosensitive solder resist to the surface of the circuit board after the printed circuit is installed, pre-baking it until it is semi-hardened, and then exposing and developing it using a photomask to solidify the parts other than the solder pads, removing the unhardened parts of the solder resist, and exposing the solder pads from the solder resist. Due to the error required for exposure energy and development, there is a limit to the accuracy, and the pitch of the solder pads cannot be made small. In addition, the introduction of direct imaging technology can reduce the cost of photomasks, but the equipment costs are very high and there are similar problems in terms of technology. Summary of the Invention [Problem to be solved by the invention]

[0003] However, due to the influence of environmental conditions such as temperature and humidity of the exposure section of the exposure device, the positional accuracy of the positioning marks on the circuit board and photomask and the positional accuracy of the exposure pattern change, and there remains a problem that a high-precision pattern cannot be generated. Furthermore, for boards with different solder pad positions, a photomask must first be manufactured to match the circuit board, which increases the production cost of the circuit board. In addition, the solder resist processing process for general circuit boards uses different inks, which increases the production cost of the circuit board. Furthermore, semi-cured solder resist is not hard enough and has poor adhesion, so it may become waste material during the work process. [Means for solving the problem]

[0004] According to the present invention, there is provided a process for removing solder resist from a substrate using a laser beam. The process comprises the steps of:

[0005] Providing a substrate having solder pads disposed thereon;

[0006] the solder resist layer has a mask portion on a surface facing the substrate, the solder resist has a removed portion at a location facing the solder pad, and the solder resist layer covers a surface of the substrate and a surface of the solder pad;

[0007] reading a QR code of the board part number by an image capture module;

[0008] automatically reading a circuit pattern corresponding to a board part number into a laser device;

[0009] A work step in which a laser beam removes the circuit pattern in sequence;

[0010] forming a solder resist in the cutout portion;

[0011] capturing an image of a board processing diagram by an image capture module;

[0012] A step of checking whether the processing drawing and the circuit pattern match; If so, terminating the substrate processing operation.

[0013] In one embodiment of the present invention, in the step of comparing whether the processing drawing and the circuit pattern are consistent, if the results are different, a laser beam is irradiated and the removal work is performed again on the different portions.

[0014] In one embodiment of the present invention, in step S104, a QR code (registered trademark) of the production flow of each unit is generated based on a predetermined rule, and is read from a specified position of each unit when work starts.

[0015] In one embodiment of the present invention, the solder resist data is read into the circuit pattern, and the solder resist data is converted into a positive image, a negative image, or a video image, and then a processing drawing is obtained.

[0016] In one embodiment of the present invention, after the processing diagram is formed, the size of the overlapping area of ​​the laser light is calculated based on the size of the light spot of the laser device, and then translated into a laser light matrix diagram.

[0017] In one embodiment of the present invention, the substrate is divided into a plurality of processing areas by the circuit pattern, and the removal operation is performed on the portions to be removed in the processing areas using a laser beam according to a predetermined rule.

[0018] In one embodiment of the present invention, the emitted laser beam is a high-frequency laser beam of milliseconds or more (milliseconds, microseconds, nanoseconds, or picoseconds).

[0019] In one embodiment of the present invention, the type of laser beam is CO2, Yag or green laser beam depending on the characteristics of the material, and the solder resist can be removed without leaving any solder resist or carbonizing it.

[0020] In one embodiment of the present invention, the laser light is emitted from a plurality of laser light sources, and the removal work is performed on the removal parts in sequence based on the circuit pattern, with each laser light source being responsible for a different area. Effect of the Invention

[0021] To sum up, the method of removing solder resist from a substrate using a laser beam disclosed in the present invention can achieve the following effects.

[0022] 1. The number of steps in the machining process can be significantly reduced.

[0023] 2. The efficiency of the production process is improved.

[0024] 3. The energy of laser light is controllable.

[0025] 4. The pattern accuracy of the processing process can be improved.

[0026] 5. For boards with different solder pad positions, there is no need to manufacture photomasks to match the circuit board.

[0027] 6. Not affected by environmental conditions such as temperature and humidity.

[0028] 7. Since there is no development process, there is no wastewater pollution and it is energy-saving.

[0029] 8. No ink selection required, reducing ink costs.

[0030] 9. The type of laser beam used is CO2, Yag or green laser beam, which leaves no solder resist and prevents carbonization.

[0031] 10. The semi-cured solder resist of the prior art is not hard enough and is sticky, so it may become waste material during the work process.

[0032] 11. Environmentally friendly, in line with ESG standards, and conducive to sustainable development. [Brief description of the drawings]

[0033] [Figure 1] FIG. 2 is a flow diagram of a process for removing solder resist from a substrate using a laser beam according to the present invention. [Diagram 2] FIG. [Diagram 3] 1 is a side view of a substrate covered with a solder resist according to the present invention; [Figure 4] 1 is a schematic three-dimensional view of substrate processing using laser light according to the present invention; [Diagram 5] FIG. 2 is a side view of substrate processing using laser light according to the present invention. [Figure 6]FIG. 13 is a diagram showing a comparison between a pattern according to the present invention and a board processing diagram. [Figure 7] FIG. 1 is a diagram translated into a laser dot matrix diagram according to the present invention. [Figure 8] 1A to 1C are diagrams illustrating substrate processing using multi-light source laser light according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] In order to facilitate understanding of the objectives, technical content, features and effects that can be achieved by the present invention, the present invention will be described in detail below with reference to specific embodiments and drawings. EXAMPLES

[0035] Regarding the various problems remaining in the known solder resist manufacturing process for electric circuit boards, the inventor has conducted research and development for many years and has come up with an improvement to the known product problems. The most effective function of the method for removing solder resist on a circuit board using laser light is explained in detail in the latter part.

[0036] Please refer to FIG. 1, which is a process flow diagram of the solder resist manufacturing process of the present invention. As shown in FIG. 1, the process method of removing solder resist on a substrate using laser light uses energy-controllable laser light to process the entire substrate or a part of it, and the present invention does not manually optimize the laser light to only a local area or one place of the circuit substrate, but the embodiment of the present invention mainly uses laser light to remove solder resist on a substrate, which reduces the complicated process flow and environmental pollution of the prior art and meets ESG standards. Incidentally, ESG is an abbreviation of environmental protection (E, Environmental), social responsibility (S, Social) and corporate governance (G, Governance). The process method 100 of removing solder resist on a substrate using laser light of the present invention is as follows:

[0037] <Steps> S101: providing a substrate having solder pads on a surface thereof;

[0038] <Steps> S102: the solder resist layer has a mask portion on a surface facing the substrate, the solder resist has a removal portion at a location facing the solder pad, and the surface of the substrate and the surface of the solder pad are covered with the solder resist layer;

[0039] <Steps> S103: reading the QR code of the board part number by an image capture module;

[0040] <Steps> S104: the circuit pattern corresponds to a board part number, and the data of the circuit pattern is automatically read into a laser device; <Steps> S105 A work step in which a laser beam removes a circuit pattern in sequence;

[0041] <Steps> S106 forming a solder resist in the cutout portion;

[0042] <Steps> S107: taking a picture of the board by an image capture module to generate a processing diagram;

[0043] <Steps> S108 A step of checking whether the processing drawing and the circuit pattern match;

[0044] <Steps> S109: If the processing drawing and the circuit pattern are the same, the board processing operation is terminated. If the result of comparing the processing drawing and the circuit pattern is different, the laser light is applied to the removal portion at the different location, i.e., the process returns to step S105.

[0045] The process method for removing solder resist from a substrate using a laser beam will be described in detail below. Please refer to Figs. 1 to 7. Please refer to Fig. 2, a side view of a substrate according to the present invention. Please refer to Fig. 3, a side view of a substrate covered with solder resist according to the present invention. Please refer to Fig. 4, a three-dimensional schematic diagram of substrate processing using laser beam according to the present invention. Please refer to Fig. 5, a side view of substrate processing using laser beam according to the present invention. Please refer to Fig. 6, a diagram showing matching of a pattern and a substrate processing diagram according to the present invention. Please refer to Fig. 7, a diagram of a configuration translated into a laser dot matrix diagram according to the present invention. As shown in the figures, the process flow of the process 100 for removing solder resist from a substrate using a laser beam is as follows:

[0046] In step S101, a substrate 200 (FIG. 2) having solder pads 210 on its surface is provided.

[0047] In step S102, the solder resist layer 220 has a mask portion 222 on the surface facing the substrate, and the solder resist layer 220 has a removal portion 224 at the location facing the solder pad 210, and the surface of the substrate and the surface of the solder pad 210 are covered with the solder resist layer 220 (FIG. 3). That is, the surface of the circuit board at this time is covered with green paint, and then a part of the green paint is removed or stripped. Then, the substrate 200 shown in FIG. 4 is attached to the laser processing device MT, and the initial position is set by the CCD of the laser processing device MT.

[0048] Then, in step S103, the image capture module reads the QR code (QR-Code) of the component number of the substrate 200;

[0049] Next, in step S104, the circuit pattern TA data is read into the laser processing device LE1, among which the circuit pattern TA corresponds to the QR code (registered trademark) of the part number. At the same time, in step S104, a QR code (registered trademark) of the production flow of each unit is generated based on a predetermined rule, and embedded in a designated position of each unit when the work starts. The circuit pattern TA is generated by a CAD (Computer-Aided Design, CAD) / Computer-Aided Manufacturing (CAM) system, which is a graphic-oriented automatic design, draft, and demonstration system. The QR code (registered trademark) is a two-dimensional matrix code, and instead of the QR code (registered trademark), which is a two-dimensional matrix code, a one-dimensional code, such as a barcode, may be used.

[0050] It is particularly important to note that in the embodiment of the present invention, during the translation process, the data of the solder resist layer 220 is imported into the circuit layout TA, which is then converted into a positive image, negative image, or graphic transfer to obtain a processing pattern. After obtaining the processing diagram, the overlapping area of ​​the laser dots is calculated from the size and energy of the laser dots of the laser device, and the result is translated into a laser dot matrix as shown in Figure 7. Figure 7 shows an example of the translation of three diagrams. The resolution of the laser dot matrix can be set by the designer or operator.

[0051] Next, in steps S105 and S106, the laser device LE1 of the laser processing device MT is connected to the host computer HT, and ablates or strips the removal portion 224 of the substrate 200 in a sequential manner based on the circuit pattern TA. That is, by using the movement mechanism in the X-axis direction and the Y-axis direction, the laser device LE1 emits an energy-controllable laser beam L1 to the substrate 200 based on the circuit pattern TA, and ablates or strips the removal portion 224 to form at least one cutout portion 226 in the solder resist 220. It should be particularly noted that the host computer HT and the laser device LE1 divide the substrate 200 into a plurality of processing areas based on the circuit pattern TA, and ablates or strips the removal portion 224 of each processing area according to a predetermined rule using the laser beam L1, and the entire flow is completed before proceeding to the next step S170. The laser light emitted from the laser beam L1 is a high-frequency laser beam (millisecond, microsecond, nanosecond or picosecond) of milliseconds or more, and the type of laser beam is selected according to the material characteristics to have the effect of leaving no solder resist and not carbonizing it. In this embodiment, the laser beam L1 is a picosecond laser beam, and the residence time of the picosecond laser beam on the substrate 200 is very short, that is, the solder pad 210 under the solder resist 220 is not excessively ablated or stripped. Then, in step S107, as shown in FIG. 5, the image capture module PA of the laser device LE1 captures an image of the substrate 200 and extracts a substrate processing image DC. Among them, the number of image capture modules PA is not limited to one. The image capture module PA can capture an image of any unit or processed area of ​​the substrate 200 and extract an image, or capture an image of the entire substrate 200 and extract an image. In this way, it can be performed according to a predetermined rule. Next, proceed to step S108, as shown in FIG. 6, the host computer HT uses high-resolution image recognition technology and calculation methods to determine whether the board processing diagram DC and the circuit pattern TA match, and the match between the board processing diagram DC and the circuit pattern TA can be viewed on the screen SC in FIG. 6.In another embodiment, the host computer HT can further improve the quality of image recognition and the comparison accuracy with the help of artificial intelligence (AI). Then, if the matching result between the board processing diagram DC and the circuit pattern TA is the same, the board processing operation is terminated. If the matching result between the board processing diagram DC and the circuit pattern TA is different, the process returns to step S105, and the laser beam L1 emitted by the laser device LE1 performs ablation or stripping operation again on a different part of the removal part 224 of the board 200. As described above, the present invention's solder resist on board removal process method 100 does not use any photomask, so there is no need to prepare a photomask to match the circuit board 200 for the circuit board 200 at different solder pad 210 positions. In addition, the present invention's solder resist on board removal process method 100 does not use an exposure device, so environmental conditions such as temperature and humidity of the exposure part of the exposure device are not changed by the positional accuracy of the positioning marks on the circuit board 200 or the photomask or the positional accuracy of the exposure pattern.

[0052] Finally, please refer to FIG. 8, which is a diagram showing the substrate processing by the multi-light source laser light according to the present invention. The laser processing device MT includes a plurality of laser devices LE2, LE3, and LE4. Each of them is connected to a host computer HT to perform multitasking. In addition, the plurality of laser devices LE2, LE3, and LE4 emit laser beams L2, L3, and L4 according to the circuit pattern TA, and sequentially perform ablation or stripping work on the removal portion 224 of the substrate 200. Among them, the laser beams of each laser device are responsible for each area, which helps to improve the efficiency of the processing process. In this embodiment, three laser devices LE2, LE3, and LE4 are exemplified, but the number is not limited to three in practical application. The laser beams L2, L3, and L4 may be, for example, high-frequency laser beams (millisecond, microsecond, nanosecond, or picosecond) of millisecond class or more.

[0053] To sum up, the method of removing solder resist from a substrate using a laser beam disclosed in the present invention can achieve the following effects.

[0054] 1. The number of steps in the machining process can be significantly reduced.

[0055] 2. The efficiency of the production process is improved.

[0056] 3. The energy of laser light can be controlled.

[0057] 4. The pattern accuracy of the processing process can be improved.

[0058] 5. For boards with different solder pad positions, there is no need to manufacture photomasks to match the circuit board.

[0059] 6. Not affected by environmental conditions such as temperature and humidity.

[0060] 7. Since there is no development process, there is no wastewater pollution and it is energy-saving.

[0061] 8. No ink selection required, reducing ink costs.

[0062] 9. The type of laser beam used is CO2, Yag or green laser beam, which leaves no solder resist and prevents carbonization.

[0063] 10. The semi-cured solder resist of the prior art is not hard enough and is sticky, so it may become waste material during the work process.

[0064] 11. Environmentally friendly, in line with ESG standards, and conducive to sustainable development. [Explanation of symbols]

[0065] 100 Removal process method of solder resist on substrate using laser light S101, S102, S103, S104, S105, S106, S107, S108, S109 steps 200 boards 210 Bonding Pad 220 Solder Resist 222 Mask Section 224 Removal section 226 Hollow section MT laser processing equipment HT host computer SC Screen LE1, LE2, LE3, LE4 laser equipment L1, L2, L3, L4 laser beams PA Image Capture Module TA circuit pattern DC board processing diagram

Claims

1. A method for removing solder resist on a substrate by using an energy-controllable laser beam to perform substrate processing, comprising the steps of: The laser processing device (MT) has a laser device (LE) and a moving mechanism, the laser device (LE) has an image capture module (PA) in addition to an emission part of a laser beam, and the moving mechanism moves a substrate to be processed and the laser device (LE) relative to each other; Step S101 of providing a substrate (200) having a code as a substrate part number and a solder pad (210) on its surface; Step S102 of covering the surface of the substrate (200) and the surfaces of the solder pads (210) with a solder resist (220); Step S103: mounting the substrate (200) on the laser processing machine (MT) and reading the code of the substrate part number by the image capture module (PA); A step S104 of automatically reading a circuit pattern corresponding to the board part number into a laser processing device (MT), reading the solder resist (220) data into the circuit pattern, converting the solder resist (220) data into a positive image, a negative image, or a video, forming a construction drawing of the circuit pattern, dividing the board into a plurality of processing areas according to the circuit pattern, and generating a production flow code for each unit based on a predetermined rule; a work step S105 of implanting the production flow code of each unit generated in step S104 at a designated position of each unit by movement by the movement mechanism and emission of laser light by the laser device (LE), and then removing the solder resist (220) with laser light for each processing area by movement by the movement mechanism according to a construction drawing of the circuit pattern and emission of laser light by the laser device (LE) so as to expose the solder pads (210) below the solder resist (220); In step S106, the solder resist (220) at a position facing the solder pad (210) is removed as a removed portion (224) to form a cutout portion (226), and the remaining solder resist (220) becomes a mask portion (222) facing the substrate (200); Step S107 of capturing an image of the processing diagram of the substrate (200) by the image capture module (PA); Step S108: checking whether the processing drawing acquired in step S107 matches the circuit pattern; If they are the same, the process ends at step S109.

1. A process for removing solder resist from a substrate using a laser beam.

2. The method for removing solder resist from a substrate by laser light according to claim 1, In step S108, where the processing drawing and the circuit pattern are compared to see if they match, if the results are different, the solder resist (220) at the different locations between the processing drawing and the circuit pattern is removed by laser light.

1. A process for removing solder resist from a substrate using a laser beam.

3. The method for removing solder resist from a substrate by laser light according to claim 1, After the processing diagram is formed, the size of the overlapping area of ​​the laser beam is calculated based on the size of the laser dot of the laser device, and translated into a laser beam matrix diagram.

1. A process for removing solder resist from a substrate using a laser beam.

4. The method for removing solder resist from a substrate by laser light according to claim 1, The laser light is a high-frequency laser beam of millisecond class or higher.

1. A process for removing solder resist from a substrate using a laser beam.

5. The method for removing solder resist from a substrate by laser light according to claim 1, The type of laser beam is determined by the material properties, and can be carbon dioxide (CO 2 ), Yag or green light laser is used to remove solder mask without residue and achieve non-carbonization effect.

1. A process for removing solder resist from a substrate using a laser beam.

6. The method for removing solder resist from a substrate by laser light according to claim 1, The laser processing device (MT) has a plurality of the laser devices (LE), The laser light is emitted from a plurality of laser light sources, and the removal work is performed on the removal section in sequence based on the circuit pattern, with each laser light source being responsible for a respective area.

1. A process for removing solder resist from a substrate using a laser beam.

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