WO2022099983A1

WO2022099983A1 - Anti-reflection laser processing device and laser processing equipment

Info

Publication number: WO2022099983A1
Application number: PCT/CN2021/084944
Authority: WO
Inventors: 许校彬
Original assignee: 淮安特创科技有限公司
Priority date: 2020-11-16
Filing date: 2021-04-01
Publication date: 2022-05-19
Also published as: CN112440003A

Abstract

An anti-reflection laser processing device (10), comprising a laser transmitter (100) and an anti-reflection mechanism (200). The anti-reflection mechanism comprises a connection pipe (210) and an anti-reflection light hood assembly (220); the anti-reflection light hood assembly comprises a light shielding hood (221) and a distance sensor (222); both ends of the connection pipe are respectively connected to the laser transmitter and the light shielding hood; the distance sensor is connected to the light shielding hood; a through hole (221a) is formed in the light shielding hood, and is communicated with a light outlet of the connection pipe; the light shielding hood is made of a light shielding material. The light shielding hood is located above a pad and covers the pad in all directions, such that energy reflected by a metal coating on the pad acts on the inner wall of the light shielding hood, and laser is blocked in the light shielding hood and cannot be emitted to the outside of the light shielding hood to prevent reflected laser from emitting to the outside and threatening equipment and personal safety, thereby effectively improving the safety of a laser ablation process. The present application further relates to anti-reflection laser processing equipment.

Description

Anti-reflection laser processing device and laser processing equipment

technical field

The utility model relates to the technical field of circuit board manufacturing and processing, in particular to an anti-reflection laser processing device and laser processing equipment.

Background technique

During the processing of the circuit board, after etching the circuit and pads of the circuit board, the circuit board needs to be treated with solder mask. Through exposure and development, the disks and holes to be soldered are exposed, and the solder mask is covered in other places to prevent short circuits during soldering. In the process of solder mask treatment, due to poor ink quality, insufficient cleanliness of the circuit board or too long ink baking time, etc., the solder mask ink will not be developed cleanly, resulting in the solder mask ink being attached to the pad. Therefore, when the surface of the pad is gold-plated or immersed in gold, the pad cannot be completely plated with gold, resulting in incomplete coating on the pad, which affects the transmission effect of the circuit board.

For the case where the above solder resist ink is attached to the pad, the following rework method is usually used for processing. First, use a laser machine to irradiate the pad for laser ablation, remove the solder resist ink and gold plating on the pad, and then re-solder the pad. The surface of the disk is gold-plated or immersed in gold. However, due to the strong reflection ability of the gold coating on the laser when the pad is ablated by the laser, the gold coating will reflect part of the laser energy, and part of the reflected laser energy will act on the external equipment and even the human body, causing Damage to life and property.

Utility model content

The purpose of the utility model is to overcome the deficiencies in the prior art, and to provide an anti-reflection laser processing device that can prevent the laser from being reflected on the equipment or the human body, can improve the safety of the processing process, and can effectively protect the equipment and personal safety. Laser processing equipment.

The purpose of this utility model is to achieve through the following technical solutions:

An anti-reflection laser processing device, comprising:

laser transmitter;

An anti-reflection mechanism, the anti-reflection mechanism includes a connecting pipe and an anti-reflection mask assembly, the anti-reflection mask assembly includes a light shield and a distance sensor, and two ends of the connecting pipe are respectively connected to the laser transmitter and the The light shield is connected, the distance sensor is connected with the light shield, the light shield is provided with a through hole, the through hole is communicated with the light outlet of the connecting pipe, and the light shield is made of light shielding material. composition.

In one of the embodiments, the connecting tube is detachably connected with the laser emitter.

In one of the embodiments, the anti-reflection mechanism further includes a snap connection component, and the snap connection component includes a first threaded protrusion structure, a second threaded protrusion structure, a first magnetic coil and a second magnetic coil, The first threaded protrusion structure is connected with the outer wall of the laser transmitter, the second threaded protrusion structure is connected with the inner wall of the connecting pipe, and the first threaded protrusion structure is connected with the second threaded protrusion The first magnetic coil is connected to the outer wall of the laser transmitter, the second magnetic coil is connected to the end of the connecting pipe, and the first magnetic coil is connected to the second magnetic coil. Magnetic connection.

In one embodiment, the inner wall of the light shield has a frosted surface structure.

In one embodiment, the anti-reflection mechanism further includes a cooling and cooling assembly, the cooling and cooling assembly includes a cooling cover and a cooling liquid circulation pipe, the cooling cover is connected to the light shield and the cooling cover The body cover is arranged on the outer wall of the light shield, so that the inner wall of the cooling cover and the outer wall of the light shield form a cooling cavity, and the cooling cover is provided with a liquid inlet and a liquid outlet The liquid inlet and the liquid outlet are both communicated with the cooling cavity, and the two ends of the cooling liquid circulation pipe are respectively arranged at the liquid inlet and the liquid outlet.

In one embodiment, the cooling cover and the light shielding cover are integrally formed.

In one embodiment, the liquid inlet and the liquid outlet are symmetrically arranged on two sides of the cooling cover, respectively.

In one embodiment, the anti-reflection light cover assembly further includes a rubber gasket, and the rubber gasket is connected to the mouth of the light shield.

In one of the embodiments, the inner wall of the light shield is spherical.

A laser processing equipment includes the anti-reflection laser processing device described in any of the above embodiments.

Compared with the prior art, the present invention has at least the following advantages:

Since the light shield is located above the pad, and the pad is covered in all directions, the energy reflected by the metal coating on the pad will act on the inner wall of the light shield, and since the light shield is composed of light-shielding materials, the laser will be blocked. In the light shield, it cannot be emitted outside the light shield, thereby preventing the reflected laser from being emitted, causing threats to equipment or personal safety, and effectively improving the safety of the laser ablation process.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings that need to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention. Therefore, it should not be regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of an anti-reflection laser processing device in an embodiment;

FIG. 2 is a flow chart of a method for laser oil-burning rework of a circuit board in another embodiment.

Detailed ways

In order to facilitate the understanding of the present utility model, the present utility model will be more fully described below with reference to the related drawings. The preferred embodiments of the present invention are shown in the accompanying drawings. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the present disclosure is provided.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in FIG. 1 , an anti-reflection laser processing apparatus 10 according to an embodiment includes a laser transmitter 100 and an anti-reflection mechanism 200 . The anti-reflection mechanism 200 includes a connecting tube 210 and an anti-reflection mask assembly 220. The anti-reflection mask assembly 220 includes a light shield 221 and a distance sensor 222. Two ends of the connecting tube 210 are respectively connected to the laser transmitter 100 and the light shield 221. The distance sensor 222 is connected with the light shielding cover 221, the light shielding cover 221 is provided with a through hole 221a, the through hole 221a communicates with the light outlet of the connecting pipe 210, and the light shielding cover 221 is composed of light shielding material.

In this embodiment, the laser emitter 100 is used to emit laser light to ablate the solder resist ink on the pad. An anti-reflection mechanism 200 is connected to the laser reflector, and the anti-reflection mechanism 200 is used to prevent the laser from being reflected on the equipment or the human body, and to improve the safety of the processing process. The anti-reflection mechanism 200 includes a connecting tube 210 and an anti-reflection mask assembly 220. The connecting tube 210 is mainly used to connect the anti-reflection mask assembly 220 with the laser emitter 100, and two ends of the connecting tube are respectively connected with the laser reflector and the light shield. 221 connection, both ends of the communication pipe are provided with nozzles, one end is a light inlet, the other end is a light outlet, the light shield 221 is provided with a through hole 221a, the light outlet of the communication pipe and the through hole 221a of the light shield 221 Connected. The laser light emitted by the laser transmitter 100 will sequentially pass through the light inlet and the light outlet of the communication pipe, and finally be emitted from the light shielding cover 221 .

Further, before the laser ablation is performed, the laser transmitter 100 is aligned with the pad of the circuit board, so that the optical path of the laser transmitter 100 can illuminate the pad, and the light shield 221 is located directly above the pad, In this way, the light shield 221 can be placed on the pad. When the laser transmitter 100 moves and aligns, it first drives the light shield 221 to move above the pad, and gradually drives the light shield 221 toward the circuit board. moving, the distance sensor 222 connected to the light shield 221 will detect the distance between the light shield 221 and the circuit board to prevent the light shield 221 from colliding with the circuit board. When the position is reached, the alignment operation is completed, and the laser ablation process can be started.

Further, the laser transmitter 100 emits laser light, and the laser light is irradiated on the pad to ablate the solder resist ink and the metal coating on the pad. When the laser is irradiated on the metal coating, the metal coating will reflect part of the laser energy. The light shield 221 is located above the pad, and covers the pad in all directions, so the energy reflected by the metal coating on the pad will act on the inner wall of the light shield 221, and because the light shield 221 is composed of light-shielding materials, the laser will It is blocked in the light shielding cover 221 and cannot be emitted out of the light shielding cover 221 , thereby preventing reflected laser light from being emitted and threatening equipment or personal safety, and effectively improving the safety of the laser ablation process.

As shown in FIG. 1 , in one embodiment, the connecting tube 210 is detachably connected to the laser transmitter 100 . When the laser processing equipment is used for a long time, it needs to be inspected or maintained. In order to facilitate the inspection or maintenance of the laser transmitter 100 and the connecting light, in this embodiment, the connection pipe 210 and the laser transmitter 100 are connected The detachable connection makes the disassembly and assembly between the connecting tube 210 and the laser emitter 100 more convenient and quicker, which helps to simplify the process of inspection and maintenance.

As shown in FIG. 1, in one embodiment, the anti-reflection mechanism 200 further includes a snap connection assembly 230, and the snap connection assembly 230 includes a first threaded protrusion structure 231, a second threaded protrusion structure 232, a first magnetic The ring 233 and the second magnetic ring 234, the first threaded protrusion structure 231 is connected with the outer wall of the laser transmitter 100, the second threaded protrusion structure 232 is connected with the inner wall of the connecting pipe 210, the first threaded protrusion structure 231 is connected with the second The threaded protrusions 232 are screwed together, the first magnetic coil 233 is connected to the outer wall of the laser transmitter 100 , the second magnetic coil 234 is connected to the end of the connecting tube 210 , and the first magnetic coil 233 is magnetically connected to the second magnetic coil 234 . In order to facilitate the inspection or maintenance of the laser emitter 100 and the connecting light, the connecting tube 210 and the laser emitter 100 are detachably connected. In this embodiment, the connecting tube 210 and the laser emitter 100 are connected by a snap button The connecting assembly 230 is detachably connected, the outer wall of the laser transmitter 100 is connected with the first threaded protrusion structure 231, and the inner wall of the connecting pipe 210 is connected with the second threaded protrusion structure 232, through the first threaded protrusion structure 231 and the second threaded protrusion structure 232. Due to the mutual cooperation of the threaded protrusion structures 232, the connecting tube 210 and the laser transmitter 100 can be directly connected by screw thread, thereby enabling quick and convenient assembly and disassembly. In addition, the outer wall of the laser transmitter 100 is connected with the first magnetic coil 233, and the connecting tube The end of the 210 is connected with the second magnetic coil 234. After the laser transmitter 100 and the connecting pipe 210 are connected by screws, the first magnetic coil 233 and the second magnetic coil 234 will be in contact with each other, and the first magnetic coil 233 and the second magnetic coil The magnetic coils 234 are attracted to each other due to the force of the magnetic field, so that the laser reflector and the communication tube tend to approach each other, thereby helping to increase the connection stability between the laser transmitter 100 and the communication tube.

As shown in FIG. 1 , in one embodiment, the inner wall of the light blocking cover 221 has a frosted surface structure. When the laser is irradiated on the metal coating, the metal coating will reflect part of the laser energy. Since the light shield 221 is located above the pad and covers the pad in all directions, the energy reflected by the metal coating on the pad will act on the shield In the inner wall of the light shield 221, in order to prevent the laser light irradiated on the inner wall of the light shield 221 from being reflected again, causing the laser to be reflected on the circuit board and damaging the circuit board, in this embodiment, the inner wall of the light shield 221 is frosted. Surface structure, after the laser is irradiated on the frosted surface, diffuse reflection will occur, and the laser energy after diffuse reflection is very dispersed, which is not enough to cause damage to the circuit board, and thus can protect the circuit board.

As shown in FIG. 1 , in one embodiment, the anti-reflection mechanism 200 further includes a cooling and cooling assembly 240 . The cooling and cooling assembly 240 includes a cooling cover 241 and a cooling liquid circulation pipe 242 , and the cooling cover 241 is connected to the light shield 221 . And the cooling cover 241 is covered on the outer wall of the light shield 221, so that the inner wall of the cooling cover 241 and the outer wall of the light shield 221 form a cooling cavity 243, and the cooling cover 241 is provided with a liquid inlet 241a and an outlet. The liquid port 241b, the liquid inlet port 241a and the liquid outlet port 241b are all communicated with the cooling cavity 243, and the two ends of the cooling liquid circulation pipe 242 are respectively disposed at the liquid inlet port 241a and the liquid outlet port 241b. The laser light reflected by the metal coating will act on the inner wall of the light shielding cover 221, so the local temperature of the light shielding cover 221 will rise. When the irradiation time is too long, the light shielding cover 221 may be damaged. In this embodiment Among them, the cooling cover 241 is covered on the outer wall of the light shielding cover 221, the inner wall of the cooling cover 241 and the outer wall of the light shielding cover 221 form a cooling cavity 243, the cooling cavity 243 is filled with cooling liquid, and the cooling liquid directly interacts with the light shielding cover 221. The contact with the outer wall of the light shield 221 can effectively cool the light shield 221 and prevent the light shield 221 from being damaged due to overheating, and the cooling liquid circulation pipe 242 passes through the liquid inlet 241a and the liquid outlet 241b of the cooling cover 241 connected, the cooling liquid circulation pipe 242 continuously replaces the cooling liquid in the cooling cavity 243, so as to improve the cooling effect of the cooling liquid on the light shielding cover 221, thereby effectively preventing the light shielding cover 221 from being damaged due to overheating, and improving the light shielding cover. 221 reliability.

As shown in FIG. 1 , in one embodiment, the cooling cover 241 and the light shielding cover 221 are integrally formed. Since the cooling cavity 243 is composed of the cooling cover 241 and the outer wall of the light shield 221, in order to increase the sealing of the cooling cavity 243 and improve the reliability of the cooling and cooling assembly 240, in this embodiment, a cooling cavity is formed. The cooling cover 241 of 243 and the light blocking cover 221 are integrally formed. Because of the integral molding mechanism, the connection between the cooling cover 241 and the light blocking cover 221 is tighter, and it is not easy to form a gap, thereby the sealing of the cooling cavity 243 It is better and less likely to leak, so the reliability of the cooling and cooling component 240 is also better.

As shown in FIG. 1 , in one embodiment, the liquid inlet 241 a and the liquid outlet 241 b are symmetrically arranged on both sides of the cooling cover 241 respectively. The liquid inlet 241a and the liquid outlet 241b are respectively used to deliver the cooling liquid to the cooling cavity 243 and discharge the cooling liquid from the cooling cavity 243. In order to improve the cooling effect of the cooling liquid on the light shield 221, in this embodiment, the inlet The liquid port 241a and the liquid outlet 241b are symmetrically arranged on both sides of the cooling cover 241, respectively. With this structure, the cooling liquid entering from the liquid inlet 241a must flow from one side of the cooling cavity 243 to the other side of the cooling cavity 243. When the cooling liquid flows from one side of the cooling cavity 243 to the other side of the cooling cavity 243, the cooling liquid can fully exchange heat with the light shielding cover 221, and fully The heat of the light shielding cover 221 is taken away, so as to achieve a better cooling effect on the light shielding cover 221 .

As shown in FIG. 1 , in one embodiment, the anti-reflection light cover assembly 220 further includes a rubber gasket 223 , and the rubber gasket 223 is connected to the mouth of the light shielding cover 221 . In the alignment operation before laser ablation, the light blocking cover 221 needs to be covered on the circuit board. 223 is connected with the cover mouth of the light shield 221. Therefore, in the process of covering the circuit board on the light shield 221, the rubber gasket 223 can play a good buffering effect to avoid the collision between the cover mouth of the light shield 221 and the circuit board. This further plays a protective role for the light shield 221 and the circuit board.

As shown in FIG. 1 , in one embodiment, the inner wall of the light blocking cover 221 is spherical. Since the flatness of each point on the metal coating is not completely uniform, when the laser is irradiated on the metal coating, the radiation angle of the laser is also random, and the position of the reflected laser on the light shield 221 is also random. When the light shield 221 is square, since the probability of the side plate of the light shield 221 being irradiated is smaller than that of the top plate of the light shield 221, the top plate of the light shield 221 is more easily damaged. For consistent intensity, in this embodiment, the inner wall of the light shielding cover 221 is spherical. Since the inner wall of the light shielding cover 221 is spherical, compared with the square light shielding cover 221, the reflected laser light is irradiated on the light shielding cover. The probability is more uniform throughout the 221 , thus helping to improve the service life of the light shield 221 .

The present application further provides a laser processing apparatus, as shown in FIG. 1 , including the anti-reflection laser processing device 10 in any of the above embodiments. The anti-reflection laser processing apparatus 10 includes a laser transmitter 100 and an anti-reflection mechanism 200 . The anti-reflection mechanism 200 includes a connecting tube 210 and an anti-reflection mask assembly 220. The anti-reflection mask assembly 220 includes a light shield 221 and a distance sensor 222. Two ends of the connecting tube 210 are respectively connected to the laser transmitter 100 and the light shield 221. The distance sensor 222 is connected with the light shielding cover 221, the light shielding cover 221 is provided with a through hole 221a, the through hole 221a communicates with the light outlet of the connecting pipe 210, and the light shielding cover 221 is composed of light shielding material.

In one of the embodiments, the laser processing equipment described in any of the above embodiments processes the circuit board by using the laser oil-burning rework method of the circuit board. As shown in FIG. 2 , the laser oil-burning rework method of the circuit board includes the following steps: Coat the dark photosensitive ink on the circuit board, so that the surface of the circuit board is covered with the dark photosensitive ink; make an exposure negative film according to the pad position of the circuit board; exposing the circuit board to cure the dark photosensitive ink on the pad; developing the circuit board to remove the dark photosensitive ink covering the pad; The dark photosensitive ink on the surface is subjected to laser ablation to remove the dark photosensitive ink, solder resist ink and inferior coating on the pad to obtain a semi-finished circuit board; the semi-finished circuit board is cleaned and cleaned. Visual inspection; surface treatment of the pads so that the pads are re-covered with metallization.

The laser is emitted by the laser machine to ablate the solid dark photosensitive ink layer attached to the pad. The dark photosensitive ink layer absorbs the energy of the laser and heats up rapidly, and the heat continues to radiate to the solder mask and the solder mask covered by the dark photosensitive ink layer. On the incomplete coating, under the action of laser ablation, the dark photosensitive ink, solder resist ink and the incomplete coating are melted together. Due to the shielding of the dark photosensitive ink layer, the laser emitted by the laser machine will not directly act on the resistance of the pad. Therefore, the damage to equipment or human body caused by the reflection of laser light from the gold coating can be avoided, and the safety of laser processing can be improved. The dark photosensitive ink has a stronger light absorption ability, so it can absorb the energy of the laser more effectively, which can prevent the reflection or diffuse reflection of the laser, and because the energy of the laser is fully absorbed by the dark photosensitive ink, laser ablation efficiency can be improved accordingly.

In order to better understand the laser oil burning rework method of the circuit board of the present invention, the laser oil burning rework method of the circuit board of the present invention is further explained below. The laser oil burning rework method of the circuit board in one embodiment is used for The circuit board is reworked. The laser oil burning rework method of the circuit board includes the following steps:

S100: Coat the dark photosensitive ink on the circuit board, so that the surface of the circuit board is covered with the dark photosensitive ink. In this step, the dark photosensitive ink can be dark brown, dark blue, dark gray or black, etc., and the light absorption capacity of the photosensitive ink can be increased by increasing the depth of the color. The method of coating the dark photosensitive ink on the circuit board is by screen printing. By placing the mesh on the top of the circuit board, the squeegee attached with the dark photosensitive ink moves horizontally from the mesh, and the dark photosensitive ink passes through the mesh. The yarn is attached to the circuit board, and then the dark photosensitive ink is coated on the circuit board. Due to the leveling effect of the scraper, the dark photosensitive ink layer coated on the circuit board is very flat, and the dark photosensitive ink layer is very smooth through the mesh yarn. The limited role of the light ink can clear the residual air bubbles in the dark photosensitive ink, so that the dark photosensitive ink coated on the circuit board is flat and dense.

S200: An exposure negative will be produced according to the positions of the pads of the circuit board. After coating the dark photosensitive ink on the circuit board, it is necessary to retain the dark photosensitive ink on the pad of the circuit board, and remove the dark photosensitive ink outside the pad. To achieve the above effect, the dark photosensitive ink coating needs to be applied Exposure and development, so it is necessary to make an exposure film according to the pad position of the circuit board. The area of the exposure film corresponding to the pad position is the irradiation area, and the area of the exposure film corresponding to the non-pad position is the cover area.

S300: Expose the circuit board according to the exposure film, so that the dark photosensitive ink on the pad is cured. After the exposure film is made, align the exposure film with the circuit board so that the irradiated area of the exposure film is opposite to the pad position of the circuit board, and the covered area of the exposure film is opposite to the non-pad position of the circuit board. The exposure film is placed in the exposure machine, the exposure film is located above the circuit board, and the exposure film is irradiated by the exposure machine. The ink is cured by ultraviolet radiation to form an all-solid dark photosensitive ink layer.

S400: Develop the circuit board to remove the dark photosensitive ink covering the pads. After exposing the circuit board, the circuit board is rinsed with the developer solution. The developer solution is a slightly alkaline sodium carbonate solution. The unexposed dark photosensitive ink on the circuit board will fall off after being rinsed by the developer solution. The solid dark photosensitive ink layer on the pad cannot be washed away and continues to adhere to the pad.

S500: performing laser ablation on the dark photosensitive ink on the pad to remove the dark photosensitive ink, solder resist ink and inferior coating on the pad to obtain a semi-finished circuit board; After the dark photosensitive ink of the circuit board is exposed and developed, the circuit board is placed in a laser machine, and the laser machine emits a laser to ablate the solid dark photosensitive ink layer attached to the pad, and the dark photosensitive ink layer absorbs the laser light. After the energy, the temperature rises rapidly, and the heat continues to radiate to the solder resist ink and the incomplete coating covered by the dark photosensitive ink layer. Under the action of laser ablation, the dark photosensitive ink, solder resist ink and incomplete coating are melted together. With the shielding of the dark photosensitive ink layer, the laser emitted by the laser machine will not directly act on the solder resist ink and the incomplete coating of the pad, so it can avoid the damage to the equipment or the human body caused by the reflection of the laser by the gold coating, and improve the laser processing. security. The dark photosensitive ink has a stronger light absorption ability, so it can absorb the energy of the laser more effectively, which can prevent the reflection or diffuse reflection of the laser, and because the energy of the laser is fully absorbed by the dark photosensitive ink, laser ablation efficiency can be improved accordingly.

S600: Cleaning and visual inspection of the semi-finished circuit board. After laser ablation of the dark photosensitive ink on the pad, the dark photosensitive ink, solder mask ink and incomplete coating are melted together, and the melted material remains on the pad of the circuit board, so the circuit board needs to be cleaned. In order to remove the ablation products on the pads, the cleaning process is to use a weakly alkaline sodium carbonate solution to rinse the circuit board until the ablation products on the pads are cleaned up and the surface of the copper foil is exposed. Visually inspect the circuit board to observe whether the solder resist ink and residual coating on the pads are completely ablated, and observe whether there are any unwashed ablation products remaining on the pads and the circuit board body.

S700: Perform surface treatment on the pad. The pads are re-covered with metal plating. After cleaning the circuit board, the pads are exposed to the surface of the copper foil again. Since the exposed copper foil surface is prone to moisture and oxidation, the surface treatment of the copper foil of the pads is required, and gold plating is added to the surface of the copper foil. In this implementation For example, the surface treatment of the pad is immersion gold or gold plating. After the surface of the copper foil is covered with gold plating, the conductivity, wear resistance and corrosion resistance of the pad will be significantly improved.

In one embodiment, after the steps of cleaning and visual inspection of the semi-finished circuit board, the following step is further included: grinding the surface of the pad. After cleaning the circuit board, the pad is exposed to the surface of the copper foil again. During the laser ablation process, the copper foil will also be ablated by the laser. The absorption of the laser energy by the copper foil is very weak. The ablation effect is not strong, but in order to ensure that the solder resist ink and incomplete coating on the copper foil are completely clear, the intensity of the laser will ablate part of the copper foil, causing the surface of the copper foil to be uneven, and the surface of the copper foil is uneven. It will lead to poor contact with the soldered parts and affect the signal transmission efficiency of the circuit board. Therefore, after cleaning the pads, the copper foil of the pads needs to be polished to make the surface of the pads flat again to ensure the pads. It can be stably connected with the welding parts, thereby ensuring the transmission efficiency of the circuit board. When the copper foil is too ablated and the thickness of the copper foil is too low, the copper foil needs to be thickened by electroplating, and then the copper foil pads should be polished.

In one embodiment, in the step of laser ablation of the dark photosensitive ink on the pad, the laser machine uses a flat-top beam to perform laser irradiation. A flat-top beam means that the laser beam intensity cross-section is flat in a large area. This differs from Gaussian beams, whose intensity gradually decreases from a maximum value to zero along the beam axis. The dark photosensitive ink is irradiated by the flat-top beam. Since the intensity difference of each point of the beam section of the flat-top beam is not large, when the flat-top beam is irradiated to the dark photosensitive ink, the dark photosensitive ink absorbs the laser evenly. Better performance, that is, it can make the ablation degree of dark photosensitive ink, solder resist ink and incomplete pads at various positions on the pad more even, which helps to make the ablation effect better and make the ablated pads more uniform. The surface is relatively flat.

In one embodiment, the dark photosensitive ink is a black photosensitive ink. In this application, the function of the dark photosensitive ink is to improve the absorption capacity of laser light and prevent laser reflection. In order to strengthen the laser absorption capacity and anti-reflection capacity of photosensitive ink, in this embodiment, the dark photosensitive ink is specifically black photosensitive ink, Black is the color with the strongest ability to absorb light. The use of black photosensitive ink can make the photosensitive ink absorb the laser more quickly, and achieve the effect of quickly melting the solder resist ink and the incomplete coating on the bottom layer of the ink. The reflection ability is the weakest, which is helpful for further anti-reflection. In addition, due to the strong light absorption ability of black photosensitive ink, it can speed up the curing speed of the exposure process and improve the curing effect, so that the efficiency and quality of rework are improved.

In one of the embodiments, after the step of coating the dark photosensitive ink on the circuit board, the following step is further included: baking the dark photosensitive ink covered on the surface of the circuit board . After the dark photosensitive ink is coated on the circuit board, in order to speed up the subsequent exposure and development efficiency, in this embodiment, the coated dark photosensitive ink is baked, and the dark photosensitive ink will be semi-cured after baking. The dark photosensitive ink in the semi-cured state is not easy to flow and can be stably attached to the circuit board, which is helpful for the subsequent exposure and development of the circuit board. At the same time, since the dark photosensitive ink is in a semi-cured state, it is It is easier to form a fully cured dark photosensitive ink layer under the exposure operation, thereby speeding up the efficiency of exposure.

In one embodiment, in the step of baking the dark photosensitive ink covering the surface of the circuit board, the baking temperature is 75°C-80°C, and the baking time is 25min-30min. The baking time and temperature have an important influence on the exposure and development quality of the dark photosensitive ink. When the baking time is too long or the baking temperature is too high, the pre-curing degree of the dark photosensitive ink layer is too high. When the non-exposed area is rinsed, the dark photosensitive ink in the non-exposed area cannot be fully rinsed because the curing degree is too high, resulting in the phenomenon of unclean development. When the baking time is too short or the baking temperature is too low, the dark color The pre-curing degree of the photosensitive ink layer is too low, the subsequent exposure process will not be able to completely cure the dark photosensitive ink, and part of the dark photosensitive ink on the pad will be washed away during the development process. In order to improve the quality of exposure and development of the dark photosensitive ink, in this embodiment, the baking temperature of the dark photosensitive ink is 75°C-80°C, and the baking time is 25min-30min. Within the baking time range, the dark photosensitive ink can have a better semi-curing degree, so that the dark photosensitive ink on the pad can be fully cured during the exposure process, and the dark photosensitive ink in the non-pad area can be cured. It can be thoroughly rinsed during the developing process, which can effectively improve the exposure and developing quality of the dark photosensitive ink.

In one embodiment, before the step of coating the dark photosensitive ink on the circuit board, the method further includes the following step: cleaning the circuit board. When the cleanliness of the board is not good, the dark photosensitive ink will not be able to completely cover the pad. Because the dark photosensitive ink is not completely covered on the pad, the bonding between the cured ink layer and the pad is not good. High, resulting in the subsequent development process, the dark photosensitive ink layer on the pad is easily washed away by the developer, and thus cannot function in the laser ablation. Therefore, in this embodiment, before the dark photosensitive ink is applied, the circuit board needs to be cleaned to wash away impurities and dust on the circuit board, so that when the dark photosensitive ink is subsequently applied, the photosensitive ink can be closely attached Combined on the circuit board and pad. The cleaning method is as follows: the circuit board is immersed in the cleaning solution of the cleaning tank. The cleaning tank is externally connected with an ultrasonic cleaner. The ultrasonic cleaner continuously oscillates the cleaning solution, thereby enhancing the cleaning effect of the cleaning solution on the circuit board. The cleaning time is 2-4 minutes, the cleaning temperature is 25-40 ℃. It should be noted that the circuit board needs to be dried after cleaning, so that the circuit board can be restored to a dry state, so as to facilitate the subsequent ink coating work.

In one embodiment, in the step of performing laser ablation on the dark photosensitive ink on the pad, the laser used for the laser ablation is a carbon dioxide laser. In the field of PCB manufacturing, laser processing mainly uses carbon dioxide laser and UV laser, and carbon dioxide laser is mostly used. This process has high speed, high efficiency and low cost. Effectively reduce the damage of the laser to the copper foil of the pad during the laser ablation process, and maximize the surface quality of the copper foil of the pad after laser ablation, so as to reduce the subsequent grinding work on the surface of the copper foil.

In one of the embodiments, after developing the circuit board to remove the dark photosensitive ink covering the pads, it further includes the following step: curing the hardened ink on the pads. Dark photosensitive ink for sanding. Since the surface flatness of the developed dark photosensitive ink is insufficient, in the subsequent laser ablation process, the absorption of the laser light by each point on the surface of the dark photosensitive ink will be uneven. Therefore, in this embodiment In the process, the developed dark photosensitive ink is polished to make the surface of the dark photosensitive ink more flat, so that the absorption of the laser light is more uniform everywhere on the surface of the dark photosensitive ink, which in turn makes the solder resist ink and incomplete coating on the pads. On the basis of being completely ablated and melted, the damage to the pad copper foil is minimized.

In one embodiment, in the step of polishing the cured dark photosensitive ink on the pad, the thickness of the polished dark photosensitive ink is 2 mm-3 mm. In the process of laser ablation, the dark photosensitive ink, solder resist ink and incomplete coating are melted together. Due to the occlusion of the dark photosensitive ink layer, the laser emitted by the laser machine will not affect the solder resist ink and defects on the pad. On the coating, it can avoid the reflection of laser light because of the gold coating. Before the laser burns the paper, if the thickness of the dark photosensitive ink is insufficient, the dark photosensitive ink will be ablated and vaporized before the heat of the dark photosensitive ink is transmitted to the gold coating, which will lead to the exposure of the gold coating and cause laser reflection. Case. In this embodiment, the thickness of the polished dark photosensitive ink is 2mm-3mm, and the dark photosensitive ink layer of this thickness can melt the gold coating before the gold coating is exposed, so that the gold coating loses its reflective ability, and then plays a role in To prevent the incomplete gold coating from reflecting laser light, the removal effect of the incomplete gold coating is not good, and the reflected light damages the equipment and the human body.

The above-mentioned embodiments only represent several embodiments of the present utility model, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the utility model patent. It should be pointed out that for those of ordinary skill in the art, some modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for this utility model shall be subject to the appended claims.

Claims

An anti-reflection laser processing device, comprising:

laser transmitter;

An anti-reflection mechanism, the anti-reflection mechanism includes a connecting pipe and an anti-reflection mask assembly, the anti-reflection mask assembly includes a light shield and a distance sensor, and two ends of the connecting pipe are respectively connected to the laser transmitter and the The light shield is connected, the distance sensor is connected with the light shield, the light shield is provided with a through hole, the through hole is communicated with the light outlet of the connecting pipe, and the light shield is made of light shielding material. composition.
The anti-reflection laser processing device according to claim 1, wherein the connecting pipe is detachably connected to the laser emitter.
The anti-reflection laser processing device according to claim 2, wherein the anti-reflection mechanism further comprises a snap connection component, and the snap connection component includes a first thread protrusion structure, a second thread protrusion structure, The first magnetic coil and the second magnetic coil, the first thread protrusion structure is connected with the outer wall of the laser transmitter, the second thread protrusion structure is connected with the inner wall of the connecting pipe, the first thread protrusion structure is connected with the inner wall of the connecting pipe The protruding structure is screwed with the second thread protruding structure, the first magnetic coil is connected with the outer wall of the laser transmitter, the second magnetic coil is connected with the end of the connecting pipe, and the first magnetic coil is connected with the end of the connecting pipe. A magnetic coil is magnetically connected to the second magnetic coil.
The anti-reflection laser processing device according to claim 1, wherein the inner wall of the light shield is of a frosted surface structure.
The anti-reflection laser processing device according to claim 1, wherein the anti-reflection mechanism further comprises a cooling and cooling component, and the cooling and cooling component includes a cooling cover and a cooling liquid circulation pipe, and the cooling cover is connected to the cooling cover. The light shield is connected and the cooling cover is provided on the outer wall of the light shield, so that a cooling cavity is formed between the inner wall of the cooling cover and the outer wall of the light shield, and the cooling cover A liquid inlet and a liquid outlet are provided, and both the liquid inlet and the liquid outlet are communicated with the cooling cavity, and the two ends of the cooling liquid circulation pipe are respectively arranged at the liquid inlet and the cooling chamber. Describe the liquid outlet.
The anti-reflection laser processing device according to claim 5, wherein the cooling cover and the light shield are integrally formed.
The anti-reflection laser processing device according to claim 5, wherein the liquid inlet and the liquid outlet are symmetrically arranged on both sides of the cooling cover, respectively.
The anti-reflection laser processing device according to claim 1, wherein the anti-reflection light cover assembly further comprises a rubber gasket, and the rubber gasket is connected to the mouth of the light shield.
The anti-reflection laser processing apparatus according to claim 1, wherein the inner wall of the light shield is spherical.
A laser processing equipment, characterized by comprising the anti-reflection laser processing device according to any one of claims 1 to 9.