CN116748709A - Laser processing system for improving PFC drilling efficiency - Google Patents

Abstract

The present invention is a laser processing system that improves PFC drilling efficiency. It includes a laser, an optical device, a processing platform and two sets of products to be processed; the optical device includes a variable magnification beam expander, a half-wave plate, and a polarizing beam splitter. , and two sets of galvanometers and field lenses used together; the beam emitted by the laser is divided into parts through the variable magnification beam expander, the half-wave plate, and the polarizing beam splitter in sequence. Two beams of light, the two beams of light include a beam of reflected light and a beam of transmitted light, the reflected light is injected into the at least two sets of galvanometers and field mirrors used in conjunction with the beam processing and is placed on the One of the two groups of products to be processed is on the processing platform. It can double the processing efficiency. By adjusting the angle of the half-wave plate, the two beams of light have different powers, so that products with the same drawings but different product specifications can be processed at the same time.

Description

A laser processing system to improve PFC drilling efficiency

Technical field

The present invention relates to the field of laser processing, and in particular, to a laser processing system that improves PFC drilling efficiency.

Background technique

FPC is also called flexible circuit board or flexible circuit board. The double-sided copper foil flexible board is composed of two layers of copper foil and an insulating film sandwiched in the middle layer. The insulating film forms the base layer of the circuit and is also used as a protective Covered to insulate the circuit from dust and moisture and to reduce stress during flexing, the copper foil forms the conductive layer. There are many types of insulating film materials, but the most commonly used are polyimide and polyester materials. The thickness of common copper foil is generally about 12-25um, and the thickness of insulation film is generally about 12-25um. Since the copper layers need to conduct electricity, the copper foil flexible board needs to be processed with via holes or blind holes. At present, the processing method of galvanometer and field mirror is generally used, which not only has high positioning accuracy, but also has fast drilling efficiency. The laser generally uses an ultraviolet nanosecond laser. The focused spot of the ultraviolet nanosecond laser is generally 7-15um, which can increase the power density and effectively process the copper layer.

Prior art CN115464280A discloses a laser drilling device, which includes a laser, a pulse train generation module and a processing component. The laser is used to generate a single pulse laser beam; the pulse train generation module is located at the exit end of the laser to generate a single pulse. The laser beam forms a laser pulse train including at least two sub-pulses with the same focus position and time differences; the processing component is provided at the output end of the pulse train generation module to process the workpiece, so that the sub-pulses with time differences sequentially target the same position of the workpiece During drilling processing, after the previous sub-pulse is processed, while waiting for the next sub-pulse to be processed, the plasma generated by the previous sub-pulse will be removed by auxiliary equipment such as external dust removal, and will not block the subsequent sub-pulse into the workpiece. The next sub-pulse will not be absorbed, and the overall energy actually produced during drilling is increased, thereby improving drilling efficiency, reducing the thermal impact and thermal radiation caused by a large amount of plasma accumulation, and effectively improving the quality of drilling.

However, as the market demand for circuit boards continues to increase, the production efficiency of drilling equipment has encountered a bottleneck. Blindly increasing the processing speed will not only lead to poor drilling quality, but also reduce product yield. Purchasing more drilling equipment can Improve productivity, but excessive drilling equipment not only increases costs, but also increases the floor space. Therefore, how to improve FPC productivity while ensuring quality has become an urgent problem that needs to be solved.

Contents of the invention

The main purpose of the present invention is to provide a laser processing system that improves PFC drilling efficiency, including a laser, an optical device, a processing platform and two sets of products to be processed; the optical device includes a variable magnification beam expander, a half-wave plate, A polarizing beam splitter, and two sets of galvanometers and field lenses used together; the beam emitted by the laser passes through the variable magnification beam expander, the half-wave plate, and the polarization lens in sequence. The flat spectroscopic plate is divided into two beams of light. The two beams of light include a beam of reflected light and a beam of transmitted light. The reflected light is injected into one of the at least two sets of galvanometers and field lenses used in conjunction. A second galvanometer and a second field lens are assembled, and the beam emitted from the second field lens processes the second product to be processed in the at least two groups of products to be processed on the processing platform; the transmitted light Input one of the at least two sets of galvanometers and field lenses used in conjunction with one galvanometer and one field lens, and process the beam emitted from the field lens one that is placed on the processing platform. The first product to be processed among the two groups of products to be processed.

Preferably, the optical device further includes at least one reflecting mirror, the two beams of light first enter the reflecting mirror before being incident, and then the reflected light reflected by the reflecting mirror enters the galvanometer.

Preferably, the light beam emitted from the half-wave plate is first reflected by at least one reflecting mirror, and then the reflected light reflected by the reflecting mirror enters the polarizing light splitting plate.

Preferably, the light beam emitted from the half-wave plate is first reflected by at least one reflector, wherein the number of the at least one reflector is two.

Preferably, the transmitted light is first reflected by the two reflecting mirrors and then enters the galvanometer one.

Preferably, the laser is a nanosecond laser.

Preferably, the polarizing light splitting plate is an SP light splitting plate incident at 45°.

Preferably, when the two beams of light reaching the processing platform need to have the same power, this is achieved by adjusting the angle of the half-wave plate.

Beneficial effects:

This invention uses the method of dividing the optical path into two, dividing the laser beam into two beams of light, each beam of light enters a galvanometer respectively, and can complete the drilling process of the FPC soft board:

(1) On the basis of a single nanosecond laser beam processing, a second beam of light is separated for simultaneous processing, which doubles the processing efficiency while ensuring the processing quality.

(2) By adjusting the angle of the half-wave plate, the two beams of light have different powers, so that products with the same drawings but different product specifications can be processed at the same time.

Description of the drawings

Figure 1 is a schematic diagram of the implementation of the technical solution of the present invention.

Figure 2 is a schematic diagram of the light splitting principle of a polarizing light splitting plate.

in:

1. Nanosecond laser; 2. Variable magnification beam expander; 3. Half wave plate; 4. Reflector one; 5. Reflector two; 6. Polarizing beam splitter; 7. Reflector four; 8. Reflector five; 9. Galvanometer two; 10. Field mirror two; 11. Back plate; 12. Reflector three; 13. Galvanometer one; 14. Field mirror one; 15. Processing platform; 16. FPC one; 17 , FPC II.

The realization of the purpose, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings.

Detailed ways

It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " The directions indicated by "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" etc. or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention. In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, features defined as “first” and “second” may explicitly or implicitly include one or more of the described features. In the description of the present invention, "plurality" means two or more than two, unless otherwise expressly and specifically limited.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. Connection, or integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or an internal connection between two elements or an interactive relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise expressly provided and limited, the term "above" or "below" a first feature of a second feature may include direct contact between the first and second features, or may also include the first and second features. Not in direct contact but through additional characteristic contact between them. Furthermore, the terms "above", "above" and "above" a first feature on a second feature include the first feature being directly above and diagonally above the second feature, or simply mean that the first feature is higher in level than the second feature. “Below”, “under” and “under” the first feature is the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is less horizontally than the second feature.

Referring to Figure 1, a laser processing system to improve FPC drilling efficiency includes a laser, optical devices, processing platform and products to be processed.

Laser - A device that emits laser light. In 1954, the first microwave quantum amplifier was made and a highly coherent microwave beam was obtained. In 1958, A.L. Schowlow and C.H. Townes extended the principle of microwave quantum amplifier to the optical frequency range. In 1960, T.H. Maiman and others made the first ruby laser. In 1961, A. Jiawen and others made a helium-neon laser. In 1962, R.N. Hall and others created the gallium arsenide semiconductor laser. In the future, there will be more and more types of lasers. According to the working medium, lasers can be divided into four categories: gas lasers, solid lasers, semiconductor lasers and dye lasers. Free electron lasers have also been developed recently, and high-power lasers usually have pulse output. The present invention uses a nanosecond laser 1.

The nanosecond laser is a physical performance testing instrument used in the fields of materials science and mechanical engineering. It was launched on January 1, 2016. Wavelengths include: 1064nm, 532nm, 355nm; maximum pulse energy: 2000mJ; repetition rate: 10Hz; energy stability.

A beam expander is a lens component that can change the diameter and divergence angle of a laser beam. The laser beam emitted from the laser has a certain divergence angle. For laser processing, only by adjusting the beam expander to make the laser beam a collimated (parallel) beam, can the focusing mirror be used to obtain a small high-power density spot; in In laser ranging, the collimation of the laser must be maximized through the beam expander to obtain the ideal long-distance measurement effect; the beam diameter can be changed through the beam expander so that it can be used in different optical instruments and equipment; the beam expander fits the space The use of optical filters can change the asymmetric beam distribution into a symmetrical distribution and make the light energy distribution more uniform. The beam expander of the present invention is a variable magnification beam expander 2.

A polarizing beam splitter prism is an optical element used to separate the horizontal polarization and vertical polarization of light. The polarizing beam splitting prism of the present invention adopts polarizing beam splitting flat plate 6.

A half-wave plate is a birefringent crystal with a certain thickness. When normal incident light passes through, the phase difference between ordinary light (o light) and extraordinary light (e light) is equal to π or an odd multiple thereof, like this The chip is called a half-wave plate, or half-wave plate for short. Select the thickness of the crystal plate so that the phase difference between the o light and the e light is π or an odd multiple thereof, then the synthetic light coming out of the crystal plate is still plane polarized light, but the vibration plane of the outgoing light is rotated relative to the vibration plane of the incident light 2θ angle. This θ angle is the angle between the vibration plane of the incident light and the optical axis on the crystal surface. That is to say, when a certain plane polarized light passes through the half-wave plate, the outgoing light is still plane polarized light, but the polarized light is The vibration surface rotates by a certain angle (2θ), and the size of this rotation angle only depends on the angle θ between the incident light vibration plane and the optical axis of the crystal.

Lenses that work near the focal plane of the objective lens and can effectively reduce the size of the detector are called field lenses. To be precise, the field lens should work in the image plane of the objective lens. The object plane of the field lens coincides with the main plane. From the characteristics of the main plane, it can be seen that its magnification is 1, so it does not contribute to the magnification of the system; the field lens should project the diaphragm surface of the objective lens onto the entrance pupil of the eyepiece. For a single For lenses, the diaphragm surface is also the exit pupil, which ensures that the light emitted from the objective lens can pass through the eyepiece to the maximum extent. If used in a scanning system, the detector replaces the entrance pupil of the eyepiece.

Simply speaking, a galvanometer is a scanning galvanometer used in the laser industry. Its professional term is called high-speed scanning galvanometer Galvo scanning system. The so-called galvanometer can also be called an ammeter. Its design idea completely follows the design method of an ammeter. The lens replaces the needle, and the signal of the probe is replaced by a computer-controlled -5V-5V or -10V-+10V DC signal. , to complete the predetermined action. Like the rotating mirror scanning system, this typical control system uses a pair of retracting mirrors. The difference is that the stepper motor that drives this set of lenses is replaced by a servo motor. In this control system, a position sensor is used The design idea of and negative feedback loop further ensures the accuracy of the system, and the scanning speed and repeated positioning accuracy of the entire system reach a new level.

The galvanometer and field lens are a pair of optical components commonly used in laser processing.

A variable-magnification beam expander 2 is placed at the exit of the nanosecond laser 1. The laser beam is changed to a suitable spot size through the variable-magnification beam expander 2. Behind the variable-magnification beam expander 2 is a half-wave plate 3. The reflecting mirror 4 is placed after the half-wave plate 3; after being reflected by the reflecting mirror 4, it passes through the reflecting mirror 25, and then is divided into two beams of light by the polarizing beam splitter 6, one beam is reflected and the other is transmitted; the reflected light passes through Reflector three 12 then enters galvanometer one 13; the transmitted light enters galvanometer two 9 after being reflected by reflector four 7 and five 8 respectively. Galvanometer one 13 and galvanometer two 9 are fixed on the back plate 11. The galvanometer A field lens 14 and a field lens 2 10 are respectively installed below the galvanometer 13 and the galvanometer 2 9. The light beam passing through the field lens 14 and the field lens 2 10 processes FPC one 16 and FPC two 17 simultaneously. FPC one 16 and FPC Two 17 is placed on the processing platform 15.

The optical path is divided into two types, with one path being a reflected beam and the other path being a transmitted beam.

The beam emitted by the nanosecond laser 1 must be linearly polarized light, which facilitates the control of the polarization state of the beam with the half-wave plate 3 .

The half-wave plate 3 needs to be used in conjunction with the polarizing beam splitter 6, and the half-wave plate 3 is rotated according to different power requirements.

The polarizing light splitting plate is an SP light splitting plate incident at 45°, and the energy ratio of transmission and reflection can be changed by adjusting the polarization state of the incident light.

The two beams of light reaching the platform must have the same power, and the energy ratio of the two beams of light can be adjusted by adjusting the angle of the half-wave plate 3 .

The galvanometer one 13 and the galvanometer two 9 must be kept horizontal relative to the platform, so as to ensure that the focus of the two beams of light on the platform is consistent.

The invention adopts the method of dividing the optical path into two, dividing the nanosecond laser beam into two beams of light and entering the two galvanometers respectively, and simultaneously drills the FPC soft board.

This system device has the following characteristics:

1. On the basis of single laser beam processing, a second beam of light is separated and processed at the same time, which doubles the processing efficiency while ensuring the processing quality.

2. The energy ratio of the two beams of light is adjustable, and it has a more flexible processing method. It can process products with the same drawings but different product specifications at the same time.

The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description and drawings of the present invention, or directly or indirectly applied to other related The technical fields are all equally included in the scope of patent protection of the present invention.

Claims (14)

1. A laser processing system that improves PFC drilling efficiency, including a laser (1), an optical device, a processing platform (15), and two sets of products to be processed (16, 17); characterized in that the optical device includes a variable magnification amplifier. beam device (2), a half-wave plate (3), a polarizing beam splitter (6), and two sets of galvanometers (9, 13) and field lenses (10, 14) used in conjunction; The light beam emitted by the laser (1) is divided into two beams of light through the variable magnification beam expander (2), the half-wave plate (3), and the polarizing beam splitter (6) in sequence. The two beams of light include a beam of reflected light and a beam of transmitted light. The reflected light is injected into the at least two sets of galvanometers (9, 13) and field lenses (10, 14) used in conjunction. A set of galvanometer two (13) and a field lens (14). The beam emitted from the field lens two (14) processes the at least two groups to be processed placed on the processing platform (15). The second product (17) to be processed in the product (16, 17); the transmitted light is incident into one of the at least two sets of galvanometers (9, 13) and field lenses (10, 14) used in conjunction A galvanometer one (9) and a field lens (10) are assembled, and the beam emitted from the field lens one (10) processes the two sets of products to be processed (15) placed on the processing platform (15). The product to be processed in 16, 17) is (16). 2. A laser processing system for improving PFC drilling efficiency according to claim 1, characterized in that: the optical device further includes at least one reflector (4, 5, 7, 8, 12), The two beams of light first enter the reflector before being incident, and then the reflected light reflected by the reflector enters the galvanometer. 3. A laser processing system for improving PFC drilling efficiency according to any one of claims 1-2, characterized in that: the light beam emitted from the half-wave plate (3) first passes through at least one Reflected by the reflecting mirrors (4, 5, 7, 8, 12), the reflected light reflected by the reflecting mirrors then enters the polarizing light splitting plate (6). 4. A laser processing system for improving PFC drilling efficiency according to claim 3, characterized in that: the light beam emitted from the half-wave plate (0) first passes through at least one reflector ( 4, 5, 7, 8, 12), wherein the number of at least one reflecting mirror (4, 5, 7, 8, 12) is two. 5. A laser processing system for improving PFC drilling efficiency according to claim 4, characterized in that: the transmitted light is first reflected by the two mirrors (7, 8) before being incident on the target. The galvanometer one (9) mentioned above. 6. A laser processing system for improving PFC drilling efficiency according to any one of claims 1-2 and 4-5, characterized in that: the laser (1) is a nanosecond laser. 7. A laser processing system for improving PFC drilling efficiency according to claim 3, characterized in that: the laser (1) is a nanosecond laser. 8. A laser processing system for improving PFC drilling efficiency according to any one of claims 1-2, 4-5, and 7, characterized in that: the polarizing light splitting plate (6) is an SP light splitter incident at 45°. Plain film. 9. A laser processing system for improving PFC drilling efficiency according to claim 3, characterized in that: the polarizing light splitting plate (6) is an SP light splitting plate incident at 45°. 10. A laser processing system for improving PFC drilling efficiency according to claim 6, characterized in that: the polarizing light splitting plate (6) is an SP light splitting plate incident at 45°. 11. A laser processing system for improving PFC drilling efficiency according to any one of claims 1-2, 4-5, 7, 9-10, characterized in that: when it is necessary to reach the processing platform (15 ) have the same power, this is achieved by adjusting the angle of the half-wave plate (3). 12. A laser processing system for improving PFC drilling efficiency according to claim 3, characterized in that: when the two beams of light that need to reach the processing platform (15) have the same power, by adjusting the This is achieved by the angle of the half wave plate (3). 13. A laser processing system for improving PFC drilling efficiency according to claim 6, characterized in that: when the two beams of light that need to reach the processing platform (15) have the same power, by adjusting the This is achieved by the angle of the half wave plate (3). 14. A laser processing system for improving PFC drilling efficiency according to claim 8, characterized in that: when the two beams of light that need to reach the processing platform (15) have the same power, by adjusting the This is achieved by the angle of the half wave plate (3).