A method and system for laser cutting a three-layered quartz crystal

Abstract

This invention proposes a method and system for laser cutting a three-layer quartz crystal. Specifically, the method involves: capturing Mark points on the three-layer quartz crystal and calculating the actual cutting path; cutting the first surface of the three-layer quartz crystal at a first cutting depth according to the actual cutting path to form a first cutting layer; flipping the three-layer quartz crystal and capturing the Mark points again to calculate the actual cutting path; cutting the second surface of the three-layer quartz crystal at a second cutting depth according to the actual cutting path to form a second cutting layer; the first and second cutting layers forming a spliced ​​cutting layer; and separating the three-layer quartz crystal into flakes along the spliced ​​cutting layer. In this method, the cutting effect is ensured by controlling the laser pulse train energy, the number of sub-pulses in the pulse train, and the Bezier cutting head. Simultaneously, a vision camera positioning system is used to capture Mark points, ensuring cutting accuracy, reducing edge grinding and polishing processes, and improving cutting efficiency and yield.

Description

Technical Field

[0001] This invention relates to the field of laser processing technology, and in particular to a method and system for laser cutting a three-layer quartz crystal. Background Technology

[0002] Quartz crystals are among the most commonly used electronic components in electronic circuits. They are widely used in electronic devices due to their stability, high precision, and strong reliability, playing a vital role in communications, computers, and radio. The quality of their processing directly affects their performance and production cost. Traditional processing methods for quartz crystals include cutting, grinding, and polishing. Cutting commonly uses diamond wire saw blades and germanium-manganese blades, which generate a lot of dust and require coolant. Grinding smooths the surface of the cut quartz crystal, using tools such as diamond wheels and alumina wheels. Polishing commonly uses alumina plates, leather discs, and polishing cloths. During polishing, different grades of polishing materials are used, gradually increasing the polish to achieve the desired high gloss.

[0003] The above processing methods rely on traditional techniques and processes, using mechanical means to process quartz crystals to achieve the required shape and size. The processing generates a lot of dust, requires liquid cooling, and easily contaminates and damages the product structure; moreover, the process is cumbersome and has an extremely low yield, greatly limiting the development of thinner and more refined quartz crystal components.

[0004] With advancements in technology, such as the application of laser technology, new possibilities have been provided for the processing of quartz crystal components. To address the aforementioned shortcomings, this invention provides a method for laser cutting three-layer quartz crystals, which not only simplifies the processing steps for three-layer quartz crystal products but also optimizes the cutting quality, thereby significantly improving cutting efficiency and yield. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for laser cutting three-layer quartz crystals, to solve the problems of existing processing methods that easily contaminate and damage the product structure, and that are cumbersome and have extremely low yields. The specific technical solution is as follows:

[0006] A method for laser cutting a three-layer quartz crystal, the method comprising the following steps:

[0007] S1. Place the three-layer quartz crystal on the processing platform, capture the Mark points on the three-layer quartz crystal, and identify and calculate the actual cutting path;

[0008] S2. Cut the first surface of the three-layer quartz crystal to the first cutting depth according to the actual cutting path to form the first cutting layer;

[0009] S3. After the processing personnel flip the three-layer quartz crystal, the Mark points on the three-layer quartz crystal are captured again, and the actual cutting path is identified and calculated.

[0010] S4. Cut the second surface of the three-layer quartz crystal to the second cutting depth according to the actual cutting path to form the second cutting layer;

[0011] S5. The first and second cutting layers form a splicing cutting layer, and the three layers of quartz crystal are separated into flakes along the splicing cutting layer.

[0012] The first cutting depth is less than the thickness of the three-layer quartz crystal, the second cutting depth is less than the thickness of the three-layer quartz crystal, and the sum of the first cutting depth and the second cutting depth is the thickness of the three-layer quartz crystal.

[0013] Furthermore, step S2 specifically includes: controlling the laser pulse energy to focus the laser beam from the first face of the three-layer quartz crystal into the three-layer quartz crystal, with the focusing depth being the first cutting depth; the laser cutting head and the laser beam focus moving relative to the three-layer quartz crystal along the actual cutting path to form the first cutting layer within the three-layer quartz crystal.

[0014] Step S4 specifically includes: controlling the laser pulse energy to focus the laser beam from the second surface of the three-layer quartz crystal into the three-layer quartz crystal, with the focusing depth being the second cutting depth; the laser cutting head and the laser beam focus moving relative to the three-layer quartz crystal along the actual cutting path to form a second cutting layer within the three-layer quartz crystal.

[0015] Furthermore, the misalignment between the first cutting layer and the second cutting layer is less than 20µm.

[0016] Furthermore, the laser pulse comprises a pulse train, and a pulse train has at least two sub-pulses.

[0017] Furthermore, the cutting speed of the laser beam focal point is 50–200 mm / s, the dot pitch is 3–10 μm, the Q frequency is 30–60 kHz, and the focal position is positive.

[0018] Furthermore, the laser cutting head is a Bezier cutting head, and the cutting focal depth of the laser cutting head is greater than or equal to 3mm.

[0019] Furthermore, step S5 specifically includes: using external force to separate the three-layer quartz crystal along the splicing and cutting layer into multiple small pieces;

[0020] The external force is applied by laser heating to split the disc, and the laser heating to split the disc uses a carbon dioxide laser with a heating power greater than 100W.

[0021] Furthermore, after step S5, the method further includes: inspecting the small pieces after the cleavage, including inspecting the edge breakage of the small pieces and the slurry loss in the interlayer.

[0022] The present invention also provides a system for laser cutting a three-layer quartz crystal, used to implement the steps of the above-described method for laser cutting a three-layer quartz crystal. The system includes an industrial vision camera, a vision computing unit, a control unit, a laser cutting unit, a laser dicing unit, and a detection unit. The output terminal of the industrial vision camera is connected to the input terminal of the vision computing unit, the output terminal of the vision computing unit is connected to the input terminal of the control unit, and the output terminal of the control unit is connected to the laser cutting unit and the laser dicing unit.

[0023] Furthermore, the industrial vision camera is used to capture Mark points on the three-layer quartz crystal;

[0024] The visual computing unit is used to calculate the actual cutting path on the quartz crystal, automatically compensate for the offset value, and ensure the accuracy of the cutting path.

[0025] The control unit is used to control the laser cutting unit to perform cutting and to control the laser dicing unit to perform dicing and separation.

[0026] The laser cutting unit is used to cut the front and back sides of the three-layer quartz crystal according to the actual cutting path.

[0027] The laser dicing unit is used to dice and separate the three-layer quartz crystal along the splicing and cutting layer by applying external force.

[0028] The detection unit is used to detect the edge chipping of small pieces after cleavage and the shedding of slurry in the interlayer.

[0029] The present invention provides a method and system for laser cutting a three-layer quartz crystal, which has the following beneficial effects:

[0030] 1. The present invention provides a method and system for laser cutting of three-layer quartz crystals, which ensures the cutting effect of quartz crystal materials by controlling the laser pulse train energy and the number of sub-pulses contained in the pulse train, as well as a customized Bezier cutting head.

[0031] 2. The present invention provides a method and system for laser cutting a three-layer quartz crystal. By using a vision camera to locate and capture Mark points, the three-layer quartz crystal is cut twice, on both the front and back sides, so that the three-layer quartz crystal is completely cut through. The cutting misalignment is small, the splicing is good, and the laser-cut pieces are easy to separate.

[0032] 3. The present invention provides a method and system for laser cutting three-layer quartz crystals, which optimizes the precision of laser cutting, reduces the edge grinding and polishing processes, simplifies the processing flow, and thus improves cutting efficiency and yield. Attached Figure Description

[0033] Figure 1 This is a flowchart illustrating a method for laser cutting a three-layer quartz crystal according to the present invention.

[0034] Figure 2 These are top and side views of a three-layer quartz crystal in an embodiment of the present invention;

[0035] Figure 3 These are the Mark points and actual cutting paths of the three-layer quartz crystal in this embodiment of the invention;

[0036] Figure 4 This is a schematic diagram of the cutting of a three-layer quartz crystal in an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the cutting of a three-layer quartz crystal in an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of a system for laser cutting three-layer quartz crystals provided by the present invention. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.

[0040] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connection" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] In the description of this invention, terms such as "upper," "lower," "left," "right," "front," "back," "center," "horizontal," "vertical," "top," "bottom," "inner," and "outer," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] Example 1

[0043] This embodiment provides a method for laser cutting a three-layer quartz crystal, see reference. Figure 1 As shown, the method includes the following steps:

[0044] S1. Place the three-layer quartz crystal on the processing platform, capture the Mark points on the three-layer quartz crystal, and identify and calculate the actual cutting path;

[0045] For details, please refer to Figure 2 As shown, the three-layer quartz crystal is formed by bonding three different thicknesses of quartz crystal discs together with a special slurry. Circuits are printed in the middle of the quartz crystal interlayers, laser cutting paths are reserved on the cutting path, and four Mark points required for visual camera positioning are printed on the material.

[0046] A three-layer quartz crystal is placed on a processing platform, with a first face facing away from the platform and a second face facing it. Four mark points on the three-layer quartz crystal are captured using a vision camera, and the actual cutting path on the crystal is calculated simultaneously. (See reference...) Figure 3 As shown.

[0047] Optionally, the positioning accuracy of the visual camera is -10um to 10um, the Mark points on the three-layer quartz crystal are clearly imaged, and the visual camera can easily capture and position the image.

[0048] S2. Cut the first surface of the three-layer quartz crystal to the first cutting depth according to the actual cutting path to form the first cutting layer;

[0049] For details, please refer to Figure 4 As shown, a laser is used to cut the first surface of a three-layer quartz crystal according to an actual cutting path to form a first cutting layer. The first cutting depth is less than the thickness of the three-layer quartz crystal. In a specific implementation, the laser pulse energy is controlled to focus the laser beam on the first and second layers within the three-layer quartz crystal. The laser cutting head and the laser beam focus move relative to the three-layer quartz crystal according to the actual cutting path, so that the laser beam focus forms the first cutting layer in the first and second layers within the three-layer quartz crystal.

[0050] Optionally, the laser used for cutting is an infrared picosecond laser with a pulse width of less than 10 ps and a pulse train energy of more than 1.5 mJ.

[0051] Optionally, the laser pulse contains a pulse train, and a pulse train has at least two sub-pulses. During cutting, the subsequent laser cutting point can supplement the previous laser cutting point to ensure the cutting effect.

[0052] Optionally, the cutting speed of the laser beam focal point is 50-200mm / s, the dot pitch is 3-10um, the Q frequency is 30-60KHz, and the focal position is positive.

[0053] Optionally, the laser cutting head is a Bezier cutting head, and the cutting depth of the laser cutting head is ≥3mm.

[0054] S3. After the processing personnel flip the three-layer quartz crystal, they capture the Mark points on the three-layer quartz crystal again and calculate the actual cutting path.

[0055] Specifically, since the thickness of the three-layer quartz crystal was not completely cut, the processing personnel flipped the three-layer quartz crystal over, captured the four Mark points on the three-layer quartz crystal again through a vision camera, and calculated the actual cutting path on the three-layer quartz crystal.

[0056] S4. Cut the second surface of the three-layer quartz crystal to the second cutting depth according to the actual cutting path to form the second cutting layer;

[0057] Specifically, a laser is used to cut the second surface of the three-layer quartz crystal according to the actual cutting path to form a second cutting layer. The second cutting depth is less than the thickness of the three-layer quartz crystal, and the sum of the second cutting depth and the first cutting depth is equal to the thickness of the three-layer quartz crystal. This ensures that the laser completely cuts through both the first and second surfaces of the three-layer quartz crystal, forming a spliced ​​cutting layer of the full thickness of the three-layer quartz crystal.

[0058] See Figure 5 As shown, after flipping the three-layer quartz crystal, the Mark point is captured again and the actual cutting path is calculated. The energy of the laser pulse train is controlled so that the laser beam focus is focused on the third layer of the three-layer quartz crystal, so that the laser beam focus forms the second cutting layer in the third layer of the three-layer quartz crystal.

[0059] S5. The first and second cutting layers form a splicing cutting layer, and the three layers of quartz crystal are separated into flakes along the splicing cutting layer.

[0060] Specifically, the first and second cutting layers, formed after positioning by a visual camera, are well spliced ​​together with a misalignment of less than 20 μm. External force is then applied to separate the three layers of quartz crystal along the spliced ​​cutting layers, breaking them into multiple small pieces.

[0061] Optionally, the external force applied is laser heating for dicing, using a carbon dioxide laser with a power greater than 100W.

[0062] After the shards are separated, the small pieces formed from the shards need to be inspected, including checking for edge chipping and slurry loss from the interlayer. Edge chipping is measured using a metallographic microscope at magnification of 200X or higher to observe the chipping at the edges of the cut shards. Slurry loss is detected by visually inspecting the product under light to see if the slurry in the interlayer of the three quartz crystals changes color and if air bubbles are generated inside, in order to determine if the slurry has lost its viscosity, causing the three quartz crystals to separate.

[0063] Embodiment 1 of this invention provides a method for laser cutting a three-layer quartz crystal. By controlling the energy of the laser pulse train and the number of sub-pulses contained in the pulse train, the cutting effect of the quartz crystal material is guaranteed. Simultaneously, a vision camera positioning system is used to capture mark points, enabling two-stage cutting on both the front and back sides to completely cut through the three layers of quartz crystal. The cutting misalignment is minimal, the splicing is good, and the laser-cut fragments are easy to separate. Furthermore, the edge grinding and polishing processes are reduced, simplifying the processing flow and thus improving cutting efficiency and yield.

[0064] Example 2

[0065] This embodiment provides a system for laser cutting a three-layer quartz crystal, which can implement the steps of the laser cutting method for a three-layer quartz crystal in Embodiment 1 above. (See also...) Figure 6 As shown, the system includes an industrial vision camera, a vision computing unit, a control unit, a laser cutting unit, a laser dicing unit, and a detection unit. The output of the industrial vision camera is connected to the input of the vision computing unit, the output of the vision computing unit is connected to the input of the control unit, and the output of the control unit is connected to the laser cutting unit and the laser dicing unit.

[0066] Specifically, an industrial vision camera is used to capture Mark points on the three-layer quartz crystal; a vision computing unit is used to calculate the actual cutting path on the quartz crystal, automatically compensate for offset values, and ensure the accuracy of the cutting path; a control unit is used to control the laser cutting unit to cut and control the laser dicing unit to dicing and separating the crystals; the laser cutting unit is used to cut the three-layer quartz crystal on both sides according to the actual cutting path; the laser dicing unit is used to dicing and separating the three-layer quartz crystal along the spliced ​​cutting layer by applying external force; and a detection unit is used to detect the chipping of small pieces after dicing and the loss of slurry in the interlayer.

[0067] Those skilled in the art should understand that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the invention. Any changes or modifications made by those skilled in the art based on the embodiments of the present invention and the above disclosure shall fall within the protection scope of the claims.

Claims

1. A method for laser cutting a three-layer quartz crystal, characterized in that, The method includes the following steps: S1. Place the three-layer quartz crystal on the processing platform, capture the Mark points on the three-layer quartz crystal, and identify and calculate the actual cutting path; S2. According to the actual cutting path, the first surface of the three-layer quartz crystal is cut to a first cutting depth to form a first cutting layer; specifically, the laser pulse energy is controlled so that the laser beam focus is focused from the first surface of the three-layer quartz crystal into the three-layer quartz crystal, and the focusing depth is the first cutting depth. The laser cutting head and the laser beam focus move relative to the three-layer quartz crystal along the actual cutting path to form a first cutting layer in the three-layer quartz crystal. S3. After the processing personnel flip the three-layer quartz crystal, the Mark points on the three-layer quartz crystal are captured again, and the actual cutting path is identified and calculated. S4. According to the actual cutting path, the second surface of the three-layer quartz crystal is cut at the second cutting depth to form a second cutting layer; specifically, the laser pulse energy is controlled so that the laser beam focus is focused from the second surface of the three-layer quartz crystal into the three-layer quartz crystal, and the focusing depth is the second cutting depth. The laser cutting head and the laser beam focus move relative to the three-layer quartz crystal along the actual cutting path to form a second cutting layer in the three-layer quartz crystal. S5. The first and second cutting layers form a splicing cutting layer, and the three layers of quartz crystal are separated into flakes along the splicing cutting layer. Specifically, the three layers of quartz crystal are separated into flakes into multiple small pieces by external force. The external force is applied by laser heating for flake separation, and the laser heating for flake separation uses a carbon dioxide laser with a heating power greater than 100W. After step S5, the following steps are also included: inspecting the small pieces after flake separation, including inspecting for edge chipping and slurry loss in the interlayer. Edge chipping is detected by measuring the edge chipping position after cutting and splitting with a metallographic microscope at magnification of 200X or higher. Slurry loss is detected by placing the product under light and visually observing whether the slurry in the interlayer of the three layers of quartz crystal changes color and whether air bubbles are generated inside, in order to determine whether the slurry has lost its viscosity, causing the three layers of quartz crystal to separate. The first cutting depth is less than the thickness of the three-layer quartz crystal, the second cutting depth is less than the thickness of the three-layer quartz crystal, and the sum of the first cutting depth and the second cutting depth is the thickness of the three-layer quartz crystal. The misalignment between the first and second cutting layers is less than 20 μm; the laser used for cutting is an infrared picosecond laser with a pulse width of less than 10 ps and a pulse train energy greater than 1.5 mJ; the laser pulse contains a pulse train, and a pulse train has at least two sub-pulses, so that the subsequent laser cutting point can supplement the previous laser cutting point to ensure the cutting effect; the cutting speed of the laser beam focal point is 50~200 mm / s, the dot pitch is 3~10 μm, the Q frequency is 30~60 kHz, and the focal position is positive; the laser cutting head is a Bezier cutting head, and the cutting focal depth of the laser cutting head is greater than or equal to 3 mm.

2. A system for laser cutting a three-layer quartz crystal, used to implement the steps of the method for laser cutting a three-layer quartz crystal as described in claim 1, characterized in that: The system includes an industrial vision camera, a vision computing unit, a control unit, a laser cutting unit, a laser dicing unit, and a detection unit. The output of the industrial vision camera is connected to the input of the vision computing unit, the output of the vision computing unit is connected to the input of the control unit, and the output of the control unit is connected to both the laser cutting unit and the laser dicing unit. The industrial vision camera captures Mark points on a three-layer quartz crystal. The vision computing unit calculates the actual cutting path on the quartz crystal, automatically compensates for offset values, and ensures the accuracy of the cutting path. The control unit controls the laser cutting unit to perform cutting and controls the laser dicing unit to perform dicing separation. The laser cutting unit cuts the three-layer quartz crystal on both sides according to the actual cutting path. The laser dicing unit uses external force to dicing the three-layer quartz crystal along the spliced ​​cutting layers. The detection unit detects edge chipping of small pieces after dicing and the shedding of slurry in the interlayer.

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