High-precision optical module circuit board profile processing method and system

Abstract

The invention provides a high-precision optical module circuit board shape processing method and system, and the method comprises the steps: S1, obtaining the routing data of an optical module circuit board, and formulating the feeding path of rough routing and fine routing; s2, the gong board is fixed; s3, performing optical alignment on the gong board, generating an alignment digital signal in real time, calculating the offset of the gong board unit according to the alignment digital signal, and dynamically adjusting the cutter path; and S4, executing rough milling and fine milling processes step by step, wherein the allowance is eliminated by adopting a dynamic compensation algorithm for fine milling. By performing optical alignment on the routing unit, position deviation, expansion deviation and angle deviation are obtained in real time, so that feeding path instructions of rough routing and fine routing can be adjusted in real time, and influence on the true position of a golden finger due to error superposition of alignment precision difference of an outer-layer pattern and a routing process is avoided. The rough milling process and the fine milling process are executed step by step, a dynamic compensation algorithm is adopted for fine milling to eliminate the allowance, the cutter relieving phenomenon caused by uneven stress of a process milling cutter in the feeding process is avoided, and it is guaranteed that the overall dimension of a machined milling plate cannot be out of tolerance.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit boards, and particularly relates to a method and system for machining the shape of a high-precision optical module circuit board. Background Art

[0002] The optical module circuit board needs to achieve high-speed signal transmission and precise mechanical assembly. Its outer shape size and the ortho-position tolerance of the gold fingers directly affect the stability of the optical module device. Therefore, equipment manufacturers have strict requirements for the outer shape size accuracy of the plug part of the optical module circuit board, requiring the accuracy of the outer edge and the ortho-position of the gold fingers to be ±0.05 mm, which is twice that of the traditional outer shape tolerance accuracy of ±0.1 mm. In traditional routing processing, there are problems such as poor alignment accuracy between the outer layer pattern and the routing process, which affects the ortho-position of the gold fingers, and uneven force on the routing tool causes the tool deflection phenomenon, resulting in out-of-tolerance outer shape size.

[0003] In view of this, the present application is proposed. Summary of the Invention

[0004] The present invention provides a method and system for machining the shape of a high-precision optical module circuit board to solve at least one of the above technical problems.

[0005] A method for machining the shape of a high-precision optical module circuit board includes: S1, obtaining the routing data of the optical module circuit board and formulating the tool paths for rough routing and fine routing; S2, fixing the routing board; S3, performing optical alignment on the routing board, generating alignment digital signals in real time, calculating the offset of the routing board unit according to the alignment digital signals, and dynamically adjusting the tool path; S4, performing the rough routing and fine routing processes step by step, where the rough routing leaves a margin of 0.08 - 0.12 mm, and the fine routing uses a dynamic compensation algorithm to eliminate the margin.

[0006] Preferably, the dynamic compensation algorithm includes: collecting the alignment digital signals in real time, performing dynamic error calculations for position deviation, shrinkage deviation, and angle deviation, and according to the error parameters, adjusting the tool path command of the fine routing in real time, so that the tool path offset compensates for the error in the reverse direction and eliminates the margin left by the rough routing.

[0007] Preferably, in step S2, the routing board is vacuum adsorbed, and the negative pressure reaches -25 Kpa to -50 Kpa.

[0008] Preferably, the number of stacks when the routing board is placed in the vacuum adsorption area is controlled to be 1 Pn l / stack.

[0009] Preferably, in step S3, a charge-coupled device (CCD) image sensor is used to capture the optical positioning target on the routing board.

[0010] Preferably, in step S4, the rough routing leaves a margin of 0.1 mm.

[0011] Also provided is a high-precision optical module circuit board contour machining system for performing the circuit board machining method as described in any one of claims 1 to 6, including:

[0012] A vacuum adsorption platform equipped with a negative pressure control unit for fixing the routing board;

[0013] An optical positioning device, including a photoelectric sensor and a digital signal processor, for capturing the optical positioning target on the routing board to generate a digital signal;

[0014] A routing tool control device, including a drive control unit, a rough routing tool, and a fine routing tool; the drive control unit is signal-connected to the digital signal processor to dynamically adjust the tool path.

[0015] Preferably, the negative pressure control unit is a multi-axis independent negative pressure control unit, and the negative pressure of a single axis is -25 Kpa to -50 Kpa.

[0016] Preferably, the tool diameter of the rough routing tool is less than or equal to twice the difference between the slot width and the rough routing remaining allowance, and the tool diameter of the fine routing tool is less than or equal to the minimum inner chamfer radius.

[0017] Further, the rough routing remaining allowance is 0.1 mm, and the tool diameter of the rough routing tool is less than or equal to the slot width minus 0.2 mm.

[0018] Preferably, the photoelectric sensor includes a camera for positioning and photographing the optical positioning target of the routing board, and the digital signal processor can calculate the position deviation value, expansion and contraction deviation value, and angle deviation value of each routing board unit according to the photographing result.

[0019] In the high-precision optical module circuit board contour machining method of the present invention, by performing optical alignment on the routing board units, the position deviation, expansion and contraction deviation, and angle deviation are obtained in real time, so that the feed path commands of rough routing and fine routing can be adjusted in real time, avoiding the error superposition caused by the poor alignment accuracy between the outer layer pattern and the routing process, and affecting the ortho-position degree of the gold finger.

[0020] By performing the rough routing and fine routing processes step by step, the fine routing uses a dynamic compensation algorithm to eliminate the allowance, avoiding the tool deflection phenomenon caused by uneven force on the process routing tool during the feed, and ensuring that the contour dimensions of the processed routing board do not exceed the tolerance. By reasonably controlling the rough routing remaining allowance, while meeting the contour dimension accuracy of ±0.05 mm, the ortho-position degree CPK of the gold finger is greatly improved.

[0021] Further, by performing vacuum adsorption on the routing board, the machining offset caused by the gap between the positioning pin and the positioning hole is avoided. Description of the Drawings

[0022] Figure 1 is a schematic diagram of the rough and fine routing machining paths of the high-precision optical module circuit board contour machining method of the present invention;

[0023] Figure 2 It is a schematic diagram of the vacuum adsorption platform of the method and system for machining the outer shape of the high-precision optical module circuit board of the present invention.

[0024] Figure 3 It is a schematic flow diagram of the method for machining the outer shape of the high-precision optical module circuit board of the present invention.

[0025] Reference numerals:

[0026] 1. Rough milling path; 2. Fine milling path; 3. Vacuum adsorption platform; 31. Vacuum adsorption holes. Detailed implementation manners

[0027] To make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0029] The following will give a detailed description of specific embodiments of the present invention with reference to the accompanying drawings.

[0030] Please refer to Figures 1 to 2 , a method for machining the outer shape of a high-precision optical module circuit board, comprising:

[0031] S1. Obtain the milling data of the optical module circuit board and formulate the tool paths for rough milling and fine milling;

[0032] S2. Fix the copper-clad laminate. Preferably, vacuum adsorb the copper-clad laminate with a negative pressure ranging from -25 Kpa to -50 Kpa, and control the number of stacked copper-clad laminates placed in the vacuum adsorption area to be 1 Pn l / stack. Thus, firmly adsorb the copper-clad laminate during the processing, effectively reduce the positioning gap error, and provide a stable processing environment for high-precision processing.

[0033] By vacuum adsorbing the copper-clad laminate, avoid the processing deviation caused by the gap between the positioning pin and the positioning hole.

[0034] S3. Conduct optical alignment on the copper-clad laminate, generate alignment digital signals in real time, calculate the offset of the copper-clad laminate unit according to the alignment digital signals, and dynamically adjust the tool path.

[0035] Use a charge-coupled device (CCD) image sensor to capture the optical positioning targets on the copper-clad laminate; by introducing CCD optical positioning, with its high-precision optical alignment system, accurately identify the reference marks on the copper-clad laminate, achieve precise alignment, and obtain the position deviation, shrinkage deviation, and angle deviation in real time. Thus, it is possible to adjust the feed path commands for rough routing and fine routing in real time, avoiding the error superposition caused by poor alignment accuracy between the outer layer pattern and the copper-clad laminate process, which affects the ortho-position degree of the gold finger.

[0036] The entire copper-clad laminate refers to the complete board used in the manufacturing process. A copper-clad laminate may contain multiple identical or different copper-clad laminate units. Each copper-clad laminate unit may be an independent circuit board design with complete functions. During the processing, each copper-clad laminate unit needs to be aligned separately. Correspondingly, multiple optical positioning targets are provided on the copper-clad laminate, and the multiple optical positioning targets correspond to specific copper-clad laminate units respectively, enabling the real-time offset of each copper-clad laminate unit to be detected. Therefore, calculating the offset with the copper-clad laminate unit as an independent unit can ensure the accurate position of a single unit and improve the accuracy of copper-clad laminate processing.

[0037] In step S3, use a charge-coupled device (CCD) image sensor to capture the optical positioning targets on the circuit board. The charge-coupled device image sensor is the CCD image sensor, and the optical positioning target is the Mark point. The CCD image sensor is an optoelectronic sensor based on semiconductor technology, which captures images by converting optical signals into electrical signals. Its core principle is to transmit signals through charge coupling and is widely used in industrial inspection, machine vision, digital photography, and other fields. The CCD image sensor is used for Mark point positioning. By accurately capturing the optical positioning targets on the circuit board, it realizes automatic alignment and processing path compensation, with high sensitivity and low noise, but high power consumption and cost, and is suitable for high-speed precision imaging.

[0038] S4. Execute the rough routing and fine routing processes step by step, where 0.08 - 0.12 mm of allowance is reserved for rough routing, and the dynamic compensation algorithm is used for fine routing to eliminate the allowance.

[0039] By adopting the step-by-step strategy of rough milling + finish milling, please refer to Figure 1 , the rough milling path 1 represented by the thick solid line. After the rough milling path 1 is completed, a rough milling allowance is evenly reserved on both sides of the slot that has been milled. Most of the allowance is quickly removed during the rough milling stage. Please refer to Figure 1 , the finish milling path 2 represented by the thin dotted line evenly removes the rough milling allowance reserved on both sides of the slot width. During the finish milling stage, key dimensions are finely trimmed, the force distribution of the tool during processing is optimized, the phenomenon of tool deflection caused by uneven tool force during the feed process is avoided, and the outer shape dimensions of the milled board after processing are ensured not to exceed the tolerance. By reasonably controlling the rough milling allowance, while meeting the outer shape dimension accuracy of ±0.05 mm, the CPK of the gold finger alignment is greatly improved.

[0040] Preferably, a 0.1 mm allowance is reserved for rough milling. Experiments have proved that this allowance can balance the tool life and processing accuracy, and the CPK is increased by 0.76.

[0041] Taking the optical module circuit board of 8-layer TU883A board as an example, the board goes through the following pre-treatment processes: blanking, inner layer, lamination, drilling, electroplating, outer layer pattern, solder mask, characters, surface treatment, and then reaches the milling process. The processing method steps are as follows:

[0042] Step 1, obtain the milling board data, clarify the inner slots and outer contours to be milled on the milling board according to the engineering design specifications and specific customer requirements, and make the "rough milling + finish milling" feed path.

[0043] In this embodiment, the rough milling allowance is 0.1 mm. During rough milling, the tool diameter of the rough milling tool is selected according to the principle of slot width - 0.2 mm. In this way, most of the allowance in the milling slot can be quickly removed, preventing dimensional deviation caused by uneven force of the finish milling tool in subsequent processing.

[0044] During finish milling, the tool diameter is determined according to the minimum inner R corner. Usually, a smaller tool diameter is selected to perform fine trimming operations on key dimensions. It should be noted that the finish milling feed path must completely cover all rough milling feed paths, and ensure precise machining of the inner R corner to meet the overall processing accuracy requirements.

[0045] At the same time, taking Set as a unit, select the optical positioning target on the milling board, that is, the Mark point, as the alignment point for CCD milling and add it to the milling board program. Among them, the number of Mark points is controlled to be 3 - 4 per Set, the shape of the Mark point target is circular (such as a light punctuation or a round hole), and the target size is 0.5 - 4 mm.

[0046] Step 2, vacuum adsorb and fix the plate parts. According to the design requirements of the routing plate data, pins are planted on the bakelite board of the CCD optical router. The plate parts to be routed are placed flat in sets of 1Pn l / stack and sleeved into the pins, so that they are located within the area of the vacuum adsorption platform 3 of each axis. Press the vacuum adsorption switch of the lower table surface to firmly adsorb and fix the plate parts on the vacuum table surface under the action of the vacuum adsorption holes 31. Among them, the number of stacks of plate parts is controlled to be 1Pn l / stack, the vacuum negative pressure is -30Kpa, and the table surface must be kept clean without foreign objects to avoid affecting the adsorption and fixation effect.

[0047] Step 3, CCD optical alignment. Turn on the photographing function of all-axis CCD cameras. The system will perform positioning and photographing according to the Mark point positions in the CCD routing plate data, and automatically calculate the shrinkage and expansion values and angle offset values of each Set of plate parts based on the photographing results. After the above relevant data is processed by the system, it can generate an accurate motion trajectory for controlling the tool. Among them, the exposure time of the camera is controlled appropriately to ensure high contrast between the inside and outside of the contour.

[0048] In this embodiment, the dimensional accuracy of the current scheme reaches ±0.05mm. Compared with the traditional processing method, the CPK of the gold finger ortho-position is increased from 0.74 to 1.37; the dimensional accuracy ability is increased from ±0.1mm to ±0.05mm, a 100% increase; it is applicable to high-precision scenarios with high dimensional requirements such as optical modules and high-speed server motherboards.

[0049] Utilize the cooperation of Mark points and vacuum adsorption for positioning: The comprehensive accuracy is improved by 45% compared with the mechanical hole without Mark point positioning; Dynamic tool diameter compensation algorithm: Automatically adjust the compensation amount for the rough and fine routing stages to eliminate the tool deflection phenomenon.

[0050] In a preferred embodiment, between steps 2 and 3, it also includes loading the routing plate data and setting the tool parameters: Select the corresponding routing plate data at the specified position in the network disk and load it, convert the format of the loaded data to meet the requirements of the CCD routing plate format, and set the tool parameters according to the tool parameter table. Among them, the name and version of the routing plate data are controlled to be consistent with the plate parts, and the tool life optimization is controlled within 2 - 4m.

[0051] In a preferred embodiment, it also includes the production and measurement of the first piece and batch routing.

[0052] In the production and measurement of the first piece, according to the above method and settings, 1Set of the first piece is processed for each axis and sent to the CMM for measurement according to the drawing requirements. The ortho-position of the gold finger of the optical module is monitored keyly during the measurement process. Among them, the dimensional tolerance from the center of the gold finger to the center of the card slot is controlled to be ±0.05mm.

[0053] In batch PCB routing, after the first piece is processed and qualified, start the six-axis for PCB routing. Among them, control the number of stacked boards to be 1Pn l / stack, align the PCB by grabbing the CCD Mark point according to Set, use vacuum adsorption to assist in fixing the PCB, adopt the "rough routing + fine routing" PCB routing program, and control the router tool life within 2 - 4m.

[0054] This application also provides a high-precision optical module circuit board profile processing system for performing the circuit board processing method described in any one of claims 1 - 6, including:

[0055] A vacuum adsorption platform equipped with a negative pressure control unit for fixing the PCB.

[0056] An optical positioning device, including a photoelectric sensor and a digital signal processor, for capturing the optical positioning target on the PCB to generate a digital signal.

[0057] A router tool control device, including a drive control unit, a rough routing tool, and a fine routing tool; the drive control unit is signal-connected to the digital signal processor to dynamically adjust the tool path.

[0058] Preferably, the negative pressure control unit is a multi-axis independent negative pressure control unit, and the negative pressure of a single axis is -25Kpa to -50Kpa. In this embodiment, the negative pressure of a single axis reaches -30Kpa, the number of axes is six, and the negative pressure control unit uses a vacuum pump to provide vacuum adsorption for different-axis workbenches of the CCD router through 6 air pipes.

[0059] Preferably, the diameter of the rough routing tool is less than or equal to twice the difference between the slot width and the rough routing remaining allowance. For example, if the slot width is 2.0mm and the rough routing remaining allowance is 0.1mm, then the selected rough routing tool diameter D ≤ (2.0 - 0.1 * 2)mm, that is, the rough routing tool diameter D ≤ 1.8mm.

[0060] In this embodiment, the rough routing remaining allowance is 0.1mm. The diameter of the fine routing tool is less than or equal to the minimum inner chamfer radius, so that the tool can accurately cut along the inner corner contour, avoiding the inability to completely machine the rounded corners required by the design due to the tool being too large.

[0061] The slot width is the slot width at the narrowest position of the PCB slot, so as to ensure that the rough routing tool can still retain the rough routing allowance when passing through the narrowest position of the slot.

[0062] Furthermore, the diameter of the rough routing tool is less than or equal to, after subtracting twice the rough routing remaining allowance from the slot width, and then subtracting 0.2mm. For example, if the slot width is 2.0mm and the rough routing remaining allowance is 0.1mm, then the selected rough routing tool diameter D ≤ (2.0 - 0.1 * 2 - 0.2)mm, that is, the rough routing tool diameter D ≤ 1.6mm.

[0063] Preferably, the optoelectronic sensor includes a camera for positioning and photographing the optical positioning target of the routing board, and the digital signal processor can calculate the position deviation value, expansion and contraction deviation value, and angular deviation value of each routing board unit according to the photographing result.

[0064] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention.

Claims

1. A method for processing the appearance of a high-precision optical module circuit board, characterized in that: include, S1, obtain the gong board data of the optical module circuit board and formulate the tool path for rough gong and fine gong; S2, fix the gong plate; S3, optically align the gong plate, generate alignment digital signals in real time, calculate the offset of the gong plate unit according to the alignment digital signals, and dynamically adjust the tool path; S4, the roughing and fine gonging processes are performed step by step, wherein the roughing retains a margin of 0.08 to 0.12 mm, and the fine gong uses a dynamic compensation algorithm to eliminate the margin.

2. The high-precision optical module circuit board shape processing method according to claim 1 is characterized in that: The dynamic compensation algorithm includes real-time acquisition of the alignment digital signal, dynamic error calculation of position deviation, expansion and contraction deviation and angle deviation, and real-time adjustment of the tool path instructions of the fine gong according to the error parameters, so that the tool path offset reversely compensates the error and eliminates the margin retained by the rough gong.

3. The high-precision optical module circuit board shape processing method according to claim 2 is characterized in that: In step S2, the gong plate is subjected to vacuum adsorption, and the negative pressure reaches -25Kpa to -50Kpa.

4. The high-precision optical module circuit board shape processing method according to claim 3 is characterized in that: The number of stacks when the control gong plate is placed in the vacuum adsorption area is 1Pnl / stack.

5. The high-precision optical module circuit board shape processing method according to claim 3 is characterized in that: In step S3, the optical positioning target on the gong board is captured using a charge coupled device image sensor.

6. The high-precision optical module circuit board shape processing method according to claim 1, characterized in that: In step S4, the rough gong retains a margin of 0.1 mm.

7. A high-precision optical module circuit board shape processing system, characterized in that: A method for processing a circuit board according to any one of claims 1 to 6, comprising: Vacuum adsorption platform, equipped with negative pressure control unit to fix the gong plate; An optical positioning device, including a photoelectric sensor and a digital signal processor, for capturing an optical positioning target on the gong plate to generate a digital signal; The gong tool control device includes a drive control unit, a rough gong tool and a fine gong tool; the drive control unit is connected to the digital signal processor by signal to dynamically adjust the tool path.

8. The high-precision optical module circuit board shape processing system according to claim 7, characterized in that: The negative pressure control unit is a multi-axis independent negative pressure control unit, and the negative pressure of a single axis is -25Kpa to -50Kpa.

9. The high-precision optical module circuit board shape processing system according to claim 7, characterized in that: The tool diameter of the roughing tool is less than or equal to the groove width minus twice the roughing reserve margin, and the tool diameter of the fine grinding tool is less than or equal to the minimum inner chamfer radius.

10. The high-precision optical module circuit board shape processing system according to claim 7, characterized in that: The photoelectric sensor includes a camera for positioning and photographing the optical positioning target of the gong plate, and the digital signal processor can calculate the position deviation value, expansion and contraction deviation value and angle deviation value of each gong plate unit according to the photographing results.

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