A kind of optical module pcb forming method

Abstract

The invention discloses an optical module pcb forming method. The forming method comprises steps of S1, outer layer drilling; S2, electroplating; S3, outer layer film drying and etching; and S4, forming. The method is characterized in that during practical use, optimized design is employed, through utilizing a drilling groove instead of a forming fishing plate on both sides of a front gold fingerslot, normal precision of the drilling hole is improved, errors of alignment between a pattern and a hole and the alignment degree between the hole and the pattern are avoided, moreover, the toleranceof a hole wall to the hole wall + / -2mil is convenient for measurement of the drilling first plate, through manufacturing the outer layer pattern, an LDI machine is made to perform proportional production, and drilling is utilized to realize hole alignment to guarantee pattern to impedance accuracy + / -2mil tolerance. The method is advantaged in that slot width shape tolerance + / -2mil tolerance andgold finger center to slot center + / -2mil tolerance can be realized, alignment of the pattern and the hole is guaranteed, and alignment of the hole and the pattern is further guaranteed.

Description

technical field [0001] The invention relates to the technical field of circuit board processing, in particular to a method for forming an optical module pcb. Background technique [0002] At present, with the development of optical communication technology, the data transmission rate has developed from 1G to the current 40G / 100G, and the higher rate 200G, 400G, and 800G are currently being developed, and the volume of communication equipment required by the data center is about to increase. The smaller the interface density is, the higher the interface density will be. As the transmission rate increases, the connector and the server host must be plugged accurately. If there are too many errors, the contact area will be reduced, and the transmission loss will also increase, which will affect the use. Performance, therefore, the dimensional tolerance of the optical module interface is also more and more strict, because the optical module interface mainly depends on the size of...

AI Technical Summary

Problems solved by technology

[0002] At present, with the development of optical communication technology, the data transmission rate has developed from 1G to the current 40G / 100G, and the higher rate 200G, 400G, and 800G are currently being developed, and the volume of communication equipment required by the data center is about to increase. The smaller the interface density is, the higher the interface density will be. As the transmission rate increases, the connector and the server host must be plugged accurately. If there are too many errors, the contact area will be reduced, and the transmission loss will also increase, which will affect the use. Performance, therefore, the dimensional tolerance of the optical module interface is also more and more strict, because the optical module interface mainly depends on the size of the gold finger slot on the front end of the optical module PCB, and connects the PCB gold finger to the interface of the communication device to transmit data. Therefore, the size of the front-end card slot of the optical module PCB, the size of the center of the gold finger and the center of the card slot are becoming more and more strict. At present, the tolerance of the high-end product optical module PCB requires + / -2mil, but the traditional processing technology cannot meet this size requirement, because The traditional molding processing method adopts the integrated molding method, using the pin hole plate in the PCB set board to fix it on the board surface, and the pin hole is used as the positioning hole at the same time, and the traditional CNC 4-6 axis machine is used to mill the board, resulting in the following disadvantages:

[0003] 1. Use the PIN hole for alignment, because the PIN hole is drilled out, which ensures the alignment of the graphics and the hole, but cannot guarantee the alignment of the hole and the graphics

[0004] 2. Generally, CNC 4-6 axes are used, and the accuracy of each axis will have errors, and the dimensional accuracy cannot be guaranteed + / -2mil

[0005] 3. The PCB board will be affected by expansion and contraction, and the dimensional accuracy cannot be guaranteed + / -2mil

[0006] 4. The lateral force is received during the forming process of CNC scooping board, and the board will have lateral force, which will change with the influence of tool diameter / stack number / milling cutter quality. There are many influencing factors. The error is large, and it cannot be suitable for such boards with high-precision size requirements

[0007] 5. Based on the above, if it is made by conventional CNC, the tolerance of external dimension can only meet + / -4mil, and the tolerance of external shape and graphics can only meet + / -5mil

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