PCB Technical - ​How to apply CAM technology in circuit board design?

As the circuit design of the PCB circuit board becomes more and more complex and the circuit density is getting higher and higher, the golden fingers are also developed from simple finger graphics to various peculiar shapes (such as finger-shaped, round, square, and even local circuit needs. The gold finger consumer line is plated with thick gold). In traditional gold finger electroplating, hand-wrapped anti-electroplating blue adhesive tape is used to maintain the non-electroplating area. Hand-wrapped blue adhesive paper is difficult to train for workers (usually 1-2 months), slow speed, difficult to meet the peculiar graphics and restrict the gold finger electroplating consumption; some PCB circuit board factories in Taiwan use the method of manually opening the skylight, although the blue plastic can be improved Speed, but because manual operation is easy to scratch the green oil and graphics, the green tape should be added after the manual opening of the skylight, which greatly improves the cost, and the control is difficult to meet the requirements of high-end boards.

When the output of gold finger board is large, the gold finger consumption line can adopt various methods (such as increasing the voltage, increasing the gold concentration, increasing the temperature of the potion tank) to increase the output, and the blue adhesive paper station must be seconded from the external process.

Consumption by non-skilled workers. The consumption rate of these non-skilled workers is extremely low. The quality of the blue tape is worrying, and the scrap of PCB circuit boards will follow; when the output of gold finger boards increases, a small number of skilled workers have nothing to do ; The consumption capacity of different types of gold finger boards covered with blue adhesive paper varies greatly (from 1 piece/minute to 1 piece/8-10 minutes). PPC must consider the consumption of different types of gold finger boards with blue adhesive paper when planning the consumption plan. Time and effort; the consumption of special-shaped gold finger boards is time-consuming, laborious and material (need to manually wrap the green tape) and the quality is still difficult to guarantee; Very low. The rubber-coated paper station has become a bottleneck restricting the gold finger electroplating program and the smooth stop of consumption, and the constraint controls the consumption beat and output rate of the gold finger electroplating workshop [1]. This article analyzes the process consumption of detailed examples to find out Restrict the bottleneck position of gold finger electroplating and the improvement method.

Goldfinger electroplating production process:

Receiving the board - cutting board edge/gong copper skin - hand-wrapped blue tape - hand-wrapped green tape (optional) - laminated paper - nickel-plated gold - peeling tape - washing board - introspection.

Analysis of the consumption ability of each station of gold finger electroplating:

Analysis of bottleneck station

If the monthly order is 120,000 ft2, due to the uneven distribution of orders, the daily plan consumption will fluctuate between 2000 ft2 and 6000 ft2. When the load is 6000 ft2 per day, the consumption ability/load analysis shows that: manual package Blue glue and gold-plated fingers are the bottleneck positions, which will form a backlog of work-in-progress and delays in consumption plans. Hand-wrapped blue glue cannot meet the requirements even for 24-hour consumption, and manual operation must deduct the necessary meal/shift handover time. The 12-hour consumption of workers is not ideal. According to the survey foremen and workers, the gold-plated fingers slowed down the consumption rate due to the insufficient supply of blue rubber. When the supply of blue rubber is sufficient, the consumption rate of nickel and gold can be increased by 20%, and consumption can meet the requirements of the consumption plan. The blue glue station is the real bottleneck station. If you want the plan and consumption to stop smoothly and the consumption logistics to move smoothly, improvement measures must be taken to break the bottleneck.

Analysis of improvement methods

A, add 5 people/class;

When the output drops (such as 2000 ft2) workers have nothing to do

B, daily consumption of 4000 ft2;

Too ideal, PPC cannot be deployed

C, usually 10 people/class, 15 people/class when the output is large;

The veteran's efficiency is too low, only 30-50% of the standard output, not much assistance

D, using TL04-07 automatic blue glue machine;

Large investment, wasting 4-6 workers/shift, wasting 20% of blue rubber cost, and wasting 70% of green rubber cost

TL04-07 type automatic blue glue machine adopting PCB circuit board design CAM technology

CAM is the abbreviation of Computer Aided Manufacture in English. It refers to the general term for the use of computers to stop the manufacture of goods. There are narrow CAM and broad CAM. In a narrow sense, CAM refers to the use of computers to assist in the completion of all manufacturing processes from original materials to commodities, including indirect manufacturing processes and direct manufacturing processes. In a broad sense, CAM refers to the use of a computer in a certain part of the manufacturing process. In computer-aided design and manufacturing (CAD/CAM), it usually refers to computer aided machining. More clearly, it is index-controlled machining. The output information is the process path and process content of the part, and the input information is the motion trajectory (tool position file) and numerical control sequence of the tool during processing. (1) Copper is recovered from the copper-containing waste liquid without chelate.

Add excessive iron filings in the copper-containing waste liquid, control the temperature of the solution to 30-50 degree Celsius, and after the response is about 1 hour, take out the iron filings, filter, wash and dry the replaced copper to obtain metal copper powder. The purity is over 99%.

(2) Recover copper from copper waste liquid containing chelating agent.

In the PCB-containing copper waste liquid, adjust the PH value to above 11, add calcium hydroxide that exceeds the amount of copper ions, and stir the solution at the same time to generate copper hydroxide precipitation, filtration, washing, and precipitation. Add excess sulfuric acid to the precipitation, and then evaporate and crystallize. Take out the crystals and obtain copper sulfate crystals after drying.