Dongguan QiMao Electronics Co., Ltd.

The copper thickness is 4.5OZ aluminum substrate, and the following difficulties will be encountered in manufacturing:

1. Line width compensation for engineering design: Due to the thickness of copper, the line width must be compensated for, otherwise the line width after etching is too poor, and the customer will not accept it, and the line width compensation value must be accumulated.

2. Uniformity of printed resist soldering: Since the copper thickness of the circuit after pattern etching is unconventional, printed resist soldering is very difficult, and customers who skip printing, too thick or too thin can not bear it. How to print this layer of green oil is also one of the difficulties.

3. Etching: The line width after etching must meet the customer's drawing requirements. Residual copper is not allowed, and cannot be scraped off with a knife. Moving a knife will scratch the insulating layer, causing sparks and leakage in the withstand voltage test.

4. Machining: The aluminum substrate can be drilled, but no burrs are allowed on the inside of the hole after drilling, which will affect the withstand voltage test. Milling profiles is very difficult. And punching the shape requires the use of high-end molds, and mold manufacturing is very tricky, which is also one of the difficulties in making aluminum substrates. After the shape is punched, the marginal requirements are very regular, without any burrs, and the solder mask on the edge of the board will not be damaged. Generally, the drill is used, the hole is punched from the line, the shape is punched from the aluminum surface, and the force when the circuit board is punched is to cut up and down, etc. are all tricks. After punching the shape, the warpage of the board should be less than 0.5%.

5. The whole production process is not allowed to scratch the aluminum base surface: the aluminum base surface will be discolored and blackened by hand contact or some chemicals, which are definitely not acceptable, and some customers who re-grind the aluminum base surface also have It is not acceptable, so the whole process does not bruise, does not touch the aluminum base surface is one of the difficulties in producing aluminum substrates. Some companies choose passivation technology, and some put protective films before and after hot air leveling (tin spraying)... There are many tips, and the Eight Immortals cross the sea, each showing their magical powers.

6. Over high voltage test: 100% high voltage test is required for the aluminum substrate of the communication power supply. Some customers require direct current, and some require alternating current. The voltage requires 1500V and 1600V, and the time is 5 seconds and 10 seconds. 100% printed board for testing. Dirt on the board surface, holes and burrs on the edge of the aluminum base, line saw teeth, and bumps on any bit of the insulating layer will cause fire, leakage, and breakdown in the high-voltage test. The pressure test board is delaminated and blistered, all of which are rejected.