The construction of component packaging is an important link in PCB design. A small mistake may cause the whole board to be unable to work and the time limit to be seriously delayed. The packaging library of conventional devices has its own CAD tools, and can also be obtained from the original design documents and reference design source diagrams.
Package name with graphics as follows：
7.The variable capacitance
11.Row type resistance
15.The integrated circuit
A good and qualified device package should meet the following conditions:
1. The designed welding pad should meet the dimension requirements of the length, width and spacing of the target device pin.
In particular, note that the size error caused by the pin itself should be taken into account in design - especially for precise, detailed components and connectors.
Otherwise, it may lead to different batches of incoming materials of the same model of components, sometimes welding processing yield is high, sometimes it is a big production quality problem!
Therefore, pad compatibility design (suitable for most large manufacturers of device pad size design), is very important!
The simplest requirement and test for this is:
Put the object device on the pad of PCB board for observation, if each pin of the device is in the corresponding pad area.
The packaging design of this welding pad is basically without much problem. On the other hand, if some of the pins are not in the pad, that's not good.
2, The design of the welding pad, should have a clear direction identification, preferably general, easy to identify the direction of polarity identification. Otherwise, when there is no qualified physical sample of PCBA for reference,
The third-party (SMT factory or private outsourcing) to do welding processing, it is easy to occur polarity welding reverse, welding wrong problem!
3, The design of the pad, should be able to comply with the specific PCB line factory itself processing parameters, requirements and technology.
For example, can design the size of the pad line, line spacing, the length and width of the character, and so on. If the size of PCB is large, it is suggested to design according to the process of popular and general PCB factories in the market, so as to delay the production schedule due to the shortage of alternative PCB manufacturers when changing PCB suppliers due to the quality or business cooperation problems.
Contact Person: Mr. Steven Luo