Common component pad graphics library

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Common component pad graphics library [Copy link]

In order to facilitate the production of mounting, it is hoped that the zero-degree direction and positioning reference of the surface mount components are determined in the CAD library according to unified regulations. In principle, the zero-degree direction of the component pad graphics is required to be consistent with the direction of the device in the package. The packaging here mainly refers to the disc packaging. If the direction is inconsistent, it is necessary to modify it one by one in the program of the mounting equipment during production. In case of omission, it will cause defects. It should be pointed out here that the components with relatively large usage, such as resistors, capacitors, and inductors, must abide by this rule. Because the usage is too large, if there is a problem, the workload of checking and modifying during production is also very large. For designers, it is only a matter of raising a hand, but if it is solved in production, it may take one or two days. As for components such as IC, they must be checked one by one during production, as long as the unified rules are followed. The positioning reference of the component must be the center of the component body. This is because the mounting equipment uses the center of the component as the center point of the mounting position. When automatically identifying and positioning, the data is corrected and compensated based on the center of the component body. In actual production, it is found that some designers use the center of the first foot of the component as the positioning reference of the component. In this case, the production process cannot be discovered in advance, but can only be discovered during the production process. Once it occurs, it can only be modified one by one on the production line. Imagine that if the coordinates of thousands of components need to be modified one by one, the equipment engineer will go crazy. Some products with more complex circuits may be designed and laid out by several engineers. At this time, it is important to pay attention to the fact that the pad graphic library used must be unified. If everyone builds their own library, there will be problems in the final product. I have encountered this situation in Beijing. A communications company that produces Da Lingtong mobile phones asked us to produce a product. During production, it was found that the zero-degree direction of the components of the same package in different areas of the circuit board was different. After communication, it was learned that this circuit board was designed by several people. Of course, this situation is relatively rare, but I still hope it can attract attention. The following are the requirements for the common component pad graphic library for reference: 1. Chip components (non-polar) resistors, capacitors, inductors [attach] 334537 [/attach] The zero degree direction is 1 foot on the left, with the center of the component body as the reference point 2. Tantalum capacitors [attach] 334538 [/attach] The zero degree direction is the negative pole on the left, with the center of the component body as the reference point 3. Diodes [attach] 334539 [/attach] The zero degree direction is the negative pole on the left, with the center of the component body as the reference point 4. Inductors [attach] 334540 [/attach] The zero degree direction is 1 foot on the left, with the center of the component body as the reference point 5. Cylindrical diodes [attach] 334541 [/attach] The zero degree direction is the negative pole on the left, with the center of the component body as the reference point 6. SMD aluminum electrolytic capacitors [attach] 334542 [/attach] The zero degree direction is the positive pole on the left, with the center of the component body as the reference point. 7. SOT23 package [attach] 334543 [/attach] The zero degree direction is pin 1 at the lower left, with the center of the component body as the reference point. 8. SOT25 package [attach] 334544 [/attach] The zero degree direction is pin 1 at the lower left, with the center of the component body as the reference point. 9. SOT343 package [attach] 334545 [/attach] The zero degree direction is pin 1 at the lower left, with the center of the component body as the reference point. 10. SOT223 package [attach] 334546 [/attach] The zero degree direction is pin 1 at the lower left, with the center of the component body as the reference point. 11. T0252 (DPAK) package [attach] 334547 [/attach] The zero degree direction is pin 1 at the lower left, with the center of the component body as the reference point. 12. SOIC, SOP, SSOP Package [attach] 334549 [/attach] Zero degree direction is 1 foot at the lower left, with the center of the component body as the reference point 13. TSOP package [attach] 334550 [/attach] Zero degree direction is 1 foot at the lower left, with the center of the component body as the reference point 14. SOIC J-shaped lead [attach] 334551 [/attach] Zero degree direction is 1 foot at the lower left, with the center of the component body as the reference point 15. QFP package [attach] 334552 [/attach] Zero degree direction is 1 foot at the lower left, with the center of the component body as the reference point 16. PLCC package [attach] 334553 [/attach] [attach] 334554 [/attach] Zero degree direction is 1 foot at the center of the left, with the center of the component body as the reference point 17. QFN package [attach] 334555 [/attach] The zero degree direction is 1 foot at the lower left, with the center of the component body as the reference point 18. BGA package [attach]334556 [/attach] The zero degree direction is 1 foot at the lower left, with the center of the component body as the reference point For other types of devices, you can refer to the above principles. Reprinted from Network