When designing the structure of the high-frequency transformer, it should be based on the drawings or samples provided by the customer, plus its own design experience, try to design the model in 3D, avoid the defects of 2D drawing and modification, and then gradually modify it to finalize the case. If the customer design is unreasonable, you should take the initiative to re-confirm the skeleton structure with the customer's technical staff. When designing the skeleton, pay attention to the following aspects:
1. The raw materials must conform to the customer's process and requirements, and the skeleton design must be carried out according to the characteristics of the materials. Generally, the yellow wall is used to confirm the wall thickness of the skeleton. At the same time, the temperature indicated by the yellow card is compared with the baking and soldering temperature of the customer's process to meet the customer's process conditions.
2. Metal pins can smoothly pass or flatten the PCB board of the client. Generally, iron (steel) pins are used. When there is a special requirement for the customer to have better conductivity, it is necessary to consider a material with good conductivity such as copper.
3. At present, environmental protection requirements such as RoHS, halogen-free, and SVHC are becoming more and more urgent, and these requirements must be met at the same time.
4. It is required to meet the requirements of the high-frequency transformer model, and the external dimensions should be smaller than the finished product size.
5. The core hole needs to match the size of the core column, which is generally larger than the upper limit of the core; the blade of the fixed core is generally smaller than the lower limit of the inner diameter of the core. The purpose of this design is to modify the mold for subsequent wear. The frame type skeleton is suitable for the tightness in the automatic winding operation of the customer (the loosening of the frame during the winding process will cause the skeleton to fall off, and the operator is difficult to insert or pull out), the core hole and the winding fixture The tolerance of the fit should be controlled at around 0.05.
6. The wire trough is the turning path of the copper wire. At the same time, in order to avoid the abnormal situation such as breakage, pin cracking, sand inclusion, etc. in the production, the width of the wire trough needs to be considered together: the diameter of the copper wire and the pinhole The edge wall thickness and the burr handle the size of the sand. Under normal circumstances, the wire trough is suitable for large, so as to avoid sanding, and it is convenient for customers to pass the copper wire. However, when the wire trough is enlarged, the remaining pinhole edge thickness will be small, and the pin is prone to occur during production. Cracked feet.
7. The pinhole should not be too deep, and the wall thickness at the bottom of the pinhole should be above 0.5mm to avoid the occurrence of cracking or perforation during pin insertion.
8. Need to do R angle transition, in addition to increasing strength to prevent damage, it can also improve some problems in production. In particular, the edge of the wire groove can prevent the insulating enamel coating on the outer layer of the copper wire from being scratched; the edge of the core hole can facilitate the insertion of the magnetic core; the strength of the blade can be increased around the winding pipe.
9. Need to design the anti-reverse structure of the pin, the best effect of the bump, so that the groove and the bump can be added in the direction corresponding to the runway to avoid the dislocation of the foot caused by the reverse of the product.
10. If the retaining wall is high or the blade is large, the drafting angle should be designed to facilitate demoulding during production.
11. When the skeleton has a matching cover, you should pay attention to the size of the joint with the cover.
12. The blade in the middle of the frame-type bobbin winder should be designed with corresponding hooks to prevent the copper wire from being in place when winding; the blade should also be designed with a notch so that the winding needle can pass smoothly.
13. It is better to design the notch of the recess at the inlet, depending on the size of the skeleton. Generally, the notch is 0.5-1.0 mm deep. This can avoid the influence of the residual material at the time of material selection on the external dimensions of the product. If it is not possible to design a notch, increase the jig of the grinding feed to meet the size requirements.
14. The thicker plastic skeleton should be designed with recessed notch in the plastic area to ensure uniform wall thickness and avoid serious shrinkage.