There are many kinds of power modules. There are two major categories of AC-DC power modules and DC-DC power modules. DC-DC power modules have a huge production and sales volume. The laser marking content includes specifications and models, parameters, Logo, and pin definitions, etc..
The material of the power module shell is divided into:
1. Plastic (civil products, large quantity and low profit, suitable for non-heating shells, usually in the form of pasted paper labels and PVC stickers).
2. Aluminum shell oxidation treatment (civil products, screen printing is often used).
3. Painted copper (military products, small quantity and big profit, mostly screen printing).
4. Nickel-plated copper, nobelium-plated copper(military products, suitable for heat-generating shells and special requirements for shielding and grounding. Screen printing or heat-resistant plastic stickers are often used).
Problems with the old process
1. Although the paper label is cheap, it affects the heat dissipation of the module. When the temperature rises, the paper label is easy to bulge, deform, or even fall off.
2. When the screen printing volume is large, it takes more time and labor. When there are many types, the layout changes are not flexible. The nickel-plated copper has a smooth surface and does not print well.
3. There are many types of module power supplies, and the unit price of paper labels is very expensive when the printing volume is small.
4. When the paper labels is stored in the warehouse for a long time, it is easy to lift up, and the adhesive is easy to fail and affect the stickiness.
5. The wide variety of products makes it easy for workers to make mistakes when labeling, and the labor intensity is high.
6. For the varieties with a small quantity, the paper label printing cost is high, just use the printer to print and paste directly, like the laboratory product, which is not exquisite.
Requirements for laser marking
1. Plastic: The composition of plastic is complex, so the effects of laser marking machines are very different. It is recommended that module manufacturers ask their shell suppliers to change the composition ratio of plastics until a clear and exquisite logo is printed by laser marking machines. It will not affect the protective effect of the shell.
2. Aluminum shell oxidation treatment: The effect of the laser marking machine is very good. The newly exposed aluminum gradually oxidizes and changes color but still has obvious contrast, especially the black shell, the contrast color is more obvious. Alumina is relatively stable and will not affect the protective effect of the shell.
3. Painted copper: The laser marking machine can only remove the paint layer to reveal the copper background. The manufacturer is worried that the green patina will affect the appearance after a long time. According to the manufacturer’s process test, the effect is still no problem.
4. Nickel-plated copper, nobelium-plated copper: The thickness of the coating is 7-8U, and 4U is required to removed by marking to avoid damage to the coating.
Laser marking technology, as a non-contact modern precision processing method, can mark on the surface of the power module housing, the workpiece will not produce deformation and internal stress, high-precision processing quality can be obtained, and the uniformity of the processing quality guaranteed. The use of a vision system to assist laser marking can make the advantages of laser processing more comprehensive, which not only solves the accuracy of marking, but also has high adaptability. No need to use fixtures, reduce costs, and improve the automated process of the product line, it also reduces manual participation and improve system efficiency.