With the continuous development of the electronic industry, the demand for pcb board is also increasing. Common surface processes of pcb board include spraying tin, depositing gold, gold plating, OSP, etc. In fact, spraying tin can be divided into lead-free spraying tin and lead-based spraying tin. Here’s a small sample of pcb proofing to introduce the difference between them.
1. From the surface of tin, lead tin is bright, while lead-free tin (SAC) is dull. The wettability of lead-free is a little worse than that of lead-containing.
2. Lead in lead is harmful to human body, but lead-free is not. The eutectic temperature with lead is lower than that without lead. How much depends on the composition of lead-free alloy, such as the eutectic of SNAGCU is 217 degrees, and the welding temperature is the eutectic temperature plus 30~50 degrees. It depends on the actual adjustment. The eutectic with lead is 183 degrees. Mechanical strength, brightness, etc. Lead is better than lead-free.
3. The lead content of lead-free tin shall not exceed 0.5, and that of lead-containing tin shall reach 37.
4. Lead will improve the activity of tin wire in the welding process. Lead-tin wire is relatively easier to use than lead-free tin wire, but lead is toxic, and long-term use is not good for human body. Moreover, lead-free tin will have a higher melting point than lead-tin wire, so the welding point is much stronger.
5. Lead will improve the activity of tin in the welding process. What about lead-tin wire? Compared with lead-free tin wire, it should be easy to use, and the melting point of lead-free tin spraying is higher than that of lead-tin spraying, and the solder joints will be much stronger.
6. The price of pcb proofing for lead-free tin spraying is the same as that for lead-free tin spraying, and there is no difference.
What is the difference between lead-free tin spraying and lead-free tin spraying on PCB? What are the temperatures?
1. Lead-free tin spraying on PCB belongs to the environmental protection category and does not contain the harmful substance “lead”, with a melting point of about 218 degrees; The temperature of tin spraying furnace needs to be controlled at 280-300 degrees; The peak temperature should be controlled at about 260 degrees; The reflux temperature is 260-270℃.
2. PCB with lead and tin spraying does not belong to environmental protection category, and contains harmful substance “lead”, with a melting point of about 183 degrees; The temperature of tin spraying furnace should be controlled at 245-260℃; The peak temperature should be controlled at about 250 degrees; The reflux temperature is 245-255 degrees. In industrial design, mold opening refers to the tool set that forms the product design, including mechanical equipment and molds. Do you want to open the mold for PCB proofing? With this doubt, Brother Jie, let’s get to know each other. First of all, we have to figure out what mold opening specifically means. In fact, mold opening usually refers to the mold used to punch the board when making the shape. Some factories also refer to the test rack. Everyone’s understanding is different. Knowing this, we’ll know whether or not to open the mold for PCB proofing. In fact, the sample is only used for testing and debugging, and it’s not necessary to open the mold, including the test rack. It’s the same, so you don’t need to open it. What if the structure drawing is wrong when the mold is opened, and the data needs to be modified? So it is not necessary to open the mold, just make it by CNC. In terms of testing, you can choose flying needle testing, which will reduce many risks. At least don’t worry about reopening the mold. If it’s mass production, it’s recommended to open the mold and make the goods faster, so it will be slightly cheaper. It depends on the positioning of your own products, and some don’t accept die punching. With regard to the charge of pcb proofing V-cutting, normal pcb proofing V-cutting is free. If there is a large number of sets, such as more than 50PCS, an additional V-cutting fee will be charged, mainly for small boards. In addition, if there are many sets of V-cutting together, an appropriate fee will also be charged when quoting.
