Welcome to Guangzhou Tongsen Electronic Technology Co., LTD. Website!
SMT processing meaning and processing and disassembly
SMT surface mount technology refers to the process of installing and soldering surface mount components onto their designated positions on a printed circuit board (PCB). SMT is a popular technology in the electronics manufacturing industry.
What is the meaning of SMT surface mount processing?
SMT surface mount processing means installing and soldering the required surface mount components to the fixed positions on the printed circuit board. SMT, or surface mount technology, is a popular technology in the electronics processing industry. The materials required for SMT surface mount processing mainly include solder paste, solder paste, and surface mount adhesive. Solder paste is a kind of paste and is used in the reflow soldering process. Currently, SMT surface mount processing plants mainly use solder paste, using the stencil-free printing method. The advantages of this method are simple operation, but the reliability is unstable, and the cost is high.
The surface mount adhesive cures after heating, and the curing temperature is 150 degrees. Select the type of surface mount adhesive according to the different PCBs. The flux is generally used with tin powder, and sometimes some solvents are added to prolong the effect of the activator. The composition of the flux determines the wettability, viscosity change, storage life, expansibility, collapse, and cleanability of the solder paste. PCB design is closely related to SMT surface mount processing. If the PCB design is improper, it will cause waste of labor, materials, and components, resulting in significant losses.
Printed Circuit Board
The charging standard for SMT surface mount processing is that the first batch of products is calculated according to the number of processing points, and products that do not exceed 1200 yuan are calculated at 1200 yuan. If it is a product that has already been produced, it is also calculated according to the number of processing points, and less than 500 yuan is calculated at 500 yuan. If the production process is more difficult, it will be charged according to other standards.
The cost of SMT surface mount processing consists of several parts: one is the material cost, including auxiliary material costs and direct material costs; the other is the manufacturing and labor costs, including management personnel wages, depreciation costs, ordinary worker wages, water and electricity fees, and rent, etc. The equipment used in SMT surface mount processing includes high-speed surface mount machines, multi-functional surface mount machines, solder paste printing machines, solder paste mixers, etc. Cheap equipment costs tens of thousands of yuan, while expensive equipment costs millions of yuan.
Products that can be processed using SMT include wireless business phone control boards or motherboards, walkie-talkie motherboards, decoder boards, VCD motherboards, MP3 motherboards, car audio motherboards, remote control airplanes, Doraemon toys, network cards, graphics cards, keyboard boards, and a series of other processed products. The price of SMT surface mount processing is determined by the complexity of the processed product, the difficulty of welding, and the number of welding times.
How is desoldering performed in SMT surface mount processing?
For surface mount components with many pins and large spacing, a similar method is used. First, tin is plated on the pads, then the component is clamped with tweezers, one leg is soldered on the left side, and then the other leg is soldered with solder wire. It is usually better to remove these components with a hot air gun. On the one hand, the solder is melted with a hand-held hot air gun, and on the other hand, after the solder is melted, the component is removed with tweezers or other clamps.
For components with high pin density, the welding process is similar, that is, one leg is soldered first, and then the remaining legs are soldered with solder wire. For components with many and dense pins, the alignment of the pins and pads is crucial. Normally, very little tin is plated on the pads at the corners. The component is aligned with the pads using tweezers or hands, so that the edges of the pins are aligned. These components are pressed slightly onto the printed circuit board, and the corresponding pins are soldered to the pads with a soldering iron.
Surface mount red glue is a chemical compound, the main components of which are polymer materials, surface mount fillers, curing agents, and other auxiliaries. Surface mount red glue has viscosity, fluidity, temperature characteristics, and wetting characteristics. According to the characteristics of surface mount red glue, the purpose of using red glue in production is to firmly adhere the components to the surface of the PCB to prevent the components from falling off.
For surface mount components with fewer pins, such as resistors, capacitors, bipolar and triode transistors, first tin-plate one pad on the PCB, then use tweezers to clamp the component to the installation position with the left hand, fix it on the PCB, and solder the pins on the pad to the fixed pad with a soldering iron in the right hand. Release the tweezers in the left hand, and the remaining pins can be soldered with solder wire. This type of component is also easy to remove. Just heat both ends of the component with a soldering iron simultaneously. After the solder melts, slightly lift it to remove it.
SMD processing red glue is a purely consumable material and not a necessary process product. Now, with the continuous improvement of surface mount design and technology, SMT processing through-hole reflow soldering and double-sided reflow soldering have been achieved. The trend of chip processing surface mount adhesive mounting is decreasing.
RECOMMENDED NEWS
High-end Custom Services: SMT Chip Processing Meets Diverse Industry Needs
(Telephone contact)
Email:
Address： Room 502, Building 1, No. 13, Bohua 4th Road, Huangpu District, Guangzhou City
COPYRIGHT © 2025 Guangzhou Tongsen Electronic Technology Co., Ltd. All rights reserved.