SMT ProcessingWhat is the composition of our technology?
SMT assembly printing (red adhesive/bismuth solder paste) - SMT assembly component placement inspection (AOI automated or visual inspection options) - SMT assembly attachment (first placing small devices, then installing large components with 3360 points high-speed placement and integrated circuits).
SMT ProcessingAOI inspection (optional, optical/visual) - SMT assembly welding (using hot air reflow) - SMT assembly inspection (separable AOI optical inspection for appearance and functional testing)
SMT Processing Repairs (Tools: soldering stations and hot air desoldering stations, etc.) - SMT SMT Soldering Process Decolorization (Manual or Machine Cutting Boards)
SMT ProcessingProcess Simplification: Printing - Soldering - Welding - Maintenance (each process can include a quality control link).
Printing Gypsum
Its function is to carve the gypsum at a 45-degree angle onto the PCB pads with a scraper, preparing for component welding. The equipment used is a printer (gypsum printer) located at the front of the SMT production line.
Installation Parts
Its function is to accurately install surface assembly components at the fixed positions on the PCB. The equipment used is a batch machine located behind the SMT production line printer, typically utilizing high-speed and versatile machines according to production requirements.
Reflow Soldering
Its function is to melt solder paste, and securely solder surface mount components to the PCB. The equipment used is a reflow oven located behind the placement machine on the SMT line, with stringent temperature requirements that necessitate real-time temperature measurement, which is reflected through cross-sections.
AOI Optical Inspection
The function is to inspect the welding quality of PCBs. The equipment used is an Automatic Optical Inspection (AOI) system, which can be configured at the appropriate location on the production line as needed for testing. Some inspections occur before the reflow welding, while others take place after.
Repair
The purpose is to re-maintain and inspect the PCBA that has been detected with defects. Tools used include soldering irons, rework stations, etc., and are configured after AOI optical inspection.
Color Separation
This feature allows for the segmentation of multi-connection PCBAs into individual items. Typically, V-cutting and machine cutting methods are employed.
Basic Knowledge
Solder paste is a paste made by mixing solder powder with a膏body that functions as a flux. Generally, solder powder constitutes about 90%, with the remainder being chemical components.
We refer to objects that can be deformed or divided into any shape or size as fluids. The science that deals with the laws and characteristics of deformation and flow behavior caused by external forces is known as rheology. However, in engineering, the concept of viscosity is used to indicate the degree of fluid viscosity.
Welding Paste's Rheological Behavior
The solder paste contains a certain amount of thixotropic agent with plastic fluid properties. During the printing process, influenced by the force of the squeegee, the viscosity decreases, allowing it to pass through the stencil window with low viscosity, thereby successfully adhering to the pads on the PCBA. As the external force stops, the viscosity of the solder paste rapidly increases again, achieving a good printing effect without the collapse or spreading of the printed pattern. Factors affecting the viscosity of the solder paste include: solder powder content; solder powder particle size; temperature; and shear rate.
Tin Solder Powder Content
The addition of solder powder in solder paste increases its viscosity.
2. Solder Paste Particle Size
The particle size of the solder powder will increase, while the viscosity will decrease.
3. Temperature
As temperatures rise, viscosity decreases. The ideal printing environment temperature is 23±3.
Our company is a SMT贴片加工厂 and SMT贴片厂, with business scope covering SMT.SMT ProcessingSMT assembly, SMT assembly processing, PCBA, circuit board welding, wire harnesses, and more. Welcome to contact us.
