SMT processing in the processing quality of many factors, the quality of solder paste printing is one of them, today's SMT processing manufactory in the stencil printing machine is mainly used in automatic solder paste printing machine to complete. Here is a brief introduction to some common solder paste printing points.
I. The squeegee angle
Squeegee angle is smaller, the force applied to the solder paste downward is also larger, but also less easy to scrape the stencil surface of the solder paste. If the angle is too large, the filling effect of solder paste will also be poor.
Recommended scraper angle of 45 ° ~ 75 ° (generally fixed at 60 ° or so fully automatic machine).
II. Scraper speed
SMT patch processing solder paste printing squeegee speed on the solder paste graphic impact is complex. In general, the speed of 100mm / s before the filling time plays a dominant role. after 100mm / s, solder paste viscosity plays a dominant role. However, one thing is common, that is, the speed is too fast (higher than 180mm/s) or too slow (lower than 20mm/s), are not conducive to the filling of solder paste.
Recommended range of squeegee speed
The installation of ordinary pitch components of the board: 140 ~ 160mm / s
The installation of fine pitch components of the board: 25 ~ 60mm / s
III. Squeegee pressure
Squeegee pressure is also an important parameter in the process of SMT processing solder paste printing, in order to meet the bottom of the stencil and PCB gapless contact, the surface of the solder paste scraped clean under the premise that the solder paste can be fully filled and can be scraped clean under the circumstances of the squeegee pressure the smaller the better, too much pressure may lead to the middle of the large-size pad graphics are dug. Squeegee pressure is generally in accordance with the initial setting of 0.5kg / 1 "and then adjusted according to the graphics.
IV. The speed of descreening
In general, the speed of descreening, easy to occur at the hole wall residual solder paste, resulting in less tin or pull the tip of the phenomenon. If the speed is too fast, it may also cause the stencil to rebound.
Features of NeoDen ND1 Full Automatic Stencil Printer
PCB parameters
Max. plate size (X x Y): 450mm x 350mm
Minimum plate size (Y x X): 50mm x 50mm
PCB thickness: 0.6mm ~ 14mm
Warping quantity Max. PCB diagonal: 1%
Max. plate weight: 10KG
Plate edge clearance Configuration to: 3mm
Maximum bottom clearance: 20mm
Transmission speed: 1500mm /second(Max)
Transfer height from the ground: 900 ±40mm
Equipment
Power AC: 220V ± 10%, 50/ 60HZ, 15A
Compressed air: 4 ~ 5KG /cm2, 10.0 diameter pipe
Operating system: Windows XP
Exterior size: L (1140mm) x W (1400mm) x H (1480mm)
Machine weight: 1000KG