Through Lead Component Boards Labels, Labels affixed to the bottom surface of the PCB are usually exposed to solder waves in the temperature range of 450°F to 510°F (232°C to 266°C). Generally solder temperatures as high as 550°F (288°C) are used. The solder contact time is 2 to 6 seconds. The conveyor speed is 4 feet per minute, the welding zone is 3 inches, and the contact time is 3.8 seconds.
Through Lead Component Boards Labels
Mibils automatic labeling video of PCB stickers
Application of PCB Labels:
Labels affixed to the top surface of the board may experience very different temperatures, depending on whether they are placed near the through holes. In order to obtain the most accurate worst-case data of the highest temperature encountered on the top surface, the label was adhered to a 1.5 mm thick epoxy-coated circuit board that had a solder contact time of 10 seconds. Measurements have shown that the top surface temperature is lower than 350°F (177°C) in areas without through holes. The temperature near the via is much higher.
Since the top surface temperature varies greatly, a safe method is to choose label materials that can withstand the soldering temperature. Another method is to dedicate the through-hole-free area of each board to labels. In the latter case, it is best to measure the top surface temperature for each board thickness and material to ensure sufficient.
For the common surface mount technology method, the solder paste containing flux and solder powder is screen printed or stencil printed on the precise point of the circuit board where the component terminals will be placed. Place the component in the solder paste. The printed circuit board is then heated, the flux is activated, the solder is melted, and the components are bonded to the board. Depending on the solder alloy, different temperatures and times are required.
When the label is on the bottom or edge of the board, the label is sometimes directly exposed to the flux. They are usually exposed to degreasing liquids.
The purpose of the flux is to eliminate and prevent the formation of oxides and promote wetting so as to completely cover the copper. Harmful side effects may leave harmful contaminants on the board. For some types, including OA, RA and RSA, complete removal is essential. Otherwise, ionic contaminants will cause humidity-sensitive leakage current and long-term corrosion.
Common degreasing methods are washing and steam degreasing in detergent water at 150°F to 170°F (66°C to 77°C). Trichloroethane is rarely used. During military circuit board rework, methyl ethyl Keytone is usually used to remove the conformal coating.
Multifunctional label materials must be able to withstand multiple fluxes and desolvents, and avoid absorbing or trapping them. The laminate must be tightly bonded to the underlying layer during use to prevent flux or other liquids from penetrating between the layers. The adhesive must be solvent resistant and viscous enough to closely fit uneven contours, such as printed wires.
Yellow backing color kapton film labels with heat proof adhesive
Heatproof, anti-corrosion and good stickiness high temperature resistant PCBA labels
Mibils Precision, founded in 2002, is a professional through lead component boards labels supplier in China, offering you the customized service. Welcome to buy the high quality label with competitive price from us.