Products

SIPAD LF

SIPAD LF is our lead free version of the SIPAD solid solder deposit. This product is excellent for the transition from leaded to lead free products. Like regular SIPAD boards, SIPAD LF boards come out of the box ready to place parts without stencil printing.

Lead free HASL finish is preferred for SIPAD LF processing. Lead free HASL has proven to be flat and durable.
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Lead free HASL finish can withstand multiple heat cycles.
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SIPAD LF uses a SAC 305 solder paste blend unless otherwise specified. Any lead free paste blend can be used as long as it is a water soluble version.
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SIPAD LF paste is printed 1:1 with the surface mount pads for maximum coverage.
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Lead free solder paste does not always spread like 63/37 eutectic so it is important to balance the stencil design to accommodate that.
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Surface mount designs using soldermask defined pads can experience spread and volume issues when the stencil openings are cut to the data sheet instead of the solder mask size. Lead free stencils should be cut 1:1 to the copper for non solder mask defined pads, and 1:1 to the solder mask for solder mask defined pads.
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Lead free surface finishes

Lead free surface finishes come in a lot of forms. Below are some of them and some comments bases on SIPAD Systems experiences.

Gold is a preferred lead free finish. Properly applied, gold prints and flows well, while withstanding multiple heat cycles.
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Immersion tin is a commong lead free finish. If properly applied, immersion tin works but in our experience the immersion tin finish can be difficult to handle and process. Mutiple heat cycles and moisture are not recommended for immersion tin and the SIPAD ssd process uses both.
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Lead Free Hot Air Solder Leveling (HASL) is a SSi preferred lead free finish. Lead free HASL is flat and does not exhibit any adverse reactions to multiple heat cycles or moisture.
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Make sure to check out the SIPAD Soldermask Requirements to learn more about the design and application of SIPAD boards.