声音刺耳
发表于 2025-3-28 16:09:34
PCB Laminates,rgets and long term product reliability requirements. The SAC305 tin-silvercopper alloy (3.0 percent silver and 0.5 percent copper) recommended for lead-free assembly reflow processing and rework has a melting point about 40°C higher than the melting point of eutectic tin-lead.
confederacy
发表于 2025-3-28 21:33:44
Lead-Free Board Surface Finishes,een the external board circuitry and the bonding medium (i.e. solder). The use of lead-free solders requires higher assembly temperatures and places increased demands on the surface finish if it is to survive multiple reflow cycles. In PWB fabrication, the surface finish can serve several interrelated functions, including:
Infinitesimal
发表于 2025-3-28 23:05:45
Lead-Free Solder Joint Reliability,riety of lead-free solders such as SnAgCu, SnAg, SnAgBi, SnBi, SnCu, SnZn alloys of near-eutectic or other compositions, some with known additive elements (e.g., nickel, cobalt, germanium) and others with proprietary compositions.
粗野
发表于 2025-3-29 05:24:51
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溃烂
发表于 2025-3-29 11:13:50
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乳白光
发表于 2025-3-29 14:56:34
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AGATE
发表于 2025-3-29 16:20:34
antly exposed to storms, flooding, earthquakes and volcanic activity, but overall risk is exacerbated by vulnerability due to under development. As in many developing countries, disaster management historically focused on response and recovery with the military and national police as central actors.