元件吃錫效果與pcblayout關(guān)系(存儲(chǔ)版)
【正文】 NDER NOTED BY MED/ STEVEN KUO 51 Drawbridge PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 52 Conveyor angle PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 53 Solder joint fail ? Residual plating chemicals ? Inplete cleaning after plating ? Surface contamination ? Surface oxidation PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 54 SOLDER BUMPING: VOIDING 1. solvents in the flux system unable to diffuse through the molten solder during reflow 2. alloy shrinkage on cooling 3. joint shape the path of escape for vapors can be difficult and lead to entrapped gases 4. improper or nonoptimized heating profile 5. plating or solder mask related issues (outgassing, inadequate cleaning, etc.) 6. type of solder paste and powder size used PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 55 印刷電路板 167。 Internal planes (Multilayer) 167。 Flux foamed low 167。 Solder wave uneven 167。 Boards pollution 167。 Temperature spike at the wave(s) 167。 SMD PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 28 good No good SCREW HOLE PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 29 不好的 layout 吃錫易不足 散熱快 good HEAT TRANSFER PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 30 測(cè)試點(diǎn) layout TEST POINT PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 31 過 Wave solder時(shí)電解質(zhì)電容容易遭熱氣上沖而 Fail 電容易被熱氣沖壞 PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 32 BGA LAYOUT: DOG BONS BETTER THAN TEAR DROP Dog bone Vs Tear drop PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 33 背板 拖錫棒 拖錫 進(jìn)板方向 PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 34 測(cè)試點(diǎn) LAYOUT 方式 TEST POINT PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 35 WAVE SOLDER PROFILE PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 36 Assembly PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 37 SMT Process Flow PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 38 SMT Process Flow PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 39 SMT Process Flow PHOTO BY QC/ WONDER NOTED BY MED/ STEVEN KUO 40 SMT Process Flow PHOTO BY QC/ WONDER
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