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Recently WorkingBear got complaint from R&D and ask increase the solder paste volume on the MLCC (Multi-Layer Ceramic Capacitor) component pads to improve the capacitor broken issue. R&D said he had verified that the capacitor’s footprint in the board design is correct and followed manufacturer’s design guidelines. However, looks like there is not enough solder paste to form proper heel fillet on the terminal of capacitor. This insufficient solder paste volume make the solder cracking?
《舊文複習》一般來說BGA焊接同時會有空焊(insufficient solder)及短路(solder short)的情形並不多，但也不是全無可能，就像第53期的「電路板會刊」，就刊出由於BGA載板及電路板由於熱縮率(CTE)差距過大，造成BGA載板的板邊上翹，形成了類似笑臉的曲線(simile up)，而電路板則因為TAL(Time Above Liquidus)過長，與迴焊爐的上下爐溫溫差過大，兩相交互作用下形成電路板板邊下彎，造成了所謂的哭臉曲線(cry down)。
《How to use SMT Line to produce a printed circuit board? (8)》
The Touch-up phase happens when some of the PCB parts cannot be soldered correctly during the SMT assembling process. The touch-up is usually performed after the AOI system and visual inspection process. Normally the touch-up operator will use the microscope to verify component's position, and manually check SMT parts before soldering. Then the touch-up operator will using the method to manually assemble the components and perform post re-flow inspection method. They are using iron and solder wire to improve the problem such as not enough solder, insufficient solder. By using the touch-up method, they have to maintain a high temperature to melting the solder wire. After that, the components will cool and be welded on the circuit board.
A processing fault before soldering (adhesive on the pad) caused a solder joint with insufficient solder. The solder joint has be to cleaned of the adhesive and ... ... <看更多>
Another common cause of insufficient solder is poor design. It can happen when the pads are too small or too close together. It can also occur when the traces ... ... <看更多>
insufficient solder 在 電路板上常見的焊錫缺點中英文對照與解釋| 電子製造 - 工作狂人 的相關結果
錫少：Solder insufficient，錫量不足，可能影響焊接強度。 錫鬚：Whisker，錫鬚在無鉛製程特別受到重視，因為它比有鉛製程時容易生成，尤其是純錫的製程。 ... <看更多>