SOT23 crack during solder reflow

After reflow proces in convection-IR oven we find broken body of SOT23 elements. There is no problems on other elements (SOIC, chip R,chip C, etc) Where is the problem?

Thanks in advance!

reply »

| After reflow proces in convection-IR oven we find broken body of SOT23 elements. There is no problems on other elements (SOIC, chip R,chip C, etc) | Where is the problem? | | Thanks in advance! | Check your profile at the site of cracked components. Could be your delta T (rate of rise) exceeds the rating for these parts. Don't forget the cooling delta T as well. If your oven is primarily or pure IR, differing absorbtion rates could be overstressing these components. Problems in a convection oven (or perhaps an inferior unit) can also produce localized hot spots. If it is only one component type and/or production lot, get a different one to try. Could your placement machine be cracking them slightly with too high a placement force? Has this always happened or did it just start. If it just started - what changed? good luck |

reply »