# Solder Joint Defect Log with DPMO > Source: https://netray.co/tools/solder-joint-defect-log-and-dpmo-worksheet > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Log solder defects by board, reference designator and type, with opportunities per board and DPMO calculated per entry and overall. ## Category quality ## Industry Defense Electronics ## Audience - Quality engineer - Process engineer - Production supervisor ## Tool **Kind:** worksheet **Mode:** editable **Columns:** #### Date **Key:** date **Type:** date #### Board / lot **Key:** board **Type:** text #### Ref des **Key:** refdes **Type:** text #### Defect type **Key:** defect **Type:** select **Options:** - Insufficient solder - Excess solder - Bridge - Solder ball - Cold joint - Tombstone - Non-wetting - Void - Lifted lead - Missing part - Wrong part - Other #### Suspected cause **Key:** cause **Type:** select **Options:** - Paste print - Placement - Reflow profile - Wave / selective - Hand solder - Component - PCB - Unknown #### Boards inspected **Key:** boards **Type:** number #### Opportunities per board **Key:** opps **Type:** number #### Defects found **Key:** defects **Type:** number #### Total opportunities **Key:** total_opps **Type:** number **Expr:** boards * opps **Format:** integer #### DPMO **Key:** dpmo **Type:** number **Expr:** defects / (boards * opps) * 1000000 **Format:** integer **Rows:** #### Paste print **Date:** 2026-10-12 **Board:** LOT-4417 **Refdes:** U7 **Defect:** Bridge **Boards:** 40 **Opps:** 1850 **Defects:** 6 #### Placement **Date:** 2026-10-13 **Board:** LOT-4417 **Refdes:** C112 **Defect:** Tombstone **Boards:** 40 **Opps:** 1850 **Defects:** 3 #### Wave / selective **Date:** 2026-10-14 **Board:** LOT-4421 **Refdes:** J3 **Defect:** Insufficient solder **Boards:** 36 **Opps:** 1850 **Defects:** 4 #### Reflow profile **Date:** 2026-10-15 **Board:** LOT-4421 **Refdes:** U12 **Defect:** Void **Boards:** 36 **Opps:** 1850 **Defects:** 2 #### Paste print **Date:** 2026-10-16 **Board:** LOT-4425 **Refdes:** R45 **Defect:** Solder ball **Boards:** 52 **Opps:** 1850 **Defects:** 5 #### Component **Date:** 2026-10-17 **Board:** LOT-4425 **Refdes:** U3 **Defect:** Non-wetting **Boards:** 52 **Opps:** 1850 **Defects:** 1 **Totals:** #### Total defects **Key:** defects **Agg:** sum **Format:** integer #### Total boards inspected **Key:** boards **Agg:** sum **Format:** integer **Summary:** #### Overall DPMO **Key:** overall_dpmo **Expr:** sum_defects / sum_total_opps * 1000000 **Format:** integer **Primary:** true **Notes:** Opportunities per board is usually the count of solder joints plus placements, as agreed with your customer or your own method. Keep the counting method constant so DPMO trends are comparable. Enter one row per inspection batch and defect type. ## Content **Intro:** A defect log is only useful if you can turn it into a rate. This worksheet captures each solder defect with its cause and computes DPMO, defects per million opportunities, so you can compare lots, lines and shifts on one scale. **Sections:** #### How to use the log **Body:** Add a row for each batch and defect type found. Enter boards inspected, opportunities per board and defects counted, and the sheet calculates total opportunities and DPMO for that row. The summary shows overall DPMO across the log. Export to Excel and sort by defect type to build a Pareto for your next quality review. #### The DPMO formula **Body:** DPMO equals defects divided by total opportunities, multiplied by one million. Total opportunities is boards inspected times opportunities per board. In the sample data, forty boards with 1,850 opportunities each give 74,000 opportunities; six defects therefore equal about 81 DPMO. Overall DPMO uses summed defects over summed opportunities, not an average of row values. **Bullets:** - Do not average row DPMO values, compute from sums - Define opportunities the same way every time - Count each defect once, per its location #### Using the data **Body:** Group defects by cause to see where to act. A cluster of bridges and solder balls tied to paste print points to stencil, squeegee or printer settings. Tombstones suggest pad design, placement offset or reflow ramp. Voids call for profile, paste and board finish checks. Record the corrective action against the lot so you can see whether the rate moves. #### Common mistakes **Body:** Teams change how they count opportunities between months and then wonder why DPMO moved. Others log only rejects and skip process indicators, losing early trend data. Another is mixing defects found by AOI with defects confirmed by a human, which inflates the count with false calls. **Cta:** Netray can pull inspection results from your MES or ERP quality module into this view automatically so DPMO updates itself each shift. **Faq:** #### What is a good DPMO for PCB assembly? **Answer:** It depends on how opportunities are counted and the complexity of the product. Many shops track their own trend and aim for steady reduction. Compare only against figures that use the same counting method. #### How do I count opportunities per board? **Answer:** A common method counts every solder joint, plus a placement for each component. Some customers specify their own method. Pick one, document it and keep it fixed so results are comparable over time. #### Should AOI false calls be counted? **Answer:** No. Count confirmed defects only, and track false call rate separately. Mixing them overstates defects and hides the true process capability. #### Can I log defects found in test or at the customer? **Answer:** Yes, but keep a column or separate log for detection point. Defects found later cost more, and the escape rate between inspection and test is itself a useful measure. ## Search terms solder defect log, dpmo calculator pcb assembly, defects per million opportunities electronics, solder defect tracking excel, smt defect log template, pcb inspection log, solder joint defect types, aoi defect log --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json