# OSAT Supplier Qualification Assessment for Fabless and IDM Teams > Source: https://netray.co/tools/osat-supplier-qualification-assessment > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Ten-question assessment that scores an OSAT on quality, process control, traceability, capacity and continuity. ## Category quality ## Industry Semiconductors ## Audience - Supplier quality engineer - Procurement - Operations manager ## Tool **Kind:** assessment **Questions:** #### What quality system certifications and customer audits does the OSAT hold? **Help:** Examples: ISO 9001, IATF 16949 for automotive, AS9100 for aerospace, ISO 13485 for medical. **Options:** ##### None or unclear **Score:** 0 ##### ISO 9001 only **Score:** 2 ##### ISO 9001 plus sector standard for our market **Score:** 3 ##### Sector standard plus our own on-site audit passed **Score:** 4 #### How does the OSAT control key assembly processes (wire bond, die attach, mold, plating)? **Options:** ##### Operator checks only **Score:** 0 ##### Periodic checks with records **Score:** 2 ##### SPC on key parameters with defined limits **Score:** 3 ##### SPC with out of control action plans reviewed with us **Score:** 4 #### How good is lot traceability from wafer to finished unit? **Options:** ##### Lot level only, paper based **Score:** 0 ##### Lot level, electronic **Score:** 2 ##### Includes wafer and die location on request **Score:** 3 ##### Full unit level genealogy with materials, tools and dates **Score:** 4 #### How does the OSAT handle test, including program control and correlation? **Options:** ##### No formal test program control **Score:** 0 ##### Version controlled programs **Score:** 2 ##### Version control plus periodic golden unit correlation **Score:** 3 ##### Golden unit correlation, guard bands and gauge studies reviewed with us **Score:** 4 #### How mature is the OSAT's change control and notification process? **Options:** ##### Changes are made without notice **Score:** 0 ##### Major changes notified **Score:** 2 ##### Documented notification with agreed lead time **Score:** 3 ##### Formal change approval with requalification data supplied **Score:** 4 #### How are failure analysis and corrective actions managed? **Options:** ##### Ad hoc **Score:** 0 ##### Corrective actions on request **Score:** 2 ##### 8D or equivalent with defined response times **Score:** 3 ##### 8D with in-house failure analysis capability and trend reviews **Score:** 4 #### Is capacity committed and visible? **Options:** ##### No commitment **Score:** 0 ##### Verbal forecast sharing **Score:** 2 ##### Written capacity agreement for our volume **Score:** 3 ##### Capacity agreement plus regular utilization and WIP reporting **Score:** 4 #### How is ESD, contamination and moisture sensitivity handled on the line? **Options:** ##### No formal programs **Score:** 0 ##### Basic ESD controls **Score:** 2 ##### ESD program audited plus moisture sensitive part handling **Score:** 3 ##### Audited ESD, contamination and MSL programs with records we can review **Score:** 4 #### What supply chain and continuity risks have been assessed? **Help:** Consider substrate, lead frame, mold compound and single-site dependency. **Options:** ##### None assessed **Score:** 0 ##### Known risks, no plan **Score:** 2 ##### Documented plan for key materials and site risks **Score:** 3 ##### Tested continuity plan with second source or second site options **Score:** 4 #### How well does the commercial and data relationship support you? **Options:** ##### Limited data sharing **Score:** 0 ##### Monthly reports **Score:** 2 ##### Lot data and yield shared per lot **Score:** 3 ##### Electronic data exchange with lot status and test data feeds **Score:** 4 **Bands:** #### High risk **Min:** 0 **Max:** 35 **Verdict:** The OSAT shows large gaps and should not be used for production without major improvements. **Recommendations:** - Run an on-site audit before committing volume - Require a corrective action plan for traceability and change control - Keep a second source qualified in parallel #### Conditional **Min:** 36 **Max:** 60 **Verdict:** The OSAT can support limited or lower risk products with active oversight. **Recommendations:** - Agree on SPC and out of control action plans for the key processes - Define change notification lead times in the quality agreement - Schedule quarterly business and quality reviews #### Qualified with watch items **Min:** 61 **Max:** 85 **Verdict:** The OSAT is solid. Close the remaining gaps through the quality agreement and routine audits. **Recommendations:** - Close the lowest scoring areas within two quarters - Add data feeds for lot status and test results - Review continuity plans yearly #### Strongly qualified **Min:** 86 **Max:** 100 **Verdict:** The OSAT shows mature controls. Maintain the relationship with regular audits and data reviews. **Recommendations:** - Keep annual on-site audits - Track yield and quality trends against targets - Share forecast and roadmap early ## Content **Intro:** Choosing or re-evaluating an outsourced assembly and test (OSAT) partner means looking past price and capacity. This ten-question assessment scores the controls that most often decide whether a subcontractor protects your yield, traceability and delivery. **Sections:** #### How to use the assessment **Body:** Answer each question based on evidence from audits, quality agreements, shared data and past performance, not on sales presentations. Run it per OSAT site, since a company with several factories can differ widely between them. The score places the supplier in one of four bands and returns suggested actions you can place in the quality agreement. **Bullets:** - Use audit findings and records as evidence - Assess each site separately - Reassess after major changes or incidents #### What the questions test **Body:** The questions cover quality system maturity, process control, traceability, test control, change management, corrective action, capacity commitment, ESD and moisture handling, continuity and data exchange. These are the areas where subcontracted semiconductor operations most commonly fail customers, for instance through undetected process drift or unannounced changes to materials. #### How to read the score **Body:** The score is a percentage of the maximum, and the bands guide the level of oversight. A high score with a low result on traceability still deserves action, because a single weak area can dominate a field return investigation. Look at the lowest answers, not only the total. #### Common mistakes **Body:** Do not rely on a certificate alone, since it shows a system exists, not that it works for your product. Do not skip the quality agreement, which is where change notification and data sharing obligations belong. Avoid single-site dependency without a documented fallback. **Cta:** If you want OSAT lot status, yield and delivery data flowing into your ERP automatically, Netray can help design that integration with your team. **Faq:** #### Is this a replacement for an on-site audit? **Answer:** No. It structures the evidence you collect and highlights gaps. Critical or automotive, medical and defense products usually require an on-site audit as well. #### What does OSAT stand for? **Answer:** Outsourced semiconductor assembly and test. These companies package wafers into finished devices and test them for fabless companies and integrated device manufacturers. #### How often should an OSAT be reassessed? **Answer:** At least annually for critical suppliers, and after any significant change such as a site move, ownership change, process change or quality escape. #### Which score is good enough? **Answer:** It depends on product risk. Consumer parts may tolerate the conditional band with oversight, while safety critical parts should aim for the upper bands plus an on-site audit. ## Search terms osat supplier audit checklist, osat qualification, outsourced semiconductor assembly and test evaluation, assembly subcontractor assessment, choose an osat, semiconductor supplier audit, osat risk assessment --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json