Last Friday at 3 PM,a client named Lao Zhang from a servo motor company called me in a panic: "Our production line has shut down.The newly installed Fujitsu IGBT modules just exploded!" I asked him to send me a photo,and I immediately recognized it as a typical "refurbished part" — the pins were severely oxidized,and there were micro-burrs around the logo.To save 10% on costs,Lao Zhang opted for unofficial channels,but this batch of goods not only failed to solve the problem but also burned out the surrounding driver boards,resulting in losses ten times greater than the cost savings.In high-end power device procurement,this "save a little money,lose a lot" scenario plays out every day.

Why has "genuine imported products" become a major problem area?

As a leading player in the IGBT field,Fujitsu Electric’s series such as 7MBR and 2MBI are considered industry standards in the industrial control sector.However,the company’s production capacity has been constrained for years,resulting in a large number of "unofficial products" circulating in the market.Many purchasers mistakenly believe that products shipped from Japan are genuine,but overlook the complexity of the intermediary process.To address this issue,it is first necessary to understand the underlying differences in the logistics of different channels.

Build a high-reliability IGBT procurement SOP

Don’t try to use "luck" to fight against probability.You must establish standard operating procedures (SOPs).Here’s the procurement process I’ve reorganized for enterprises like Lao Zhang’s.This process can filter out 95% of the counterfeit goods on the market.

Step 1: Conduct a thorough review of the source’s qualifications

Output:

Don’t just look at the supplier’s business license.You should also request scanned copies of the upstream authorization chain.

• Checkthevalidityperiodoftheauthorizationletter:Ensurethattheauthorizationletteriswithinitsvalidityperiodandthattheauthorizationscopeincludesthespecificmaterialnumberyouarepurchasing(suchas2MBI100VB-120).
• OriginalFactoryBackgroundCheck:DirectlycontactthesalesortechnicalsupportofFujitsuSemiconductor(China)toverifywhetherthesupplierisontheofficialagentlist.

Step 2: Microscopic inspection of the physical appearance of the product

Output:

After receiving the goods,don’t rush to power them on.First,conduct a static visual inspection.Prepare a magnifying glass with a magnification of more than 10 times.

• ObserveFontCraftsmanship:ThelaserengravingontheoriginalFujifilmmodulesisclearandconsistentindepth.Ifit’salater-addedinkjetcode,theedgeswillhaveroughedges,andtheinkmayeasilyfadewhenwipedwithalcohol.
• CheckPinOxidation:Thepinsoftheoriginalnewpartsareshinyandhaveauniformplating.Ifthepinsareblackenedorhavesolderresidue,theymustbedisassembledpartsorrefurbishedparts.
• Batchnumberconsistency:CheckwhethertheDateCode(productiondate)onthemoduleshellmatchestheoneontheouterboxlabel.

Step 3: Compliance check of key documents

Output:

For "original imports",the documents are the key to success.

• CustomsDeclarationInspection:RequiresupplierstoprovideCheckwhetherthe"domesticconsignorandconsignee"areconsistentwiththesupplier’sname,andwhethertheproductnameis"InsulatedGateBipolarTransistorModule".
• :AnorigincertificateissuedbyJapanmustbeprovided.Thisisalegaldocumentthatprovestheproductis"genuine".

The overlooked trap of "batch consistency"

Many purchasing managers only focus on whether the products they purchase are genuine,but they overlook the risk of "batch mixing".This is an invisible killer that is rarely mentioned by those outside the industry.There are minor generational differences in the manufacturing process of IGBT modules.For modules from different production batches (Lot No.),their Vce(sat) (saturation voltage drop) and switching characteristic parameters may have slight deviations within the tolerance range.

If you mix modules of different batches in a parallel circuit,even if they are all genuine products,it may still lead to problems.Dynamic load sharing and imbalanceWhen operating at full capacity,the module with "soft bias" parameters will suffer from excessive current,leading to heat accumulation and premature failure.Therefore,in the technical agreement,it is mandatory to require suppliers to provideThe same production batchThe products,which are particularly important in the repair and replacement market.

Immediate Action List

After reading this article,we recommend that you implement the following three actions this afternoon to plug the loopholes in your supply chain:

• StockInventory:GotothewarehouseandrandomlyselectthreeFujitsuIGBTmodules.Useamagnifyingglasstocheckthepinsandengravingstoconfirmwhetherthereareanyrefurbishedpartsmixedin.
• Interviewwiththesupplier:ContactyourcurrentIGBTsupplierandrequestthemtoprovidethecustomsdeclarationformandthecertificateoforiginfortheirmostrecentimporttransaction.
• Updatethepurchasecard:InthematerialprocurementcardoftheERPsystem,addamandatoryvalidationfieldfor"batchconsistency"topreventmoduleswithdifferentDateCodesfrombeingmixedinthesameBOM.