Walsin Passive Components for Europe: AEC-Q200, Safety Certification and High Reliability

Venatech Limited, an authorised Walsin Technology (Walsin) distributor in Hong Kong, ships
to Europe from Hong Kong. There is no European entity. What Europe buys is qualification:
AEC-Q200 automotive parts, safety-certified X1/Y1 and X1/Y2 capacitors, and high-reliability
industrial grade. Walsin’s catalogue separates those three cleanly, and the series code tells
you which one you have.

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Does Venatech have a European entity?

No. The group’s operating entities are Venatech Limited in Hong Kong, 颐威纳（深圳）国际贸易有限公司
in Shenzhen, VENATECH PTE LTD in Singapore and the Jiangmen factory in Guangdong, with Chengdu
in preparation. Hong Kong is the authorised distribution entity and the shipping origin for a
European ship-to.

It is worth being direct about that, because the question a European buyer is really asking is
not “where is your warehouse” but “can you evidence the chain of custody”. That is answerable
without a local entity. Sourcing is authorised-only, direct from the manufacturer, with no
grey market or unauthorised channels. Parts arrive in original manufacturer packaging, sealed
and unbroken, with full lot and date code traceability and a Certificate of Conformity
available on request.

Which Walsin MLCC series are AEC-Q200 qualified?

Two, by series name. The MT series is “Automotive Caps Qualified to AEC-Q200” with 2,176 part
numbers in Walsin’s 24,026-row parametric extract. The ST series is “Automotive Soft term Caps
Qualified to AEC-Q200” with 118. Together that is 2,294 AEC-Q200 designated MLCC part numbers,
9.5% of the MLCC catalogue.

The ST series exists because soft termination and automotive qualification are separate
requirements that sometimes both apply. ST is a conductive-polymer termination qualified to
AEC-Q200 and tested to a 5 mm board bend, which is what a module facing depanelling stress
needs. It is thin on coverage: 118 parts spread across eight case sizes, with 34 at 0603 and
27 at 1206.

The third automotive series is the trap. The MG series carries 788 part numbers and Walsin’s
own series name is “Automotive Caps Without AEC-Q200 Certification”. It is built for
automotive-adjacent reliability. It is not AEC-Q200 certified, and if a European tier-one’s
requirement names AEC-Q200, MG does not satisfy it.

How do I tell an AEC-Q200 part from one that only looks automotive?

By the series prefix, not the case size or the specification. MT and ST are qualified. MG is
not. The two-letter prefix at the front of the part number is the whole answer, and the
specifications can otherwise be identical.

Field	MT18B104K500	MG18B104K500	ST18B473K500	Match / mismatch
Series	MT, AEC-Q200 qualified	MG, without AEC-Q200	ST, AEC-Q200 + soft term	Mismatch — MG is not qualified
Case size	0603	0603	0603	Match — all three
Dielectric	X7R	X7R	X7R	Match — all three
Capacitance	100 nF	100 nF	47 nF	Mismatch — ST part is a different value
Rated voltage	50 Vdc	50 Vdc	50 Vdc	Match — all three
Length	1.60 +0.15/−0.10 mm	1.60 +0.15/−0.10 mm	1.60 ±0.30 mm	Mismatch — ST tolerance is 3× wider
Thickness	0.80 +0.15/−0.10 mm	0.80 +0.15/−0.10 mm	0.80 ±0.30 mm	Mismatch — ST tolerance is 3× wider
Termination	standard	standard	conductive polymer	Mismatch — different termination system
Tolerance as exported	+-10%	-0.1	+-10%	Mismatch — MG uses a different notation

Note the last row, because it breaks tooling.

Unique to Venatech’s data. 656 of the 788 MG-series rows in Walsin’s MLCC export write
the capacitance tolerance as a bare negative decimal — -0.1 for ±10%, -0.05 for ±5%,
-0.2 for ±20%, -0.01 for ±1% and -0.02 for ±2% — while the MT series writes +-10%
and +-5%. The notation appears on no other series in the 24,026-row extract. A string or
numeric filter on tolerance silently separates the two automotive series that a European
qualification engineer is most likely to be comparing side by side.

Which Walsin parts carry safety certification for mains-connected equipment?

Two families, and they are not interchangeable. In MLCC, the S2 series is safety certificated
X1/Y2 with 173 part numbers at 5,000 or 6,000 Vdc. In leaded disc capacitors, the AH series is
X1/Y1, the AC series is X1/Y2 and the AS series is X1/Y1 at a higher working voltage.

Family	Part	Class and rating	Parts in extract	Match / mismatch for a 230 V line-to-earth net
MLCC S2	S242B102K502	X1/Y2, 5,000 Vdc, 1808, X7R 1000 pF	173	Mismatch — Y2, not permitted where Y1 is specified
MLCC S2	S252B222K502	X1/Y2, 5,000 Vdc, 2211, X7R 2200 pF	173	Mismatch — Y2 class, larger case
Disc AH	YP0AH101K060	X1-400 Vac / Y1-250 Vac, 100 pF	166	Match — Y1 class, but check the Y1 voltage
Disc AH 500 V	SL5AH100J060	X1-500 Vac / Y1-500 Vac, 1500 Vdc, 10 pF	166	Match — highest Y1 rating in the family
Disc AC	YP0AC101K060	X1-440 Vac / Y2-250 Vac, 100 pF	186	Mismatch — Y2 class
Disc AC auto	YP7AC101K060	X1-440 Vac / Y2-300 Vac, 1500 Vdc	186	Mismatch — Y2 class, automotive variant
Disc AS	YP0AS101K070	X1-760 Vac / Y1-500 Vac, 100 pF	15	Match — highest X1 rating, only 15 parts

Walsin’s disc capacitor breakdown across the 929-row export is 166 AH parts in X1/Y1, 186 AC
parts in X1/Y2 and 15 AS parts in X1/Y1 at 760 Vac. The AS family is the narrowest and the
highest rated. If a design needs X1 above 500 Vac, those 15 parts are the whole selection.

Unique to Venatech’s data. Walsin publishes a separate datasheet for an AEC-Q200
automotive variant of the S2 safety series, WTC_MLCC_Safety_Auto_AECQ200_S2_H.pdf. The
parametric export returns one undifferentiated S2 series of 173 parts across four part number
stems — S242, S243, S252 and S255 — with no H variant anywhere in the data. An automotive
safety capacitor selection cannot be made from Walsin’s search tool; it has to be made from
the datasheet and confirmed in writing.

Note also that the disc capacitor export declares T.C., Lead Spacing, Packing, SPQ and
MOQ as columns and leaves all five empty on all 929 rows. Body diameter, thickness and lead
pitch are absent too. For a European creepage and clearance calculation those dimensions are
mandatory, and they exist only in the datasheet drawing tables.

What varistor do I need for a 230 V European mains input?

A 275 Vac maximum continuous working voltage part, which in Walsin’s range means a 430 Vdc
varistor voltage. Seventeen part numbers sit at 275 Vac, spread across the D, E, V and Industrial
series. The choice among them is disc diameter and surge energy, not voltage, and all seventeen
share the same 430 Vdc rating.

Part	Series	Size	Varistor voltage	Peak current	Match / mismatch for a 230 V input stage
SR431K07D	Standard (D)	7 mm	430 Vdc ±10%	1,200 A	Mismatch — too small for an exposed mains input
SR431K14D	Standard (D)	14 mm	430 Vdc ±10%	4,500 A	Match — common choice for a Class II input
SR431K20D	Standard (D)	20 mm	430 Vdc ±10%	6,500 A	Match — headroom for a longer line run
SR431K14E	Super High Energy (V)	14 mm	430 Vdc ±10%	8,000 A	Match — 1.8× the surge of the 14 mm D part
SR431K34R	Industrial	34 mm square	430 Vdc ±10%	40,000 A	Match — industrial and energy storage duty
SR431K34RD	Industrial	34 mm square	430 Vdc ±10%	80,000 A	Match — same footprint, double the surge
SR431K53D	Industrial	53 mm	430 Vdc ±10%	70,000 A	Mismatch — lower surge than the 34RD at more volume

The 34 mm square pair is the one to watch. SR431K34R and SR431K34RD share a footprint and
a varistor voltage and differ by a factor of two in peak current. Walsin’s part number
distinguishes them only by a trailing D. Any script that splits the MOV range on the last
character will misfile them.

How much of Walsin’s chip resistor catalogue is automotive grade?

Close to half. Walsin designates 102,995 of its 234,815 chip resistor part numbers as automotive
series, which is 43.9% of the line. The designation runs across every major series group rather
than sitting in one dedicated automotive family, so an automotive-grade counterpart usually
exists for whatever function the general purpose part was doing.

The split by series group is 50,891 general purpose, 15,099 high power, 12,675 high precision,
8,840 anti-surge, 8,305 high voltage, 5,381 low-ohm current sense, 1,386 arrays and 418 metal
low-ohm current sense. For a European industrial or automotive selection that breadth matters:
the automotive grade is not a small corner of the catalogue you have to design around.

Two further constraints apply to the whole chip resistor line and are worth knowing before a
European BOM is loaded. 39,576 of the 234,815 part numbers contain an embedded space and
cannot be pasted into a BOM or a search box as written. And 1.5 W and 1/5 W parts — 3,615 of
them — are missing from Walsin’s own public filter dropdown, so they are invisible to anyone
selecting through the website.

What does authorised sourcing give a European buyer that a broker cannot?

Documentary continuity. Authorised-only supply means the part came from the manufacturer
through a named distribution agreement, arrived in original sealed manufacturer packaging, and
carries full lot and date code traceability with a Certificate of Conformity available on
request. A broker can supply the part; it cannot supply that chain.

For a European buyer this is not an abstraction. A safety-certified capacitor or an AEC-Q200
part whose provenance cannot be evidenced is a part that fails an audit regardless of whether
it works. Venatech’s authorised line card covers seven brands, with Walsin as the core
strategic partner alongside KAMAYA, INPAQ, STACKPOLE, VIKING, TA-I and GOODWORK.

What delivery terms work for a European ship-to?

DDP, DAP and EXW, arranged to suit the customer’s terms and destination. The Hong Kong entity
handles offshore trade and foreign currency settlement, so the invoicing currency is a separate
question from the delivery term and should be raised at quotation rather than assumed. Ask for
all three terms quoted and compare them against your own import handling.

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FAQ

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Next step

If a European build needs AEC-Q200 or safety certification evidenced rather than asserted, the
series prefix is where it starts. Send the BOM lines and Venatech Limited, an authorised Walsin
distributor in Hong Kong, will return the series designation, whether it is AEC-Q200 or
explicitly not, the safety class where one applies, and what documentation accompanies it.

Send your BOM to Venatech · Browse the
Walsin disc and safety capacitor range · Read
AEC-Q200 MLCC: MT vs MG series and
Disc capacitor safety classes: AH, AC and AS.

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Cross it yourself. The cross-reference tool takes a single part number or a whole BOM column and returns the Walsin candidates with every field that differs stated plainly — qualification stays with you. Ready stock shows what is held in Hong Kong today, with an RFQ against any line.