Replacing an MLCC Without Redesigning the Board: the Method, for a United Kingdom Buyer

12,299 of the 13,193 Walsin MLCC part numbers outside the automotive and soft-termination families sit in a dielectric, capacitance and voltage combination that Walsin offers at more than one case size. So a United Kingdom buyer replacing an MLCC usually has room to move without touching the layout. This post is the method, measured on the real ladder.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, works from Walsin Technology (Walsin) 24,026-row MLCC parametric export and 26 MLCC datasheet PDFs. The counts here cover the six series in that export outside the automotive and soft-termination families: General Purpose, Middle & High Voltage, large sizes, ultra-small 01R5, high temperature HT and low profile TT — 13,193 distinct part numbers. Every part number quoted is real.

Can you tell me whether my incumbent MLCC is going away?

No, and we will not guess. Venatech holds no manufacturer’s affected-part list, so we cannot and will not tell you that any specific competitor part number is discontinued, obsolete or end-of-life. That statement belongs to the manufacturer who made the part, in writing, with a reference number on it.

What we can do is the engineering half. Give us the part number and the specification it has to meet, and we will return Walsin candidates field by field. We will not tell you a part is equivalent. We will show you where it differs. Competitor families are discussed at series level only, and we reproduce no competitor’s specifications — the incumbent column stays yours to fill from your own datasheet.

What has to match before a replacement MLCC is a drop-in?

Five electrical fields and three mechanical ones. The electrical five are case size, dielectric, capacitance, tolerance and rated voltage. The mechanical three are length, width and thickness, each with its own published tolerance. A candidate that passes the five and fails one of the three is a layout problem, not a sourcing one.

The order matters. Fix the case size last, not first. If you start from the case size you lock yourself into one column of the catalogue before you know whether the value exists elsewhere — and most of the time it does.

How much room does Walsin’s catalogue actually give you?

More than most cross attempts use. Across those 13,193 part numbers there are 2,265 distinct combinations of dielectric, capacitance and rated voltage. Here is how many case sizes each combination is available at.

Case sizes the combination exists at	Combinations	Share of 2,265	Match / mismatch vs a same-footprint swap
1 only	646	28.5%	Mismatch — no case-size alternative exists
2	401	17.7%	Match — one alternative footprint
3	396	17.5%	Match — two alternatives
4	362	16.0%	Match — three alternatives
5	294	13.0%	Match — four alternatives
6	125	5.5%	Match — five alternatives
7	35	1.5%	Match — six alternatives
8	6	0.3%	Match — the widest ladders in the catalogue

Unique to Venatech’s data. Of the 2,265 distinct dielectric, capacitance and rated voltage combinations across the 13,193 part numbers in Walsin’s six non-automotive, non-soft-termination MLCC series, 1,619 are available at more than one case size, 1,218 at three or more, 822 at four or more and six at eight. Counting the part numbers rather than the combinations, 12,299 of 13,193 — 93.2% — sit in a value Walsin offers at more than one case size. The six widest ladders are NP0 100 pF at 630 Vdc, NP0 1,000 pF at 630 Vdc, NP0 100 pF at 50 Vdc, X7R 47 nF at 50 Vdc, X7R 10 nF at 1,000 Vdc and X7R 1,000 pF at 25 Vdc.

That is the measurement behind “you probably do not have to redesign”. It is not a promise about your line. It is the shape of the catalogue you are crossing into.

What does one real value look like across the whole case-size ladder?

Take X7R, 4,700 pF, ±10%, 500 Vdc. Walsin publishes it at five case sizes, and every one of the five carries the same nominal thickness. The decision is entirely length and width.

Part number	Case size	Length	Width	Nominal thickness	Match / mismatch vs 0805B472K501
0805B472K501	0805	2.00 ± 0.15 mm	1.25 ± 0.10 mm	1.25 ± 0.10 mm	reference
1206B472K501	1206	3.20 ± 0.15 mm	1.60 ± 0.15 mm	1.25 ± 0.10 mm	Match on all five electrical fields and on thickness · mismatch on length and width
1210B472K501	1210	3.20 ± 0.30 mm	2.50 ± 0.20 mm	1.25 ± 0.10 mm	Match electrically and on thickness · mismatch — twice the width, looser length tolerance
1808B472K501	1808	4.50 +0.50/−0.30 mm	2.03 ± 0.25 mm	1.25 ± 0.10 mm	Match electrically and on thickness · mismatch — asymmetric length tolerance
1812B472K501	1812	4.50 +0.50/−0.30 mm	3.20 ± 0.30 mm	1.25 ± 0.10 mm	Match electrically and on thickness · mismatch — largest footprint of the five
Your incumbent	—	—	—	—	fill from your own datasheet and compare

Two things to notice. First, thickness is constant across the ladder, so moving case size here does not change the height budget — which is unusual and worth checking rather than assuming. Second, the length tolerance is not constant: 0805 and 1206 are symmetric at ±0.15 mm, 1210 loosens to ±0.30 mm, and 1808 and 1812 switch to an asymmetric +0.50/−0.30 mm band. If the land pattern was drawn to a symmetric tolerance, the 1808 and 1812 options need the pad check redone even though the nominal length is published.

For how the five electrical fields map onto a Walsin code, see how to cross-reference an MLCC.

Which values have no case-size alternative at all?

646 of the 2,265 combinations — 28.5%. Those are the lines where a replacement has to keep the footprint or change the value, and they are worth identifying early because they are the ones that turn into a board revision.

The pattern is at the edges of the catalogue. The single 3,500 Vdc part number in the whole export, 1812B103K352, is one of them: X7R 10 nF at 3,500 Vdc exists at 1812 and nowhere else. At the opposite end, every one of the 317 ultra-small 01R5 part numbers carries 01R5 in the Size field and no other case size serves those values at all — 01R5N101J160 is a 100 pF NP0 part at 16 Vdc in a 0.40 × 0.20 mm body, and there is no larger sibling of it in the series.

What can go wrong if you trust the parametric export alone?

The export can disagree with the part number it is describing. We audited every part number in the six series whose three-digit capacitance code can be decoded — 13,191 of them — against the Capacitance column on the same row.

Part number	Capacitance code in the part number	Capacitance column in the export	Factor	Match / mismatch
0402X683M500	683 — 68 nF	680 nF	10×	Mismatch — column is ten times the code
0805A474K101	474 — 470 nF	1000 nF	2.1×	Mismatch — column is the 105 value, not 474
1210B154K250	154 — 150 nF	15 nF	10×	Mismatch — column is a tenth of the code
0805B472K501	472 — 4,700 pF	4700 pF	1×	Match — the normal case

Unique to Venatech’s data. Three of the 13,191 decodable part numbers in those six series carry a Capacitance column value that contradicts the capacitance code inside their own part number: 0402X683M500, 0805A474K101 and 1210B154K250. Two are out by a factor of ten and one carries the value of a different code entirely. 1210B154K250 also publishes no length, width or thickness at all. Decoded the Walsin way — two significant digits followed by a power-of-ten multiplier — and checked row by row against the column.

Three in 13,191 is a low rate. It is not zero, and a cross that keys on the capacitance column is exactly the operation that would carry the error through to a purchase order. Check the code against the column on every candidate — it takes a second and it is the cheapest check in the process. For the voltage side of the same discipline, see MLCC DC bias and voltage derating.

What does a United Kingdom buyer send us to start?

The incumbent part number and, if you have it, the five electrical fields from your own datasheet. You do not need a manufacturer notice, and we will not ask you to prove one exists. We hold no such list and make no statement about any other manufacturer’s part status.

Everything ships from Hong Kong — Venatech has no United Kingdom entity, office or stock — so tell us the incoterm you want quoted alongside the technical question. DDP, DAP and EXW are all available. The whole range is on the Walsin MLCC product page.

The short version

Fix the case size last. 93.2% of the part numbers in Walsin’s six general MLCC series sit in a value that exists at more than one case size, so the footprint is usually negotiable; the 646 combinations that exist at one size only are where a board revision starts. Thickness can be constant across a ladder and the length tolerance can still change shape, so check both. Three part numbers in 13,191 contradict their own capacitance code — check the code against the column. And we will never tell you a competitor part is going away; that notice is the manufacturer’s to issue.

Send the line and we will return the Walsin candidates at every case size the value exists at, with length, width, thickness and each published tolerance, and a blank column for your incumbent. Qualification stays with you.

Two things you can do now. Cross your part — paste one number or upload the whole line, and each result names what matches and what differs. And ready stock is a dated snapshot of what is physically in Hong Kong, so you can see which candidates are a stock pull before you choose between them.

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"Can Venatech tell me if my capacitor is discontinued?","content":"No. Venatech holds no manufacturer's affected-part list and makes no statement about any other manufacturer's part status. That notice has to come from the manufacturer who made the part, in writing. What we will do is cross the specification to real Walsin part numbers and show you, field by field, where each one differs.","visible":true},{"id":"faq-question-02","title":"How often can I change case size instead of changing value?","content":"Often. 12,299 of the 13,193 part numbers in Walsin's six non-automotive MLCC series — 93.2% — sit in a dielectric, capacitance and rated voltage combination available at more than one case size. Of the 2,265 combinations, 1,619 exist at two or more sizes and 822 at four or more.","visible":true},{"id":"faq-question-03","title":"How many Walsin MLCC values exist at only one case size?","content":"646 of the 2,265 dielectric, capacitance and rated voltage combinations, which is 28.5%. Those are the lines where a replacement has to keep the footprint or change the value. They cluster at the extremes of the catalogue — the single 3,500 Vdc part number and the 317 ultra-small 01R5 parts among them.","visible":true},{"id":"faq-question-04","title":"Does moving case size always change component height?","content":"No. X7R 4,700 pF 500 Vdc exists at 0805, 1206, 1210, 1808 and 1812, and all five publish the same 1.25 ± 0.10 mm nominal thickness. That is unusual enough to be worth checking rather than assuming, because on many other ladders the thickness rises with the case size.","visible":true},{"id":"faq-question-05","title":"What is the trap in the dimensional tolerances?","content":"The shape of the band changes along the ladder. On the 4,700 pF 500 Vdc ladder, 0805 and 1206 publish ±0.15 mm on length, 1210 loosens to ±0.30 mm, and 1808 and 1812 switch to an asymmetric +0.50/−0.30 mm. A land pattern drawn to a symmetric tolerance needs rechecking for the two larger options.","visible":true},{"id":"faq-question-06","title":"Can I trust the capacitance column in Walsin's export?","content":"On 13,188 of 13,191 decodable part numbers in those six series, yes. Three contradict the capacitance code inside their own part number: 0402X683M500, 0805A474K101 and 1210B154K250. Check the code against the column on every candidate and ask for written confirmation on those three.”,”visible”:true},{“id”:”faq-question-07″,”title”:”Does Venatech hold stock in the United Kingdom?”,”content”:”No. There is no Venatech entity, office, warehouse or stock in the United Kingdom. Everything ships from Hong Kong, where the authorised Walsin distribution entity sits. DDP, DAP and EXW terms are available, and ready stock is published as a dated snapshot rather than a live feed.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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Three ways to get this answered today

1. Cross a part, free. Paste up to 500 part numbers, or drop an Excel or CSV file, into the free cross-reference tool. It is matched against Walsin’s published catalogue and returns candidates field by field, with every difference from your original stated rather than hidden. Filter by commercial or automotive grade, or for soft termination, high temperature, safety certified, high Q / low ESR or low profile. There is no login and no charge.

2. Send the whole BOM. Upload a BOM and request a quote and we will come back line by line — including the lines we cannot help with, which is usually the more useful half of the answer.

3. Check the shelf before you commit. Ready stock shows what was physically in Hong Kong as at 23 September 2026. It is a dated snapshot, never a live feed, and quantities are never permanent.

Why take our word for any of this? Don’t — check it.

Venatech Limited (威納電子有限公司) is an authorised Walsin Technology distributor in Hong Kong. Confirm that with Walsin rather than with us. On the safety capacitor series we hold UL file E182369, which is searchable in UL’s own public database, together with TUV certificates R50381780 and R50195920 and CQC CQC20001280137 and CQC20001280136, against EN 60384-14:2023, IEC 60384-14:2023 and UL 60384-14. We hold 28 Walsin datasheets, 451 pages, and we will send the one covering your part number. Shipments arrive in original sealed Walsin packaging with lot and date-code traceability, and a certificate of conformity is available per shipment on request.

We will also tell you what we do not hold, which no competitor publishes. REACH, SVHC, conflict minerals, PFAS, China RoHS, ISO 9001, IATF 16949, PPAP, IMDS and a Declaration of Conformity appear nowhere in those 451 pages. You would rather hear that from us now than from your own supplier-approval team later. AEC-Q200 is compliant in Walsin’s own words and never certified, we hold no manufacturer’s end-of-life or allocation list for any brand, and qualification in your own circuit stays with you. We will not tell you a part is equivalent. We will show you where it differs.

Venatech Limited · Unit 207, 2/F, Sun Ling Plaza, 30 On Kui Street, Fanling, N.T., Hong Kong · (852) 2628 4777 · Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation.