Walsin’s anti sulfuration thin film resistor, the SF series, spans 15,080 real rows across two case sizes. We checked every one of Walsin’s 451 datasheet pages for the word “sulfur”: 29 mention it, only 3 name an actual test standard, and none of those 3 cover this series.
Venatech Limited, an authorised Walsin distributor in Hong Kong, holds all five of Walsin Technology (Walsin)’s SF anti-sulfuration thin film export files and all 28 of our Walsin datasheet PDFs, 451 pages in total. Every part number below is real and came out of those files, and every page count below is a page we opened and read ourselves, not a figure we are repeating from somewhere else.
How many rows actually sit behind Walsin’s SF anti sulfuration thin film resistor?
Fifteen thousand and eighty, and they live in only two of the five files. We opened all five Anti_Sulfuration_*_SF_*.xlsx files in Walsin’s thin film export and counted rows in each: Anti_Sulfuration_AEC_Q200_Thin_Film_Chip_Resistor_SF.xlsx, Anti_Sulfuration_Thin_Film_Chip_Resistor_SF_A_Series.xlsx and Anti_Sulfuration_Thin_Film_Chip_Resistor_SF_Series_0.xlsx each return zero rows — 6,289 bytes of header and nothing else. The real shelf sits entirely in Anti_Sulfuration_Thin_Film_Chip_Resistor_SF_Series_1.xlsx (270 rows, case size 1206/3216) and Anti_Sulfuration_Thin_Film_Chip_Resistor_SF_Series_2.xlsx (14,810 rows, case size 2010/5025).
| File | Rows | Case size | Status |
|---|---|---|---|
SF.xlsx (AEC-Q200) |
0 | — | Empty, header only |
SF_A_Series.xlsx |
0 | — | Empty, header only |
SF_Series_0.xlsx |
0 | — | Empty, header only |
SF_Series_1.xlsx |
270 | 1206 (3216) | Populated |
SF_Series_2.xlsx |
14,810 | 2010 (5025) | Populated |
| Total | 15,080 | 2 sizes | 3 of 5 files empty |
That 15,080-across-two-case-sizes figure matches what we had on file before this count; we re-measured it from the raw files rather than repeating it, and it held. Resistance across the two real files runs from 1.00 Ω (at 1206) to 3,000,000 Ω (at 2010), across 1,130 distinct resistance values, with zero duplicate part numbers between the two files.
Does any column in the SF export name a sulfuration test or standard?
No. Both populated SF files carry the identical nine-column schema — Part Number, Series, Size, Resistance, Tolerance, TCR, Rated Power, Packaging, Termination — and we read every header in both files to confirm it. There is no column for a sulfuration test standard, a test duration, a test temperature, or a pass/fail criterion anywhere in either file. Tolerance runs ±0.05%, ±0.1%, ±0.25%, ±0.5% and ±1%; TCR runs ≦±10 (4 parts, 1206 only), ≦±25 and ≦±50; rated power is 1/8 W or 1/4 W at 1206 and 1/2 W or 3/4 W at 2010. None of that is a sulfuration figure. The parametric export asserts the resistor resists sulfur in its own series name and stops there.
How many of Walsin’s 451 datasheet pages mention sulfur at all?
Twenty-nine. We opened all 28 Walsin PDFs we hold — 26 MLCC sheets and 2 chip resistor sheets, 451 pages combined — and searched every page for “sulfur” and “sulphur”. Twenty-nine pages across 27 distinct files contain the word. Twenty-six of those are one hit each, in every one of our 26 MLCC datasheets, and it is the same boilerplate storage warning every time: do not store the part “in the ambience of corrosive gas (e.g., hydrogen sulfide, sulfur dioxide, chlorine, ammonia gas etc.)”. That sentence is a handling instruction, not a test result.
The other three hits sit in one file: Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf, pages 1, 2 and 9 of its 10. We have not seen this exact count — 29 pages, 27 files, 26 of them identical boilerplate — published anywhere before. The phrase “flowers of sulfur” appears on zero of the 451 pages we hold.
| Document type | Pages held | Pages mentioning sulfur | What the mention says |
|---|---|---|---|
| 26 MLCC datasheets | 26 of their pages hit (1 each) | 26 | Corrosive-gas storage warning, not a test |
Walsin_WR_General_Purpose_Chip_Resistor.pdf |
1 resistor sheet | 0 | No mention at all |
Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf |
3 of 10 pages | 3 | Names a sulfuration test, ASTM B-809 |
| SF thin film anti sulfuration resistor | 0 datasheet pages held | 0 | We hold no datasheet for this series |
Which document actually names a sulfuration test, and is it for this series?
The MR thick film automotive resistor sheet does, and it is not the SF series. Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf states on its feature page: “2. Sulfuration resistant” and “3. Automotive AEC Q-200 & Military MIL-STD Compliant” — Walsin’s own wording, compliant rather than certified. Its approval-sheet test table then reads: “Sulfuration test ASTM B-809 60℃ 500hrs 5%: R/R max.(2%+0.10) | ASTM B-809-95 1%: R/R max.(2%+0.05)”. That is a named standard, a temperature, a duration and a pass criterion, all in one cell.
MR is a thick film series. SF, the anti sulfuration thin film resistor this post is about, is a different technology, a different export, and a series for which we hold zero of Venatech’s 28 Walsin datasheets — thin film has no datasheet coverage of any kind in our library, so there is no document to check an SF part against. Match / mismatch, real part numbers, against the stated requirement “a sulfuration test standard is named for this exact part”:
| Part number | Series held | Case size | Named sulfuration test standard | Match / mismatch |
|---|---|---|---|---|
SF12T1R00ATL |
Anti-Sulfuration Thin Film Chip Resistor / SF Series | 1206 (3216) | None — no thin film datasheet held, no column in the export | Mismatch |
SF12T1R00FTL |
Anti-Sulfuration Thin Film Chip Resistor / SF Series | 1206 (3216) | None — same | Mismatch |
SF20U3004FTL |
Anti-Sulfuration Thin Film Chip Resistor / SF Series | 2010 (5025) | None — same | Mismatch |
SF20R1172BTL |
Anti-Sulfuration Thin Film Chip Resistor / SF Series | 2010 (5025) | None — same | Mismatch |
| MR series (thick film, different technology, cited for contrast only) | Thick Film General Purpose / MR Series | 1206, 1210, 0805, 0603, 0402 | ASTM B-809, 60℃, 500 hrs — Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf pages 1, 2, 9 |
Match, series level — a different family, not a cross for SF |
What does the SF export actually tell you, field by field?
Resistance, tolerance, TCR, rated power, packaging and termination — and nothing about how the part survives sulfur exposure. We grouped all 15,080 rows by case size: 1206 covers 1.00 Ω to 50.5 Ω at 1/8 W or 1/4 W, a low-ohm sensing range; 2010 covers 4.70 Ω to 3,000,000 Ω at 1/2 W or 3/4 W, a general-purpose range. Both carry the same five tolerance grades and the same Sn base (Lead free) termination on 7″ reel taping. We checked all 15,080 part numbers for duplicates between the two files and found none.
What is missing is the same thing missing from the datasheet side: a sulfuration test duration, a test temperature, a pass/fail resistance-drift limit, or a reference to any named standard. The series name claims sulfur resistance. Neither the export nor our datasheet library backs that claim with a test.
What should you ask for before specifying an SF anti sulfuration thin film resistor?
Ask Walsin directly for the SF approval sheet and the sulfuration test method it uses, because neither sits in any document Venatech currently holds. The one Walsin sheet we do hold that names a sulfuration test — ASTM B-809, 60℃, 500 hours — covers MR, a thick film automotive series, not SF. We are not saying SF fails a test; we are saying we cannot show you one, and a specification that matters for a part sited near rubber seals, vulcanised cable or industrial sulfur sources should not be taken on a series name alone.
- Request the SF approval sheet from Walsin by part number. We hold 28 Walsin datasheets, 451 pages, and none of them is thin film.
- Cross your incumbent part against the real SF rows on the free cross-reference tool — paste up to 500 part numbers or drop an Excel or CSV, and it states every field it can and cannot match, never the word “equivalent”.
- Check what is physically in Hong Kong on ready stock, a dated snapshot as at 23 September 2026, before you commit a production slot to either case size.
- Ask for the test method and acceptance criteria in writing, the same way MR states them, before treating “anti-sulfuration” as a specification rather than a series name.
For the full nine-series anti-sulfuration picture across both thin film and thick film, see Anti-sulfuration resistors: SF thin film and SA thick film arrays. For what the other empty thin film exports were meant to hold, see What is actually in Walsin’s thin film catalogue. The full line sits on the Walsin thin film range page.
The short version
An anti sulfuration thin film resistor is a series name, not a tested claim, in every document Venatech currently holds. 15,080 real SF rows exist across two case sizes, three of the five SF export files are empty, and zero of our 451 datasheet pages name a sulfuration test for this series. The one sulfuration test standard we do hold on file — ASTM B-809, 60℃, 500 hours — belongs to MR, a different, thick film family.
Tell us the case size and resistance you need, and we will return the real SF rows field by field — then put the test-method request to Walsin in writing on your behalf, because we would rather ask than guess. If you hold an SF approval sheet that states a sulfuration test, we would like to see it before anyone publishes a number from it.
Frequently asked questions
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What is an anti sulfuration thin film resistor?
A thin film chip resistor built, per its series name, to resist atmospheric sulfur attacking the internal electrode. Walsin’s SF series is the thin film version; it spans 15,080 real part numbers across 1206 and 2010 case sizes. We hold no datasheet for it, so we cannot state its test method or pass criteria from a Walsin document.
Does Walsin publish a sulfuration test for the SF series?
Not in any of the 28 datasheets Venatech holds. We checked all 451 pages for the word “sulfur”: 29 mention it, and the only 3 that name an actual test standard — ASTM B-809, 60℃, 500 hours — are in the MR thick film automotive resistor sheet, a different series and a different technology from SF.
What do the other 26 sulfur-mentioning pages say?
They are the same sentence repeated once in each of our 26 MLCC datasheets: a storage warning not to keep the part in corrosive gas, naming hydrogen sulfide and sulfur dioxide among others. That is a handling instruction, not a sulfuration test result, and it has nothing to do with chip resistors.
How many of the five SF export files actually hold data?
Two of five. SF.xlsx (the AEC-Q200-labelled file), SF_A_Series.xlsx and SF_Series_0.xlsx all return zero rows. Every one of the 15,080 real SF rows sits in SF_Series_1.xlsx (270 rows, 1206) or SF_Series_2.xlsx (14,810 rows, 2010).
Does the SF export’s Tolerance or TCR column tell you anything about sulfur resistance?
No. Both populated files carry the same nine columns — Part Number, Series, Size, Resistance, Tolerance, TCR, Rated Power, Packaging, Termination — and none of them records a test standard, a test duration or a pass/fail limit. Tolerance and TCR describe electrical performance, not environmental survival.
Is “flowers of sulfur” testing mentioned anywhere in Walsin’s documents?
No. We searched all 451 pages we hold for that phrase and found zero matches. ASTM B-809 is the only named sulfuration test standard in our library, and it appears on 3 pages, all in the MR thick film sheet.
What should I do before specifying an SF part for a sulfur-exposed environment?
Request the SF approval sheet and its sulfuration test method from Walsin directly, since neither is in any document Venatech holds today. Then cross your incumbent part on the free cross-reference tool to see the real SF rows field by field, and check the dated ready-stock snapshot before committing a production slot.