A Vishay thin film alternative is found inside Walsin Technology (Walsin)’s WF thin film
precision series, and the case size you pick decides the ceiling before any part number
does. Walsin’s tightest published TCR, ≤±3 ppm/°C, exists at only 4 of the 8 WF case sizes —
0402, 0603, 0805 and 1206. It is absent at 0201, 1210, 2010 and 2512. Venatech holds no Vishay
lifecycle data and no Walsin thin film datasheet at all.
Venatech Limited, an authorised Walsin distributor in Hong Kong, writes this from Walsin’s
WF thin film precision export — 58,314 real rows — held across eight per-case-size files.
Every part number below exists in that export. This post does not name a Vishay part number
and does not reproduce Vishay’s specifications.
What is a Vishay thin film alternative at series level?
A candidate read from Walsin’s WF thin film precision series, checked case size by case
size, because the tightest TCR and tolerance grades are not available at every size. Vishay’s
ultra-precision thin film lines are sold on exactly those two numbers — TCR in parts per
million per degree Celsius and tolerance in fractions of a percent — so the cross has to
start with whether Walsin’s catalogue even reaches the grade claimed, before it gets to a
part number.
Which Walsin thin film series is the comparison point?
Thin Film Precision Chip Resistor, the WF series, 58,314 parts across eight case sizes from
0201 to 2512. It sits alongside three other thin film lines in Venatech’s data — tantalum
nitride MF, anti-sulfuration SF, and the AEC-Q200 WF-Q professional series, which Venatech has
already found returns zero rows in the current export — but WF precision is the one built for
tight tolerance and low TCR, the properties an ultra-precision cross is run against.
| WF case size | Parts | Tightest tolerance | Tightest TCR |
|---|---|---|---|
| 0201 (0603) | 5,506 | ±0.1% | ≤±25 ppm/°C |
| 0402 (1005) | 6,359 | ±0.01% | ≤±3 ppm/°C |
| 0603 (1608) | 7,562 | ±0.01% | ≤±3 ppm/°C |
| 0805 (2012) | 7,985 | ±0.01% | ≤±3 ppm/°C |
| 1206 (3216) | 8,427 | ±0.01% | ≤±3 ppm/°C |
| 1210 (3225) | 7,216 | ±0.01% | ≤±5 ppm/°C |
| 2010 (5025) | 7,436 | ±0.01% | ≤±5 ppm/°C |
| 2512 (6432) | 7,823 | ±0.01% | ≤±5 ppm/°C |
Figures measured from all eight WF export files, September 2026. This builds on Venatech’s
own published finding that Walsin’s ±0.1% shelf runs far deeper in thick film than thin film,
and that thin film precision WF tops out at 3 MΩ against 10 MΩ in thick film — both already
established separately from the case-size ceiling below.
Does every WF case size reach the same TCR ceiling?
No, and the split is clean rather than gradual.
Unique to Venatech’s data. Walsin’s tightest published TCR grade for WF thin film
precision resistors, ≤±3 ppm/°C, exists at exactly 4 of the 8 WF case sizes — 0402,
0603, 0805 and 1206 — and at no others. It is not available at 0201, 1210, 2010 or 2512
at any resistance or tolerance. 0201 is worse again on the other axis: its tightest
tolerance is ±0.1%, where every other WF case size reaches ±0.01%. A Vishay thin film line
specified below ±3 ppm/°C or at ±0.01% tolerance in an 0201 footprint has no WF candidate
at that case size at all, regardless of resistance value.
That is a case-size ceiling, not a defect — Walsin may simply not build a tighter grade at
those four sizes. The point for a cross is that the ceiling has to be checked before a
resistance value is even looked up, because no amount of searching finds a part that is not
in the catalogue at that case size.
What does a real 1 kΩ line look like across all eight WF case sizes?
Eight real parts, same resistance, same ±0.01% tolerance target where it exists, and the TCR
figure moves with case size exactly as the ceiling table predicts.
| Walsin part number | Case size | Tolerance | TCR | Your Vishay part — fill in from its datasheet | Match / mismatch |
|---|---|---|---|---|---|
WF02Q1001BTL |
0201 | ±0.1% | ≤±25 | ||
WF04B1001TTL |
0402 | ±0.01% | ≤±3 | ||
WF06B1001TTL |
0603 | ±0.01% | ≤±3 | ||
WF08B1001TTL |
0805 | ±0.01% | ≤±3 | ||
WF12B1001TTL |
1206 | ±0.01% | ≤±3 | ||
WF10Z1001TTL |
1210 | ±0.01% | ≤±5 | ||
WF20Z1001TTL |
2010 | ±0.01% | ≤±5 | ||
WF25Z1001TTL |
2512 | ±0.01% | ≤±5 |
At 1 kΩ, every case size from 0402 up reaches ±0.01% tolerance; only the TCR figure changes,
stepping from ≤±3 at 0402–1206 to ≤±5 at 1210, 2010 and 2512. 0201 is the one row that loses
on both axes — ±0.1% tolerance and ≤±25 ppm/°C, two full grades behind 0402 immediately above
it in the table. If your incumbent part is a Vishay 0201 ultra-precision resistor, there is no
WF case-size match for it; the next size up is where the comparison can actually start.
Why is there no datasheet link under any thin film claim in this post?
Because Venatech holds none. Every specification in this post is read from Walsin’s
parametric export, not from a datasheet — unlike the MLCC posts in this series, where every
claim links the specific Walsin PDF it came from. For thin film, no PDF exists in anything
Venatech has on file, for WF or for any of the other three thin film lines.
How do I find out whether my Vishay thin film line is still available?
Ask Vishay, or your Vishay distributor, in writing, for the exact part number on your BOM. We
hold no such list, so nothing here states that any Vishay part is discontinued, obsolete,
end-of-life or constrained; only Vishay can tell you that.
We will run the Walsin side in parallel — case size, tolerance and TCR checked against the
ceiling table above — so you know before anything else whether a WF candidate exists at your
case size at all.
The short version
Check the case-size ceiling before the part number. Walsin’s tightest WF thin film TCR,
≤±3 ppm/°C, exists only at 0402, 0603, 0805 and 1206; 0201, 1210, 2010 and 2512 all stop one
or two grades short, and 0201 also drops to ±0.1% tolerance. Every figure here comes from the
parametric export, not a datasheet, because none is held. Confirm status with Vishay and
qualify any candidate yourself.
Send your Vishay thin film specification, case size first, and we will tell you whether a
WF candidate exists at that size before we go any further — with a column left for your
part.
Frequently asked questions
Does Walsin’s WF thin film series reach ≤±3 ppm/°C at every case size?
No. That TCR grade exists at exactly 4 of the 8 WF case sizes — 0402, 0603, 0805 and 1206. 0201, 1210, 2010 and 2512 do not offer it at any resistance or tolerance.
What is the tightest tolerance available in WF thin film at 0201?
±0.1%, against ±0.01% at every other WF case size from 0402 up. 0201 is behind on both tolerance and TCR compared with the rest of the series.
Is a specific Vishay thin film resistor line discontinued?
We hold no such list, so we cannot tell you. There is no Vishay lifecycle data, affected-part list or allocation information on file here. Ask Vishay or your distributor in writing for the status of the exact part number on your BOM.
Why does this post not link a Walsin thin film datasheet for every claim?
Because Venatech holds no Walsin thin film datasheet of any kind, for WF or any of the other three thin film lines. Every specification here is read from the parametric export instead and flagged accordingly.
Does Walsin’s thin film catalogue include an AEC-Q200 qualified series?
By name, yes — the WF-Q professional series. It returns zero rows in the current export, a finding already established separately, so it has to be requested from Walsin directly rather than found through a parametric search.
What do you need from me to start a Vishay thin film cross?
Case size first, then resistance, tolerance and TCR. If your case size is 0201, 1210, 2010 or 2512, tell us which TCR grade you actually need before we look up a candidate, since the ceiling varies by size.
How does WF thin film compare with Walsin’s high precision thick film line?
Venatech has already published that comparison in depth — thick film reaches a tighter ±0.1% tolerance shelf and a higher 10 MΩ ceiling, while WF thin film holds 52,808 of its 58,314 parts at a single ±0.01% tolerance. This post adds the case-size TCR ceiling inside WF itself, which that comparison did not cover.
Next step
Send the case size first. Venatech Limited, an authorised Walsin distributor in Hong Kong,
will tell you immediately whether Walsin’s WF thin film series reaches your required TCR and
tolerance at that size, then return the candidate part number with a column left for your
incumbent Vishay part. Confirm the status of your current line with Vishay, and qualify any
candidate in your own circuit before release.
Send your BOM to Venatech · Browse the
Walsin thin film range · Read
Thin film vs thick film chip resistors and
High precision thick film vs thin film precision.
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.