Component Body Dimensions in Walsin Exports: 20 Notations Across 5 of 8 Families, and Not One MLCC Length Is a Plain Number

Component body dimensions are the one field every footprint check needs and the one Walsin writes least consistently. We parsed all 359,974 export rows: only 5 of 8 families state a size in millimetres, in 20 distinct notations, and not one of 23,679 MLCC length cells is a plain number.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds all 203 parametric export files published by Walsin Technology (Walsin). This post is written from every column that carries a physical size, in the eight primary export sets, read as raw strings. We replaced each run of digits with the letter N so that 1.00±0.05 and 3.20±0.60 count as one shape and 1.00±0.05 and 1.00+0.30/-0.10 count as two. We excluded the QA test row Test123999. Every part number below is real.

Which Walsin families publish a body dimension in millimetres at all?

Five of eight. We counted the rows with a length-and-width pair in millimetres. 29,142 of 359,974 rows (8.1 percent) carry one; 329,658 rows in three families (chip resistor, thin film and disc capacitor) carry none, and the MOV and RF rows give a diameter or a case code, apart from nine RF switch rows.

Family	Rows	Dimension column	Rows with a mm size	A real part	Match / mismatch against a length-by-width filter
MLCC	24,026	L, W, T	23,679	MT15N0R5C500	Mismatch — every cell embeds a tolerance
Inductor	5,410	Size L*W (mm), Thickness (mm)	5,410	WLCW1005Z0J1N0TB	Match on 5,391 rows; mismatch on 19
Antenna	44	Dimension	44	RFANT6050110L0T	Mismatch — one string, three axes, unit repeated
RF	457	Size	9	RFASWA630PTF0E	Mismatch — 1.1x0.7 on 9 rows, a case code on 448
MOV varistor	379	Size	0 (diameter only)	SR180K05D	Mismatch — 5mm is a disc diameter, not a pair
Chip resistor	234,815	none (Size is a code)	0	MR06W1R00FTL	Mismatch — 0603(1608) names a case, not millimetres
Thin film	93,914	none (Size is a code)	0	WF04B10R0TTL	Mismatch — same
Disc capacitor	929	none	0	SL0AH150J060	Mismatch — Lead Spacing is empty on all 929 rows

We have not seen this counted anywhere. 20 notations, 5 families, 8.1 percent of rows. The only dimension in the whole catalogue stored as a native number is inductor thickness, on 5,410 of 5,410 rows. Every other size is a string, and the 91.9 percent of rows with no usable millimetre pair must be derived from a case code, a lookup we cannot perform from the export alone. Our post on metric and imperial case sizes covers the code side.

Why is no MLCC length a plain number?

Because the tolerance is welded into the cell. We read all 23,679 populated length cells in 00_ALL_MLCC_parts_combined.xlsx: 23,678 hold a size and a tolerance in one string, and the other one holds 25Vdc, a voltage, for the part 0201N0R1D250. The width column is the same: all 23,679 cells carry a tolerance. The 347 remaining rows have no L, W or T at all.

Shape of the length cell	Rows	A real part	Cell reads	Match / mismatch against a plain number
N±N	20,931	MT15N0R5C500	1.00±0.05	Mismatch — parses only after splitting on the sign
N+N/-N	2,551	MT31B105K500	3.20+0.30/-0.10	Mismatch — asymmetric, two tolerances
N +N/-N	135	RF22N2R2B501	2.79 +0.51/-0.25	Mismatch — a space before the plus sign
N±N/-N	27	MG43B103K101	4.50±0.40/-0.30	Mismatch — a plus-minus and a slash in one cell
N±N with a trailing space	21	MT32N103J12E	3.20±0.60	Mismatch — invisible on screen
N+N/-N with a trailing space	11	ST31B472J102	3.20+0.4/-0.1	Mismatch — one decimal place fewer, plus a space
N+N /-N	2	ST46B104K102	4.60+0.60 /-0.40	Mismatch — a space before the slash
NVdc	1	0201N0R1D250	25Vdc	Mismatch — not a length

Eight shapes in the length column, four each in width and thickness. One thickness shape is not a thickness at all: ≤ 1.78, an upper bound, on 127 Microwave RF rows such as RF22N2R2B501. One width cell, for 2220B223J202, holds two values, 6.30±0.40 5.00±0.40. A script that splits on the plus-minus sign will silently drop the second.

The Thickness column also exists in this file and is empty on all 24,026 rows; the real thickness is in T. For the ordering key that tells you what the thickness letter means, see how to read a Walsin MLCC part number.

How do the inductor, antenna, RF and varistor exports write the same dimension?

Four different ways, none of them the MLCC way. The inductor export is the only family that separates a plain length-by-width from its thickness: 5,391 rows write 1.0*0.5 with an asterisk, 19 write 3.2&1.6 with an ampersand, and thickness is a native number on all 5,410 rows.

Family	What a cell reads	Separator	Unit	A real part	Match / mismatch against the inductor convention
Inductor	1.0*0.5 and 0.66	asterisk	in the header	WLCW1005Z0J1N0TB	reference
Inductor, 19 rows	3.2&1.6	ampersand	in the header	WLBD3216K2U310TP	Mismatch — a different separator inside the same column
Antenna	5.9mm x 5.1mm x 1.1mm	lowercase x with spaces	in every cell, three times	RFANT6050110L0T	Mismatch — three axes, unit in the cell
Antenna, 14 cells	171.8mm x Ø13mm x 18mm	lowercase x	in every cell	RFDPA141300SMGB701	Mismatch — a diameter symbol replaces one axis
RF antenna switch	1.1x0.7	lowercase x, no spaces	nowhere	RFASWA630PTF0E	Mismatch — two axes, no unit anywhere
MOV varistor	5mm and 34mm Square	none	in the cell	SR201K34R	Mismatch — a diameter, and 42 rows that say Square

The antenna Dimension column has 35 distinct strings in 5 shapes. The cylinder antennas replace a width with a diameter, so the second figure is a diameter on 14 of 44 parts, and nothing in the column says which. The RF export has no unit in the header or the cell for its nine switch sizes.

Where does the unit live in each family?

In four places, and in one file nowhere. In the inductor export the unit is in the header, in the antenna and MOV exports it is in every cell, in the 173-row MLCC sample file it is in the header as Length (mm), and in the 24,026-row combined MLCC file the header is a bare L. The RF switch size has no unit in either place.

That matters for one reason: a parser that reads the unit from the header gets the right answer on the inductor file and no answer on the combined MLCC file, where the same parts appear under a header that has lost its unit.

How should a cross-reference compare body size across families?

By parsing, not by matching strings, and by saying what could not be parsed. Three rules handle the 29,142 rows with a millimetre pair, bar three exceptions: split on the first sign, treat *, & and x as one separator, and read the unit from wherever it lives. The exceptions are the 127 upper-bound thickness cells, the one two-value width cell and the one stray voltage. The rest of the catalogue needs a case-code lookup.

1. Keep the nominal and the tolerance in two fields. A nominal of 1.00 and a tolerance of 0.05 compare. The string 1.00±0.05 does not.
2. Accept three separators. Reject nothing for using & or x; 19 inductor rows would otherwise vanish from a footprint search.
3. State the unmatched. For chip resistor, thin film and disc capacitor, 329,658 rows, say plainly that the size is a code and that the footprint must be confirmed in the datasheet. That is how our free cross-reference tool states a difference from your original instead of hiding it behind a tick.

We hold 28 Walsin datasheets, 451 pages, and the dimension table in the datasheet is the figure to design a land pattern against; ask for the sheet covering your part number and it will be in your inbox. For inductor, thin film, MOV, disc, RF and antenna we hold none, so confirm those on Walsin’s own site. Our post on published and missing land patterns counts what the MLCC datasheets give.

What is in Hong Kong is on ready stock: 1,125 part numbers as at 23 September 2026, a dated snapshot and not a live feed. The capacitor range sits on the MLCC page.

The short version

Body size is stated in millimetres on 29,142 of 359,974 rows, in 20 notations, in 5 of 8 families. Chip resistor, thin film and disc capacitor, 329,658 rows, state none. All 23,679 MLCC width cells carry a tolerance in the string, and the length column has 8 shapes including one stray voltage. The inductor file writes * on 5,391 rows and & on 19. The unit is in the header, in the cell or nowhere depending on the family. We will not tell you a footprint matches on a string we cannot parse. We will show you the cell as stored. Qualification stays with you.

Send us the footprint line from your BOM and the part numbers you filtered to and we will tell you which family the size came from and how it was written. And a question back: when your last footprint search missed a part, was the part wrong, or was the separator?

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Frequently asked questions

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