MLCC Land Patterns: What Walsin Publishes and What It Omits

Walsin’s MLCC application guide publishes land patterns for three footprints that match zero real
parts — 0508, 0612 and a C Array — and omits a published footprint for two real part groups: the
0306 case size (3 parts) and the three-terminal FT feed-through series (8 parts). Venatech checked
every size and series named in the guide’s footprint tables against the parametric extract directly.

Venatech Limited, an authorised Walsin distributor in Hong Kong, cross-checked every footprint table
in Walsin Technology (Walsin)’s MLCC application guide against the 24,025-part MLCC parametric
extract. Every part number named below is real and appears in that extract.

Which MLCC land patterns does Walsin’s application guide actually publish?

Two tables, covering different processes. The reflow soldering footprint table lists dimensions for
17 named sizes — 01005, 0201, 0402, 0508, 0505, 0603, 0612, 0805, 1111, 1206, 1210, 1808, 1825,
1812, 2211, 2220, 2225 — and the wave soldering footprint table lists four: 0603, 0805, 1206 and
1210, plus a separate footprint for a “C Array” in 0603×4 and 0402×4 formats. Both tables are in the
MLCC application
guide,
pages 4 and 5.

Not every size named in those tables has a matching part in Walsin’s parts catalogue, and not every
case size or series in the catalogue has a matching footprint in those tables. The two documents —
the land pattern guide and the parametric extract — were not built against each other.

Which published land patterns correspond to parts that do not exist?

Three. 0508, 0612 and the C Array (0603×4 and 0402×4) each have a published reflow or wave-solder
footprint and zero matching parts anywhere in Walsin’s 24,025-row MLCC extract.

This is not a case-size naming mismatch — 0508 and 0612 do not appear under any spelling or series
prefix anywhere in the Size column of the extract, and no array-format MLCC part exists in the
file at all. A land pattern exists on paper for a part Venatech cannot source through Walsin’s
current parametric data.

Which real parts have no published land pattern at all?

Two groups, covering 11 real part numbers between them. Neither the 0306 case size nor the
three-terminal FT feed-through series appears in either footprint table, despite both having real,
current parts in the extract.

0306 is a reverse-geometry case — 0.8 mm long by 1.6 mm wide, the length and width of a standard
0603 swapped — so even substituting the nearest two-terminal footprint by case-size name would put
the pads on the wrong axis. FT parts are physically three-terminal devices: a standard two-pad
footprint for the host case size (0402 or 0805) does not provide a pad for the centre ground
terminal, so there is no safe substitute footprint in the guide’s two-terminal tables at all.

Substituting the 0603 reflow footprint for a 0306 part would rotate the pad geometry 90 degrees from
what the part needs.

Is the wave-solder footprint table consistent with Walsin’s own process guidance?

Not entirely, and this is a new inconsistency Venatech found while checking the tables against each
other, not against the parts data. The wave-solder footprint table on page 5 of the application
guide publishes a land pattern for 1210, including a specified number of dummy tracks. Two pages
later, the process guidance on page 8 states: “Wave soldering is recommended only for the following
case sizes: 0603 (1608); 0805 (2012) & 1206 (3216) thickness < 1 mm.” 1210 is not on that list.

So the same document publishes a wave-solder footprint for a case size its own process
recommendation excludes. Either the footprint is informational only and 1210 should default to
reflow, or the process note is out of date relative to the footprint table — we cannot tell which
from the guide alone.

How do I check a land pattern before I commit a PCB layout?

1. Look up the exact case size in both application-guide tables, reflow and wave solder
   separately — a size appearing in one does not mean it appears in the other.
2. If the size does not appear in either table, do not improvise from a similar case size. 0306
   demonstrates why: the same two digits as 0603 but a rotated geometry.
3. For a three-terminal part (FT series), do not reuse a two-terminal footprint for the same
   host case size. Request the centre-pad geometry from Walsin directly.
4. Confirm the part actually exists in current parametric data before laying out its footprint.
   0508, 0612 and the C Array formats show that a published footprint is not proof of a current
   part.
5. If the published footprint conflicts with the published process note, as it does for 1210 wave
   soldering, get written confirmation before committing the process to production.

For the related wave-solder thickness limit that applies to 0603, 0805 and 1206, see Which Walsin
MLCC can be wave soldered. For general mounting and
reflow guidance, see MLCC reflow profile and mounting. The
full range is on the Walsin MLCC range page.

The short version

Walsin’s MLCC application guide publishes land patterns for 0508, 0612 and a C Array format that
match zero real parts in the current extract, and omits a footprint for 0306 (3 parts, reverse
geometry) and the FT feed-through series (8 parts). The wave-solder footprint table additionally
publishes a 1210 land pattern that the guide’s own process text does not recommend for wave
soldering. None of this is asserted as a Walsin error — it is what the two documents say when read
against each other and against the parts data.

Send us the case size or series you are laying out, and we will confirm whether a Walsin land
pattern exists for it and whether a real part backs it, before you commit the PCB.

Two things you can do without waiting for a reply. Cross your part — paste a single number or drop in an Excel or CSV of the whole line, and each result names what matches and what does not. And ready stock lists the ceramic capacitor part numbers held in Hong Kong, with an RFQ against any of them.

Frequently asked questions