MLCC Termination Code for Mexico: One Letter C, Four Stacks on 18 Walsin Sheets, and 21 Electrical Tables That All Say Ni/Sn

The MLCC termination code C names four different electrode stacks across 18 Walsin approval sheets, and 21 electrical tables print one identical line, “Ni/Sn (lead-free termination)”, including all five sheets whose drawing shows a polymer or resin electrode. We read all 24 sheets. Read the drawing, not the table.

Venatech Limited, an authorised Walsin distributor in Hong Kong, holds 28 datasheets from Walsin Technology (Walsin), 451 pages, and the 24,026-row capacitor export. This post is for the quality or sourcing engineer in Mexico who is filling a “termination” field in a bill of materials or a supplier-approval record for a Walsin multilayer ceramic capacitor and wants to know what the field can truthfully hold. It is written from the “How to order” block, the electrical table and the construction drawing of each of the 24 series approval sheets, and from 00_ALL_MLCC_parts_combined.xlsx. Every part number below is real.

What does the termination code C mean on a Walsin MLCC approval sheet?

Four different things, depending on the sheet. We counted 18 sheets that define the letter C in their ordering code: 13 define it as Cu/Ni/Sn, 3 as Cu plus conductive resin over Ni and Sn, 1 as Ag polymer over Ni and Sn, and 1 as Cu polymer over Ni and Sn. The code is the thirteenth character of an orderable number such as 1812B103K352MT. It is absent from all 24,026 exported part numbers, which are 12 characters on every row.

The letter has company. On 04 and 05, M means surface coating over Cu/Ni/Sn; on 12 and 13, M means the resin stack plus surface coating. Everywhere else M is the ±20% tolerance, and on the Mega Cap M sheet it is also the series prefix. The safety sheets use E, Z, K, Y and X, and the two Mega Cap sheets state a lead type instead of a finish. Row counts here are by export series name; the Middle to High Voltage series is described by both 04 and 05.

Which Walsin sheets draw a polymer or resin electrode, and what does their electrical table say?

Five sheets draw one, and all five print the same electrical line as everyone else. Each sheet’s electrical table has a “Termination” row, and 21 of the 24 sheets read “Ni/Sn (lead-free termination)”. Five of those 21 draw “Cu + Conductive Resin”, “Cu + Ag Polymer” or “Cu + Cu Polymer” as the inner layer in the construction figure. The table cannot separate the soft sheets from the standard ones; the figure can.

We have not seen this counted anywhere. 1,707 of the 24,026 exported rows, 7.1 percent, belong to the three soft series ST, SH and SG whose figures show a polymer or resin electrode. Not one of those rows, and not one of the 21 electrical tables, says so in the line a bill-of-materials field usually copies. The series name does: ST32N103J12E, SH32B224K401 and SG18N100J500 sit in series called “Soft term”, “Ag-poly” and “Cu-poly”. For the reason these parts exist, see soft termination MLCC SH, SG, ST and VT and flex cracking and board bend.

Is the outer layer matt tin or plain tin?

It depends on the sheet, and the sheets do not agree within a family. Of the 18 construction figures, 10 print the outer layer as “Sn (Matt)” and 8 as plain “Sn”. The word “Matt” appears in no electrical-table row, no ordering code and no export cell. We searched the 65-page catalogue as well, and it prints no such word.

We do not know what the word signals, because Walsin does not say, and we would not infer a different process from one word. A finish you must control, such as solderability after storage, is a reason to ask Walsin for the exact part number’s finish rather than read it off a sibling sheet. Seven sheets also say “pure tin” in prose: 01, 11, 14, 21 in the feature list, and the three safety sheets, 16, 17, 18, as “plated nickel and pure tin”.

Which Walsin sheets draw no termination construction at all?

Six of 24. 05_Surface_Coating_Type.pdf, the three safety sheets 16, 17 and 18, and the two Mega Cap sheets 23 and 24 draw no layers. Four of them still print the Ni/Sn row. The safety sheets say in prose that the terminations are “plated nickel and pure tin”, and offer soft termination by ordering letter: E or Z on 16 and 18, Y or X on 17. The 173 S2 rows, for example S242N390K502, therefore carry a soft or standard termination that only the thirteenth character of the orderable number can tell you.

The Mega Cap sheets state the termination as a lead type, “L type lead” or “M type lead (customizable)”, with no tin or nickel anywhere. Neither series has a row in the combined export.

Does the Walsin MLCC export say what the termination is?

No. The Termination column is empty on 22,920 of 24,026 rows, and on the 1,106 rows where it is filled it holds a tolerance, not a finish. We published that defect in the termination column contains tolerances. The same rows have no termination letter in the part number either. The only place the stack is stated is the sheet, and only for the series, not for the part.

So a bill-of-materials field cannot be filled by lookup from the export. It needs the series sheet and, for the exact termination letter, the orderable number.

What should a Mexico BOM line and supplier-approval record carry for MLCC termination?

Three things, in this order. Record the orderable number with its thirteenth character, the series sheet filename with its footer month, and the construction drawing’s inner and outer layer as drawn, not the electrical-table line. A line reading “Ni/Sn” cannot be the control, because 21 sheets print it for five different electrode structures.

1. Keep the letter. C alone is ambiguous across sheets; C plus the sheet is not.
2. Cite the drawing. Inner layer, middle layer, outer layer, as printed.
3. Ask for the part-specific finish if a process control depends on it.

We hold 28 Walsin datasheets, 451 pages, and send the sheet for your series on request. We will not tell you a part is equivalent to the one you use today. If you are replacing another maker’s capacitor, compare the construction field by field, confirm against both datasheets and qualify in your own circuit. The range is on the MLCC page, a free cross-reference will list the fields that differ, and 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 short version

The letter C means Cu/Ni/Sn on 13 Walsin sheets, a resin stack on 3, Ag polymer on 1 and Cu polymer on 1. 21 electrical tables print “Ni/Sn (lead-free termination)”, five of them over a polymer or resin drawing, covering 1,707 export rows. The outer layer is “Sn (Matt)” on 10 drawings and “Sn” on 8, and the word reaches no table, code or export cell. Six sheets draw no construction. The export holds no finish. Send us the termination line from your BOM and the part number, and we will return the drawing from the sheet for that series. And a question back: if your record says “Ni/Sn”, which of the five structures did you just approve?

Frequently asked questions