MLCC Date Code Age: 22 of 683 Hong Kong Ready-Stock Lines Carry a Lot Over Five Years Old, Read for Germany

We decoded the MLCC date code on all 683 ready-stock lines that carry one, against our Hong Kong snapshot dated 23 September 2026. 549 of 683 hold nothing older than 12 months. 22 hold a lot over five years old, and the oldest decodes to 2017. A date code is a manufacturing date, not a shelf life.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, publishes a dated ready-stock position rather than a live feed, and this post is written from that position: our Hong Kong ready-stock snapshot as at 23 September 2026, read with its header on row 4, joined against all 203 Walsin Technology (Walsin) parametric export files. Every part number below is real and every one resolves to a row in Walsin’s own published catalogue, principally 00_ALL_MLCC_parts_combined.xlsx. No piece quantity appears anywhere in this post — the counts are counts of part numbers.

How old is the MLCC date code material on the Hong Kong shelf?

Mostly under a year, with a long tail nobody had measured. We decoded every date code on the 683 lines that carry one and compared each against the snapshot date, as at 23 September 2026. 549 of 683 lines, 80.4%, hold nothing older than 12 months. 43 hold a lot older than three years. 22 hold a lot older than five. The median line sits at 9.7 months. We have not seen this counted anywhere, by us or by any other distributor, because no distributor publishes the age of its own shelf.

Age of the oldest lot on the line, as at 23 September 2026	Part numbers	Share of 683
Under 6 months	78	11.4%
6 to 12 months	471	69.0%
12 to 24 months	25	3.7%
24 to 36 months	66	9.7%
36 to 60 months	21	3.1%
Over 60 months	22	3.2%

Two extremes frame the shelf. The newest material is 49 lines carrying a September 2026 lot, decoded from the notation 26+9月 — manufactured in the same month the snapshot was taken, and one example is 0402B103K500. The oldest is a single line, 0402N181J500, whose date-code cell reads 17+ and nothing else. Decoded, that is 2017: 116 months, nine years and eight months, before the snapshot date.

Our snapshot is two concatenated registers, which we have published before: 683 of the 1,125 lines carry both an internal description and a date code, the other 442 carry a pack quantity instead, and the 59 lines holding all three fields are the 59 held in two locations. Every one of the 683 date-coded lines is a ceramic capacitor — 565 standard MLCC, 117 specialty MLCC and one uncategorised line. We checked all 254 chip resistor codes, both inductor codes and all three safety capacitor codes in the snapshot: not one of them carries a date code at all. The date-code register is a capacitor register, and a buyer asking for the date code on a resistor line is asking for a field that does not exist in that half of the file.

How many notations does one 683-row date-code column actually use?

Eleven. We parsed all 801 individual lot codes sitting inside those 683 cells — 89 lines carry more than one lot, up to four on a single line — and classified every token. Eleven distinct notations appear in one column. That is the finding a German buyer should care about most, because it is the reason a date code cannot be sorted, filtered or compared without being decoded first.

Notation, as it appears in the cell	Example	Lot codes using it	Match / mismatch vs a machine-readable date code
Stringified timestamp	2025-12-01 00:00:00	420	Mismatch — a timestamp, not a date code; the original notation is gone
Year plus month, Chinese month marker	26+9月	238	Match — resolves to a single month
Year only, no month	26+	105	Mismatch — no better than plus or minus 12 months
Year plus bare month digits	23+12	25	Mismatch — indistinguishable by shape from a week number
Year plus week, Chinese week marker	19+34周	4	Match — resolves to a week
Four digits, year and week	2134	2	Mismatch — same shape as a year plus month
Year marker plus week marker	19年31周	2	Match — resolves to a week
Full dotted date	2020.10.26	2	Match — resolves to a day
Four digits plus week marker	2213周	1	Match — resolves to a week
Four digits plus month marker	2307月	1	Match — resolves to a month
Bare four-digit year	2019	1	Mismatch — no month, no week

104 of the 683 lines give a year and no month or week at all. On those lines the tightest honest statement about age is a 12-month band, and we would rather say that than imply a precision the cell does not carry.

Why do 420 of 683 date-code cells read as a timestamp rather than a date code?

Because the field has been round-tripped through a date type. We counted 420 of 683 cells containing the literal text 2025-12-01 00:00:00, and on 397 of those it is the whole cell. It is stored as text, not as a date — we read the cell type directly with openpyxl to confirm that, so the destruction is already baked in rather than a display artefact.

That single value is 61.5% of the date-coded shelf, and it is why the 6-to-12-month band holds 471 lines. A date code written 25+12月 and a timestamp written 2025-12-01 00:00:00 are not the same statement: the first is a manufacturing month in a manufacturer’s notation, the second is a midnight on a specific day that no manufacturer marked on a reel. Nothing in Walsin’s own export corroborates either reading — we checked, and no column in any of the 203 files carries a date code at all.

Which case sizes carry the oldest material, and which carry none of it?

The big case sizes are the youngest on the shelf, and 0805 carries the oldest. We resolved 582 of the 683 date-coded lines to a row in 00_ALL_MLCC_parts_combined.xlsx; the remaining 101 have no row in Walsin’s published catalogue at all, a gap we have measured and published separately. Of the 20 resolvable lines carrying a lot over five years old, nine are 0805 — more than any other case size, and more than 0201, 0402, 0603, 1206 and 1210 carry individually.

Case size	Date-coded lines	Lines with a lot over 36 months	Lines with a lot over 60 months	Example part number
0201	90	12	4	0201B472K100
0402	98	5	4	0402N181J500
0603	106	4	1	0603N1R2C500
0805	113	13	9	0805B334K160
1206	81	2	1	1206B475K100
1210	43	2	1	1210B473K631
1808	12	0	0	1808B102K302
1812	37	0	0	1812B104K501

All 37 of the 1812 lines and all 12 of the 1808 lines decode to the same single month, and none of them exceeds ten months of age. Those two case sizes arrived as one cohort. The five smallest case sizes did not: each of 0201, 0402, 0603, 0805 and 1206 carries at least one lot older than five years alongside lots under a year old.

One line shows the problem in a single cell. 0805N102J500 carries two lots, 26+7月 and 2020.10.26 — 69 months apart on one order code. Its newest lot is under three months old and its oldest predates the snapshot by nearly six years. A buyer told only “this part is in stock” learns nothing about which of those two lots would ship. That is why we quote part-number counts and a snapshot date rather than a quantity.

Does an MLCC date code tell a German buyer anything about shelf life?

It tells you when the part was made. It does not tell you how long it may sit. A date code is a manufacturing date, and there is no shelf-life column anywhere in Walsin’s 203 export files. We hold 28 Walsin datasheets, 451 pages, and we read all of them: storage and handling guidance appears, but no datasheet in 28 states a shelf-life limit for a stocked reel, and no datasheet in 28 names a manufacturing site, plant or country — so we will not state a country of origin either.

If your incoming inspection or your own works standard sets a maximum age between manufacture and solder, the age of the lot is a gate you apply yourself, against your own number, using the date code printed on the reel. We can tell you what our snapshot recorded as at 23 September 2026. We cannot tell you that a 2017 lot passes your standard, and we will not imply it does.

For the handling side of the same question, see MLCC shelf life, storage and handling. For how the lot code, the date code and the certificate of conformity fit together on a shipment, see certificate of conformity, lot codes and date codes. The full capacitor line is on the Walsin MLCC page.

What should a German buyer ask for instead of a date code?

Three things, and all three are already how we ship. Lot and date-code traceability, a certificate of conformity per shipment on request, and original sealed Walsin packaging — those are the three items a supplier-approval questionnaire actually asks for, and they are more useful than any age figure in a spreadsheet, because they attach to the reel you receive rather than to a position recorded as at 23 September 2026.

1. Ask for the date code on the specific lot being allocated, not on the line. 89 of 683 lines carry more than one lot, and one carries lots 69 months apart. The line-level answer is not an answer.
2. Ask for the current position before you plan a build. Our ready stock page is a live public page showing a dated snapshot, not a live feed. What was there as at 23 September 2026 may not be there now.
3. Cross the whole bill of materials in one pass first. Paste up to 500 part numbers or drop your Excel or CSV into the free cross-reference tool, which matches against Walsin’s published catalogue and states every difference. An age question on the wrong part number is wasted.

The short version

We decoded the MLCC date code on all 683 Hong Kong ready-stock lines that carry one, measured against our snapshot as at 23 September 2026. 549 of 683 hold nothing older than 12 months, 43 hold a lot older than three years, and 22 hold a lot older than five, the oldest decoding to 2017 on 0402N181J500. The column uses 11 distinct notations across 801 lot codes, 104 lines give a year with no month, and 420 cells have been overwritten with the text 2025-12-01 00:00:00. All 37 1812 lines and all 12 1808 lines are one young cohort; 0805 carries nine of the oldest lots. Every one of the 683 date-coded lines is a ceramic capacitor, and not one of the 254 chip resistor codes carries a date code at all. Qualification stays with you.

Send us the capacitor lines off your German bill of materials and we will tell you, part number by part number, what our snapshot recorded as at 23 September 2026, what the date code on the allocated lot decodes to, and where we are reading an internal field rather than a manufacturer’s marking. Then tell us this: does your own works standard set a maximum age between manufacture and reflow — and has any distributor ever volunteered that number before you asked?

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"How old is the MLCC stock in Venatech's Hong Kong ready-stock snapshot?","content":"We decoded all 683 date-coded lines against the snapshot date of 23 September 2026. 549 of 683, 80.4%, hold nothing older than 12 months, and the median line sits at 9.7 months. 43 lines hold a lot older than three years and 22 hold a lot older than five years. The oldest decodes to 2017.","visible":true},{"id":"faq-question-02","title":"What is the oldest MLCC date code on the Hong Kong shelf?","content":"One line, 0402N181J500, a 0402 General Purpose part whose date-code cell reads 17+ and nothing more. Decoded, that is 2017 — 116 months, nine years and eight months, before 23 September 2026. No month or week is recorded, so the honest age is a 12-month band, not a point.”,”visible”:true},{“id”:”faq-question-03″,”title”:”How many date-code notations does the snapshot use?”,”content”:”Eleven, across 801 individual lot codes on 683 lines. They range from a Chinese month marker such as 26+9月, through bare year-and-week forms such as 2134, to a full dotted date such as 2020.10.26. 104 lines give a year with no month or week, so no reading tighter than 12 months is honest on those.”,”visible”:true},{“id”:”faq-question-04″,”title”:”Does an MLCC date code tell me the shelf life?”,”content”:”No. A date code is a manufacturing date. There is no shelf-life column in any of Walsin’s 203 parametric export files, and no file in the 28 datasheets we hold, 451 pages, states a shelf-life limit for a stocked reel. If your own works standard sets a maximum age before reflow, that gate is yours to apply against the code printed on the reel.”,”visible”:true},{“id”:”faq-question-05″,”title”:”Do the chip resistor lines in the snapshot carry date codes too?”,”content”:”No. We checked all 254 chip resistor codes, both inductor codes and all three safety capacitor codes: not one carries a date code. All 683 date-coded lines are ceramic capacitors — 565 standard MLCC, 117 specialty MLCC and one uncategorised line. The date code sits in one of the file’s two registers, and resistors are in the other.”,”visible”:true},{“id”:”faq-question-06″,”title”:”Which case size carries the oldest material?\n\nOf the 20 resolvable lines carrying a lot over five years old, nine are 0805 — more than any other case size. By contrast all 37 1812 lines and all 12 1808 lines decode to one single month and none exceeds ten months of age. The five smallest case sizes each mix young and old lots.\n\nCan Venatech tell me the date code before I place an order?”,”content”:”We can tell you what our 23 September 2026 snapshot recorded and we can request the code on the lot being allocated. We ship with lot and date-code traceability, a certificate of conformity per shipment on request, and original sealed Walsin packaging. Ask us for the current position rather than relying on a dated page.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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