MLCC Hand Soldering Iron and Ultrasonic Cleaning for Poland: 5 of 26 Walsin Files State an Iron Limit, in 3 Versions

The MLCC hand soldering iron limit for a Polish rework line is not one number. Of 26 Walsin MLCC PDFs, 5 state an iron limit, in 3 versions, and a 2220 part gets 260 or 280 degrees Celsius depending on the file. Only 674 of 24,026 export rows sit under a sheet that says anything.

Venatech Limited, an authorised Walsin distributor in Hong Kong, holds 28 datasheets from Walsin Technology (Walsin), 451 pages, and the parametric export behind them. This post is written from the soldering and cleaning paragraphs of the 26 MLCC PDFs in _Walsin_Datasheets/MLCC/ and from the 24,026 rows of 00_ALL_MLCC_parts_combined.xlsx. Every part number is real. The question is the one a process engineer in Poland asks when a placed board needs one capacitor touched up: which iron, how hot, and may the board then go into an ultrasonic bath?

How many of Walsin’s 26 MLCC files state a hand soldering iron limit?

Five, in three versions. We opened each PDF and searched every page for an iron, a tip, a wattage and a hand-soldering profile. The 12-page application guide (Jan. 2022) states one. The 1825/2220/2225 sheet states a second. The three safety sheets (S2, S2-H, S3) state a third, identical across all three. The other 21 files, including the 65-page full catalogue and 20 of the 24 series sheets, contain no iron limit of any kind.

The sources are Walsin’s own: the application guide, the large-size sheet and the S2 safety sheet. We have not seen this counted anywhere. The three safety sheets list sizes 1808 to 2220 only, so their 1206-and-below row cannot apply to any part they cover, and the 150 C against 190 C difference is a template difference rather than a live conflict.

The reach is narrow. We mapped the 16 series in the export to their sheets. Only the large-size series (501 part numbers) and the S2 safety series (173) have a sheet that states an iron limit: 674 of 24,026 rows, 2.8 percent. The other 23,352 rows sit under a series sheet that is silent, and none of the 24 series sheets cites the application guide; we searched every one for the word guide and found only a solder-paste heading on the feed-through sheet.

What iron temperature applies to a 2220 part?

260 degrees Celsius if you read the large-size sheet, 280 if you read the application guide or the S2 safety sheet, and “not recommended” in the same paragraph as the 260. We counted 327 part numbers at 2220 in the export. 258 are in the large-size series, 41 in the SH soft-termination series, 23 in the S2 safety series and 5 in the ST automotive series. The governing sheets differ.

The large-size sheet contradicts itself on its own page. It recommends a temperature-controlled iron “not exceeding 30 watts” with a tip “less than 1.2 mm” at “not more than 260 C”, and in the next paragraph says that for “bigger chips such as 1210, 1808, 1812, 2220 and 2225, etc. wave soldering and hand soldering are no recommended”. Every one of the sheet’s 501 export parts is 1825 or larger. 2220 and 2225 are named (383 parts); 1825 (118) falls under “etc.”. A rework instruction written from that sheet has to choose between the two sentences, and the sheet does not choose for you.

Which iron band does a 1111 part belong to?

The guide does not say, because its bands are written by name. They read “1206 (3216) or less” and “1210 (3225) or more”, and 1111 sorts below 1206 by name and by metric code. We measured the 149 RF-series parts named 1111 from the length and width columns: 2.79 by 2.79 mm, 7.78 square mm. A 1206 measures 3.20 by 1.60 mm, 5.12 square mm. A 1210 measures 3.20 by 2.50 mm, 8.00 square mm. A 1111 is 1.52 times the area of a 1206 and 97 percent of a 1210.

The RF sheet (06_Microwave_RF.pdf) states no iron limit, so for RF22N2R2B501 nothing on our shelf tells you which band applies.

Which files say anything about ultrasonic cleaning, and with what numbers?

Seven of 26 mention it and one gives numbers. We searched every page for the word ultrasonic. The application guide (Jan. 2022, page 10) gives a recommended condition: power 20 W per litre maximum, frequency 40 kHz maximum, washing time 5 minutes maximum, wait at least 5 minutes after reflow, and keep the temperature difference below 100 C if parts are dipped in solvent. Six series sheets say only that “good results can be obtained by using ultrasonic cleaning of the solvent” and give no power, no frequency and no time.

The only numeric ultrasonic limit comes from the oldest document, four years older than the 2026 sheets. The 674 export rows whose sheet mentions ultrasonic cleaning get the sentence without the limit.

Do the datasheets and the guide agree on whether to clean at all?

No. 6 of the 24 series sheets say “All flux residues must be removed by using suitable electronic-grade vapor-cleaning solvents”. The guide says “In general, washing is not necessary if rosin-based flux is used”, and gives cleaning fluids only for active flux. The same six sheets also say to use mildly activated rosin RA or RMA flux and not activated flux. Read together, they ask for a rosin flux that the guide says needs no washing, and then require its residue to be removed.

That is two instructions we cannot resolve for you. The guide’s own reason to clean is halogen from flux lowering insulation resistance, worse with water-soluble flux. We read the insulation-resistance side in the insulation resistance limit post. The guide’s mounting figures are summarised in MLCC reflow profile and mounting; this post is the cross-file audit.

What should a Polish rework procedure be written from?

From the strictest statement that applies to the exact part number, with the source file named in the procedure. Three rules follow from the counts: 5 of 26 files state a limit, 674 of 24,026 rows sit under one, and 246 RF parts carry size names the guide does not band.

1. Write the iron limit per case size, not per board. For 1206 and below use the guide’s 350 C; for 1210 and above use 280 C; for the large-size series (1825, 2220, 2225) use 260 C, 30 W and a tip under 1.2 mm, and record that the same sheet advises against hand soldering at those sizes.
2. Treat 1111 and 0505 as open questions. 149 and 97 RF parts carry size names the guide does not band. Ask for written confirmation before a rework instruction names a temperature.
3. Set the ultrasonic bath inside the guide’s 20 W/L, 40 kHz, 5 minute envelope unless Walsin confirms otherwise, because the sheets give none. Wait 5 minutes after reflow before the bath.

We hold 28 Walsin datasheets, 451 pages, and send the one covering your part number on request. For thin film, inductors, varistors, disc capacitors, RF filters, couplers and baluns, and antennas we hold no datasheet, so none of this applies there. Confirm against both datasheets and qualify in your own circuit. To cross a whole list in one pass, use the free MLCC cross-reference tool: paste up to 500 part numbers or drop an Excel or CSV. What Hong Kong holds is on ready stock, 1,125 part numbers as at 23 September 2026, a dated snapshot and not a live feed. The range sits on the MLCC page.

The short version

Five of 26 Walsin MLCC files state a hand-soldering iron limit, in three versions: the guide (350 C and 280 C), the large-size sheet (260 C, 30 W, tip under 1.2 mm, hand soldering not recommended) and the three safety sheets (350 C and 280 C, 20 W, tip 1.0 mm or less). Only 674 of 24,026 export rows sit under a sheet that states one. A 2220 part carries 260 C or 280 C by sheet. The 149 parts named 1111 are 97 percent of a 1210 by area and fall in no named band. Seven files mention ultrasonic cleaning and one, dated Jan. 2022, gives numbers: 20 W/L, 40 kHz, 5 minutes. We will not tell you which version is right for your part. We will show you which file says what. Qualification stays with you.

Send us the part numbers on your rework list and we will name the governing file, page and iron statement for each, and say plainly where none exists. And a question back: when your rework instruction quotes a temperature, does it name the document it came from?

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