Takeaway
- Solder wick (desoldering braid) is a flux-pre-impregnated woven copper strip that removes solder from PCB pads and component leads by capillary action — no pump, no vacuum required.
- Width selection: use the narrowest braid that covers the target pad. Fine (0.8–1.0 mm) for 0402/0603 SMD pads; medium (1.5–2.0 mm) for SOIC and QFP leads; wide (2.5–2.8 mm) for through-hole and bridge cleanup.
- Iron temperature: set 20–50°C above the solder liquidus — approximately 330–370°C for SAC305 lead-free; 280–320°C for Sn63/Pb37.
- Lift the braid and iron together in one motion while solder is still molten — never drag a cooling braid across a pad or you will lift the copper.
- Flux types: rosin (fastest wicking, needs cleaning); no-clean (residue acceptable in most designs); flux-free (add your own, mandatory for water-soluble flux processes).
- Discard saturated braid immediately — cutting back to fresh copper is mandatory before the next joint. Dark or oxidized braid will not wick.
- Standards: MIL-F-14256, IPC J-STD-004 (flux classification), NASA NHB 5300.4, ANSI/IPC SF-818.
A solder bridge appears between two QFP pins after reflow. A via is packed with excess solder from a rework attempt. A BGA has been removed by hot-air and the pads need to be clean and flat before a replacement lands. In each of these scenarios, the fastest and least invasive tool available is a length of desoldering braid — a strip of flux-impregnated woven copper that pulls molten solder off a pad through capillary action, leaving the land clean and solderable without disturbing adjacent components or subjecting the board to the broad thermal footprint of a hot-air station.
What Is Solder Wick and How Does It Work?
Solder wick — also called desoldering braid, solder braid, or desoldering wick — is a flexible strip of precision-woven oxygen-free copper wire, pre-impregnated with a flux compound. The weave geometry creates a dense network of inter-wire capillary channels. When the braid is placed against a solder joint and heated by a soldering iron tip pressed on top of it, the flux activates (cleaning oxidation from both the braid and the solder surface), the solder melts, and the molten solder is drawn up into the copper weave by capillary action — the same surface-tension phenomenon that draws liquid up a paper towel.
How to Choose the Right Solder Wick Width
Width is the primary selection criterion for solder wick. The braid should be as narrow as possible while still covering the target pad or lead pitch — excess width wastes braid, draws unnecessary heat into adjacent areas, and makes controlled placement harder on fine-pitch components.
| Width (mm) | Width (inch) | Size Code / Color | Recommended Use |
| 0.76–1.0 mm | 0.030≈0.040″ | #1 / Yellow | Ultra-fine SMD: 0201/0402/0603 pads, fine-pitch QFP/QFN leads ≤0.5 mm pitch |
| 1.0–1.5 mm | 0.040≈0.060″ | #2 / Blue | Small SMD pads: 0603/0805, SOT-23, 0.65 mm pitch IC leads |
| 1.5–2.0 mm | 0.060≈0.080″ | #3 / Green | Medium pads: SOIC-8/16, QFP 0.8 mm pitch, bridge cleanup on 1206 passives |
| 2.0–2.5 mm | 0.080≈0.100″ | #4 / White | Larger IC leads: LQFP, power transistors, PTH lead-exit cleanup |
| 2.5–2.8 mm | 0.100≈0.110″ | #5–6 / Red | Through-hole pads, connectors, large bridge cleanup, multi-pad solder floods |
Flux Type Selection: Rosin, No-Clean, and Flux-Free
The flux pre-impregnated in solder wick serves two functions: it cleans oxidation from the copper braid and the solder surface to promote wetting, and it lowers the surface tension of the molten solder to accelerate capillary draw. Flux type must match the downstream cleaning process to avoid reliability problems from residue incompatibility.
| Flux Type | IPC J-STD-004 Classification | Wicking Speed | Post-Use Cleaning Required | Best For |
| Rosin (R/RA/RMA) | ROL0, ROH0 | Fastest | Yes — IPA or saponifier wash | Military, aerospace, medical (IPC Class 3); maximum wicking performance |
| No-Clean | REL0, REL1, ROM0 | Fast | Optional (inspect under 10x magnification) | General EMS rework, field repair, prototype; residue passes surface insulation resistance (SIR) test |
| Flux-Free | N/A (no flux) | Slowest (add externally) | Matches externally applied flux | Water-soluble flux processes where rosin/no-clean residue would cause process incompatibility |
| No-Clean Low-Residue | REL0 low-solid | Moderate | No (minimal residue by design) | High-reliability assemblies where optical cleanliness is required but full wash is impractical |
How to Use Solder Wick: Step-by-Step Technique
Equipment Setup
- Soldering iron: temperature-controlled station (not a fixed-wattage iron). Tip condition is critical — a tinned, clean tip transfers heat in under one second; an oxidized tip may never reach the threshold.
- Iron tip selection: chisel or bevel tip for SMD pads; fine conical tip for ultra-tight QFN/QFP pitches; larger chisel for through-hole. The tip should contact both the braid and the target pad simultaneously.
- Temperature setting: 330–370°C for SAC305 lead-free (liquidus 217°C + 110–150°C overage for rapid heat transfer through the braid); 280–320°C for Sn63/Pb37 (liquidus 183°C).
Step-by-Step Procedure
Inspect and prepare the braid:
Unroll 20–30 mm from the spool. Check the color — fresh braid is bright copper-colored. Darkened or greenish braid is oxidized and must be discarded; cut back to bright copper before use. Do not touch the braid with bare fingers (skin oils contaminate the flux).
Optional:
add supplemental flux. For stubborn joints or when using no-clean braid on heavily oxidized surfaces, apply a small amount of compatible liquid flux to the target pad before placing the braid. This significantly speeds wicking and reduces required dwell time.
Position the braid flat on the target pad or bridge.The braid should lie flat, not folded or kinked. For a pad, center the braid over the full pad width. For a solder bridge, position so the braid covers both offending joints simultaneously.
Place the iron tip on top of the braid, directly over the target solder. The iron tip should contact the braid, not the pad directly.
Wait for wicking to begin:
typically 1–3 seconds for a hot, clean tip on fresh braid. You will see the braid darken at the contact point as it fills with solder. Do not increase pressure or move the iron sideways.
Lift the braid and iron together in one motion while the solder is still molten. This is the most critical step. If you lift the iron first and the braid cools against the pad, the residual solder will resolidify and bond the braid to the pad — pulling the pad copper when you remove the braid. Always lift both simultaneously.
Inspect the pad immediately at 10× magnification. A clean result shows shiny, flat copper with no solder residue. If solder remains, cut back to fresh braid (do not reuse the saturated section) and repeat.
Cut and discard the saturated braid segment. Attempting to reuse a saturated section will transfer contaminated flux back onto the board and wick no solder. Cut 5–10 mm past the visible solder fill line and re-roll to expose fresh braid.
Clean residual flux if required. No-clean residue under 10× inspection should be clear and non-tacky. Rosin flux requires IPA (isopropyl alcohol ≥99%) or a saponifier wash. For medical and aerospace applications, clean regardless of flux type and verify surface insulation resistance.
Lead-Free and High-Temperature Considerations
Lead-free solder alloys (SAC305: Sn96.5/Ag3.0/Cu0.5 being the most common) have a liquidus temperature of 217°C — 34°C higher than eutectic tin-lead (Sn63/Pb37 at 183°C). This difference has direct implications for solder wick technique.
A higher liquidus requires a higher iron tip temperature and a faster thermal transfer rate to reach wicking conditions before the pad substrate begins to absorb excessive heat. Standard rosin-flux solder wick performs adequately on lead-free joints, but single-layer flat-braid constructions designed specifically for lead-free use have lower thermal mass and heat up faster, reducing the total time the pad spends above 200°C. For fine-pitch SMD work at 0.4–0.5 mm pitch with SAC305 solder, a lead-free optimized braid with no-clean flux is the preferred specification.
Technical Specifications
| Parameter | Value / Range |
| Core material | Oxygen-free high-conductivity copper (OFHC) braid |
| Width range | 0.76 mm (0.030″) to 2.8 mm (0.110″); common sizes: #1 through #6 |
| Spool length | 1.5 m (5 ft) small; 3 m (10 ft) standard; 7.5 m (25 ft) high-volume |
| Flux types available | Rosin (ROL0 / ROH0), No-Clean (REL0 / ROM0), Flux-Free, No-Clean Low-Residue |
| Compatible solder alloys | Sn63/Pb37 (eutectic); SAC305; SAC405; SnBi (low-temperature) |
| Recommended iron temperature (Sn63/Pb37) | 280–320°C |
| Recommended iron temperature (SAC305 lead-free) | 330–370°C |
| Typical wicking time per joint | 1–3 seconds (fresh braid, clean tip, correct temperature) |
| Shelf life (unopened) | ~2 years from manufacture date (flux degrades with oxidation) |
| Storage conditions | Room temperature, sealed packaging, away from humidity and direct light |
| Packaging | ESD-safe antistatic spool (blue); sealed foil pouch for individual reels |
| Standards compliance | MIL-F-14256; IPC J-STD-004 (flux classification); NASA NHB 5300.4; ANSI/IPC SF-818 |
| Substance compliance | RoHS 3 (EU 2011/65/EU); REACH SVHC-free (EC No. 1907/2006) |
Key Features and Advantages
| Feature | Description | Benefit |
| Oxygen-free copper braid | Precision woven OFHC copper maximizes capillary channel density and thermal conductivity | Faster wicking per dwell second, reduced pad exposure time, lower thermal stress on substrate |
| Pre-impregnated flux | Factory-applied rosin, no-clean, or low-residue flux activated at working temperature | No additional flux preparation needed; immediate activation at iron contact |
| Multiple width sizes (#1–#6) | From 0.76 mm for 0402 pads to 2.8 mm for through-hole and bridge cleanup | Pad-matched width minimizes heat spread to adjacent components |
| ESD-safe spool packaging | Antistatic blue spool construction for 25+ ft reels | Safe use in ESD-controlled assembly environments without special handling precautions |
| Localized heating profile | Heat is applied only at the target joint; board remains at ambient temperature | Critical for reworking BGA pads and fine-pitch components without disturbing adjacent joints |
| No capital equipment required | Works with any temperature-controlled soldering iron; no pump, compressor, or vacuum needed | Immediate deployment in any lab, field repair, or prototype environment |
| Standards-compliant flux chemistry | MIL-F-14256, IPC J-STD-004, NASA NHB 5300.4 certified formulations available | Qualified for aerospace, military, and medical rework specifications |
Application Scenarios
PCB Rework and Repair
The primary application for solder wick is correcting solder bridges (shorts between adjacent pads or leads), removing excess solder from insufficiently reflowed joints, and cleaning pads after component removal to prepare for replacement part placement. For QFP and SOP bridges, a medium-width braid (#3, 1.5–2.0 mm) drawn steadily along the lead row in a single pass typically clears all bridging in one operation. After component removal, fine braid (#1–#2) cleans individual SMD pads to a flat, re-solderable surface.
BGA Pad Preparation After Component Removal
After hot-air BGA removal, solder balls and residual solder remain on both the PCB pads and often on the component. The PCB pads must be cleaned flat before a replacement BGA lands — any solder protrusion above the pad surface prevents co-planarity across the ball array and causes open joints after reflow. Solder wick is the standard tool for this cleanup step: a #2 or #3 braid in a temperature-controlled iron, working one row of pads at a time with supplemental flux, removes residual solder without damaging the OSP or ENIG pad finish. After cleaning, confirm flatness across the pad array under 20× magnification before applying fresh solder paste or flux for reballing.
Prototype Development and Engineering Change Orders (ECOs)
Prototype engineers remove and replace SMD components repeatedly during bring-up, applying design changes without fabricating new PCBs. Solder wick provides a low-cost, zero-capital-equipment method for pad cleanup between rework cycles. The no-clean formulation is standard in prototype environments where cleaning time is not available between rework iterations.
EMS Production Line Rework Stations
SMT production lines generate defects at a statistical rate across all processes: paste printing misalignment, placement offset, reflow bridging, and component skew. Rework stations at the end of the AOI loop use solder wick as the primary consumable for bridge and excess-solder correction before boards proceed to functional test. The no-clean formulation is standard at production rework stations to avoid introducing a wash step for individual reworked boards.
Aerospace, Military, and High-Reliability Electronics
IPC Class 3 and military program rework requires solder wick that meets MIL-F-14256 flux specifications and NASA NHB 5300.4 workmanship standards. Rosin flux braid is standard in these applications because it provides the strongest flux activity (lowest resistance to wetting) and its post-rework residue can be completely removed and verified by ionic contamination testing. Complete IPA or saponifier cleaning of all rework areas is mandatory; no-clean residue is not accepted in most aerospace programs regardless of SIR test data.
Medical Device Assembly and Repair
IEC 60601-compliant medical device assemblies require controlled rework processes with full traceability.For implantable device circuits (pacemakers, neural stimulators), the lowest available thermal dose per rework operation is mandatory — fine braid at minimum effective width, supplemental flux to reduce dwell time, and mandatory optical and electrical inspection after each rework operation.
Solder Wick vs. Desoldering Pump vs. Hot-Air Rework Station
| Attribute | Solder Wick / Desoldering Braid | Desoldering Pump (Solder Sucker) | Hot-Air Rework Station |
| Capital equipment cost | None (iron only) | Low (≈£10–£150 for manual/electric) | High (£300–£5,000+) |
| Localized thermal control | Excellent — only target joint receives heat | Moderate — iron + suction at joint | Requires precise nozzle selection and temperature calibration; adjacent components at risk |
| Joint types supported | Any exposed pad, bridge, PTH, lead | PTH and larger SMD primarily | All types including BGA, QFN, flip-chip, CSP |
| Reusable | No — saturated braid is discarded | Yes (nozzle cleared each use) | Yes (nozzles replaceable) |
| Portability | High — fits in any toolkit | Medium | Low — fixed workstation equipment |
| Skill level required | Low–medium (technique matters) | Low | High (temperature profiling, nozzle selection) |
| Best application | SMD bridge cleanup, pad prep after component removal, PTH excess solder | PTH component removal (single pass) | BGA/QFP/QFN removal and replacement; complex package rework |
Frequently Asked Questions
What is the difference between solder wick and flux-core solder wire?
Solder wick (desoldering braid) removes solder from a joint by capillary action. Flux-core solder wire adds solder to form new joints; it is a tin-alloy filament with an internal flux channel that activates during soldering. They are functionally opposite tools and cannot substitute for each other. Both come wound on a spool, so visually confirm which material you have — solder wire is round in cross-section; braid is flat and woven.
Can I use solder wick on lead-free solder joints?
Yes. Standard rosin or no-clean solder wick is compatible with all common lead-free alloys including SAC305, SAC405, and SnBi. For lead-free work, increase iron tip temperature to 330–370°C (versus 280–320°C for Sn63/Pb37) to compensate for the higher liquidus temperature. Single-layer flat-braid constructions marketed specifically as “lead-free optimized” have lower thermal mass and heat up faster, reducing total thermal dwell time per joint — the preferred specification for fine-pitch SMD rework on lead-free assemblies. Adding a drop of supplemental no-clean liquid flux to the pad before placing braid further reduces required dwell time.
Which standards and certifications apply to solder wick?
The primary standards for solder wick flux chemistry are MIL-F-14256 (US military flux specification), IPC J-STD-004 (industry standard for flux classification by activity level and residue type), and NASA NHB 5300.4 (workmanship standards for soldering). The braid material itself must meet IPC J-STD-004 flux categories and ANSI/IPC SF-818 (flux activity classification). RoHS compliance (EU Directive 2011/65/EU) and REACH SVHC-free status (EC No. 1907/2006) are standard for products sold in the EU. For telecom applications, Bellcore TR-NWT-000078 SIR and corrosion testing may also be specified.
How long does solder wick last, and how do I know if it has expired?
Unopened solder wick in factory-sealed packaging typically retains usable flux activity for approximately two years from the manufacture date. Flux degradation is the limiting factor — the copper braid itself does not degrade, but the flux pre-impregnant oxidizes and loses activity over time. Visual inspection is the practical field test: fresh braid is bright copper-colored (orange-pink). Braid that has darkened to brown, grey, or shows green patches has undergone oxidation and will wick poorly or not at all, regardless of iron temperature.
Can the flux type on solder wick be customized, and how do I choose?
Yes. Most manufacturers offer rosin (ROL0/ROH0), no-clean (REL0/ROM0), no-clean low-residue, and flux-free variants. Choose based on your post-rework cleaning capability and assembly class: rosin flux provides the fastest wicking and strongest oxide removal, making it the first choice for aerospace, military, and medical assemblies where post-rework ionic contamination testing is mandatory. No-clean is the standard for commercial and consumer rework where a cleaning step is not practical. Flux-free braid is specified where the assembly uses a water-soluble flux process — adding rosin or no-clean flux would create a system incompatibility. Never use rosin-flux braid on a board assembled with water-soluble flux without cleaning the board completely first.
Conlusion
Select the narrowest width braid that covers the target pad. Match flux type to your downstream cleaning process — rosin for high-reliability with mandatory cleaning, no-clean for general rework, flux-free for process-specific flux control. Set iron temperature 110–150°C above the solder liquidus: approximately 330–370°C for SAC305, 280–320°C for Sn63/Pb37. Lift the braid and iron together while solder is molten — never drag a cooling braid across a pad. Cut back to fresh copper after every joint. Discard any braid that has darkened from oxidation.
Done correctly, solder wick is the fastest, least invasive, and most universally applicable rework tool in any electronics assembly environment. Done incorrectly, it is one of the easiest ways to damage pad copper and create latent reliability problems that only appear under thermal cycling or vibration. The technique is simple; the discipline — correct width, correct temperature, and the simultaneous lift — is what separates clean rework from costly board damage.
Find What You Need on LCSC
LCSC Electronics stocks a wide range of solder wick and desoldering braid consumables — covering all standard widths from ultra-fine #1 (0.76 mm) for 0402 SMD pads up to wide #6 (2.8 mm) for through-hole and bridge cleanup, in rosin, no-clean, and flux-free formulations from established brands. Whether you need a single reel of no-clean braid for prototype rework, MIL-F-14256-compliant rosin wick for an aerospace rework station, or ESD-safe packaged braid for a Class 3 assembly environment, LCSC’s search tools let you filter by width, flux type, spool length, and compliance standard in seconds.
