I. Introduction: Solderable Enameled Wire – The “Efficiency Revolution” of Electronic Component Assemblyolution” in electronic component assembly
Solderable Enameled Copper Wire (sew) is the key base material for modern electronics manufacturing. Its core advantage is no need to remove the paint film beforehand , it can be welded directly by heating – greatly simplifying the process, improving efficiency and improving consistency.
Weldable enameled wire vs. plain enameled wire :
– Ordinary enameled wire: the paint film (mechanical/chemical/laser) needs to be removed→ before welding
– Weldable enameled wire: heated film is → automatically decomposed and welded at the → same time
– Process reduction: 3-5 steps → 1-2 steps
– Efficiency improvement: 50-200%
8 Typical Applications :
– Electronic component leads
– Transformer coil terminals
– Relay coil
– Inductive devices
– Micro-motor windings
– Smart wear
– IoT devices
– Instrument coil
Core Technology Benefits :
– 1-step welding (vs 3-5 steps)
– Local heating (to avoid thermal damage)
– Suitable for automatic welding (dip/wave/reflow)
– High reliability (no mechanical damage)
– Environmentally friendly (no chemical paint stripping)
1.1 Development of weldable enameled wire
3 phases :
– 1950s: Polyurethane (PU) enameled wire appears (first solderable enameled wire)
– 1980s: Self-adhesive enameled wire + solderable enameled wire popularization
– 2000s-present: Eco-friendly + high-temperature + high-speed welded enameled wire
1.2 6 Core Strengths Quantification
| Strengths | Plain enameled wire | Solderable enameled wire | Lift |
|---|---|---|---|
| Number of operations | 3-5 steps | 1-2 steps | -60% |
| Welding Time | 5-10 s | 1-3 s | -70% |
| Welding Temperature | 380-420°C | 350-400°C | -10-30°C |
| Yield | 95-98% | 99-99.5% | +1-4% |
| Equipment Investment | Medium | Low | -30-50% |
| Labor Costs | High | Low | -50-70% |
1.3 5 technical indicators
| Metrics | Typicals | Units | Importance |
|---|---|---|---|
| Solderable Temperature | 370-400 | °C | Critical |
| Solderable Time | 1-3 | s | Critical |
| Solder Wettability | > 95 | % | Critical |
| Film Residue | < 0.5 | % | Critical |
| Dielectric Strength | > 5 | kV | Critical |
II. Enamel Material System of Solderable Enameled Wire
2.1 Polyurethane (PU/UEW) enameled wire
Chemical composition :
– Body: polyurethane
– Isocyanate group (NCO)
– Solvents: toluene, xylene
– Additives: catalysts, stabilizers
Features :
– Weldable temperature: 370-380°C (minimum)
– Soft and stretchy paint film
– Dielectric strength: > 5 kV
– Applicable temperature class: Class B (130°C)
Benefits :
– Lowest weldable temperature (energy saving)
– No residue from the decomposition of the paint film
– Suitable for high speed welding
Limitations :
– Low temperature rating (B)
– Moderately strong paint film
– Can’t be used above H level
Typical applications :
– Electronic component leads
– Instrument coil
– Communication equipment
– Home appliance motors
2.2 Polyesterimide/polyurethane composite enameled wire
Chemical composition :
– Interior: Polyesterimide
– Outer layer: polyurethane
– Composite structure
– Temperature resistant and weldable
Features :
– Weldable temperature: 380-400°C
– Applicable temperature class: Class F (155°C)
– High mechanical strength of the paint film
– Dielectric strength: > 6 kV
Benefits :
-Temperature resistant + solderable
– High strength of paint film
– Wide application area
Typical applications :
– General Motors
– Small transformers
– Relays
– Automotive electronics
2.3 Polyamide imide/polyurethane enameled wire
Chemical composition :
– Bottom layer: Polyamideimide (Pai)
– Skin: Polyurethane
– Bi-level structure
– Complementary performance
Features :
– Weldable temperature: 390-410°C
– Applicable temperature class: Class H (180°C)
– Extremely high mechanical strength of the paint film
– Dielectric strength: > 8 kV
Benefits :
– High temperature rating (H)
– High mechanical strength
– High dielectric strength
– Excellent combined performance
Typical applications :
– High-end motor windings
– Traction motor
– Industrial motors
– High Frequency Transformer
2.4 Self-adhesive + solderable composite enameled wire
Chemical composition :
– Interior: Polyurethane
– Outer layer: Self-adhesive layer (hot melt adhesive)
– Bi-level structure
– solderable + self-adhesive
Features :
– Weldable temperature: 370-400°C
– Self-adhesive temperature: 110-150°C
– Applicable temperature class: Class B-F
Benefits :
– solderable + self-adhesive combination
– Skeleton free coil
– High efficiency
Typical applications :
– Skeletonless coil
– Micromotor
– Sensors
– RFID
2.5 Comparison table of 5 major paint film materials
| Film Type | Weldable Temperature | Temperature Rating | Film Strength | Dielectric Strength | Main Applications |
|---|---|---|---|---|---|
| PU | 370-380°C | B (130°C) | Medium | > 5 kV | Electronics |
| Polyesterimide + PU | 380-400°C | F (155°C) | High | > 6 kV | General Motors |
| Pai + PU | 390-410°C | H (180°C) | Very High | > 8 kV | High-end motors |
| PEI + PU | 380-400°C | F-H (155-180°C) | High | > 7 kV | Universal High Frequency |
| Self-adhesive + PU | 370-400°C | B-F (130-155°C) | Medium | > 5 kV | Skeletonless coil |
III. Key Technical Parameters of Solderable Enameled Wire
3.1 Conductor Specifications
Conductor material :
– Soft copper (T1/T2/TU1/TU2)
– Silver and copper alloys
– Tinned copper
– Nickel-plated copper
Conductor shape :
– Circular line: Φ 0.05-2.0 mm
– Flat wire: 0.5-2.5 × 2-8 mm
– Coated copper wire: Φ 0.1-1.5 mm (mainstream)
Conductor diameter tolerance :
– Standard: ± 0.005 mm (Φ < 0.5 mm)
– Standard: ± 0.01 mm (Φ ≥ 0.5 mm)
– Strict: ± 0.003 mm
3.2 Paint film thickness
Film Grade :
– Grade 0 (Thin): 5-10 μm
– Grade 1 (standard): 8-15 μm (most commonly used)
– Grade 2 (thick): 12-20 μm
– Grade 3 (thick): 18-25 μm
Paint film thickness selection :
– High Frequency Application: Grade 1 (Thin)
– High voltage applications: Grade 2-3 (thick)
– General application: Grade 1
– Welding application: Grade 1
3.3 Solderability Indicators
Weldable Temperature :
– Starting weldable: 370°C (typical)
– Best weldable: 380-400°C
– Limit weldable: 420°C
– Not recommended: > 450°C
Solderable time :
– Dip welding: 1-3 s
– Wave soldering: 0.5-1.5 s
– Reflow soldering: 30-90 s
– Soldering: 1-5 s
Solder wettability :
– Solder expansion rate: > 95%
– Wetting time: < 1 s
– Full immersion: 1-3 s
Paint film decomposition residue :
– Residue < 0.5%
– No residue
– Does not affect conductivity
3.4 Electrical performance
Dielectric strength :
– Grade 1: > 5 kV (single layer)
– Grade 2: > 7 kV
– Grade 3: > 10 kV
Insulation resistance :
– Normal: > 10 ¹ ³ Ω · cm
– After humid heat: > 10 ¹ ¹ Ω · cm
Media loss :
– 1 kHz: < 0.02
– 100 kHz: < 0.03
3.5 Mechanical properties
Elongation :
– Soft copper: > 30%
– Film: > 10%
Tensile strength :
– Soft copper: > 200 MPa
Flexibility :
– Round rod winding: 1-3x
– Paint film does not crack
Adhesion :
– Sharp pull test: no shedding
– Strong adhesion between paint film and copper
IV. Application Areas of Solderable Enameled Wire
4.1 Electronic component leads
Application : diode, triode, capacitor, inductor, resistance lead
Specifications :
– Circular line Φ0.1-0.5 mm
– Grade 1 paint film
– Length: 10-50 mm
Process :
– Automatic thread trimming
– Automatic dip welding
– Autopositioning
– High-speed production
Efficiency :
– Normal process: 30 pcs/min
– Weldable process: 60-120 pcs/min (+100-300%)
4.2 Transformer coil terminals
Applications : high-frequency transformers, low-voltage transformers, signal transformers
Specifications :
– Circular line Φ 0.1-1.0 mm
– Three layers of insulation + solderable paint film
Process :
– Automatic winding
– Terminal dip welding (tin furnace)
– Welding temperature: 370-400°C
– Welding time: 1-3 s
Benefits :
– No need to paint
– Solder joints are consistent
– Automatic welding
– Suitable for mass production
4.3 Relay Coil
Applications : automotive relays, signal relays, power relays
Specifications :
– Circular line Φ 0.05-0.3 mm
– solderable varnish
Process :
– Automatic winding
– Automatic terminal welding
– High-speed production
Efficiency gains :
– Normal: 60 pcs/min
– Weldable: 100-200 pcs/min (+50-150%)
4.4 Micromotor winding
Applications : Micro DC motors, Stepper motors, Core Cup motors
Specifications :
– Circular line Φ 0.05-0.3 mm
– solderable + self-adhesive paint film
Process :
– Automatic winding
– Terminal dip welding
– Self-adhesive + drying
Benefits :
– solderable + self-adhesive
– Automated production
– Suitable for miniaturization
4.5 Summary of Top 5 Apps
| Application | Wire Diameter | Paint Film | Welding Method | Efficiency Improvement |
|---|---|---|---|---|
| Electronic component leads | Φ 0.1-0.5 mm | PU Grade 1 | Immersion soldering/peaks | +100-300% |
| Transformer terminals | Φ 0.1-1.0 mm | PU Grade 1-2 | Dip soldering | +50-100% |
| Relay Coil | Φ 0.05-0.3 mm | PU Grade 0-1 | Dip Soldering/Soldering Iron | +50-150% |
| Micro motor winding | Φ 0.05-0.3 mm | Self-adhesive + PU | Immersion welding + Self-adhesive | +50-100% |
| Instrument Coil | Φ 0.05-0.5 mm | PU Grade 0 | Soldering/Dip Soldering | +30-80% |
V. Soldering Process of Solderable Enameled Wire
5.1 6 major welding methods
Method 1: Dip Soldering
– Solder temperature: 370-400°C
– Immersion time: 1-3 s
– Fit: Lead Terminal
– Equipment: Tin furnace
Way 2: Wave Soldering
– Solder temperature: 380-410°C
– Contact time: 0.5-2 s
– Fit: PCB welding
– Equipment: wave soldering machine
Way 3: Reflow Soldering
– Peak temperature: 250-260°C (lead-free)
– Time: 30-90 s
– Suitable for: SMT process
– Equipment: reflow oven
Mode 4: Iron Soldering
– Soldering iron temperature: 350-400°C
– Time: 1-5 s
– Suitable for: Manual + Automatic
– Equipment: soldering iron
Way 5: Selective wave soldering
– Local dip welding
– Suitable for: Precision devices
– Automation
Mode 6: laser welding
– Local heating
– Suitable for: Precision devices
– No contact
5.2 Welding temperature selection
Temperature Selection Principle :
– Safety lower limit: 370°C
– Optimum temperature: 380-400°C
– Not recommended: > 420°C (paint film may overheat)
– Extreme temperature: 450°C (short term acceptable)
Factors :
– Paint film type
– Paint film thickness
– Conductor diameter
– Welding time
– Solder type
5.3 6 welding process elements
- Preheat : 100-150°C/30-60 s
- Removes moisture
- Reduce thermal shock
Improve weld consistency
Flux :
- Resin type (no cleaning)
- Water soluble
Good weldability
Welding time :
- Dip welding: 1-3 s
- Wave soldering: 0.5-2 s
Soldering: 1-5 s
Cooling :
- Natural cooling
- Forced air cooling
Avoid quenching
Post-processing :
- Wash (remove flux)
- Testing (solder joint quality)
Aging test (optional)
Inspection :
- Visual inspection
- Automatic AOI detection
- X-Ray detection
- Slicing analysis
VI. Solderable Enameled Wire vs Ordinary Enameled Wire
6.1 Process comparison
| Steps | Plain Enameled Wire | Solderable Enameled Wire |
|---|---|---|
| 1. Cord trimming | ✓ | ✓ |
| 2. De-painting | ✓(3-5 steps) | ✗(No need) |
| 3. Pre-Welding | ✓ | ✓ |
| 4. Welding | ✓ | ✓ |
| 5. Inspection | ✓ | ✓ |
| Total process | 5-7 steps | 3 steps |
6.2 6 Dimensions Comparison
| Dimensions | Plain Enameled Wire | Solderable Enameled Wire | The Winner |
|---|---|---|---|
| Process Steps | 5-7 | 3 | Weldable |
| Welding Efficiency | 30-60 ppm | 60-200 ppm | Weldable |
| Welding Temperature | 380-420°C | 370-400°C | Weldable |
| Yield | 95-98% | 99-99.5% | Solderable |
| Equipment investment | High (paint stripping + welding) | Low (welding only) | Weldable |
| Consistency | Medium | High | Weldable |
| Labor Costs | High | Low | Solderable |
| Environmentally friendly | Medium (chemical stripping) | Excellent (chemical-free) | Weldable |
6.3 Comparison of Top 5 Application Scenarios
Scenario 1: HF transformer winding
– Normal enameled wire: 3-5 steps (paint removal + welding)
– Solderable enameled wire: 2 steps (direct welding)
– Strengths: Efficient, consistent
Scenario 2: Relay coil
– Normal enameled wire: manual de-painting + welding
– Solderable enameled wire: automatic welding
– Benefits: Automatic, efficient
Scenario 3: Micromotor winding
– Plain enameled wire: loosely embedded + soldered
– Solderable enameled wire: solderable + self-adhesive
– Benefits: Reliable, automatic
Scenario 4: Instrument Coil
– Plain enameled wire: soldered (slow)
– Solderable enameled wire: dip welded (fast)
– Strengths: Efficient, consistent
Scenario 5: Electronic component leads
– Ordinary enameled wire: chemical/mechanical paint removal
– Solderable enameled wire: direct immersion welding
– Advantages: Eco-friendly and efficient
VII. Quality Control of Solderable Enameled Wire
7.1 6 Core Tests
Test 1: solderability test
– Standard: IEC 60851/GB 4074
– Method: soldering ball method, impregnation method
– Qualified: > 95% infiltration
Test 2: Dielectric Strength Test
– Standard: IEC 60851/GB 4074
– Method: Pressurized in water
– Qualified: > 5 kV (Grade 1)
Test 3: Paint film continuity test
– Standard: IEC 60851/GB 4074
– Method: Saline Bath + Voltage
– Qualified: 0 defects
Test 4: Paint film adhesion test
– Standard: IEC 60851/GB 4074
– Method: Quick pull test
– Qualified: No detachment
Test 5: Heat Shock Resistance Test
– Standard: IEC 60851/GB 4074
– Method: High Temperature + Bending
– Qualified: No cracking
Test 6: solder joint strength test
– Standard: IPC-A-610/IPC J-STD-001
– Method: Tensile test
– Qualified: Tensile > 30 N
7.2 6 Major Reliability Tests
- Aging test :
- Temperature: 150°C/175°C/200°C
- Time: 1,000h – 5,000h
Arrhenius model
Damp heat test :
- Temperature: 40°C
- Humidity: 95% RH
Time: 96h – 1,000h
Temperature cycle :
-40°C ↔ +85°C/-55°C ↔ +125°C- Number of cycles: 100 – 1,000
Inspection: Cracked paint film
Vibration test :
- Frequency: 10-500 Hz
- Acceleration: 10-50 m/s ²
Orientation: triaxial
Weld Wetting Aging :
- Storage time: 6-24 months
90% wettability after aging
Environmental testing :
- RoHS 2.0
- reach
- Lead-free soldering adaptation
7.3 Quality Level
| Level | Defect Rate | Apply |
|---|---|---|
| AAA | < 0.1% | Military, Aerospace |
| AA | < 0.5% | Automotive, Medical |
| A | < 1% | Industry |
| B | < 2% | General, Consumer |
VIII. Selection Guide for Solderable Enameled Wire
8.1 5 Large dimensional selection comparison
| Dimension | PU | Polyesterimide + PU | Pai + PU | Self-adhesive + PU |
|---|---|---|---|---|
| Solderable Temperature | Lowest | Medium | Higher | Lowest |
| Temperature Rating | B (130°C) | F (155°C) | H (180°C) | B-F |
| Film Strength | Medium | High | Very High | Medium |
| Dielectric Strength | > 5 kV | > 6 kV | > 8 kV | > 5 kV |
| Main Applications | Electronic Components | General Motors | High-End Motors | Frameless Coils |
8.2 6 Application Selection Recommendations
Application 1: HF transformer (< 1 MHz)
– Recommended: PU Grade 1
– Wire diameter: Φ 0.1-0.5 mm
– Film thickness: 8-15 μm
Application 2: Power transformer
– Recommended: Polyesterimide + PU Grade 2
– Wire diameter: Φ 0.3-1.0 mm
– Film thickness: 12-20 μm
Application 3: Relay Coil
– Recommended: PU Grade 0-1
– Wire diameter: Φ 0.05-0.3 mm
– Film thickness: 5-15 μm
Application 4: Micromotor
– Recommended: Self-adhesive + PU
– Wire diameter: Φ 0.05-0.3 mm
– Film thickness: 5-15 μm
Application 5: Automotive Electronics
– Recommended: Pai + PU Grade 1-2
– Wire diameter: Φ 0.2-1.0 mm
– Film thickness: 8-20 μm
Application 6: Air Military
– Recommended: PI + PU Grade 1-3
– Wire diameter: Φ 0.1-1.0 mm
– Film thickness: 8-25 μm
8.3 Selection decision tree
Scenario
↓
Temperature rating requirements?
Class ├─ B → PU
├─ F-grade → polyesterimide + PU
└─ H-class → Pai + PU
↓
Is self-adhesive required?
├─ Is → self-adhesive + PU
└─ No → Single film
↓
Paint film thickness requirements?
├─ Thin → Grade 0-1
├─ Standard → Grade 1-2
└─ Thick → Grade 2-3
↓
Wire size?
├─ Micro (< 0.3 mm)→ Grade 0-1
├─ Small (0.3-1.0 mm)→ Grade 1-2
└─ Medium (> 1.0 mm)→ Grade 2-3
IX. Development Trends of Solderable Enameled Wire
9.1 4 Technology Trends
Trend 1: Higher temperature tolerance
– Target: Class H (180°C) Class→ C (200°C +)
– Application: high frequency, high power density motor
– Status: Partially commercialized
Trend 2: Thinner paint film
– Target: < 8 μm
– Purpose: high frequency, high power density
– Advantages: Small size, good heat dissipation
Trend 3: Higher invasiveness
– Target: > 99%
– Application: High-end electronics
– Strengths: Increased reliability
Trend 4: Eco-friendly paint film
– Target: Solvent-free
– Purpose: Environmental requirements
– Advantage: Zero VOC emissions
9.2 5 Emerging Applications
Application 1: 5G HF devices
– Demand: high frequency + low loss
– Specifications: Φ 0.05-0.3 mm
– Paint film: low loss PU
Application 2: NEV IGBT
– Demand: high power + high frequency
– Specifications: Φ 0.5-2.0 mm
– Paint film: high temperature weldable
Application 3: IoT sensors
– Demand: miniaturization + automation
– Specifications: Φ 0.02-0.1 mm
– Paint film: solderable + self-adhesive
Application 4: Medical Electronics
– Demand: Reliable + Eco-friendly
– Specifications: Φ 0.1-0.5 mm
– Paint film: medical grade PU
Application 5: Aerospace
– Demand: Extremely reliable
– Specifications: Φ 0.1-1.0 mm
– Paint film: PI + weldable
9.3 3 major industry directions
Direction 1: Intelligent Production
– Digital Workshop
– Online monitoring
– AI Optimization
Direction 2: Localization
– Regional supply
– Reduced logistics
– Improve responsiveness
Direction 3: Sustainability
– Eco-friendly paint film
– Recycling
– Carbon neutral
X. Common Problems and Solutions of Solderable Enameled Wire
10.1 6 Frequently Asked Questions
Question 1: Can’t be soldered (can’t be tinned)
– Cause: Insufficient temperature/Paint film not decomposed/Paint film deterioration
– Solution: Increase the temperature + check the paint film
Question 2: solder joints are not full
– Cause: Over Temperature/Over Time/Paint Residue
– Resolve: Adjust Temperature + Time
Question 3: Copper oxide
– Cause: Over Temperature/Over Time/Solder Impurities
– Resolve: Optimize Temperature + Solder Quality
Question 4: Bogus soldering
– Cause: Insufficient flux/Low welding temperature/Insufficient time
– Solution: Increase Flux + Increase Temperature
Question 5: Brittle cracking of solder joints
– Cause: Solder contamination/Cooling too fast/Stress
– Solution: Optimize solder + slow cooling
Question 6: Batch yield decreases
– Reason: Paint film batch difference/equipment aging/parameter drift
– Resolution: Batch Testing + Equipment Maintenance
10.2 5 Precautions
Action 1: Incoming Inspection
– Film thickness + solderability + dielectric strength
– Batch sampling
– Unqualified Batch Isolation
Action 2: Process monitoring
– Temperature monitoring
– Time monitoring
– Real-time alarms
Measure 3: Equipment Maintenance
– Regular cleaning of the tin furnace
– Soldering Head Replacement
– Calibrate temperature sensor
Action 4: Environmental control
– Temperature 22-28°C
– Humidity 40-60%
– Cleanliness
Measure 5: Personnel Training
– Operating Specifications
– Exception handling
– Continuous improvement
XI. 20 Glossary of Terms
| Chinese | English | Abbreviations | Definitions |
|---|---|---|---|
| Solderable Enameled Copper Wire | sew | Directly Weldable Enameled Wire | |
| Polyurethane | PU | Commonly Used Solderable Films | |
| Polyesterimide | PEI | High Temperature Resistant Film | |
| Polyamide-imide | Polyamide-imide | Pai | High Temperature Resistant Paint Film |
| Polyimide | Polyimide | PI | Very High Temperature Resistant Paint Film |
| Self-Bonding Enameled Wire | sew | Heating Self-Bondable Enameled Wire | |
| Dip Soldering | – | How to Dip Solder | |
| Wave Soldering | – | Wave Soldering | |
| Reflow Soldering | – | Soldering Method | |
| Solder Wettability | – | Ability of the solder to expand on the surface of the conductor | |
| Film Decomposition | Enamel Decomposition | – | Film Decomposition at High Temperatures |
| Dielectric Strength | Dielectric Strength | – | Ability of the paint film to withstand voltage |
| Solder Spread Rate | – | Percent Coverage of Solder on Conductor Surface | |
| Immersion Testing | Dip Test | – | Immersion Solderability Testing |
| Solder Ball Test | Solder Ball Test | – | Solder Ball Test |
| Film Grade | Grade | – | Film Thickness Grade |
| Tensile Testing | Jerk Test | – | Method for Testing Film Adhesion |
| Solder Joint Strength | – | Mechanical Strength of Solder Joint | |
| Electronic Component Lead | – | Electronic Component Lead | |
| Lead-Free Solder | – | Lead-Free Solder |
XII. Introduction to LP Winding Wire
LP Winding Wire is the world’s leading manufacturer of winding wires. Its main products include enameled wires, paper coated wires, glass fiber coated wires, Nomex paper coated wires, PI film coated wires and other series.
Weldable enameled wire products :
Circle line series :
– PU enameled wire (solderable) :
– Φ 0.05-0.5 mm
– Grade 0-2 Paint Film
– Weldable temperature 370-380°C
– Applicable temperature class B
– Polyesterimide + PU enameled wire (solderable) :
– Φ 0.1-1.5 mm
– Grade 1-3 Paint Film
– Weldable temperature 380-400°C
– Applicable temperature class F
– Pai + PU enameled wire (solderable) :
– Φ 0.2-2.0 mm
– Grade 1-3 Paint Film
– Weldable temperature 390-410°C
– Applicable temperature class H
– PI + PU enameled wire (solderable) :
– Φ 0.1-1.0 mm
– Grade 1-3 Paint Film
– Weldable temperature 400-420°C
– Applicable temperature class C
Flat wire series (weldable) :
– PU solderable flat wire :
– 0.5-2.0 × 2-8 mm
– Weldable temperature 370-400°C
– Applicable Class F
Self-adhesive + weldable composite :
– Self-adhesive + PU :
– Φ 0.05-0.5 mm
– Self-adhesive temperature 110-150°C
– Weldable temperature 370-400°C
– Applicable to Class B-F
8 industry-specific products :
– For electronic component leads :
– Micro-diameter weldable enameled wire
– Φ 0.05-0.5 mm
– Weldable + High Efficiency
– Applicable: diode/triode/capacitor/inductor
– For high-frequency transformers :
– PU solderable enameled wire
– Low dielectric loss
– Applicable: high frequency transformer
– For power transformers :
– Polyesterimine + PU
– High temperature resistance
– Applicable: Power transformer
– For relay coils :
– PU micro enameled wire
– High infiltration
– Applicable: Car/Signal/Power Relay
– For micro-motor windings :
– Self-adhesive + PU
– Miniaturization
– Applicable: Micro DC motor/Stepper motor
– For Automotive Electronics :
– Pai + PU
– High temperature resistance
– Applicable: Automotive electronics
– For NEV IGBT :
– High power solderable
– High frequency and high power
– Applicable: IGBT/Inverter
– For instrument coils :
– PU Grade 0-1
– High precision
– Applicable: Instrument Coil
Core strengths :
– Full size solderable enameled wire (Φ 0.02-2.0 mm)
– 5 major paint film systems (PU/PEI + PU/Pai + PU/PI + PU/self-adhesive + PU)
– Full temperature class (B/C/F/H class)
– Full film grade (Grade 0-3)
– Full range of applications (electronics, motors, transformers, automobiles)
– UL, VDE, TÜV, CCC, CSA, SGS, RoHS, reach fully certified
– IEC 60851/IPC-A-610/J-STD-001 standard
– Annual capacity of 50,000 tons
Contact :
– Official Website : https://www.lpwindingwire.com
– Email : sales@lpwindingwire.com
XIII. Summary and Outlook
Weldable enameled wire is the “efficiency revolution” in the electronics manufacturing industry – through 1-step welding instead of 3-5-step paint removal + welding process, it greatly improves production efficiency, reduces labor costs, and improves product consistency.
13.1 Summary of core strengths
| Strengths | Quantitative Data |
|---|---|
| Process reduction | 5-7 steps → 3 steps (-60%) |
| Welding Efficiency | +50-300% |
| Yield | +1-4% |
| Equipment Investment | -30-50% |
| Labor Costs | -50-70% |
| Solder Wettability | > 95% |
| Media Strength | > 5 kV |
13.2 5 Future Trends
- Higher temperature rating : Class H Class → C (200°C +)
- Thinner paint film : < 8 μm
- Higher wettability : > 99%
- Eco-friendly paint film : Solvent-free
- Intelligent production : online monitoring + AI optimization
13.3 6 Tips for Action
- Clarify application scenarios : temperature, frequency, intensity
- Select coating system : one of PU/PEI/Pai/PI
- Select film thickness : Grade 0-3
- Optimize the welding process : temperature, time, flux
- Establish quality control : 6 tests + 6 reliability tests
- Continuous improvement : Data analysis + AI optimization
13.4 8 Typical Apps Final Recommendations
| Application | Recommended Film | Thread Diameter | Key Benefits |
|---|---|---|---|
| Electronic Component Leads | PU Grade 1 | Φ 0.1-0.5 mm | High Efficiency + High Consistency |
| Transformer Terminal | PU Grade 1-2 | Φ 0.1-1.0 mm | High Efficiency + Automation |
| Relay Coil | PU Grade 0-1 | Φ 0.05-0.3 mm | High Efficiency + Microdiameter |
| Micro motor windings | Self-adhesive + PU | Φ 0.05-0.3 mm | Skeleton free + automation |
| Instrument Coil | PU Grade 0 | Φ 0.05-0.5 mm | High Precision + Automation |
| Automotive Electronics | Pai + PU | Φ 0.2-1.0 mm | High Temperature Resistance + Reliability |
| IGBT winding | PI + PU | Φ 0.5-2.0 mm | High power + high frequency |
| Aeromilitary | PI + PU | Φ 0.1-1.0 mm | Extremely reliable |
LP Winding Wire is committed to providing a full range of weldable enameled wire solutions – covering 8 application scenarios such as electronic components, high-frequency transformers, power transformers, relays, micro-motors, automotive electronics, IGBTs, aviation military, etc., to provide efficient, reliable and environmentally friendly welding materials for the global electronics manufacturing industry.
XIV. Appendix A: Quick Reference of 5 Major Enamel Characteristicsop 5 Weldable Enameled Wires
| Paint Film | Weldable Temperature | Temperature Rating | Paint Film Strength | Media Strength | Main Application Areas |
|---|---|---|---|---|---|
| PU | 370-380°C | B (130°C) | Medium | > 5 kV | Electronics, Instruments |
| PEI + PU | 380-400°C | F (155°C) | High | > 6 kV | General Motors, Transformers |
| Pai + PU | 390-410°C | H (180°C) | Very High | > 8 kV | High-end motors, traction |
| PI + PU | 400-420°C | C (200°C +) | Very High | > 10 kV | Aviation Military, High Temperature |
| Self-adhesive + PU | 370-400°C | B-F (130-155°C) | Medium | > 5 kV | Frameless coils, micromotors |
XV. Appendix B: 7 Key Control Points in Production Process
B.1 Conductor pretreatment
- Brushed annealing: stress relief, hardness adjustment
- Conductor cleaning: removal of grease, oxide layer
- Surface treatment: electroless copper plating/passivation
B.2 Preparation of lacquer
- Solids content control: 18-25%
- Viscosity control: 50-150 cp
- Temperature control: 22-28°C
- Fully stirred/filtered
B.3 Painting process
- Painting method: mold painting/felt painting/roll painting
- Painting times: 4-12 times
- Baking: vertical/horizontal
- Temperature gradient: 200-400°C/zone
B.4 Baking curing
- Baking temperature: 300-450°C
- Baking time: 10-30 s/time
- Baking times: 4-12 times
- Environmental control: Nitrogen protection (optional)
B.5 Paint film thickness control
- Real-Time Thickness Measurement: Online Thickness Gauge
- Film uniformity: ± 1 μm
- Roundness: ellipticity < 5%
- Continuity: 0 defects
B.6 Paint quality inspection
- Film thickness: micrometer/laser thickness measurement
- Paint film continuity: salt water bath + voltage
- Dielectric strength: pressure test
- Paint film surface: visual inspection/microscope
B.7 Finished product inspection
- Solderability test: solder ball method + impregnation method
- Dielectric test: High voltage test
- Tensile test: elongation + tensile strength
- Visual Inspection: Chromatic Aberration + Surface
XVI. Appendix C: 6 Implementation Case Studies
C.1 Case 1: HF power transformer (5G base station)
Application : 48V/12V HF power transformer
Wire diameter : Φ 0.3 mm
Paint film : PU Grade 1
Welding process : Wave soldering (400°C/1s)
Capacity : 10,000 pieces/hour
Yield : 99.5%
Benefits : Automatic, efficient, consistent
C.2 Case 2: Automotive relays
Application : 12V automotive relay coil
Wire diameter : Φ 0.1 mm
Paint film : PU Grade 1
Welding process : Automatic immersion welding (380°C/2s)
Capacity : 100,000pcs/day
Yield : 99.7%
Benefits : High speed, high reliability
Case 3: NEV IGBT
Application : 800V High Power Motor Controller IGBT Winding
Wire diameter : Φ 1.0 mm
Paint film : PI + PU Grade 2
Welding process : Selective wave soldering (420°C/1.5s)
Production : automated production lines
Features : High power, high temperature, high frequency
Strengths : Efficient and reliable
C.4 Case 4: Smart wearables
Application : Smartwatch Heart Rate Sensor Coil
Wire diameter : Φ 0.05 mm
Paint film : PU Grade 0
Welding process : Precision dip welding (360°C/1s)
Capacity : 50,000pcs/day
Yield : 99.0%
Strengths : miniaturized, consistent
C.5 Case 5: Instrument Coil
Application : 6-digit half-digital multimeter measurement coil
Wire diameter : Φ 0.08 mm
Paint film : PU Grade 0
Welding process : Precision dip welding + soldering iron repair welding
Accuracy : 0.01%/6 digits and a half
Advantages : high precision, high consistency
C.6 Case 6: Aviation military power supply
Application : MIL-STD-704 power transformer
Wire diameter : Φ 0.5 mm
Paint film : PI + PU Grade 3
Welding process : selective dip welding (420°C/2s)
Certification : MIL-STD-1553/DO-160
Features : Very high reliability, wide temperature
Benefits : High performance and reliability
XVII. Appendix D: 4 Mainstream Standards and Certifications
D.1 International standards
- IEC 60851: Enameled round wire standard
- IEC 60317: Enameled wire model standard
- IPC J-STD-001: Welding Process Standard
- IPC-A-610: Acceptance Criteria for Electronic Components
- JIS C 3202: Enameled copper wire standard
- GB/T 6109.7: Polyurethane enameled wire
D.2 International certification
- UL: Basic Security (Electronic UL 60950)
- TÜV: Comprehensive Certification
- VDE: German Electrical Certification
- CSA: Canadian Standards Association
- CQC: China Quality Certification
- SGS: Third Party Testing Certification
D.3 Environmental certification
- RoHS 2.0: 6 Hazardous Substances Restrictions
- reach: EU Chemical Regulation
- Halogen-Free: halogen-free products
- Paint film low VOC content
- Solvent-free paint film system
- Industrial Specification IV-D-2
- ISO 14001: Environmental management system
D.4 Industry Advice
- Selection evaluation→ supplier certification
- Sample Test→ Parameters→ Test Article Testing
- Batch Capacity Assessment→ Production Capacity→ Delivery Capacity
- After Sales Tracking→ Quality Issue Response
- Long-term cooperative→ technology cultivation→ supply guarantee
Qualification inquiry : Supplier sales support includes technical support, test reports, certification, product inspection, and technical responsibility.
XVIII. Appendix E: Comparison Table with Other Enamels
| Film Type | Weldable Temperature | Temperature Rating | Main Applications | Price |
|---|---|---|---|---|
| PU (solderable) | 370-380°C | B | Electronics | Low |
| PEI + PU (solderable) | 380-400°C | F | General Motors | Medium |
| Pai + PU (solderable) | 390-410°C | H | High-End Motor | High |
| PI + PU (solderable) | 400-420°C | C | Aviation Military | Very High |
| PE (General) | Not recommended | B-F | General Motors | Low |
| PEI (Normal) | Not recommended | F-H | High-end motor | Medium |
| PI (General) | Not recommended | C | Aeromilitary | Extremely high |
| PVDF (Normal) | Not recommended | H | Special motors | High |
Price range (relative to PU enameled wire = 1.0):
– PEI + PU (solderable): 1.2-1.5
– Pai + PU (solderable): 1.6-2.0
– PI + PU (solderable): 2.5-3.5
– Self-adhesive + PU (solderable): 1.3-1.5