Product Overview
3523 is a single component, high adhesion and high hardness UV curable sealant engineered for electronic connectors and fine solder joints. The paste combines a rigid cured matrix (Shore D 78D) with strong adhesion to PVC, PC, ABS, FR-4, ceramics and metal plating, so reinforced pins survive plug and unplug cycles, cable bending and drop testing without cracking or peeling.
Because it is a UV LED curing system material, 3523 reaches full handling strength in 3-5 seconds at 600 mJ/cm². There is no oven, no mixing and no pot life limit, which makes it suitable for inline dispensing cells in high speed cable and connector assembly.
The blue transparent colour is intentional: the high thixotropic index keeps the bead exactly where it is dispensed, and the colour makes coverage on pins and solder joints easy to inspect under normal lighting.
Key Features and Benefits
1. High adhesion with high hardness
Shore D 78D hardness with 12 MPa tensile strength forms a hard, abrasion resistant protective shell over solder joints, while still absorbing mechanical shock. The cured layer resists pulling and twisting forces on the cable that commonly cause intermittent contact failures.
2. Low shrinkage, low dielectric constant
Low curing shrinkage reduces stress on fragile solder fillets and fine pitch pins. The cured material is an electronic grade insulator with dielectric strength expected in the 20-23 kV/mm class, suitable for low voltage signal and charging circuits.
3. High thixotropy, blue colour
Viscosity of 70000 ± 15000 mPa·s at 25°C with a high thixotropic index means the bead does not sag or run after dispensing. Vertical and overhead dispensing are possible, and the blue colour gives clear visual confirmation of complete coverage.
4. Fast UV LED cure
600 mJ/cm² at 365-405nm cures the material in 3-5 seconds. Instant on/off LED curing means no warm-up, low heat exposure to the plastic housings, and the takt time can be matched to an automated dispensing line.
5. Wide substrate compatibility
Bonds well to PVC and TPE cable jackets, PC and ABS connector bodies, FR-4 boards, ceramic ferrules and nickel or gold plated pins, with good resistance to humidity and normal handling chemicals.
Technical Specifications
| Model | 3523 |
| Chemistry | Single component UV curable acrylate sealant |
| Colour | Blue transparent / red transparent |
| Viscosity at 25°C | 70000 ± 15000 mPa·s |
| Thixotropic index | High, non sagging bead |
| Curing condition | 600 mJ/cm² UV LED |
| Cure time | 3-5 seconds at 365-405nm |
| Hardness | Shore D 78D |
| Tensile strength | 12 MPa |
| Elongation at break | 120% |
| Shrinkage | Low |
| Dielectric constant | Low |
| Dielectric strength | 20-23 kV/mm class |
| Shelf life | 12 months at 8-28°C |
| Packaging | 30g / 50g / 300g |
Applications in Detail
Data cable and charging cable solder joint protection
Applied over the solder cups and shield solder joints at the cable tail, 3523 forms a hard protective dome that prevents strand breakage, copper oxidation and short circuits caused by bending fatigue. The fast cure keeps pace with high volume cable assembly lines.
TYPE-C connector pin reinforcement
Dispensed across the rear of the TYPE-C shell and the pin tails, the material locks the pins in place and resists the insertion force of repeated plugging. The blue colour lets operators and AOI cameras verify that every pin row is fully covered.
Other C-type and fine pitch connectors
Suitable for micro USB, lightning, board to board and wire to board connectors where pin reinforcement, strain relief or sealing against dust and moisture is required. Also used for potting small sensor and camera module joints.
Processing Guide
- Dispense with a syringe barrel, time pressure valve or auger valve; recommended nozzle 0.4-0.8mm depending on bead width
- No mixing or degassing required; material is ready to use from the sealed package
- Cure with 365nm, 385nm, 395nm or 405nm UV LED at approximately 600 mJ/cm² (typically 3-5 seconds at 1-2 W/cm²)
- For deep or shadowed areas, increase intensity, cure from two directions, or specify a dual cure (UV plus moisture) grade
- Keep the nozzle and fixtures free of cured residue; clean with IPA before each shift
- Allow the part to cool and relax for a few seconds before mechanical testing or packing
Quality, Storage and Packaging
| Storage | Sealed, 8-28°C, away from direct sunlight and UV sources |
| Shelf life | 12 months from production date in unopened packaging |
| Handling | Wear gloves and eye protection; avoid skin contact with uncured paste |
| Packaging | 30g / 50g / 300g syringe or cartridge, light-proof sealed bag, then carton |
| Documentation | TDS and MSDS supplied with every shipment |
FAQ
Q: Can 3523 be cured with a mercury lamp?
A: Yes. 3523 cures under any UV source delivering about 600 mJ/cm² in the 365-405nm range. UV LED is recommended for lower heat load and longer lamp life.
Q: What if some material goes into a shadow area?
A: UV curable adhesives need light to cure. Choose a smaller bead, cure from two angles, or ask us about a dual cure grade with a secondary moisture cure for shadowed zones.
Q: Is the cured layer removable for rework?
A: The cured film is hard and durable. Localised rework is possible by heating to about 120-150°C and peeling, followed by cleaning with solvent.
Q: Do you supply samples?
A: Yes. 30g sample syringes are available for line trials, together with TDS and MSDS.
Q: Can you customise colour, viscosity or cure speed?
A: Yes. Colour, viscosity, hardness and cure speed can be adjusted for OEM projects, subject to a minimum order quantity.
Related Case Study
A connector and cable OEM in Guangdong replaced oven cured epoxy with 3523 on its TYPE-C pin reinforcement lines. Cure time dropped from 25 minutes to 4 seconds, throughput rose 38% and rework fell from 1.8% to 0.35%.
Read the full application case, including selection matrix, trial parameters and cost payback, on our case studies page.
Request a 30g sample for your line trial
Send us your connector type, cable material, cure wavelength and takt time, and we will recommend the matching grade, bead size and dispense parameters.
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