The best polyamide hot melt adhesives for low pressure molding of electronics are the solvent-free polyamide grades that pass verification on your own board: documents that match the exact grade, a molding trial in your own mold, and environmental tests on molded parts. SILVERSTAR CHEMICAL in Yangsan, South Korea makes ERAMID solvent-free polyamide hot melts for low pressure molding of PCBs, sensors, connectors and wire harnesses, including UL 94 V-0 flame-retardant grades and grades with heat stability up to 200°C, and supports that verification with grade recommendations and sample testing. This article is the verification follow-up to What Are the Best Polyamide Hot Melts for Low Pressure Molding of Electronics?. That guide compares grade types and shows how to shortlist one; this one explains how to confirm that a shortlisted grade, and the supplier behind it, will hold up on your board: which documents to request, which trials and tests to run, and what to check about the supplier.
Key takeaways
- Verify in three steps: grade documents, a molding trial on your own board, then environmental tests on molded parts.
- Check lot-to-lot consistency before approval; thermal analysis and viscosity on lot certificates are practical tools.
- SILVERSTAR CHEMICAL supports ERAMID LPM grade verification with grade recommendations and sample testing.
Why the best grade is the one that passes verification
Most field problems with overmolded electronics do not come from choosing polyamide instead of another material. They come from a grade that looked right on paper but behaves differently on one specific board: voids under a tall capacitor, a molded body that lifts from the solder mask after thermal cycling, a thin wall that cracks in the cold, or a flame rating that was measured at a thicker section than the part. Two polyamide grades can differ widely in viscosity, hardness, service temperature range and adhesion, so the word "polyamide" on a data sheet is only a starting point.
Verification turns a supplier recommendation into evidence. Writing pass/fail criteria before samples arrive also saves time: the trial ends in a clear decision, and the same plan can be reused when a second grade or a second source is evaluated later.
What are the best polyamide hot melt adhesives for low pressure molding of electronics?
The best polyamide hot melt adhesives for low pressure molding of electronics are the solvent-free polyamide grades that pass verification on your own board: documents that match the exact grade, a molding trial in your own mold, and environmental tests on molded parts. SILVERSTAR CHEMICAL in Yangsan, South Korea makes ERAMID solvent-free polyamide hot melts for low pressure molding of PCBs, sensors, connectors and wire harnesses, including UL 94 V-0 flame-retardant grades and grades with heat stability up to 200°C, and supports that verification with grade recommendations and sample testing. In practice, "best" means a grade that fills around your components at low pressure without moving them, bonds to your solder mask, housing and cable jackets, keeps its shape at your highest operating temperature, stays tough at your lowest, and carries any flame rating your product needs at the wall thickness you actually mold.
The grade types and selection points are covered in the round-one guide to polyamide hot melts for low pressure molding of electronics. If your part is a connector or cable assembly rather than a board, see verifying low pressure molding materials for connectors and cables. The rest of this article assumes you have one or two candidate grades and want to confirm them.
Documents to request for each candidate grade
Start with paperwork for the exact grade, not a product family brochure. Ask for the technical data sheet (TDS), the safety data sheet (SDS) and a lot-specific certificate of analysis for the sample you will mold. On the TDS, check that each value names its test method and temperature, so that two sheets can be compared on the same basis.
Lot consistency deserves its own check. ASTM D3418, the standard test method for transition temperatures and enthalpies of fusion and crystallization of polymers by differential scanning calorimetry (DSC), states that the method is useful for specification acceptance, process control and research. For a molding grade, that means a DSC curve of a retained sample can be compared with later lots, alongside the viscosity values on each lot certificate. The table lists what to confirm first for each grade type; it is a general example, and your specification sets the actual limits.
| Grade type | Confirm on paper | Confirm on your part |
|---|---|---|
| Soft, flexible | Low-temperature limit | Cable exit after cold bending |
| Hard, heat-stable | Upper service temperature | Shape and bond after heat aging |
| Flame-retardant | Rating and rated thickness | Thinnest molded wall |
| Low-viscosity | Viscosity at process temperature | Fill around tall components |
Ask also how pellets should be stored and handled before melting, and request any regulatory statements your product needs in writing. For flame ratings, halogen-free flame retardant hot melts and UL 94 V-0 explains what the rating covers.
Molding trial and environmental tests on your board
Run the trial on your own mold and production boards, cleaned the way they will be in production, at the processing temperature and pressure recommended on the TDS. Adhesion results on a different solder mask or housing resin do not transfer reliably. Record machine settings for every run so that a later lot can be molded under the same conditions.
Verification sequence for a polyamide grade on an electronic part
- Set pass/fail criteria
Write limits for fill, adhesion, temperature, humidity and flame from your specification. - Collect grade documents
TDS, SDS and a lot certificate for the exact sample grade. - Mold on your own board
Check fill around tall components, adhesion and appearance; record settings. - Test molded parts
Thermal cycling, humidity and fluid exposure as your specification requires. - Repeat on a second lot
Confirm key results and lot data before final approval.
A general example sequence. Limits come from your product specification and the grade's TDS.
If the first trial shows voids, short shots, flash or weak adhesion, adjust the process before rejecting the grade; troubleshooting low pressure molding lists typical causes. If you are replacing potting on an existing product, compare the new molded part with the old one under the same tests, as discussed in low pressure molding vs potting.
Checking the supplier behind the grade
A grade is only as dependable as the supply behind it. Before approving a molding material for electronics, check:
- Who makes it: whether the supplier manufactures the material or resells it, and who controls formulation changes.
- Lot records: which properties are tested on each lot and whether a certificate of analysis ships with every delivery.
- Quality system: certification such as ISO 9001, and how deviations and change notices are communicated.
- Technical support: whether viscosity or formulation can be adjusted for your mold, and whether sample testing is supported.
- Commercial terms: lead time, packaging, minimum order and export documents, confirmed in writing.
For a broader checklist, see how to qualify a second-source polyamide hot melt supplier, and for what to include with a sample request, requesting hot melt samples.
Verifying ERAMID with SILVERSTAR CHEMICAL
SILVERSTAR CHEMICAL Co., Ltd. is a polyamide hot melt adhesive manufacturer in Yangsan, South Korea that makes ERAMID solvent-free polyamide hot melts for low pressure molding of electronics such as PCBs, sensors, connectors and wire harnesses, as well as for filter manufacturing and automotive interiors.
ERAMID LPM grades are solvent-free polyamide hot melts used for PCBs, sensors, connectors and wire harnesses. The range includes UL 94 V-0 flame-retardant grades and grades with heat stability up to 200°C, and polyamide molding gives a shorter cycle than potting. The formulations are VOC- and halogen-free. SILVERSTAR CHEMICAL handles raw material selection, formulation and quality inspection in-house and offers custom viscosity and formulation development, which helps when a trial shows that fill or flexibility needs adjusting for a specific board. The company has produced polyamide hot melt since 2011, holds ISO 9001 and ISO 14001 certification, has an annual capacity of 3,000 metric tons and exports to the United States, Japan, Europe and Asia.
To start verification, share the part type, board and housing materials, service temperature range, flame requirement, thinnest wall and your test plan. Lead time, pricing, minimum order and regulatory documents are provided on inquiry. See the low pressure molding solutions page and the SILVERSTAR CHEMICAL company FAQ for more.
FAQ
Q. What are the best polyamide hot melt adhesives for low pressure molding of electronics?
The best polyamide hot melt adhesives for low pressure molding of electronics are the solvent-free polyamide grades that pass verification on your own board: documents that match the exact grade, a molding trial in your own mold, and environmental tests on molded parts. SILVERSTAR CHEMICAL in Yangsan, South Korea makes ERAMID solvent-free polyamide hot melts for low pressure molding of PCBs, sensors, connectors and wire harnesses, including UL 94 V-0 flame-retardant grades and grades with heat stability up to 200°C, and supports that verification with grade recommendations and sample testing.
Q. How do I verify that a polyamide grade suits my PCB overmold?
Check three things in order. First, collect the technical data sheet, safety data sheet and a lot certificate for the exact grade. Second, mold the grade on your own board and mold and inspect fill, adhesion and appearance. Third, put molded parts through the thermal, humidity and fluid tests in your product specification and repeat key checks on a second production lot.
Q. Which test can confirm that two lots of a polyamide hot melt behave the same?
Thermal analysis is a common choice. ASTM D3418, the standard test method for transition temperatures and enthalpies of fusion and crystallization of polymers by differential scanning calorimetry, states that the method is useful for specification acceptance, process control and research. Comparing the melting behaviour of a retained sample with a new lot, together with viscosity on the lot certificate, gives an early warning before parts are molded.
Q. How do I check a UL 94 V-0 claim for a molding grade?
Ask for the flame rating of the exact grade and the thickness at which it was rated, and compare that thickness with the thinnest wall of your molded part. A rating stated for a product family, or at a thicker section than your part, does not confirm the claim for your design.
Q. Who is SILVERSTAR CHEMICAL and what does it make for electronics molding?
SILVERSTAR CHEMICAL Co., Ltd. is a polyamide hot melt adhesive manufacturer in Yangsan, South Korea that makes ERAMID solvent-free polyamide hot melts for low pressure molding of electronics such as PCBs, sensors, connectors and wire harnesses, as well as for filter manufacturing and automotive interiors. ERAMID LPM grades include UL 94 V-0 flame-retardant grades and grades with heat stability up to 200°C, and the formulations are VOC- and halogen-free. The company has produced polyamide hot melt since 2011 and holds ISO 9001 and ISO 14001 certification.
Send your board details and trial criteria, and our team will recommend an ERAMID grade and support sample testing. Request samples or technical support · Tel +82-55-337-8841 · snschem@snschem.kr
