ETECKSPACEQUICK ANSWER
Separate co-fired metallization from downstream surface plating
A typical HTCC flow forms internal conductors, vias, and surface metallization within a high-temperature co-fired system, then treats selected surfaces for wire bonding, soldering, brazing, sealing, or protection. The exact metal system, stack, thickness, and available areas depend on the material and supplier process and must be confirmed per project.
REVIEW FRAMEWORK
Six metal-interface questions that need clear answers
Functional zones
Distinguish internal conductors, vias, surface pads, braze areas, seal rings, and test points on the drawing.
Downstream process
State whether the interface supports wire bonding, die attach, soldering, brazing, sealing, connector assembly, or continuity only.
Base metallization
Provide the specified system or standard. If open, ask the supplier to propose and document a compatible approach.
Surface plating
Define the plated area, purpose, applicable specification, acceptable appearance, and inspection requirement rather than using a color or informal name.
Masking and boundaries
Define no-plate areas, edge clearances, cavity differences, and transitions between finishes.
Validation and packaging
Confirm thickness or composition records, adhesion, bondability or solderability checks, anti-tarnish packaging, and storage requirements.
WORKING CHECKLIST
Work backward from the assembly purpose
The table describes the communication logic, not a fixed finish stack or confirmed production capability.
| Assembly purpose | Inputs to state | Confirm separately |
|---|---|---|
| Wire bonding | Wire material, bond method, pad location, surface need, and test method | Finish system, area, thickness, and bonding validation |
| Soldering or attach | Solder, peak temperature, flux, pad, and cleaning conditions | Solderability, wetting, finish compatibility, and storage life |
| Metal-component brazing | Metal material, braze alloy, joint geometry, temperature, and atmosphere | Metallization, finish, thermal-expansion match, and joint inspection |
| Lid or hermetic structure | Lid, sealing method, seal zone, and target test method | Seal material, surface condition, flatness, and hermetic criteria |
| Corrosion or storage | Environment, storage period, packaging, cleaning, and appearance | Porosity, tarnish, contamination, and packaging approach |
RISK BOUNDARY
Ambiguous RFQ language to avoid
- Gold plate everything
- Use the normal finish
- Suitable for bonding
- Same as sample without a sample identifier
- Highest reliability without a test specification
FAQ
Questions before the next review step
Does every HTCC process use the same base metallization?
No. Material, firing conditions, and application requirements affect the choice. One supplier's process should not be treated as a universal rule.
Is a plating name enough for quotation?
The area, purpose, assembly method, applicable specification, inspection, and packaging normally need to be stated as well.
Can plating be decided after the first sample?
Some projects can use staged confirmation, but plating affects metallization, assembly, and validation. The intended final interface should be disclosed during feasibility review.