Electrical paths
Conductor count, layout, termination, voltage/current per path and required isolation tests.
Ceramic-to-metal and glass-to-metal are construction choices.
A hermetic electrical feedthrough carries power or signals across a sealed boundary while providing electrical isolation. The insulating material, metal interfaces and joining process must work together for the intended environment.
A ceramic insulator can appear within an assembly whose hermetic barrier uses glass. A ceramic exterior alone does not identify the sealing method. Ask for a section drawing, materials and joining details.
| Term | What to clarify |
|---|---|
| Ceramic insulator | A ceramic part providing an insulating or structural function. The part alone does not establish a complete hermetic barrier. |
| Metallized ceramic | A ceramic with specified prepared metal surfaces for joining. Identify the coating pattern, materials and intended next assembly step. |
| Ceramic-to-metal sealed assembly | Specify ceramic, conductors, metal interfaces and joining process, together with the acceptance test for the completed boundary. |
| Glass-to-metal sealed assembly | Identify the glass, metal geometry and sealing process. Do not substitute a ceramic-to-metal construction without design review. |
Technical context: KYOCERA ceramic joining information, SCHOTT glass-to-metal compressor terminals and Morgan metallized ceramics. These references illustrate different constructions; their product ratings do not apply to a Hermavell sourcing inquiry.
Define the conditions together.
Installation interface
Housing material, weld or braze joint, flange/thread details, mating parts and critical tolerances.
Operating environment
Temperature range and cycling, vacuum or pressure, process media and assembly exposure such as bakeout.
Delivery boundary
Bare ceramic, metallized part or complete assembly; who performs joining, inspection and final acceptance.
“Hermetic” is not a complete test specification.
State the test medium, measurement method, units, acceptance limit and test conditions. Include pressure differential, temperature, test stage and inspection coverage where relevant. Identify whether the requirement applies to every assembly, a sample or a qualification test.
Leak-rate numbers cannot be compared reliably without matching methods, units and conditions. A dimensional inspection, a dielectric test and a leak test answer different questions.
A useful drawing and sample package
- Drawing number and revision, component boundary and mating interfaces.
- Materials, geometry, critical dimensions and joining surfaces.
- Electrical, environmental and leak-test acceptance requirements.
- Sample quantity, review responsibilities and required test records.
- Production demand, traceability expectations, packaging and delivery.
Hermavell coordinates technical sourcing around the defined component. Supplier fit and sample review establish the next step; the initial inquiry does not establish a universal performance rating.
Continue with your product family
Is a ceramic-to-metal seal always better than a glass-to-metal seal?
Selection depends on the assembly, environment, interfaces and qualification requirements. The category name alone does not establish the best construction or a valid operating limit.
Can a material data sheet replace testing the assembly?
No. Material properties describe the material under stated conditions. Assembly performance also depends on geometry, joints, mating parts and the actual acceptance tests.
Can Hermavell review an existing design?
An inquiry can begin with an existing drawing or a defined component need. Provide the revision, operating conditions, sample needs and required evidence for supplier review.