Alumina Ceramic Substrates for Thermoelectric Modules
Ceramic Substrate
SKU: FWM/CS-ALU-001
- Material
- Alumina
- Size
- Custom sizes by drawing
- MOQ
- By quotation
- Applications
- Thermoelectric Modules
96% alumina insulating substrates for thermoelectric module assembly, reviewed for outline, thickness, surface condition and circuit requirements.
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Product Description
Alumina insulating plates support the electrode and thermoelectric-element assembly while separating its electrical circuit from the external contact surfaces.
The ceramic forms part of the module's heat-transfer path. The thermoelectric elements, rather than the bare plate, produce the active cooling effect.
Shown as a bare insulating substrate, not a complete thermoelectric module. Electrodes and assembly requirements are reviewed separately.
Product Advantages
- Electrical isolation separates the electrode assembly from the external contact surfaces.
- A rigid alumina plate supports repeated electrode positions across the module footprint.
- Flat contact faces provide defined interfaces between the thermoelectric assembly and its heat-transfer surfaces.
Typical Applications
- Thermoelectric Modules: insulating plates support the electrodes and thermoelectric elements.
- Electronic Insulation: the ceramic separates live electrode patterns from adjacent contact surfaces.
Technical Data
96% Alumina Substrate (708 S) Properties
| Property | 96% Al₂O₃ — 708 S | Test conditions / measurement tolerance ±10% |
|---|---|---|
| Density (g/cm³) | ≥3.75 | DIN EN 993-1 |
| Bending strength, σ₀ (MPa) | ≥500 | — |
| Young’s modulus (GPa) | ≥300 | — |
| Thermal conductivity (W/(m·K)) | 24 | Room temperature; DIN EN 821-2 |
| Linear thermal expansion coefficient (10⁻⁶/K) | 7–9 | 100–800°C; DIN 51045-1 |
| Specific heat capacity (J/(g·K)) | ≥0.75 | 20°C; DIN EN 821-3 method B |
| Relative permittivity | ~9.8 | Room temperature, 1 MHz; Ra ≤0.4 µm |
| Dielectric loss factor | ≤0.005 | Room temperature; 1 MHz; Ra ≤0.4 µm |
| Volume resistivity (Ω·cm) | ≥10¹⁴ | Room temperature; IEC 62631-3 |
| Breakdown strength (kV/mm) | AC≥15; DC≥15 | 20°C; AC / DC |
| Fracture toughness (MPa·m½) | ≥3.0 | Indentation-fracture (IF) |
How to Read the Parameters
- Purity
Composition identifies a material class, not a guaranteed circuit result.
Specify: Grade designation and relevant property report.
- Surface texture
Ra or Rq describes a defined ceramic surface in µm or nm.
Specify: Functional face, measurement method and local defect criteria.
- Flatness and thickness
Flatness, total thickness variation and parallelism describe different geometry.
Specify: Datums, span, support state and measurement method.
- Electrical properties
Volume resistivity uses Ω·cm or Ω·m; insulation resistance uses Ω.
Specify: Temperature, humidity, voltage, electrification time and specimen geometry.
Alumina: material and surface selection
Alumina is an electrically insulating ceramic platform for printed-film, thin-film and package constructions. Purity, surface condition and geometry must be selected for the downstream process; a bare plate is not a completed circuit.
01Define the grade
Select the alumina formulation and the intended film, metallization or assembly route.
02Form and fire
Ceramic forming and firing establish the body; the chosen route must account for shrinkage and the required finished geometry.
03Finish functional features
Where specified, machine or laser-process features and prepare the functional surfaces.
04Inspect the delivered condition
Assess dimensions, surfaces and edge condition against the drawing before later circuit processing.
How the substrate fits into a thermoelectric module
Application Conditions & Design Review
The insulating platform inside a TEC
A thermoelectric module normally places P-type and N-type elements between two ceramic plates. The plates support the electrode pattern and separate the electrical circuit from the external mounting surfaces, while allowing heat to pass through. The ceramic plate itself is not the active cooling element.
Specify the interfaces, not only the material
For a compact cooler, plate thickness, flatness and parallelism must be considered together with the electrode design and attachment layers. Clean, well-matched mounting surfaces help control thermal contact resistance. Cooling capacity and temperature difference must be assessed on the complete module with its hot-side heat sink.
Film compatibility
Select the grade and surface for the actual resistor, conductor or deposited-film system, not purity alone.
Functional geometry
Identify circuit areas, datums, mounting features and separation edges.
Thermal and electrical role
Balance ceramic thickness, heat transfer and isolation within the completed assembly.
Send With Your Drawing
- Finished plate dimensions, thickness, parallelism/flatness datums and any holes, notches or scribe lines.
- Whether the supply is bare ceramic or metallized, plus electrode artwork, finish and the intended pellet-attachment process.
- Module operating conditions, mounting method, hot-side cooling arrangement and electrical-isolation test requirement.
Include the drawing revision, sample and production quantities, and required inspection documents.
Define Acceptance Before Production
- Inspect dimensions, surface condition and plate geometry using the agreed datum and measurement span; define allowable chips and cracks.
- For metallized parts, specify pattern and insulation checks separately; validate cooling performance and thermal cycling on the assembled module.
Agree the test methods, sampling plan, acceptance limits and required reports before production.
Available Forms & Processing
Product-specific geometry and processing features.
- Plate outline, thickness and corner geometry matched to the module footprint.
- Flatness, parallelism and contact-face finish defined independently for the two interfaces.
- Bare insulating plates for a separately specified electrode and thermoelectric-element assembly.
Engineering Questions
Can the ceramic plate specification tell me the cooler's cooling capacity?
No. Cooling capacity also depends on the thermoelectric elements, current, temperature difference, attachment layers and heat rejection. The plate specification defines an important thermal and electrical interface, but it does not establish a complete module rating.
Is higher-purity alumina always the better substrate?
No. The preferred grade depends on film compatibility, surface condition, geometry and assembly needs. Purity alone does not establish resistor stability or thin-film yield.
Does a hole in alumina provide an electrical via?
No. A hole is a geometric feature until a compatible conductor or metallization structure is specified and qualified.
Packaging & Shipping
Packaging is selected for substrate finish, quantity and export handling.
| Item | Details |
|---|---|
| Packaging approach | Packaging is selected for substrate finish, quantity and export handling. |
| Protection methods | Individual separation; Anti-scratch interlayers for polished surfaces; Tray or foam protection; Inner box and export carton; Moisture protection where appropriate; Wooden case for larger export consignments when required |
| MOQ reference | By quotation |
| Lead-time references | Quotation inputs: Drawing, material, finish, quantity and delivery destination |
| Payment terms | T/T / Western Union / PayPal; 50% advance payment, 50% balance before shipment |
| Shipping methods | Sea freight / Air freight / Door-to-door courier |
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