RAYPCB · Material selection & fabrication
Tg170 PCB: Material Grades & Design Requirements
Turn a Tg170 drawing note into an approved material specification. Match the supplier grade, thermal test data and manufacturing route to the board you need to build.
Send files for a material & fabrication quotePreliminary files welcome. Identify the grade, test method and unresolved requirements.
What does Tg170 PCB mean?
A Tg170 PCB specifies a laminate with a glass transition temperature around 170°C by an identified test method. It commonly sits in the high-Tg FR-4 category, but the label does not define decomposition resistance, expansion or allowable assembly cycles.
This is a frequent source of substitution errors: one supplier grade reports 170°C, another 175°C and another 180°C. They may all appear in a high-Tg shortlist, yet their thermal and electrical data differ. Retain the real manufacturer value instead of rewriting every grade as “Tg170.”
For the complete grade map and temperature-test definitions, use the High Tg PCB material selection guide.
Tg170 vs Tg180: compare more than 10 degrees
The cited FR406 datasheet reports Tg170°C by DSC, Td300°C and T260 of 10 minutes. The cited 370HR datasheet reports Tg180°C by DSC, Td340°C and T260 of 60 minutes. Those results show why the full thermal data matter; they are not interchangeable purchasing labels or finished-board lifetime predictions.
ITEQ lists IT-180A at 175°C by DSC. The “180A” product name should not become an invented 180°C Tg measurement. For the next category, see Tg180 PCB materials and multilayer requirements.
| Candidate / RAYPCB guide | Tg and method | Td, 5% mass loss | Z expansion, 50–260°C | Evidence |
|---|---|---|---|---|
| Isola FR406 | 170°C · DSC | 300°C | 3.5% | Supplier data |
| ITEQ IT-180A | 175°C · DSC | See current source | Not transcribed | Supplier data |
| Isola 370HR | 180°C · DSC | 340°C | 2.8% | Supplier data |
| Shengyi S1000-2M | 180°C · DSC (185°C DMA) | 355°C | 2.4% | Supplier data |
Typical published data, not purchase minima or a stock list. Methods, specimen construction and conditioning may differ. Confirm the supplier revision and the exact supplied construction. A missing entry is not zero.
Resolve the engineering question before choosing a grade
TG170 Engineering Workbench
Review the board around its thermal history
| Area | Engineering question |
|---|---|
| Through holes | How do board thickness, hole diameter, copper plating and expansion affect the validation plan? |
| Assembly cycles | How many reflow, selective soldering or rework exposures are expected, with what measured profile? |
| Moisture | What storage, drying and handling instructions apply to this material and assembly? |
| High-speed routing | Do the substitute’s design Dk, Df, foil and dielectric construction still support the electrical requirements? |
| Acceptance | Which thermal, electrical, workmanship and construction records are specified for the actual build? |
For hole structure and construction limits, use the rigid capability table. For impedance and loss, continue to high-frequency PCB design rather than inferring RF performance from Tg.
Prepare a Tg170 PCB fabrication enquiry
Enter the requested construction and material. The chosen grade remains a request until it is agreed for your build. You may skip the planner and send files directly. Material changes clear previously entered cost allowances.
TG170 Quotation Planner
Keep the prototype representative of the repeat build
A material change between a PCB prototype and production may alter the thermal or electrical behavior you intended to validate. Record the laminate, prepreg, copper, layer order and assembly conditions with the revision. If the first build uses an alternate, state what conclusions can and cannot be carried into production.
Cost is influenced by material availability, stackup, holes, copper and tests. Compare the same acceptance scope; do not assume a Tg170 board is always a fixed percentage more expensive than Tg150. The planner’s optional cost allowances must match the requested grade and construction.
Release requirements and evidence
Keep the approved laminate, compatible prepreg, supplier revision and permitted alternatives with the fabrication drawing. Add the finished stackup, copper, holes, finish, quantity and any assembly thermal profile. Specify the applicable bare-board standard/class/revision, electrical and construction checks, and additional thermal tests when required.
Review the quality and acceptance requirements and rigid manufacturing capability table for the actual construction. Supplier datasheet values are not a RAYPCB test report or a substitute for agreed inspection evidence. For populated samples, coordinate prototype assembly and validation with the same approved material.
Tg170 PCB questions
Which material should I specify for Tg170?
Start with a named grade and a defined measurement method, then verify the other thermal, electrical and manufacturing requirements. The comparison table provides candidates and supplier sources, not an automatic approved list.
Is IT-180A a Tg180 material?
The cited ITEQ page lists 175°C by DSC. Product naming and a measured property should not be treated as the same number.
Can 370HR be called Tg170?
The cited Isola datasheet reports 180°C by DSC. If it is accepted against a minimum Tg170 requirement, record that approval while preserving its actual reported value.
Does a higher T260 prove longer product life?
No. T260 is a specific time-to-delamination test. Product life depends on the finished construction and its actual electrical, thermal and environmental duty.
Does Tg170 guarantee a particular reflow count?
No universal count follows from Tg. Use the supplier’s data, the process profile and qualification results for the defined board construction.
What is needed for an alternate-material approval?
Compare method-specific Tg, expansion, thermal endurance, electrical behavior, recognition, moisture/CAF requirements and processing. Record the approved grade and revision before release.
Technical references
Manufacturer sources reviewed on 17 September 2026. Preserve the stated method and revision; confirm current data and supply before approving the build.
Send the material requirement with the board files
Attach fabrication/drill data, outline and stackup. State the thermal exposure, quantity, tests and required delivery date. If the grade or method is unresolved, mark it for engineering review. Downloaded tool notes must be attached manually.
Request a Tg170 PCB review
