High-Tg FR-4 Bare PCB Fabrication
High Tg PCB Manufacturing
Custom high-Tg FR-4 PCBs for multilayer and HDI designs. PCBELEC reviews your specified laminate, thermal requirements and stackup, then manufactures the released bare-board design for prototype and production orders.
Send your board files, material requirements and operating profile to sales@pcbelec.com
- Material Definition Tg170 / Tg180-Class FR-4
- Board Construction Multilayer & HDI
- Fabrication Orders Prototypes to Production
Glass Transition & PCB Material Selection
What Is a High Tg PCB?
A high Tg PCB is a printed circuit board manufactured with a laminate whose resin system has an elevated glass transition temperature. Tg170- and Tg180-class FR-4 are common descriptions in high-Tg PCB specifications.
Tg describes the transition region where the resin changes from a relatively glassy state toward a more compliant state. Material stiffness and thermal expansion behavior change through this region; Tg is not the melting point.
High-Tg materials are considered alongside the board construction, thermal exposure and reliability requirements. The selected laminate must be defined by its actual properties, not the Tg label alone.
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Tg
Glass Transition
Describes a resin transition. Compare values using the stated measurement method.
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Td
Decomposition Behavior
Describes thermal degradation under a defined test condition, not a normal operating limit.
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Z-Axis Expansion
Dimensional Change
Review CTE and total expansion separately, including their units and temperature intervals.
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T260 / T288
Short-Term Thermal Endurance
Test-specific time-to-delamination indicators. They do not by themselves qualify a complete assembly or reflow process.
Tg Grade, Test Method & Complete Material Properties
Choosing Tg and the Right Laminate
Start with the application requirements, then identify a laminate and test basis that satisfy them. A Tg130, Tg150, Tg170 or Tg180 label is a selection reference, not a complete material specification.
Tg130-Class
A common conventional FR-4 reference. Evaluate the actual grade against the operating and processing requirements.
Tg150-Class
An intermediate Tg reference. The label alone does not establish the complete thermal endurance profile.
Tg170-Class
A common high-Tg specification direction. Identify the required minimum, test method and material properties.
Tg180-Class
Another high-Tg selection direction. Compare the complete datasheet, not only the higher Tg number.
These labels are practical references, not universal material classifications or continuous operating-temperature ratings. A higher Tg does not automatically mean lower loss, higher thermal conductivity or better performance in every construction.
Material Examples: Compare Tg with Its Test Method
Swipe horizontally to view the complete material comparison.
| Manufacturer / Grade | Published Typical Tg | How to Read the Value |
|---|---|---|
| ITEQ IT-180A | 175°C by DSC | Use the manufacturer's stated method and applicable datasheet. The product name is not itself a Tg specification. |
| TUC TU-768 |
170°C by TMA 180°C by DSC 190°C by DMA | These are method-dependent results for one material, not an interchangeable 170–190°C supply range. |
| Isola 370HR | 180°C by DSC | Review Tg together with the separately published decomposition, expansion and thermal-endurance characteristics. |
Manufacturer examples are provided for specification guidance, not as a default stock list or permission to substitute grades. Typical values are not automatically minimum guaranteed values; define the order requirement and applicable datasheet revision.
Do not select a material using a fixed “Tg minus operating temperature” margin alone. Long-term endurance, processing exposure and application qualification are separate parts of the engineering assessment.
Need more detail on laminate selection? Explore our High Tg FR-4 Material Selection Guide for additional material-selection guidance.
High-Tg FR-4 Board Construction
High Tg PCB Manufacturing Capabilities
PCBELEC manufactures high-Tg FR-4 bare PCBs with the laminate, stackup and conductor requirements defined together. The ranges below describe the standard high-Tg fabrication scope for this service.
- Standard Layer Range 2–20 Layers Multilayer constructions with a released layer order and stackup.
- Finished Board Thickness 0.6–3.2 mm Define the finished dimension and required tolerance in the drawing.
- Trace / Space 4 / 4 mil Approx. 0.10 / 0.10 mm for applicable standard high-Tg constructions.
Fabrication Range and Order Definition
Swipe horizontally to view the complete capability table.
| Manufacturing Item | Range / Configuration | Define with Your Order |
|---|---|---|
| Material system | High-Tg FR-4; Tg170- and Tg180-class material requirements. | State the required grade or performance specification, Tg test method and permitted material alternatives. |
| Board construction | Multilayer, HDI and specified mixed-dielectric constructions. | Provide the layer order, dielectric requirements and applicable interconnect structures. |
| Standard layer count | 2–20 layers. | Identify the full stackup and any sequential-lamination or special layer requirements. |
| Finished board thickness | 0.6–3.2 mm. | Specify the finished thickness, tolerance and any critical local measurement requirements. |
| Processing panel size | Panel capability up to 510 × 610 mm. | Provide the finished board dimensions and requested delivery form. Processing-panel size is not a universal single-board limit. |
| Copper thickness |
Outer layers: 1–3 oz/ft². Inner layers: 0.5–3 oz/ft². | Define copper by layer and distinguish starting foil from any minimum finished conductor requirement. |
| Trace / space |
Down to 4 / 4 mil. Approx. 0.10 / 0.10 mm. | Identify critical finished dimensions. Conductor rules are reviewed with copper thickness and the actual stackup. |
| Surface finish | ENIG, immersion tin, immersion silver, OSP, lead-free HASL and specified hard-gold areas. | Identify the finish and any selective plated regions. Define contact plating separately from general soldering-pad finish. |
| Testing and inspection | 100% bare-board electrical testing, AOI and specified verification requirements. | Include impedance verification where required, acceptance criteria and requested inspection records. |
The selected material, copper, layer count and feature geometry form one manufacturing combination. Capability figures are not independent values to combine without a complete construction definition.
Material Controls & Manufacturing Preparation
High Tg PCB Stackup and DFM Review
Turn the selected laminate into a clear board construction. PCBELEC reviews the material, dielectric, copper and interconnect requirements together so manufacturing preparation follows the intended design.
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Laminate Grade & Substitution Rules
Specify the required grade or a complete property-based requirement. A matching Tg label alone does not establish equivalent expansion, electrical behavior or processing performance.
Define for Review Material reference, Tg method, relevant properties and approval rules for alternatives.
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Dielectric Construction & Copper Balance
Review the core and prepreg construction with copper distribution, resin-fill needs and finished thickness. Identify mixed-material regions or asymmetry rather than assuming the Tg grade resolves them.
Define for Review Layer order, dielectric requirements, copper by layer and finished thickness tolerance.
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Hole Structures & Interconnects
Review plated holes and vias against board thickness and the selected laminate. Identify HDI layer spans, sequential builds and filling or capping requirements where they apply.
Define for Review Finished holes, via map, annular rings, hole-wall copper and specified via treatments.
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Controlled Impedance & Electrical Properties
Provide impedance targets with the relevant layers and reference planes. Review Dk, Df, dielectric thickness and conductor geometry using the appropriate material and test conditions.
Define for Review Target values, tolerances, structures, electrical constraints and permitted geometry adjustments.
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Lamination, Drilling & Hole Preparation
Manufacturing preparation takes account of the selected resin system and construction. Lamination, drilling and desmear requirements are material-specific, not one universal high-Tg recipe.
Define for Review Material and construction requirements, relevant processing constraints and specified thermal exposures.
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Thermal Exposure & Acceptance Requirements
Share the expected downstream reflow or rework exposure and application qualification needs. Identify any additional bare-board tests or documentation required beyond the agreed fabrication scope.
Define for Review Exposure profile, test criteria, requested records and any customer-controlled acceptance conditions.
Keep Copper Requirements Layer-Specific
Distinguish nominal starting foil, finished conductor copper and plated-hole copper. Do not use one board-level copper label in place of the released stackup.
Copper Thickness ReferenceRelease One Matching Manufacturing Package
Keep the artwork, drill data, stackup and drawing on the same revision. Resolve conflicting material or construction notes before manufacturing release.
Manufacturing File RequirementsMaterial Conformity & Bare-Board Acceptance
Material Verification and Fabrication Quality
Verify the high-Tg build against the approved material and manufacturing requirements. Laminate identification, board construction and electrical integrity are separate parts of the acceptance scope.
Material Conformity
Review the specified laminate grade or property requirement, approved alternatives and the applicable material documentation.
Fabricated Construction
Check the finished board against the released drawing, stackup, critical dimensions and agreed workmanship requirements.
Electrical Integrity
Verify bare-board continuity and isolation, with controlled-impedance verification where specified in the order.
Define the Verification and Documentation Scope
Swipe horizontally to view all verification details.
| Verification Area | Review / Inspection Focus | Specify with the Order |
|---|---|---|
| Laminate and material definition | The required grade or material specification and any approved substitution against the released manufacturing definition. | Material reference, required properties, test basis and requested conformity or traceability documentation. |
| Finished construction | Board thickness, profile, relevant layer construction and drawing-controlled dimensions. | Stackup reference, datums, tolerances and any dimensions requiring recorded results. |
| Conductors and plated holes | Applicable conductor, hole and interconnect acceptance requirements for the actual build. | Finished copper and hole-wall requirements, critical structures and any specified cross-section evaluation or sampling. |
| Electrical continuity and isolation | Intended bare-board connections and isolation between nets, checked against approved test data. | Test-data reference, electrical acceptance requirements and requested test summary. |
| Controlled impedance, where required | The specified impedance structures and agreed verification approach, separate from continuity testing. | Targets, tolerances, relevant layers or structures and coupon or report requirements. |
| Additional thermal or reliability evaluation | A separately agreed evaluation scope rather than an automatic consequence of the high-Tg label. | Test method, specimen or coupon, conditioning, exposure, acceptance limits and required records for review before quotation. |
Published laminate Tg values are material data, not a claim that every finished PCB is individually retested for Tg. Inspection methods, sampling and deliverable records follow the agreed order requirements.
Bare-board acceptance does not replace validation of the completed product under its actual electrical load, temperature profile and service conditions.
Bare PCB Testing & InspectionEngineering Samples to Repeat Builds
High Tg PCB Prototypes and Production
PCBELEC supports high-Tg bare PCB orders from engineering samples through small batches and production. Keep the approved material, stackup and acceptance requirements clear as the design moves between manufacturing stages.
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01 / Engineering Samples
High Tg PCB Prototypes
Fabricate samples for your design, assembly-process and application evaluation. Identify the intended laminate and construction so the boards represent the characteristics you need to assess.
Define for This BuildSample quantity, material basis, stackup, critical dimensions and evaluation requirements.
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02 / Pilot & Small Batch
Low-Volume High Tg Fabrication
Move a selected design into a limited manufacturing run. Incorporate approved prototype changes and release one matching set of material, artwork and fabrication requirements.
Define for This BuildReleased revision, approved material and alternatives, quantity and requested records.
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03 / Production & Reorders
Production High Tg PCBs
Manufacture repeat orders against the approved board specification. Identify changes to the material, stackup or acceptance scope instead of relying only on the previous order description.
Define for This BuildPart number, production revision, quantity, delivery schedule and change-control requirements.
Include the required quantity, target delivery date and material requirements with your inquiry.
High-Tg FR-4 Bare PCB Fabrication Inquiry
Request a High Tg PCB Quote
Send your board files, material requirements and order details for engineering review and quotation. Include the thermal context and intended stackup so the laminate and fabrication requirements can be reviewed together.
Include with Your Inquiry
- Fabrication Files Gerber files, drill data, board outline, fabrication drawing and design revision.
- Material Requirement Required grade or properties, Tg requirement and method, and permitted alternatives.
- Board Construction Layer count, stackup, finished thickness, copper and relevant via structures.
- Thermal Context Operating profile, hot spots, thermal cycling and expected reflow or rework exposure, where known.
- Electrical & Inspection Needs Impedance, surface finish, acceptance criteria and requested manufacturing records.
- Order & Delivery Quantity, target delivery date, destination and previous order reference, if applicable.
Send Your High Tg PCB Requirements
Use the form below to share your contact details, project specifications and available board files. Describe the required material or thermal context without treating Tg as the operating-temperature limit.
Material Selection & Manufacturing Questions
High Tg PCB FAQ
Answers to common questions about Tg grades, thermal requirements, material alternatives and high-Tg bare PCB orders.
Preparing a new build? Include the material requirement and the conditions driving your selection with the board files.
View the Quotation ChecklistWhat is considered a high Tg PCB?
A high Tg PCB uses a laminate with an elevated glass transition temperature. Tg170- and Tg180-class FR-4 are common high-Tg specification directions.
Naming conventions are not a complete material definition. Identify the grade or required properties, test method and applicable acceptance basis.
Can a Tg170 PCB operate continuously at 170°C?
A Tg170 label does not establish continuous operation at 170°C. Tg describes a resin transition, not the maximum continuous operating temperature of the complete board or product.
Review long-term material endurance, actual board hot spots, exposure duration, cycling and the product's qualification requirements separately.
Is Tg180 always better than Tg170?
Not for every design. Compare the actual laminate properties and test methods, including expansion, decomposition behavior, electrical performance and processing requirements.
Select the material that meets the complete specification. A higher Tg alone does not guarantee lower loss, better heat spreading or longer product life.
Why can the same laminate have different published Tg values?
Tg can be measured using methods such as DSC, DMA and TMA. These methods evaluate different responses and may report different values for the same resin system.
Compare the stated methods and datasheet revisions. Do not treat method-dependent results as an interchangeable material-grade range.
Is high Tg required for every lead-free reflow process?
Tg alone does not determine compatibility with a lead-free assembly process. Material selection also considers the thermal exposure, expansion, moisture condition and relevant endurance data.
Share the expected profile, number of reflow or rework exposures and any qualification criteria. A high-Tg label is not approval for every assembly condition.
Does high Tg mean higher thermal conductivity?
No. Glass transition and thermal conductivity are different material properties. Higher Tg does not, by itself, establish a more effective heat-removal path.
Evaluate conductor geometry, vias, board construction and the system's cooling approach alongside the laminate requirements.
Can another laminate with the same Tg replace my specified grade?
Not automatically. A similar Tg does not establish equivalent electrical properties, expansion, endurance or processing behavior.
State permitted alternatives and approval requirements. Review any proposed change against the full material specification, stackup and application requirements before release.
What information is needed for a high Tg PCB quotation?
Send the fabrication files, drawing, stackup, quantity and target delivery date. Include the specified grade or material requirements, with the Tg method where defined.
Add relevant operating and assembly exposure information, impedance needs and requested inspection records. Identify any material or construction items still requiring review.