吃瓜tv 路 Material selection & fabrication
Tg135 PCB: Standard FR-4 Material Selection
A standard FR-4 choice starts with the actual duty of the board. Define the supplier grade, soldering exposure and electrical requirements before choosing whether a mid- or high-Tg material adds value.
Send files for a material & fabrication quotePreliminary files welcome. Identify the grade, test method and unresolved requirements.
What does Tg135 PCB mean?
A Tg135 PCB is specified with a laminate having a glass transition temperature around 135掳C under the stated test method. It is a standard-Tg material category, not a 135掳C operating-temperature guarantee.
The useful question is not whether every design should use the largest Tg number. It is whether the named material and finished construction meet the assembly, electrical and service requirements. A lower-Tg material may be considered for a less demanding build; that decision still needs a defined exposure and acceptance basis.
For the complete grade map and temperature-test definitions, use the High Tg PCB material selection guide.
Prepare a Tg135 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.
TG135 Quotation Planner
Tg135 vs Tg150: make the comparison specific
| Requirement | Tg135 candidate review | When to compare a different grade |
|---|---|---|
| Assembly profile | Obtain peak, duration, number of cycles and moisture condition. | The specified process or validation data exceed the candidate鈥檚 demonstrated scope. |
| Plated-hole reliability | Review thickness, hole geometry, copper and total Z expansion. | A more demanding multilayer/hole construction needs a different resin or expansion response. |
| Electrical insulation | Specify CTI, CAF, insulation resistance, cleanliness and environment separately. | A higher Tg by itself does not meet a tracking or CAF requirement. |
| Cost and supply | Quote an identified grade, thickness and copper construction. | An alternative standard construction may offer easier procurement; check current supply. |
For the next material category, see Tg150 and mid-Tg FR-4. Avoid silently replacing 鈥淭g135鈥� with a supplier鈥檚 130掳C or 140掳C grade simply because it is described as standard FR-4.
| Candidate / 吃瓜tv guide | Tg and method | Td, 5% mass loss | Z expansion, 50鈥�260掳C | Evidence |
|---|---|---|---|---|
| Shengyi S1600 | 135掳C 路 DSC | 310掳颁 | 4.5% | |
| Isola IS400 | 150掳C 路 DSC | 330掳颁 | 3.3% | |
| Shengyi S1000H | 155掳C 路 DSC (160掳C DMA) | 348掳颁 | 2.8% |
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.
A useful counterexample: high CTI does not imply high Tg
Shengyi S1600 illustrates why the property list matters: the manufacturer lists Tg135掳C by DSC and CTI at least 600 V, while excluding applications requiring CAF resistance. Those conditions belong together in a review. CTI is not a Tg scale, and high CTI does not establish CAF performance.
If the application involves voltage, moisture or contamination, provide the product insulation requirements and operating environment. Do not infer creepage distances or an approved voltage rating from this page. Confirm the recognized material construction and applicable product requirements.
Resolve the engineering question before choosing a grade
TG135 Engineering Workbench
Design and quote a standard FR-4 build
Keep the stackup and copper construction realistic for the circuit. Check the smallest holes, high copper imbalance, board thickness and any controlled impedance before approving the material. For a first revision, define what the PCB prototype needs to prove and whether it represents the eventual production construction.
The economic comparison should use the same board size, layers, finish, quantity and test scope. A Tg135 option is not automatically the least expensive available route. The planner accepts only your own grade-specific allowances; it does not assign a percentage saving against Tg150 or Tg170.
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 吃瓜tv test report or a substitute for agreed inspection evidence. For populated samples, coordinate prototype assembly and validation with the same approved material.
Tg135 PCB questions
Can a Tg135 PCB operate continuously at 135掳C?
Tg alone does not answer that question. Review the actual hot spot, exposure duration, cycling, material recognition and complete product construction.
Does Tg135 automatically rule out lead-free reflow?
No automatic conclusion should be made from Tg alone. Obtain the laminate鈥檚 thermal endurance data and qualify the actual process profile, moisture condition and number of cycles.
Is Tg135 the same as Tg130 or Tg140?
They are different specified values. Supplier tolerance, method and the exact accepted grade must be stated; do not substitute by category name alone.
Should high-voltage boards always use high Tg?
Tg does not determine tracking resistance or insulation coordination. Define CTI, CAF, insulation requirements and the operating environment separately.
Is S1600 suitable whenever CAF resistance is required?
The cited S1600 manufacturer page excludes CAF-required applications. Review another appropriate material and the finished-board construction instead of treating its high CTI as proof of CAF performance.
What should a Tg135 quotation specify?
Supply the grade or material requirement, method, stackup, copper, holes, finish, quantity, assembly exposure and required acceptance tests. Identify permitted alternatives explicitly.
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 Tg135 PCB review