Four aerospace and defense board types
Avionics controllers, satellite payloads, radar RF assemblies and 10 U.S.C. 4873 covered defense subsystems share an IPC-6012 Class 3 baseline but differ in laminate, thickness and documentation. The starting points below come from the Tecsply stackup selector.
| Board type | Typical layers · thickness | Laminate starting point | Glass |
|---|---|---|---|
| Avionics controller (DO-160 environment) | 10–20 · 2.0–3.2 mm | High-Tg FR-4 (Tg ≥ 170 °C), CAF-resistant, Class 3 | Low-CTE E-glass; T-glass on boards over 3.0 mm |
| Satellite / space payload | 8–16 · 1.6–2.4 mm | Polyimide or high-Tg FR-4, Class 3A | Low-CTE E-glass; T-glass on boards over 3.0 mm |
| Radar / phased-array RF | 10–20 · 2.0–3.2 mm | Hybrid: RO4350B / RO3003 RF layers over high-Tg core | Low-CTE E-glass in the FR-4 section |
| Defense subsystem (10 U.S.C. 4873 covered) | 10–20 · 2.0–3.2 mm | High-Tg FR-4, Class 3, loss grade by data rate | Low-CTE E-glass; T-glass on boards over 3.0 mm |
Aerospace build envelope
Every Tecsply aerospace build is specified to IPC-6012 Class 3 or 3A, including 100 thermal-shock cycles per IPC-TM-650 2.6.7.2, with laminate Tg of at least 170 °C and lot-level traceability of laminate and foil. The envelope below is the baseline we quote from; program requirements tighten it.
| Parameter | Requirement |
|---|---|
| Performance class | IPC-6012 Class 3 / 3A |
| Laminate Tg | ≥ 170 °C FR-4 · polyimide ≥ 250 °C |
| Thermal cycling (program-specified) | −55 °C to +125 °C, typically 1,000 cycles |
| Thermal shock (IPC-TM-650 2.6.7.2) | 100 cycles, ≤ 10% resistance change, no barrel cracks |
| CAF resistance | Required on all Class 3 builds |
| Copper | 1–6 oz, wrap plating on PTH |
| Traceability | IPC-1782, level per program (typ. M3 / P3), lot-level CCL and foil |
| Country of origin | Taiwan / Japan / Thailand / Vietnam / Malaysia; fabrication site named on the certificate of conformance |
Thermal cycling, z-axis expansion and PTH reliability
On a 2.4–4.0 mm avionics or satellite board, z-axis expansion of the laminate is the main driver of plated through-hole barrel cracking in IPC-6012 Class 3 thermal-shock testing. The resin expands through the thickness of the board far more than the glass-reinforced plane does, and a copper barrel running through that thickness is stretched on every heating cycle. After enough cycles the barrel, or its joint with an inner-layer pad, cracks.
For thermal-cycling boards the first CCL question is therefore not Df but z-axis CTE and Td (decomposition temperature). We specify Tg ≥ 170 °C, Td ≥ 340 °C and z-CTE below 3% total expansion (50–260 °C) on any board that will see lead-free rework, and polyimide when the operating envelope passes 200 °C. The glass decision is a separate one: T-glass or low-CTE E-glass constructions lower in-plane expansion and keep a thick board flat, but they do not replace a low z-CTE resin system, because expansion through the thickness is set mainly by the resin. We treat the glass choice as a reliability decision too and document it in the first-article report.
Thickness and drill size interact with all of this. A thicker board with a smaller hole has a higher aspect ratio, which makes the barrel harder to plate evenly and puts more strain on a thinner copper wall. Use the stackup thickness calculator to check total thickness and aspect ratio against your smallest drilled hole before the review.
CAF resistance
Conductive anodic filament (CAF) growth is a failure mode in which copper migrates along a glass fiber between two conductors under bias and humidity, and Tecsply requires CAF-resistant laminate on all Class 3 builds. The risk rises as hole-to-hole spacing shrinks and as the board sees long powered life in humid or condensing environments, which describes most avionics and defense hardware. CAF resistance is a property of the resin system, the glass finish and the fabricator's drilling quality together, so we specify the laminate by name and review the fabricator's drill and desmear process as part of qualification.
Radar and RF hybrid stackups
Phased-array and radar RF sections use PTFE or ceramic-filled laminates with Df around 0.001 (RO3003, RO4350B class), usually as one or two RF layers bonded over a high-Tg FR-4 or Megtron core. The hybrid keeps the expensive, harder-to-process RF material where the antenna feed or RF routing needs it, and keeps the digital and power layers on a laminate the fabricator can drill and plate at Class 3 yields. The bond between the two material families is the critical step, and we confirm the fabricator has laminated the specific combination before the order.
Country of origin: 10 U.S.C. 4873, IPC-1782 and IPC-1791
From January 1, 2027, 10 U.S.C. 4873 bars the Department of Defense from acquiring a covered printed circuit board from a covered nation: North Korea, China, Russia or Iran. The advance notice of proposed rulemaking issued on July 2, 2026 (comments closed August 31, 2026) proposes to test the geographic point of fabrication of bare and partially manufactured boards, backed by an Independent Hardware Assurance Framework built on ISO/IEC 20243, IPC-1782 (traceability) and IPC-1791 (trusted designer, fabricator and assembler), with certifications flowed down to every subcontract tier and verification records kept for 10 years.
Every Tecsply product, from multilayer PCBs to machined metal parts, is manufactured in a non-restricted country specified by the customer, outside the four covered nations, and the manufacturing site is named on the certificate of conformance; boards come from our partner base in Taiwan, Japan, Thailand, Vietnam and Malaysia. The records we provide with aerospace orders are:
- the material declaration, down to laminate family, glass style and copper weight;
- IPC-6012 Class 3 or 3A inspection records and microsection reports;
- a country-of-origin package covering the bare board, the laminate and the copper foil,
- lot-level traceability records built to IPC-1782.
Our partner fabricators are selected to build to IPC-6012 Class 3 and IPC-1782 traceability requirements.
Titanium, aluminum-lithium and superalloy parts
Alongside Class 3 boards, Tecsply supplies machined parts in 3 aerospace alloy families: Ti-6Al-4V titanium, third-generation aluminum-lithium, and Inconel 718 / 625 nickel superalloys, each bought to a named AMS or producer specification with the mill certificate and melt source recorded per lot. Titanium and nickel alloys fall under the DFARS 252.225-7009 specialty-metals clause, so their melt source is part of the quote, not an afterthought. See aerospace alloy parts for grades, specifications and machining notes; they are supplied by our Thermal, Enclosures & Aerospace Machining division.
Defense sourcing: current status
For US defense and aerospace programs, this is where Tecsply stands today:
- Country of manufacture. Every Tecsply product, from multilayer PCBs to machined metal parts, is manufactured in a non-restricted country specified by the customer, outside North Korea, China, Russia and Iran. Boards come from partner fabricators in Taiwan, Japan, Thailand, Vietnam and Malaysia; the fabricator and fabrication site are named on the certificate of conformance, with lot-level laminate and copper foil records.
- Controlled technical data. Export-controlled (ITAR/EAR) and CUI technical data are exchanged only through a handling path agreed with you first; please do not send them through the website or by email.
- Metal parts. For programs under DFARS 252.225-7009, titanium and nickel alloys must be melted in the United States or a qualifying country; the melt source is confirmed in each quote and the mill certificate travels with every lot.
Aerospace and defense FAQ
These four questions cover the requirements a program auditor or prime contractor most often asks about; the full list is on the FAQ page.
What PCB requirements apply to aerospace and defense boards?
Aerospace and defense multilayer PCBs are usually built and inspected to IPC-6012 Class 3 or 3A, which includes 100 thermal-shock cycles per IPC-TM-650 2.6.7.2 on test coupons. They use high-Tg (170 °C and above) or polyimide laminates, often against program-specified thermal cycling between −55 °C and +125 °C, require CAF-resistant materials, and increasingly need country-of-origin traceability. From January 1, 2027, 10 U.S.C. 4873 bars the Department of Defense from acquiring covered PCBs from North Korea, China, Russia or Iran.
What does 10 U.S.C. 4873 require from a PCB supplier?
From January 1, 2027, 10 U.S.C. 4873 bars the Department of Defense from acquiring a covered printed circuit board from a covered nation: North Korea, China, Russia or Iran. The advance notice of proposed rulemaking of July 2, 2026 (comments closed August 31, 2026) proposes to test where bare and partially manufactured boards are fabricated, backed by an Independent Hardware Assurance Framework built on ISO/IEC 20243, IPC-1782 (traceability) and IPC-1791 (trusted designer, fabricator and assembler), with certifications flowed down to every subcontract tier.
In practice a prime contractor needs to show where the bare board was fabricated, trace the laminate and copper foil lots behind it, and hold certifications from every tier. Every Tecsply product, from multilayer PCBs to machined metal parts, is manufactured in a non-restricted country specified by the customer, outside the four covered nations; boards come from partner fabricators in Taiwan, Japan, Thailand, Vietnam and Malaysia. Aerospace and defense orders ship with origin records for the board, the laminate and the foil. Whether a specific program is a covered system, and the final certification requirements, are set by the statute and the final DFARS rule; confirm them with your contracting officer.
When should an aerospace board use polyimide instead of high-Tg FR-4?
High-Tg FR-4 with Tg of 170 °C or above, Td of 340 °C or above and total z-axis expansion below 3% (50–260 °C) covers most avionics and defense boards, including boards that will see lead-free rework. Polyimide laminates, with Tg of 250 °C and above, are specified when the operating envelope passes 200 °C, and are a common choice for Class 3A satellite and space payload boards. Polyimide costs more and is harder to process, so we recommend it only when the thermal envelope requires it.
T-glass vs E-glass: what is the difference in a PCB laminate?
E-glass is the standard reinforcement in FR-4, with a fiber Dk of about 6.8 at 1 GHz and a CTE of about 5.6 ppm/°C. T-glass is a high-silica, high-modulus glass with a CTE of about 2.8 ppm/°C, half that of E-glass, and a tensile modulus of about 86 GPa against 75 GPa for E-glass (Nittobo published values). Choose T-glass when warpage and dimensional stability limit the design, such as boards under packages larger than 60 mm or thick boards that must stay flat. T-glass lowers the laminate's in-plane (X,Y) expansion; expansion through the board's thickness, which strains plated through-holes, is set mainly by the resin system and is specified through the laminate's z-axis CTE. For the lowest dielectric loss, NE-glass is usually the better reinforcement.
Check the stackup, then send us the program requirements
Check total thickness and aspect ratio in the calculator, then send the operating envelope, class, layer count and program origin requirements for a stackup review.
References
- IPC-6012 (rigid PCB qualification and performance), IPC-1782 (traceability), IPC-1791 (trusted electronic designer, fabricator and assembler requirements), IPC-TM-650 2.6.7.2 (thermal shock, thermal cycle and continuity); ISO/IEC 20243.
- 10 U.S.C. § 4873, Additional requirements pertaining to printed circuit boards (uscode.house.gov); DFARS Case 2022-D011 advance notice of proposed rulemaking, 91 FR 40508 (July 2, 2026), comments closed August 31, 2026; Crowell & Moring client alert on the ANPR (July 2026).
- Rogers RO3003/RO4350B and high-Tg FR-4 / polyimide supplier datasheets: Tg, Td, z-axis CTE.
- Nittobo Electronic Materials: glass cloth types (E, NE, T).