QJ 3086A-2016
High reliability soldering for surface and mixed mount printed circuit board assembly (English Version)
- Standard No.
- QJ 3086A-2016
- Language
- Chinese, Available in English version
- Release Date
- 2016
- Published By
- Professional Standard - Aerospace
- Introduction
Standard Evolution and Technology Upgrade
QJ3086A-2016, as the core standard for welding processes in the aerospace industry, has undergone 8 major revisions compared to the 1999 version: adding mixed installation selection principles, improving welding requirements for new packaging devices, introducing a reliability verification system, etc., reflecting the ultimate pursuit of process reliability by aerospace electronic equipment.
Key points of process control
Control dimension Surface mounting Mixed mounting Installation sequence Single-sided/double-sided mounting Surface mounting first, then through hole Temperature control 220-250℃ reflow Dual process temperature coordination Stress management Thermal expansion coefficient matching Dual control of mechanical + thermal stress Typical application cases
When a satellite control system used BGA packaged devices, it strictly followed the standard 4.1.3 to reserve 5mm of rework space, and used X-ray inspection to ensure that the solder ball offset was less than 15%, and successfully passed 200 -50~100℃ temperature cycle verifications.
Material selection specifications
- Solder: Sn63PbAA eutectic solder is preferred, and silver-containing devices use Sn62Pb36Ag2
- Flux: Rosin-based (R type) or medium-active rosin-based (RMA type)
- Cleaning agent: Non-corrosive solvents such as anhydrous ethanol and isopropyl alcohol
Reliability verification system
The standard innovatively establishes a three-level verification mechanism:
- Vibration test: sinusoidal vibration 5-2000Hz/20g, random vibration 7.1Grms
- Temperature cycle: -50~100℃/200 cycles
- Destructive analysis: Metallographic inspection crack area ≤25%
Implementation suggestions
Process optimization direction
1. For QFP devices, it is recommended that the lead forming angle be controlled at 45-90°, and the bending radius be ≥ the lead diameter
2. Adopt a step-by-step temperature curve management: preheating zone (120-150°C), insulation zone (150-180°C), reflow zone (220-250°C), cooling zone (＜100°C)
3. Establish a solder paste thickness control matrix:
Lead spacing (mm) Stencil thickness (mm) ≥0.65 0.15-0.20 0.5-0.65 0.10-0.15 <0.5 0.05-0.10
QJ 3086A-2016 Referenced Document
- GB/T 3131 Tin-lead solder
- GB/T 9491 Flux for tin soldering
- QJ 165B-2014 General technical requirement for aerospace electronic and electrical product assembly
- QJ 20023 Design requirements for high-reliability surface mount circuit assemblies
- QJ 201 Specifications for printed circuit boards
- QJ 2600 Wave soldering process technical requirements
- QJ 2711 Technical requirements for installation process of electrostatic discharge sensitive devices
- QJ 2828 Electronic assembly terms
- QJ 3012 Technical requirements for through-hole mounting of components of aerospace electronic and electrical products
- QJ 3103 Printed Circuit Board Design Specification
- QJ 3117A-2011 Technical requirements for hand soldering of aerospace electronic products
- QJ 3171 Forming Technical Requirements for Components of Aerospace Electronic and Electrical Products
- QJ 3173-2003 Technical requirements for reflow soldering of aerospace electronic and electrical products
- QJ 3259-2005 Technical requirements for protective coating of aerospace electronic products
- QJ 3267 Technical requirements for tinning process of electronic components
- QJ 831B-2011 General specification for multillayer printed board for aerospace
