This Standard has been cancelled and superseded by ECSS-Q-ST-70-61C (8 April 2022)

Scope

This Standard defines the technical requirements and quality assurance provisions for the manufacture and verification of high-reliability electronic circuits based on surface mounted device (SMD) and mixed technology. The Standard defines acceptance and rejection criteria for high-reliability manufacture of surface-mount and mixed-technology circuit assemblies intended to withstand normal terrestrial conditions and the vibrational g‑loads and environment imposed by space flight. The proper tools, correct materials, design and workmanship are covered by this document. Workmanship standards are included to permit discrimination between proper and improper work.

The assembly of leaded devices to through-hole terminations and general soldering principles are covered in ECSS-Q-ST-70-08. Requirements related to printed circuit boards are contained in ECSS-Q-ST-70‑10, ECSS-Q-ST-70-11 and ECSS-Q-ST-70-12. The mounting and supporting of devices, terminals and conductors prescribed herein applies to assemblies at PCB level designed to continuously operate over the mission within the temperature limits of -55 °C to +85 °C. For temperatures outside this normal range, special design, verification and qualification testing is performed to ensure the necessary environmental survival capability. Special thermal heat sinks are applied to devices having high thermal dissipation (e.g. junction temperatures of 110°C, power transistors) in order to ensure that solder joints do not exceed 85 °C. Verification of SMD assembly processes is made on test vehicles (surface mount verification samples). Temperature cycling ensures the operational lifetime for spacecraft. However, mechanical testing only indicates SMD reliability as it is unlikely that the test vehicle represents every flight configuration.

This Standard does not cover the qualification and acceptance of the EQM and FM equipment with surface-mount and mixed-technology. The qualification and acceptance tests of equipment manufactured in accordance with this Standard are covered by ECSS-E-ST-10-03. This standard may be tailored for the specific characteristics and constraints of a space project, in accordance with ECSS-S-ST-00.

Note:

Reason for Corrigendum 1 is the correction of requirement 14.2.2c.1:
Incorrect text:
“1. device size is between the length Lmax and the width Wmax of the verified component,”

Corrected text:
“1. the device size length is between Lmin and Lmax and the device size width is between Wmin and Wmax of the ones of the verified component,”

Attachments:

• ECSS-Q-ST-70-38C Rev.1-Corrigendum1(12September2018).pdf
• ECSS-Q-ST-70-38C Rev.1-Corrigendum1(12September2018).docx (file size about 25 MB)

Md5 checksum .doc file = DF512D596886AA763EF5E2A5AD1462B1
Md5 checksum .pdf file = 1EBF8E5ED3DEC220A50390C55D733E48

DRDs of this standard

Process Identification Document (PID): ECSS-Q-ST-70-38C Rev.1-Cor.1(12September2018)-AnnexF.docx
ECSS-Q-ST-70-38C Rev.1-Cor.1(12September2018)-AnnexG.docx
SMT summary table: ECSS-Q-ST-70-38C Rev.1-Cor.1(12September2018)-AnnexH.docx

This Standard cancels and replaces:

• ECSS-Q-ST-70-38C Rev.1 (15 September 2017)
• ECSS-Q-ST-70-38C (15 November 2008).