GB/T 18334-2025Specification for flexible multilayer printed boards (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. This document supersedes GB/T 18334-2001 "Specification for Flexible Multilayer Printed Circuit Boards with Through-Connections". This document is consistent with GB/T 18334- Compared to.2001, aside from structural adjustments and editorial changes, the main technical changes are as follows:

---The scope has been changed (see Chapter 1, Chapter 1 of the.2001 edition);

---Added terms and definitions (see Chapter 3);

---Added application levels (see Chapter 4);

---Added the priority order for file selection (see 5.2);

---Materials specifications have been added (see 5.3);

---Design requirements have been added (see 5.4);

---The requirement for simulated rework has been added (see 5.7.8);

---Added cleanliness requirements (see 5.8.2);

---The specification for damp heat insulation resistance has been added (see 5.9.3);

---Vibration specifications have been added (see 5.10.2);

---Added other performance specifications (see 5.11);

---Added quality assurance provisions (see Chapter 6);

1 Scope

GB/T 18334-2025 is the Chinese national standard covering the flexible multilayer board - the base film and adhesive, the conductor and via construction, the bend radius and the flexing endurance, the impedance control, and the acceptance criteria for a board that has to keep working while it is folded inside a phone or a camera. At 23,000 words. It replaces GB/T 18334-2001, a specification twenty-four years old. In force from 1 May 2026. Issued on 31 October 2025, it has been in force since 1 May 2026, replacing GB/T 18334-2001.

This document specifies the requirements, quality assurance, and delivery preparation for flexible multilayer printed circuit boards, and describes the corresponding inspection methods. This document applies to the design, production, and inspection of flexible multilayer printed circuit boards.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB/T 2036 Printed Circuit Terminology

GB/T 2423.4 Environmental testing of electrical and electronic products - Part

3 Terms and Definitions

The terms and definitions defined in GB/T 2036, as well as the following terms and definitions, apply to this document.