GB/T 19247.6-2024Printed board assemblies - Part 6: Evaluation criteria for voids in soldered joints of BGA and LGA and measurement method (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting.

This document is part 6 of GB/T 19247 "Printed Board Assembly". GB/T 19247 has been published in the following parts.

--- Part 1: General specification Requirements for electronic and electrical soldering assemblies using surface mount and related assembly techniques;

--- Part 2: Sectional specification Requirements for surface mount solder assemblies;

--- Part 3: Sectional specification Requirements for through-hole mounting soldering assemblies;

--- Part 4: Sectional specification Requirements for terminal welding assembly;

--- Part 6: Evaluation requirements and test methods for ball grid array (BGA) and land grid array (LGA) solder joint voids.

This document is modified to adopt IEC 61191-6:2010 "Printed board assembly Part 6: Ball grid array (BGA) and land grid array (LGA) Evaluation Requirements and Test Methods for Solder Joint Voids.

This document has made the following structural adjustments compared to IEC 61191-6:2010.

--- Appendix A corresponds to Appendix C in IEC 61191-6:2010;

--- Appendix C corresponds to Appendix A in IEC 61191-6:2010.

The technical differences between this document and IEC 61191-6:2010 and their reasons are as follows.

--- Change the normative references of IEC 60194:2006 to IEC 60194-1:2021 and IEC 60194-2:2017, and the original references to IEC the terminology standards have been split;

--- The terms "ball grid array" and "disk grid array" have been deleted, and IEC 60194-2:2017 has a clear definition;

---Added two types of voids. Type A (voids inside the solder ball when the device is incoming) and Type B (voids at the solder ball/device interface when the device is incoming) (see 4.5), which is convenient for cavity identification and cavity assessment;

--- Added the grayscale technical indicators of X-ray equipment (see 5.1). Grayscale has a significant impact on the observation, measurement and calculation accuracy of solder joints and voids.

Very important impact;

--- Add Table A.3 and Table A.4 in Appendix A of IEC 61191-6:2010 to Chapter 7 of this document as Table 3 "BGA solder joints

Table 4 "Void Evaluation Criteria for LGA Solder Joints" and Table 5 "Void Evaluation Criteria for LGA Solder Joints" are provided to facilitate the application of this document.

The following editorial changes were made to this document.

--- Deleted the last paragraph of the scope of Chapter 1;

---Change the measurement process of solder joints and voids in 5.3, and make clear definition of operation process;

---Added the header of Table 2.

This document was proposed by the Ministry of Industry and Information Technology of the People's Republic of China.

This document is under the jurisdiction of the National Printed Circuit Standardization Technical Committee (SAC/TC47).

Introduction

Printed circuit board assembly is the basic component technology of electronic products, and the printed circuit board assembly process is the basic process of electronic manufacturing.

High-quality product manufacturing process control, promote the development of electronic and electrical welding interconnection and assembly technology, establish unified assembly technology requirements and operations the primary task of printed circuit board assembly is to standardize the work. In this regard, my country has established a national standard system for printed circuit board assembly.

Among them, GB/T 19247 "Printed Circuit Board Assembly" is the basic and universal standard guiding the assembly of printed circuit boards for electronic products in my country.

GB/T 19247 is intended to specify the general application of printed circuit board surface mounting soldering, through-hole mounting soldering, lead-out terminal soldering, ball grid array and disk grid array the evaluation requirements and test method requirements for solder joint voids are listed and are intended to consist of the following parts.

--- Part 1: General specification Requirements for electronic and electrical soldering assemblies using surface mount and related assembly techniques.

Surface mount and related components used to specify materials, methods, and test criteria for high quality electronic and electrical solder interconnection and assembly Installation technology requirements.

--- Part 2: Sectional specification requirements for surface mount solder assembly. The purpose is to specify requirements for integral mounting, through-hole mounting, Surface mount solder connection requirements for chip mounting and lead terminal mounting assembly.

--- Part 3: Sectional specification requirements for through-hole mounting solder assembly. The purpose is to specify requirements applicable to surface mounting, chip assembly, terminal Requirements for lead and through-hole mounting soldering assembly in connection assembly.

--- Part 4: Sectional specification requirements for lead-out soldering assembly. The purpose is to specify requirements applicable to surface mounting, chip assembly, termination Requirements for lead terminals and wire interconnect soldering assembly during assembly.

--- Part 6: Evaluation requirements and test methods for voids in ball grid array (BGA) and land grid array (LGA) solder joints.

The requirements for void evaluation of solder joints for ball grid arrays, pad grid arrays, flip chips, and multi-chip modules on printed circuit board assemblies are determined, and A method for measuring voids using X-ray observation.

Printed Circuit Board Assembly Part 6: Ball grid array (BGA) and land grid array (LGA) Solder Joint Void Evaluation Requirements and Test Methods

1 Scope

This document specifies the requirements for evaluating solder joint voiding during thermal cycling of printed board assemblies. It describes the use of X-ray observation to determine voiding.

The method of the hole.

This document is applicable to the evaluation of voids generated by solder joints of ball grid array (BGA) and land grid array (LGA) devices soldered on printed circuit boards.

It is not suitable for the evaluation and testing of voids in the BGA device package itself before printed board assembly.

This document is also applicable to void evaluation and testing of solder joints formed by melting and resolidification, other than BGA devices and LGA devices, such as Flip chip and multi-chip assembly. Not suitable for printed circuit board assembly with bottom filling material between BGA device and printed circuit board, or device sealing Evaluation and testing of solder joints within the assembly.

This document is applicable to large voids ranging from 10µm to several hundred microns generated in solder joints, and is not applicable to smaller voids with a diameter of less than 10µm.

(such as plane micro voids).

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document.

For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies to this document.

GB/T 2421-2020 Overview and Guidelines for Environmental Testing (IEC 60068-1:2013, IDT) Note. There is no technical difference between the referenced content of GB/T 2421-2020 and the referenced content of IEC 60068-1:1998.

IEC 60194-1:2021 Printed board design, manufacture and assembly terms and definitions Part 1: Printed board and electronic assembly technology IEC 60194-2:2017 Printed board design, manufacture and assembly terms and definitions Part 2: Electronic technology and printed boards and electronic

3 Terms and definitions

For the purposes of this document, the terms and definitions defined in IEC 60194-1:2021, IEC 60194-2:2017 and the following apply.

Voidoccupancy

The ratio of the void cross-sectional area of a solder joint to the maximum cross-sectional area of the solder joint.

Macrovoid

Voids with a diameter greater than 10 µm formed during the welding process.

Planar microvoids

A series of small voids with a diameter of less than 10 µm are formed at the interface between the printed circuit board (PCB) and the solder joint.