CQI-17 – Special Process: Soldering System Assessment

Introduction

Soldering, i.e. electronics soldering or wire soldering, is one of the so-called special processes in industry. Before we delve into details related to CQI-17, let's briefly explain what a special process actually is.

What is a Special Process?

A special process is one whose result cannot be fully verified immediately after its completion through measurement and monitoring.

In other words—we cannot be 100% sure that a particular product characteristic has been created correctly, despite performing visual inspections or various measurements.

Examples of special processes:

• Soft soldering
• Brazing
• Welding
• Spot welding
• Heat treatment (hardening, carburizing, tempering, etc.)
• Coating/plating application (nickel plating, tin plating, gold plating, etc.)
• Die casting
• and many others...

Quality assurance in these processes cannot rely solely on measurements of the finished product—proper process control is necessary to obtain repeatable products that meet requirements. Typical approaches include:

• Monitoring process characteristics—temperature, time, humidity, current, etc., i.e., parameters influencing specific product features. Ideally, these should be monitored continuously and automatically, with process interlocks in case limits are exceeded.
• Testing product samples—usually, samples are taken from the process for testing, sometimes destructive, e.g., metallographic cross-sections, joint or weld tear tests, pull-force tests for crimped connections.
• Applying NDT—in certain cases, Non-Destructive Testing methods can be used, enabling more frequent inspections or even 100% checks. Examples include X-ray inspection, XRF coating thickness measurements.
• Incoming material inspection—the quality of supplied materials, alloys, fluxes, powders/granulates, etc., must also be supervised.

Like any other process, a special process requires a risk analysis through P-FMEA. Methods for process control should be detailed in the Control Plan. The measurement system should be evaluated through MSA analysis, and if sampling is involved, it's advisable to use SPC tools.

Additionally, personnel training, maintenance of machinery and tools, as well as ensuring identification and traceability in the process, are essential.

Clearly—a special process requires special handling and management.

AIAG CQI Special Process Assessments

The AIAG organization developed CQI (Continuous Quality Improvement) documents for the automotive industry.

The CQI manuals for special processes require periodic (e.g., annual) self-assessments of special processes based on audit questions prepared by AIAG. Questions are divided into general categories (quality management, materials, equipment) and process-specific tables.

As of April 19, 2025, AIAG has developed CQI manuals for the following special processes:

• CQI-9 - Heat Treat
• CQI-11 - Plating
• CQI-12 - Coating
• CQI-15 - Welding
• CQI-17 - Soldering
• CQI-23 - Molding
• CQI-27 - Casting
• CQI-29 - Brazing
• CQI-30 - Rubber (processing)
• CQI-35 - Wire Harness (assembly)

There are other CQI manuals (e.g., CQI-20 problem-solving or CQI-8 layered audits) but are omitted here, as they don't directly relate to special processes.

History of CQI-17

The first edition of CQI-17 appeared in 2010 as CQI-17 Special Process: Soldering System Assessment (SSA).

The second edition was published in 2021, changing its name to CQI-17 Special Process: Electronic Assembly Manufacturing – Soldering System Assessment (EAM-SSA). Audit forms were updated, and the process tables were almost entirely restructured.

The latest version is available for purchase on the AIAG website.

Purpose of CQI-17

The purpose of CQI-17 is:[1]

• Improving soldering systems by emphasizing process control and reducing variability throughout the supply chain.
• Defining fundamental requirements for soft soldering according to IATF-16949 and customer-specific requirements (CSR).
• Standardizing requirements for soft soldering in the automotive industry.

Applying CQI-17 helps meet IATF-16949 requirements, customer-specific requirements (CSR), and continuously improve processes through audits and corrective actions.

Scope of CQI-17

CQI-17 covers soft soldering of electronic assemblies (modules) and electromechanical devices (e.g., wires, coils).

It must be applied throughout the supply chain—if assembly is outsourced, suppliers must also implement CQI-17. Industry requirements cannot be circumvented through outsourcing.

CQI-17 includes requirements for the following areas:[1]

• Section 1 - Management Responsibility and Quality Planning
• Section 2 - Material Handling
• Section 3 - Equipment
• Section 4 - Job Audit
• Process Tables:
  • A - Paste Printing and SPI
  • B - SMD Component Placement
  • C - Reflow Soldering + AOI/AXI
  • D - Adhesive Dispensing
  • E - Wave Soldering, Selective Soldering + AXI
  • F - Iron Soldering (robot/manual)
  • G - Laser and "Soft Beam" Soldering
  • H - Induction Soldering
  • I - Press-fit Assembly
  • J - Ionic Cleanliness
  • K - Coating
  • L - PCB Depaneling
  • M - ICT Test
  • N - EOL Functional Test
  • O - Rework

Additionally, suggested parameter value ranges are provided for selected process tables.

Selected Aspects of CQI-17

CQI-17 contains many general and detailed technical requirements. Here are some subjectively :) selected highlights:

• Audits (self-assessments) should be conducted at least annually or after significant changes.
• Audits should adopt a process-oriented approach (as in internal audits).
• The lead auditor should have at least 5 years of experience in soldering (education + practical experience), understand the process, product, and customer requirements. Familiarity with core tools such as APQP, FMEA, SPC, MSA, PPAP, and IPC standards is recommended.
• The organization should implement reaction plans, traceability, EOS, and ESD protection. Details in section 1.6 of CQI-17.
• At least one job audit for an automotive customer must be conducted during the assessment.
• The audit forms assign scores (+1, 0, -1, -5) and set passing thresholds.
• Corrective actions must be closed within 90 days (root causes identified within 30 days).

The full list of requirements can be found in CQI-17, I recommend reviewing it thoroughly.

Related Standards

CQI-17 references various industry standards and norms, such as:[1]

• IPC J-STD-001
• IPC-J-STD-001 Automotive Addendum
• IPC-A-610
• IPC-A-610 Automotive Addendum
• IPC-7711/7721
• ANSI/ESD S20.20
• IEC 61340-5-3
• IEC 61760

Summary

Implementing CQI-17 audits should guide us toward improving electronic assembly and soft soldering processes. The audit questions provide valuable insights, and I recommend every soldering company to purchase and systematically implement the manual’s requirements. Some requirements can be challenging, especially for small organizations with limited budgets—but it's beneficial at least to understand the direction of improvement efforts.

Personally, I would note that some questions in the tables are unclear, with editorial mistakes and references to non-existent sections. The audit form itself can be technically flawed in places, causing frustration for some users. Hopefully, future editions will address these issues.

Despite these remarks, CQI-17 is a valuable document that highlights areas for improvement, what aspects to prioritize, and where to focus efforts when improving this special process.