|A publication of the National Electronics Manufacturing Center of Excellence||March/April 2003|
Michael D. Frederickson
IPC-A-610 or IPC J-STD-001. Why two electronic assembly acceptance standards? What is Worker Proficiency Certification? How is the J-STD-001 Operator Proficiency Certification different? This article will answer these questions.
The IPC relies on industry volunteers, working in committees, to develop the standards. The committees are apportioned into eight major function categories. One of these, the Product Assurance Committee, has responsibility for the technical content of the IPC-A-610 standard through its IPC-A-610 Task Group.
The IPC-A-610 presents acceptance requirements for the manufacture of electronic assemblies. Essentially, the IPC-A-610 is a book of pictures and illustrations portraying acceptance criteria that reflect the requirements of other standards and specifications.
Historically, electronic assembly standards did contain more comprehensive and tutorial information relating to principles and techniques. One consequence, the standardization of methods, resulted in conflicts because process methods changed faster than the standards.
The Assembly and Joining Process Committee, with the EIA Soldering Technology Committee, developed the joint standard, J-STD-001: Requirements for Soldered Electrical and Electronic Assemblies. The IPC committee deals with automatic component placement, insertion, handling, attachment and joining techniques, as well as the cleaning operation prior to coating and encapsulation. The two documents will probably not be merged. The activities of the committees are different. We have the IPC-A-610, a picture book that provides clarification and definition to the end item requirements that should result from the use of materials, processes and design (by extension) requirements described in the J-STD-001.
Both the IPC-A-610 and J-STD-001 can be referenced on contracts to define end item acceptance. The IPC-A-610 preceded the J-STD-001 by a couple of years, therefore, the 610 was the more frequently referenced. However, the Department of Defense (DoD) adopted Handbook 001B and then J-STD-001C, consequently J-STD-001 is being referenced on many DoD High Reliability contracts. In practice, the requirements of the two standards are well harmonized, but there are significant differences.
Consider this excerpt from J-STD-001 Section 3 General Requirements: The soldering operations, equipment, and conditions described in this document are based on electrical / electronic circuits designed and fabricated in accordance with the specifications listed in table 3-1. The table, courtesy of the IPC, references Design Standards and Fabrication Specifications. These govern many characteristics of the boards. Paragraph 3.1.2 states: "Mounting and soldering requirements for specialized processes and /or technologies not specified herein SHALL be performed in accordance with documented procedures which are available for review."
Compare the above requirements with the following guidelines from the IPC-A-610. Paragraph 1.2 (Purpose) states: "The visual standards in this document reflect the requirements of existing IPC and other applicable specifications. In order for the user to apply and use the content of this document, the assembly/product should comply with other existing IPC requirements, such as IPCSM- 782, IPC-2221, IPC- 6011 and IPC-A-600. If the assembly does not comply with these or equivalent requirements, then the acceptance criteria needs to be defined between the customer and supplier."
We see in the paragraphs above a significant difference between the two standards. In the case of the JSTD, referenced standards extend the standard. In the case of the 610, referenced standards are provided for reference, unless specifically identified as an extension of the standard.
Quoting from J-STD-001, "Section 5.2 Solderability: Electronic/mechanical components and wires to be soldered SHALL meet the requirements of J-STD-002 or equivalent, and printed boards SHALL meet the requirements of J-STD-003 or equivalent. When a pre-tinning and inspection operation is performed as part of the documented assembly process, that operation may be used in lieu of solderability testing." The IPC-A-610 is silent on the subject of solderability testing and dedicates one paragraph to "process control methods." These differences might go unnoticed, until something goes wrong in your customer supplier relationship.
Let's take a look a the training programs. The IPC-A-610C Worker Proficiency training will provide your company and employees with skills in discriminating acceptable conditions from defect conditions as defined by the IPC-A-610 Standard. The 610 training focuses on process results, defining what is acceptable and what is not at the end item. The operator level program requires about 24 hours of classroom instruction. Class A Instructor certification requires about 40 hours of classroom time. There is no hands-on skills component to the IPC-A-610 programs.
The IPC J-STD-001C Operator Proficiency training provides a modular approach to certification training. The JSTD program is a combination of lecture and hands on soldering skills training. There are five modules, with each module requiring about eight hours to complete. Module One is required, a prerequisite overview of the requirements of the standard. There is no hands-on component to Module One and proficiency is demonstrated through a closed book test. The remaining four modules all require operators to demonstrate proficiency in soldering skills, defect recognition and in understanding the process requirements of the standard. Class A Instructor Certification is not modular. Instructors must demonstrate soldering skills, defect recognition and pass a comprehensive test covering the requirements of all five modules.
The J-STD's modular approach to training can also save money. When a smaller company has a few workers with specialized skills that parallel the content of the existing modules. The 610 program is appropriate for companies with specialized inspectors and for companies doing final assembly only, or in large Original Equipment Manufacturers (OEMs) and contract manufacturers.
For more information on certification training call the EMPF Helpline at (610) 362-1320.
|ACI Technologies, Inc. - - www.aciusa.org - - (610)362-1200|