(This column, which originally appeared in Global SMT & Packaging magazine 6.1 (Jan 2006), is also available as a free PDF.) 

As industry changes to meet the deadline of July 2006, components, materials, printed boards and service industries that support you will also change the product and services they supply.  If you are going to conduct a technical assessment on your production facility or contract manufacturer, prepare a basic plan to help structure your project.

Let us consider some of the basic points and information that should be obtained prior to your audit to help rank potential suppliers. Often only one or two days are spent visiting each supplier, and the time can easily be consumed with company presentations, lunch and less important issues. Don’t be afraid to set out your own agenda to avoid wasting any time. Time can often be more valuably spent in reviewing material in advance and gaining a valuable insight into your chosen companies. It may also help to reduce the visits you have to do. Any good contractor will be able to supply this information for review. Sales and marketing executives will know the benefit of creating the right feeling of professionalism and technical awareness.

Consider also what your potential supplier will need from you. He would like to know what your products are, volumes, when production will start and what has been done to ensure your build of materials is compliant with WEEE and RoHS. Always remember that any project should work successfully as a partnership with information flowing in both directions.

Consider this checklist and compile your own questions prior to the visit:
Component specifications
Component storage and handling core stock
Component handling customer specific parts
Printed board procurement
Lead-free material selection
Solder paste printing controls
Components and placement stages
Reflow soldering and profiling
Manual soldering and rework and repair
Wave and/or selective soldering
Process and product inspection
Product failures analysis and field returns
Internal and external training of staff members
Customer support education for lead-free implementation

Basic Information Required before Audit

Company Information
General information on the company, location map and contact details, email, telephone, mobile and fax numbers for key contacts. Having the information allows you to co-ordinate the best timetable for travel and accommodation. This information may sound obvious but often it is not provided prior to the visit. After reviewing information on the company, there may be additional information that you may like to have in advance. This all helps to assess the company’s responsiveness.

Production Equipment
List of production equipment and capability for the lead-free production should be available, with supporting documentation and test reports to demonstrate existing lead-free capability. Many companies say they have lead-free capability, but often they don’t have much practical experience. It’s fair to say that there are few products being produced in the industry, but this is set to change very quickly. There are many ways of gaining experience in lead-free, and it is important the all staff have some practical hands-on experience. Having run many customer open days on contractor sites, I can tell you it is not just the customers who get the chance to learn.

DFM/Design Review
Example of lead-free design requirement/customer DFM/NPI (Design for Manufacture/New Product Introduction) report for new products. Obtaining an example report or a template in advance allows you an understanding what detail of information gathered on a pilot build. Often some of the minor comments can become significant problems in medium and volume manufacture. Previous customer reports may be confidential, but the format and template of what points are normally covered should not be. If the feedback is not structured and is just a long list of emails, things can be missed, and not everyone gets involved in the feedback cycle.

Assembly Process
An assembly flow diagram for conventional and mixed technology products should allow auditors to step through the process their product will pass through. It allows you to focus on key stages and highlight any obvious omissions in your requirements. It also provides a good reference to check on equipment upgrades and changes for lead-free, plus their documentation and procedures. It will assist you if there is a key stage that your product or components require, like additional moisture protection for parts--this is a critical stage with lead-free.

Inspection and Process Control
Inspection criteria/process control requirements for each assembly stage in manufacture should be provided with all key control stages in lead-free manufacture. Look for evidence of inspection standards on the shop floor and examples of process monitoring results to back up any information in your pre-visit documentation. On site, talk directly to operators and technicians about any issues they have experienced with lead-free and see if it matches up with your experience. Often staff have not actually seen the documentation that they are reportedly working to as it has not been released yet to manufacture.

Process Materials
List of soldering/cleaning materials used in production with suppliers and product reference numbers should be provided and updated when or if they change. Often companies who use two different sub-contractors or one in-house assembly facility debate the variation in quality, visual appearance and cleanliness when it is really the incompatibility of materials. There should also be some documented evidence of lead-free trials conducted on the materials and the results obtained; this should show a structured approach.

New Process or Equipment
List of future equipment purchases or upgrades for lead-free, plus their scheduled introduction dates, should be obtained. A copy of the company’s technology roadmap should list each of the process changes. It is also often worthwhile asking for previous roadmaps for the last two or three years and see if the proposed process changes were done and on schedule. It is fair to say in most medium and high volume companies changes to most equipment should not be required as they already have high end equipment. In medium to small companies that may not be the case. Issues on availability may be a problem in the near future for all companies. Suppliers of wave soldering upgrades/retrofits may not be able to cope with demand of lead-free conversion.

Training and Education
List of training modules and content should be reviewed for production staff, engineering, quality, purchasing, sales departments attend for assembly, design and PCB technology. If an extensive lead-free training schedule is underway there may be an opportunity to partner with your potential supplier so your own company can benefit. During a recent project in China, one contract assembly company was training people in lead-free materials process control and WEEE and RoHS at a rate of 50 people per week.

A record of the specific training, topics and the employee’s achievements should be on record for review. Attending training sessions is beneficial, but achieving some level of proficiency must be the real goal. Tests, pass marks, success and failures should be documented so the training courses can be updated, reviewed or strengthened. SMART Group have been looking into Lead-Free Certification of staff; further information can be obtained at www.smartgroup.org

External Services
A list and location of any processes, test and environmental assessment or defect analysis not conducted on-site should be available with evidence of their own audit results. Often x-ray inspection, conformal coating and investigation services like microsection and failure analysis are conducted off site. Each company should have a plan in place to implement sub-contracting to other suppliers if and when required. It is then necessary to get additional information on their services and capability. A contractor may vet other service providers, but it also the customer’s responsibility to make sure they meet their requirements.



At the end of your assessment, a short report should be produced covering the strengths and weaknesses of each supply with a scoring method employed to rank the companies. You should allow time after your visits to explain to potential suppliers your findings and decision so they are not left waiting. Often people forget this step. As you may like to re-evaluate the companies in the future, you should not leave them with the feeling that you have wasted their time as they have made every effort to help you.

Here are some of the interesting comments that I have received during my UK & overseas audits. Readers can draw their own conclusions on my responses!

“All the information will be provided during the visit.” - It's not and time is wasted during the visit.

“Our lead-free engineer is on holiday, we can’t provide the information.”

“We don’t have the information available in English.”

“We will provide the information when you place the order.”

“All the information is on the web site.” - But no links are provided to the information or it’s not on the site anyway.

“We don’t monitor our process stages or rework only our final test results.”

Detailed information package of hard and soft information was provided, but it conflicted with all the information seen during the visit.

“We can’t provide that information, it’s confidential.”



Bob Willis provides support in conventional and surface mount lead-free assembly processes. Bob Willis will be organising and running a Lead-Free Interactive Forum at Productronica in Germany in November. He has one of the largest collections of training videos, lead-free interactive CD-ROMs and training standards in the industry visit his web site www.leadfreesoldering.com

Keywords : Willis, lead-free

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