Hi-Tech Electronic Products and Manufacturing, Inc.’s RoHS (Lead-Free) Status
Hi-Tech is pleased to announce that we have become fully RoHS compliant and we are becoming an industry leader in lead-free manufacturing. Hi-Tech started working on its lead-free manufacturing process in early 2005, and began running lead-free trials in late 2005. We have invested a considerable amount of resources into becoming a leader in lead-free production. Obtaining new capital SMT & through hole equipment, process development, and training have helped lead the way.
Hi-Tech started full scale production on its lead-free lines in March 2006, and currently has about 50% of its production RoHS compliant.
Overview of WEEE and ROHS
WEEE (Waste Electrical and Electronic Equipment Directive) and RoHS (Restriction of Hazardous Substances Directive) are directives based in the European Union that are aimed at preventing waste from end of life electronic products (E-waste) from reaching landfills.
The WEEE directive holds manufacturers responsible for collecting and ecologically disposing of the product at containing electronic components. The ROHS directive prevents hazardous materials from reaching the environment by eliminating them from newly manufactured products.
The European Union put the directives into effect on July 1, 2006 and they apply to all imported or exported products in their market after that date. There are other regions working on similar legislature including Japan, China, South Korea, and California in the US.
From the manufacturing perspective, RoHS is the key directive. RoHS applies to all of the materials in an end product that will reach the consumer will contain no restricted materials (See list below). This includes all of the parts and the materials that make and hold them together. The “Brand Owner” has the ultimate responsibility of ensuring compliance and there have been penalties set up in the EU for non-compliance. RoHS restricts the use of 6 hazardous substances.
Restricted Substances and where they are commonly found or used.
Lead (Pb) – solder, glass, PCB finish, terminations, ceramics in active and passive devices
Cadmium (Cd) – contacts, sensors, plastics
Mercury (Hg) – sensors, switches, relays, batteries
Hexavalent Chromium (Cr (VI)) – primers, coatings on metals, metallizing plastics, hard chrome
PBB and PBDE – flame-retardants in plastics
RoHS Compliant Manufacturing
The greatest effect that the RoHS directive had on our operations was the banning of lead. Before the directive the industry was based around the use of a tin-lead alloy for the soldering process.
To implement RoHS, the purchase of new equipment and the development of new manufacturing processes were required to run in parallel with our original tin-lead production. Extensive training was given to our staff and trial runs were used to gain experience to help fine-tune the process so that we could deliver a high –quality RoHS compliant assembly to our customers. In combination with these activities we developed a management and inventory system to ensure the segregation and proper use of compliant and non-compliant products used in production.
ROHS Compliant Assembly Challenges
Some ROHS compliant (lead-free) solder alloys require a higher reflow, wave solder, and hand soldering temperature. We have specked in special alloy, which has the same melting point as leaded solder. Also all other parts that make up the products with restricted substances must be able to withstand the higher temperatures that they will experience within a RoHS compliant process. Example (Plastic parts, wires, crystals, SMT & through hole components, and labels)
Lower Wetting Forces
Lead free solder does not flow as well as tin-lead solder. To get the same quality of feed through in a lead free solder requires longer time to be spent at the soldering temperature and the surfaces to be soldered have to be at a higher cleanliness.
The looks of a lead free solder joint are a little different compared to a tin-lead assembly. The lead free joint appears to be less shiny and has a more “grainy” appearance; also the no-clean flux residues are more noticeable.
Component Availability and identification
There are a large number of components that have a direct RoHS compliant replacement, but some suppliers are still in the process of providing a direct replacement and some suppliers have no plans to. In the later case a redesign of an OEM’s legacy product may be necessary. There is no industry standard for RoHS compliant identification on parts. Some suppliers are using different suffixes in their part numbers and others are using date codes, while others are using a “RoHS Compliant” symbol.
Quality and Yields
The behavior of lead free solder alloys makes them unforgiving to variances in the process and to material defects. More time needs to be spent in process engineering for a lead free product in order to attain an acceptable yield rate. The final yield is generally lower which requires increased inspection and rework as compared to a tin-lead process. It is important for design and manufacturing groups to keep an open line of communication with each other because a poor design for manufacturing will determine the final yield of a product.
Older equipment designed around the tin-lead process rarely meet the higher requirements of a lead free process. To meet the requirements needed for lead free production new machines were purchased that were designed for lead free operation.
There are many other issues related to lead free manufacturing that need to be addressed, inspection, cleaning, and shelf life of RoHS compliant components. Hi-Tech has addressed all of these issues and we are more than willing to discuss them with your company. We have been actively involved in educating existing and potential customers about these important changes to the world of electronics.
Should you need any further information on our lead free manufacturing processes, please feel free to contact us.