RoHS/WEEE Compliance & Green Initiatives
Sealevel Systems is committed to providing our customers with high quality products that meet the RoHS (2002/95/EC), WEEE (2002/96/EC), and other green initiatives being adopted by the global community. The RoHS directive restricts the use of lead and certain other hazardous materials in electronic products marketed to the European Union. Sealevel is designing all new products for RoHS compatibility as well as modifying legacy products and manufacturing processes for RoHS compliance. We will continue to offer both RoHS compliant and non-compliant products to meet global and domestic customer demand.
Steps To Achieving RoHS Compliance
In order to comply with the RoHS directive, Sealevel engineers had to reconsider every step of the manufacturing process including:
- Eliminating banned substances
- Selecting PC board laminate materials lead-free solders
- Confirming compliant components availability and cost
- Awareness of higher manufacturing temperatures
- Choosing metal and plastic enclosure materials
- Specifying paint, silkscreen, and powder-coating materials
- Establishing benchmarks for Tg, CTE, and Td
- Identifying and stocking compliant and noncompliant products
- Considering long-term reliability of products
All RoHS Compliant Products Are Not Created Equal
To comply with the RoHS directive, Sealevel had to change the soldering processes used in manufacturing. Lead-free solders, called SAC alloys, must be used and they have a significantly higher melting point than lead alloy solders. PC boards are made using a laminate material consisting of a resin or epoxy reinforced by glass fibers. The higher manufacturing temperatures change the integrity of traditional laminate materials causing them to expand and/or delaminate. While most laminate materials were already RoHS compliant, commonly used board materials can’t withstand the higher manufacturing temperatures required by using lead-free solder. Other manufacturers have neglected this fact and continue to use traditional PC board laminate materials. Sealevel tested several laminate materials and developed prototype boards that were subjected to numerous thermal cycles over the course of several weeks, from temperatures as low as –40°C to as high as +100°C. Sealevel selected a laminate material that could handle the higher manufacturing temperatures and still be cost effective for our customers. Although extreme, these tests confirm the exceptional reliability of the products for which Sealevel is known.
RoHS Compliance Identification
Electronic products sold into the European Union must be free of six hazardous substances by July 1, 2006, as stated in Directive 2002/95/EC. RoHS compliance comes at a premium and because many customers still demand non-compliant products, Sealevel devised a unique and ingenious identification method. All new Sealevel circuit boards will have two gold-plated, etched-copper pads marked "RoHS" and "non-RoHS" in the silkscreen. The absence of these pads denotes a non-compliant product. During separate manufacturing processes, compliant boards will have a solder mark on the "RoHS" pad, while non-compliant boards will have a solder mark on the "non-RoHS" pad. Thus, the boards are clearly marked and can be visually identified.
Since compliant and noncompliant products share a common design, Sealevel chose to continue with the familiar 4-digit part numbering scheme for non-compliant products. RoHS compliant parts will append "-RoHS" to the end of the part number. Only after Sealevel could finally guarantee the reliability did we announce new industry-first RoHS compliant products.
Industry’s First RoHS-Compliant Low Profile PCI RS-232/422/485/530 Board
On 11/18/2005, Sealevel Systems, Inc. announced the first RoHS-compliant multi-interface PCI serial I/O card, the 7106-RoHS. The board offers a selectable RS-232, RS-422, RS-485, or RS-530 interface and is MD1 low profile and universal bus compatible (3.3V or 5V). The 7106-RoHS was the first in a series of forthcoming RoHS-compliant serial product introductions.
Industry’s First RoHS-Compliant Low Profile PCI Digital I/O Board
On 12/9/2005, Sealevel Systems, Inc. announced the first RoHS-compliant low profile PCI digital I/O adapter, the 8018-RoHS. The board offers easy connection to industry-standard solid-state relay racks for monitoring and control of AC and DC signals. Designed for compatibility with legacy and new computer systems, the board is MD1 low profile and universal bus compatible (3.3V or 5V). The 8018-RoHS was the first in a series of forthcoming RoHS-compliant digital I/O product introductions.
Popular PCI RS-232/422/485 Board Achieves RoHS Compliance
Sealevel's popular 7201 board is now RoHS compliant with the introduction of the 7201-RoHS. The board provides two serial ports, each individually configurable for RS-232, RS-422, or RS-485. The 7201-RoHS is capable of data rates to 460.8K bps and automatically handles RS-485 transmitter enable/disable. The board utilizes 16C850 UARTs that provide 128-byte Tx/Rx FIFOs and is Universal Bus (3.3V or 5V) compatible.
WEEE Compliance Identification
Legislation enacted on August 13, 2005, requires electronic product manufacturers that ship to the European Union to provide a means for recycling materials as stated in Directive 2002/96/EC. All WEEE compliant products are denoted by a trash receptacle icon with an 'X' through it. For questions about Sealevel’s recycling policy, please send an email to firstname.lastname@example.org.
Lead – Pb
A naturally occurring metallic element, lead is commonly found in the tin/lead solder traditionally used to mount components to circuit boards. Lead was commonly used in many electronic components, but is rapidly being phased out by the global community.
Cadmium – Cd
A naturally occurring metallic element, cadmium is commonly used in Nickel-Cadmium (NiCd) batteries and certain solders. It is also used for plating contacts, pigmenting components, stabilizing PVC plastics, and as a doping material in avalanche photodiodes.
Hexavalent Chromium – CrVI or Cr6
Chromium is a naturally occurring metallic element that exists in several forms, yet only hexavalent chromium is recognized as hazardous. It is commonly used as a dye or pigment in paints, inks, and plastics. It’s also used as an anti-corrosion agent to protect metal surfaces prior to painting or powder coating.
Mercury – Hg
The only metal liquid at room temperature, mercury is an element extracted from cinnabar ore. It is found in some metal alloys, mercury switches, mercury-wetted relays, some batteries, and many other compounds. It also has many common uses outside of the electronics industry.
Polybrominated Biphenyls – PBB
Polybrominated Diphenyl Ethers – PBDE
A family of compounds sold under a variety of trade names and primarily used as a flame retardant in molded thermoplastics and PC board laminates.
Coefficient of Thermal Expansion – CTE
The measurement of how much a PC board laminate will expand in the Z-axis (thickness) when exposed to the high manufacturing temperatures required using RoHS compliant materials. The danger is that as the laminate increases, the barrels (interconnects between PC board layers) can crack, causing an open or even worse, an intermittent open. Many other manufacturers are focusing only on Tg, but CTE and Td are equally important metrics. Expressed in parts-per-million per degree Celsius (ppm/°C), the CTE should be as low as possible. The maximum CTE allowed by Sealevel for laminate materials is 65ppm/°C, although 45ppm/°C has been achieved.
Most commercially available PC boards are made using a laminate material that consists of fiberglass reinforced resin or epoxy. Modern PC boards contain multiple layers of laminate material enclosing internal traces (also called circuits) as well as those visible on both external surfaces. Due to the higher heat requirements of manufacturing using lead-free solder, the interconnects (called vias) between the different layers are prone to cracking. The cracks can cause intermittent failures that are hard to diagnose. This is what makes the Tg, CTE, and Td metrics so important when considering new laminate materials.
Referred to as a SAC alloy by its composition of Tin (Sn), Silver (Ag), and Copper (Cu), Sealevel has adopted SAC305 as the solder used in our manufacturing process. This SAC alloy was selected by NEMI (National Electronics Manufacturing Initiative) and is recognized as the alloy of choice by the IPC (Association Connecting Electronics Industries). SAC305 has a melting point of 217°C, as opposed to 183°C for traditional tin/lead solder. A completely new reflow process was required to use this new solder.
PC Board - PCB
Refers to a 'printed circuit board'
Click the link to read the complete RoHS 2002/95/EC Directive. This will open the complete five-page PDF (116k) document in a new browser window. You may need to disable pop-up blockers, or you can right-click and save the file to your hard drive.
Thermal Decomposition Temperature – Td
A measurement of the physical degradation of a laminate material calculated based on the temperature at which the sample of laminate material loses 5% of its weight. Expressed in degrees Celsius (°C), the Td should be significantly higher than the maximum exposure temperature of the laminate material during the manufacturing process. The minimum Td allowed by Sealevel is 350°C. Many other manufacturers are focusing only on Tg, but Td and CTE are equally important metrics.
Glass Transition Temperature – Tg
The measurement of the temperature at which a laminate material changes from a semi-rigid state to a softened (rubbery) state. It is a given that the Tg of a laminate material will be exceeded during the manufacturing process. Sealevel had to first consider the magnitude of the difference between the exposure temperature and Tg of various laminate materials. Manufacturing processes had to be developed to minimize the time the Tg is exceeded. Expressed in degrees Celsius (°C), the minimum Tg allowed by Sealevel is 175°C, with the goal of finding laminate materials with a higher Tg at a reasonable cost. Many other manufacturers are focusing only on Tg, but Td and CTE are equally important metrics.
Click to read the complete WEEE 2002/96/EC Directive. This will open the complete fifteen-page PDF (288k) document in a new browser window. You may need to disable pop-up blockers, or you can right-click and save the file to your hard drive.
Please check out the Sealevel Green Commitment page for more information.