Should I Take Advantage Of Lead Free PCB Assembly?

This directive established July 1, 2006 because the deadline for restrictions on the use of six «hazardous materials» in the manufacture of electrical and electronic devices. Compliance to the directive and its subsequent amendments (which have added 4 additional substances) is obligatory for European manufacturers and all other nations that produce electronics products for the EU market. As PCBs are the primary unit in nearly all electronics systems, the RoHS directive applies on to most of the PCB manufacturing steps. By far, probably the most impacted stage of board manufacturing is PCB assembly (or PCBA), the place RoHS compliance means replacing traditional lead-based mostly solder with a lead-free alternative. But what does this mean in your PCB improvement? Before addressing this question, pcb assembly let’s take a look at both leaded and lead free board meeting. Then, you will be higher prepared to resolve whether or not you must use lead free PCB assembly. Throughout the meeting of your boards, the components, both floor mount expertise (SMT) or through-hole, are attached by way of a soldering process. For decades, most solder used for PCBA has been a tin-lead (Sn-Pb) alloy. Popular tin to steer ratios are 60/40 and 63/37, which have melting point temperatures of 188°C (370°F) and 183°C (361°F), respectively. During reflow, which is the preferred methodology for attaching floor mount system (SMD) packages, temperatures up to 235°C (455°F) may be reached as solder modifications to a liquid type prior to cooling down. Temperatures for lead free PCBA are typically greater than for Sn-Pb solder. For example, the melting point temperature for tin-silver (Sn-Ag) is 220°C (428°F) for 96.5/3.5 and pcb assembly 240°C (464°F) for 95/5, respectively. Reflow temperatures could peak at 250°C (482°F). These larger temperatures have implications for board development and element choice. If board supplies are selected with a decomposition temperature that is just too low, irreversible damage may occur following publicity to the elevated temperatures involved in lead free pcb assembly (cults3d.com). Care must also be taken when selecting elements to ensure there isn’t a damage, particularly during reflow where high temperatures are present on the board for prolonged durations of time. From a PCB manufacturing perspective, the main concern for lead free PCB board assembly is board harm because of higher temperatures. Rework is also more difficult. Materials are one other consideration as substrates. Laminates should be selected primarily based upon their temperature attributes. Before prematurely deciding that choosing lead free PCB assembly is not justifiable,however, let’s explore different reasons for making the change. It’s best to Use Lead Free PCB Assembly If … If any entry in the record under describes your scenario, you’ll doubtless profit from utilizing lead free PCB assembly. Your products may be bought in nations that have regulatory necessities, such because the EU. Your state or native government mandates a lead free manufacturing process, resembling in California. The OEM to your board(s) requires that you simply meet regulatory standards, comparable to IBM and Hewlett Packard. You’re involved concerning the well being risks for many who work with and use lead-primarily based merchandise. You’re involved in regards to the potential legal responsibility risks related to leaded merchandise. You perceive the breakthroughs in smaller PCB manufacture that lead free PCB assembly has made attainable. Want to promote the continued advancement in this area. You acknowledge the thrust for inexperienced manufacturing. Want to draw clients that place a excessive premium on these points. Today, for compliance with the RoHS directive, the next substances could solely be current at the levels shown. Ensuring that your boards are built to satisfy the RoHS requirements signifies that you need to make sure the contract manufacturer (CM) that you choose has a defined lead free process, including soldering, materials, parts, solder mask, and floor end. Lead free PCB assembly is rapidly becoming the usual for PCB manufacturing. This is due to regulatory requirements, environmental issues, and other reasons, as listed above.