All electronic manufacturers with SMT production lines have one thing in common: the dread of unplanned downtime, especially if they operate around-the-clock production. In today’s fast-paced manufacturing environment, maintaining reliable and high-yield production processes is challenging. OEMs and CEMs must balance the needs of filling orders, keeping customers satisfied, and handling maintenance downtime before it impacts their bottom line. All machines require servicing. You don’t need to see around corners to know that if you neglect your production assets, at some point, a breakdown will occur. Most manufacturers have a plan but usually seesaw between reactive and preventative maintenance.
Reactive/Run-to-Failure Maintenance
Reactive manufacturers don’t want to lose valuable production time and wait until a machine is malfunctioning before they call in the service technician to fix it. As counterintuitive as this practice may seem, run-to-failure maintenance is quite common. Some companies do not want to spend money on a maintenance plan servicing equipment that is not broken. Or, they could have a plan for some machines and not others. For example, they service the pick and place machine regularly because the mounter is a vital component that determines SMT production quality. On the other hand, they neglect the AOI until it begins to throw an error and requires cleaning and calibration. This takes the machine offline for several hours for servicing plus additional time scheduling the service technician. In total, the line could be out for action for a few days.
Preventative Maintenance
Preventative maintenance, as the name suggests, is based on a coordinated maintenance plan according to the supplier’s recommendations for each machine. Customers can perform some basic daily or weekly routine maintenance like cleaning and removing dust and debris. Expert service technicians replace parts, check for wear, clean and lubricate the internal parts, and calibrate machines to maintain stability and accuracy. Additionally, it’s proven that regular servicing prolongs the longevity of these powerhouse machines. Annual and bi-annual maintenance plans will reduce unplanned downtime. The other clear advantage is that managers can plan and regulate output without affecting customer orders.
Maintaining Your SMT Line
Hawker Richardson supplies the best SMT line machinery in Australia and New Zealand. After commissioning the goal is to maintain peak functioning of the line. Our expert service technicians prescribe the best maintenance schedule for each machine based on the output volume, the age, and the recommendation of the supplier. We’ll look at maintenance for three key machines; the Solder Paste Printer, Pick and Place, and Reflow Oven.
Solder Paste Printer
The stencil printing process is one of the most important stages of surface mount technology (SMT) assembly process. As most defects in electronics assembly can be attributed to solder paste printing errors, it is critical that solder paste is applied with accuracy to the PCB. Three things that influence the printing process and quality of solder paste printing are stencil design, printing parameters and solder paste properties. It’s crucial to maintain these areas to achieve optimal solder joint quality.
Maintenance schedules for solder paste printers range from daily, weekly, and monthly to annual service tasks. Operators remove paste and debris from the machine every day and clean and check the camera lenses and squeegee condition weekly. Depending on the volume, technicians will grease parts, replace vacuum pump filters and check for wear and damage annually or bi-annually.
Pick and Place Machine
The Pick and Place machine is the next big step in the SMT assembly process. The workhorse of the line, the surface mounter places components onto solder-pasted boards with high speed and accuracy. Using downward and upward-looking cameras, X, Y, Z and R axis and various nozzles, these machines pick up and place components with precision from component reels or trays. High-volume manufacturers with several SMT lines can pick and place more than one and a half million components per day.
Yamaha, the supplier of premium surface mount equipment recommends a proper maintenance regime by qualified technicians to minimize production losses. They consider the pick-and-place machine a vital component that requires upkeep to ensure quality SMT production. An important consideration for maintaining high-quality production is keeping nozzles in good condition with regular cleaning. Another critical task is to ensure the feeder’s pickup position is correct to keep the mounter’s component pickup rate high. Increasingly, premium machines have more diagnostic abilities that alert operators when the machine is not within specification (ie the pick-up rate). Scheduled maintenance enables better production planning eliminating downtime outages.
Reflow Oven
The next step is the reflow soldering process. An Oven will heat/reflow the solder paste and create a strong bond between soldered surface-mount components and the PCB. There are four major phases of reflow: preheating, soaking, reflowing, and cooling. To achieve a high-quality solder joint and prevent solder-related defects, each phase is crucial. High-volume manufacturers generally favour radiated heat or convection ovens which can easily accommodate fast pick-and-place machines.
Convection reflow ovens require bi-weekly to six monthly routine maintenance generally carried out by operators. These tasks range from changing flux filters and cleaning the filter compartment to vacuuming blowers and verifying battery backups. Specialised technicians are required to calibrate thermocouples and belt speeds, replace heating elements and blower motors, adjust mesh belt tension and lubricate parts. Heller, a supplier of premium convection ovens provides a comprehensive maintenance schedule and emphasises that the warranty becomes void if the oven is not maintained according to instructions.
Win the Battle Against Downtime
Automated SMT production depends on regular preventative maintenance. This article discusses servicing three key machines on the SMT assembly line: solder paste printing, pick and place and reflow soldering. Other machines in the line are as important because a poorly maintained solder paste inspection machine or an AOI can also halt production. Maintained machines improve product quality, increase productivity, extend asset life and above all limit unplanned downtime which affects the bottom line.
At Hawker Richardson, we source, supply and commission the best SMT production equipment worldwide. As your partner, we go beyond the sale and supply of equipment with our service and maintenance plans.
Win the battle against downtime. Contact us for more information about our maintenance plans or premium SMT Line solutions.
