Audit result % compliance supplier manufacturer factory audit report mgb hk supplier quality system process audit checklist audit date. Sometimes a little silver or antimony is added for extra strength. As with all surface mount processes, the wave solder process has been very dynamic. We have found that the best or optimum process is the solder process which resulted in meeting the goals of reflow soldering for the smt application.
Component placement pick and place machines are used to place components on boards. In the most common wave soldering process, the dual wave type, one wave is turbulent and the other wave is smooth, as in conventional technology soldering. The importance of solder wave height the wave solder process has a variety of settings that must be adjusted by the operator. Microsection showing partial reflow of solder paste. The information in this document is for reference only. Poor soldered joints will fail, causing partial or complete failure of the circuit cct. When mounted components pass through the solder wave at a fixed angle, solder joints are formed in the lead solder zone. Ipc jstd004 5 21 reflowvapor phase wave selectivehand options. Lead free, pb free, wave soldering, process, solder, alloy, flux. Csp behaves in a similar way to bga, except for the fact that csp is more sensitive to mishandling. Smd soldering surface mount soldering guide how to solder smd. Ecssqst7038 is dealing with qualification of surface mount.
Smt surface mount technology manufacturing process. Changes to the pcba design, the reflow oven, wave solder machine. Pcba wave pallet also helping to prevent from solder ballssplashes enter to smt. Two different pwb designs were used jedec lowk see reference 3 and jedec highk see reference 4. Typical smt problems for additional process solutions, please refer to the aim website troubleshooting guide solder balling solder beading bridging opens voiding tombstoning. Wave and selective soldering smt machines for sale. Wave of molten solder is used in the process, hence the name wave soldering. Our engineering specialists can help you select the appropriate gas, inert wave soldering technology or conduct audits and optimization studies at your facility. Wave flow soldering process engineering technical pcbway. Solderstar provides a complete solution for soldering process control within the electronics manufacturing industry. If you need an smt audit, our unique fivephase factory and smt process audit can provide you with the technical solutions to pinpoint the problems in your process, design, and workflow. Wave soldering is a largescale soldering process by which electronic components are soldered to a printed circuit board pcb to form an electronic assembly. Pdf implementation of leadfree wave soldering process.
Which soldering defects are related to the incorrect setup of the reflow profile. This will be particularly challenging for companies using ipa for flux removal, stencil cleaning, and industrial degreasing. The purpose of the flux is to remove surface oxides, prevent oxidation of the soldering pads during the preheat and soldering process and improve wettability to ensure a strong low resistance solder joint. Itm wave and selective soldering troubleshooting guide. Electrovert electra 500f wave solder system vintage. You dont need an expensive iron, but you do need to be able to control the. With the use of a wave optimizer weekly pre heat, right dwell time, left dwell time and immersion depth is measured. Mastering selective soldering processing and manufacturability. Any change in type or modification of soldering or cleaning equipment reflow oven, wave solder, wash, hand solder, rework, etc.
This troubleshooting guide outlines all the probable causes of throughhole soldering and their respective causes. Reflow process overview the capability of the equipment used will influence the dynamics of the reflow process. The downside of bga is the difficulty in inspecting the interior solder joints. The primary difference affecting the soldering process is that the snag solder has a higher melting point than the sn. Key competitive advantages can be obtained through the minimization of process defects and disruptions. Wave soldering page 14 adhesive and adhesive application page 16. The processing parameters provided by the flux manufacturer should be employed and can usually be found on their website.
How to prevent the tombstone and open defects during the. Wave solder system wave soldering is used to solder through hole components and some active smt components and smt passives, such as chip resistor and capacitors. Standard soldering and cleaning processes trimming. This is an update of the earlier kemet engineering bulletin f2101 regarding the wave solder process for surface mount applications. Smt and application notes on a variety of packagingrelated topics. Flux is applied to the underside of the printed circuit board pcb to aid the wave soldering process. Solder profile for lead free reflow process figure 1 classification reflow profile for smt components refer to ipcjedec jstd020e. Sws450 wave soldering machine wave soldering machine wave solderingis a kind of solder wave with a specific shape formed on the surface of molten liquid solder by means of pump pressure.
Assembly of bga and csp follows a typical surface mount technology smt process. Lead length limitations a straight protruding length of more than 1 mm will in general not collect more solder in the joint in machine soldering and therefore will not add more strength to the joint. Wave soldering the automated soldering process must be controlled carefully in order not to impair the performance of the relays. Each section contains a list of problems often observed.
Package reflow processing process wave soldering process process reliability process reliability plcc ok ok impossible na sop ok ok feasible 2 2. We offer a range of smart profiling devices which can be combined to provide a powerful set of process control instrumentation for each of the soldering processes you wish to setup and control. Figure 88, shows the wave shape as the pcb passes over it. These advantages can usually pay back in a few weeks with cost savings and improved yields. Measure and verify regularly that the set solder temperature is stable. Solder profile for wave soldering process figure 2 classification wave soldering profile for tht components refer to en617601. Leadfree wave soldering global leader in solder and solder. Increase the life of your stencils and make your solder printing process more effective and reliable. Wave soldering smt, pcb manufacturing products and services. Wave soldering is the most widely used method in electronics industry for large scale mass soldering of throughhole electronic components to the pcb. Other things to look for in the process solder temp too low preheat too high excess flux blowoff solder wave height high preheat too low board not seated properly solder wave height low contaminated flux board pallet to hot solder wave uneven flux sp gr too low conveyor speed high.
Pcb surface finishes implication on the smt process yield liyaindium author. Introduction the 2004 inemi roadmap identified a gap in industry. Soldering forced hot air, convection, ir, wave single and dual 2. Select wave drag soldering wave dip soldering 0,7 10 mm multi wave dip soldering 0,7 10 mm figure 10. The name is derived from the use of waves of molten solder to attach metal components to the pcb. Another look wave solder process for surface mount. The soldering should be carried as per profile mentioned in respective parts datasheet. Smt process recommendations defect minimization methods for a. This often is a jerking belt or conveyor in the oven too long of a cooling cycle. It conducts electricity between component leads and conducting wires or tracks on a printed circuit board.
Introduction many expensive defects produced by the wave soldering process are caused by process parameters operating outside their normal windows, and can be prevented by the application of process control. Soldering is a huge part of the printed circuit board design process. Axicom application note page 6 transportation, storage, handling, assembly and testing of axicom smt relays m. Technology smt, reflow soldering has expanded in the number of types and has been studied, refined and explored as never before. Due to shadowing and the inability to set the wave height. Wave soldering process environmental protection agency. Many improvements have been made in equipment, in surface mount parts, and in the understanding of effects. Basically it solders smc surface mount components onto the boards through reflow soldering. This allows assemblers to build on their extensive experience with snpb solders. Processing notes wave soldering wave soldering due to variances in equipment, solder, flux, and board design, samtec does not recommend specific wave solder profiles for our connectors.
Process applications wave solder typical solder temperature 500 f. Hi,save your investment on lead free wave soldering. How to prevent solder ball and bridging defects during the smt reflow process. Reflow oven smt smt consumbles smt cutter smt feeder smt feeder parts smt filter smt machine smt nozzle smt spare parts. Introduction reflow process overview selection of solder paste. Many different opinions have been expressed about the best process. Smt soldering process and techniques is little different from through hole technology. In selective soldering the flux should not spread too far. We are using well known smt adhesive before wave, but still having problems. Wave soldering is a bulk soldering process used in the manufacture of printed circuit boards. Alloys with high percentages of lead are naturally dull. Smd desoldering is generally done using a hot air blower while soldering can be done using a soldering iron and solder wire or using solder paste or solder balls and smd hot air blower rework station. Smt pcb has flat tinlead or goldplated copper pads without any hole. Process of smt manufacturing flow chart of smt process 1.
The processing parameters provided by the flux manufacturer. Importance of wave height measurement in wave solder. Inspections following smt sequences in the smt assembling process there are three main phases where aoi plays an important role. The solder paste printing process is key to ensure a consistent deposit of solder paste onto the pcb. This chapter addresses the surface mount technology smt board assembly process for reflow soldering smt components to boards, as well as rework soldering for removing and replacing individual components on alreadyassembled boards.
Pcb after reflow of the solder paste while the solder is still in a liquid state. Soldering and mounting techniques on semiconductor. Solder paste is a thixotropic material and requires energy to be applied in the form of print head motion for it to change viscosity and flow evenly into the stencil apertures. Soldering 101 soldering is the process of joining two metals together to form an electrically and mechanically secure bond using heat and a third metal alloy known as solder. A practical design approach to custom mmwave smt packages. Leadfree wave can be more demanding to implement as a leadfree process, when compared to smt and hand soldering operations. Cleaning solvent, aqueous, semiaqueous, noclean 1 reflow general use the optimum solder paste for the pattern, printing process, solder paste density and solder joint quality. The circuit board is passed over a pan of molten solder in which a pump produces an upwelling of solder that looks like a standing wave. Soldering considerations for surface mount packages. Lower solder temperatures give equal or even higher tensile strength if topside solder fillet is achieved. Unlike other audits, we dont just point out what you are doing wrong we make positive and objective recommendations on how to do it right. Is automatic wave height control installed to control the laminar wave height.
Bring your smt factory up to speed with the help of ray prasad. Fix the source of vibration andor adjust the reflow cool down profile so that the joints are solidified. This is a musthave for anyone involved in any wave solder process. Nov 21, 20 considerable expertise is required to maintain the solder in prime condition, at the correct temperature and wave dynamics to achieve the best soldering results. An indepth, classroom based smt training course providing practical process understanding to ensure quality and improved yields in electronics assemblies. Figure 16 19 are the control charts for the wave solder process. As the circuit board makes contact with this wave, the components become soldered to the board. Smt board assembly process intel manufacturing enabling guide 6 march 2016 process parameters such as squeegee speed, pressure, and separation speed need to be optimized for the specific solder paste used. The only reliable way to get your circuits to stick to your board and stay there is by soldering. Test series with different wave soldering parameters were run to examine the solder quality achieved in a leadfree wave soldering process.
Smt defect list smt defect list and smt troubleshooting smt smd problem and solution smt surface mount technology, like other smd soldering and pcb assembly technology is not zerodefect soldering process. The flux acts as a temporary adhesive, holding the components in place until the soldering process melts the solder and forms the electricalmechanical connection. Reflow soldering with dip and wave soldering with plcc, bga, vfqfpn, ufqfpn, and wlcsp are strictly impossible due to the leadball configuration. Reflow soldering process considerations for surface mount. However, there is still significant wave soldering where surfacemount technology. Smt legislation and marking storage reflow temperature moisture msd bga or qfn sn whiskers bi content cu or. Here we would like to introduced our hw350 lead free wave soldering machine to you. Selective soldering process recommended parameters download pdf version. Smd soldering and desoldering is little different from thruhole soldering and desoldering process. Soft solder is a filler metal made from an alloy mixture of tin 60% and lead 40% which acts as a bonding agent during the solder process.
Itms unique smt process audit begins with us bringing our pc board fabrication. Each cms production line andor revised combination of solder and cleaning process must be qualified. Affects process and yield wave soldering fast and efficient but, process is. Soldering joint criteria page 2 screen or stencil printing of solder paste. Wave solder exposure of smt packages texas instruments. Selective soldering process recommended parameters.
Smt process recommendations defect minimization methods for a noclean smt process kurt rajewski assistant manager market technology kester 515 e. Here is a solder skip mainly due to incorrect wave height as there is no evidence of solder on the pad or the termination. Reflow profile for leadfree solder paste, use a gradual soak ramp rate before reaching the melting point. Solder paste printing process surface mount process. There will always be some or the other defect in any electronics pcb assembly in both thruhole and smt. This issue is erratic with some boards running fine and others will have missing parts after wave. In the case of wave, r selective or partial soldering there are other sequences e. Simple, effective process control in wave soldering chrys shea siemens information and communication networks, inc.
Another look wave solder process for surface mount applications. Because surface mount components are normally soldered using a reflow oven process the impact of wave soldering and wave solder simulation methods must be understood. The investigation deals with quality improvement of wave soldering joints for printed circuit boards pcb by using doe approach. This can directly impact the soldering performance. Checklist at printed board assembly ordering level. An internal esd audit schedule must be executed and corrective actions must be. Copper leaching depends on contact time and solder temperature. Wave soldering is more practical for singlelayer or multilayer printed wiring boards pwb that contain components intended for plated through holes.
Soldering recommendations and package information for. Transportation, storage, handling, assembly and testing of. What are the key process requirements to achieve reliable leadfree wave soldering. Thermal profiling solutions for reflow wave soldering. Smt, short for surface mount technology, is a method that attaches electronic components onto the surface of pcb. The earlier process steps within surface mount assembly are critical to an effective reflow soldering process. Isopropyl alcohol, also referred to as ipa, isopropanol, and 2propanol, may be in short supply for the coming weeks or months because of the covid19 novel coronavirus pandemic. A common area sometimes overlooked versus surface mount is wave solder. This month, smt magazine features strat egies for improving. Controlling the assembly process with the use of spc. Lead free wave and selective soldering technologies. This often is a jerking belt or conveyor in the oven. The right and left dwell time measurements we very useful in our initial set up of the wave solder spc process.
Any fault at this stage will lead to undesired results and so complete control of this process along with effective stencil design is. Lead length limitations a straight protruding length of more than 1 mm will in general not collect more solder in the joint in machine soldering and. Is there a solder pot hot air knife installed and used on the wave equipment. Melting point of pbfree solders pb free solders are usually tinsilver snag solder, or variations on snag solders. If there had been solder on the termination the process p arameters may have been correct. Zestrons product line of cleaning agents are designed to reliably remove solder pastes and smt adhesives from stencils, screens, and misprinted pcbs.
Itms unique smt process audit begins with us bringing our pc board fabrication and smt assembly expertise onsite to your facility. Smt adhesive problems after wave solder process we are having issues with glued smt parts falling off after going through wave solder process. Leadfree wave soldering can be achieved reliably and is being done in a large scale in asia now for some time. Reliable selective soldering for high volume assemblies. By deploying a double reflow process, you can maximize your yields through the wave solder process. Smd soldering or surface mount technology assembly needs different smt equipment and greater experience and expertise. Pcb surface finishes implication on the smt process yield liyakathali. Because surface mount components are normally soldered using a reflow oven process the impact of wave soldering and wave solder simulation methods must. There are clear work instructions for assembly and packaging process. Ipc checklist for producing rigid printed board assemblies. Hand soldering uses an iron, solder, soldering wick, and sometimes flux to attach surface mount components to a circuit board. Pdf a practical design approach to custom mmwave smt packages.