Designing optimized selective soldering process for thruhole. Ipc 3000 lakeside drive, suite 309s bannockburn, illinois 600151249 tel 847 615. Pbfree selective wave solder guidelines for thermally challenging pcbs. Dip soldering with this nozzle can be done horizontally or. Selective solder the simplified process of using a selective solder machine. Carrier stability and longevity euler buckling of the masking due to differential heating. Since no typical selective soldering fluxes have yet been designed, and wave solder fluxes are also used in selective soldering, the same fluxes and amounts of flux used in wave soldering, per solder area, are used in selective soldering. Pth components should, to the extent possible, be placed together. Sampling solder from a wave or selective soldering. Selective soldering is an automated throughhole method soldering. Selective soldering is the process of selectively soldering components to printed circuit boards. Due to technical requirements, components may contain dangerous substances. As the use of leadfree alloys has increased in electronic assemblies, much work has been done to develop design for.
Considerations for choosing wave versus selective solder. Lead free wave and selective soldering technologies. Selective soldering is the process in which through hole components on a printed circuit board are processed by applying solder to individual sets of leads. Selective soldering machines solder throughhole components and connectors on smt and mixed technology pcbs with either of manncorps highprecision, ultima series selective soldering solutions. This workshop will look at systems, materials and process but also design for manufacture along with the most common defects and cures. Soldering considerations for surface mount packages recommended footprints for surface mounted applications surface mount board layout is a critical portion of the total design. Selective soldering troubleshooting ddm novastar learning. This paper focuses on the effect of selective wave solder pallet aperture size on pth barrel fill, on a relatively thick test vehicle with a large quantity of plane layers. Sampling has a significant influence on the chemical composition of the sample and the transferability of the results to your production. Short lead length, small pads, and wider pitch between the pins will reduce the potential. Selective soldering is the process of selectively soldering components to printed circuit boards and molded modules that could be damaged by the heat of a reflow oven or wave soldering in a traditional surfacemount technology smt or throughhole technology assembly processes. As the circuit board makes contact with this wave, the components become soldered to the board.
Tarr, 2014, what you always wanted to know about wave soldering. Selective soldering machines for low to medium volume solder. You can use a selective solder machine to replace more timeconsuming and expensive systems using wave or hand soldering with fixtures systems that are also not as repeatable. Many designs have their roots in wave soldering and defects can be dramatically reduced when some simple improvements are made to enhance compatibility with selective soldering applications.
Mar 06, 2018 these design attributes do not support the use of full board wave soldering and the added cost of its usage cannot be balanced against its speed. Selective soldering defining the correct soldering process. Both expose the pcb to a molten wave of solder, but in wave soldering, the entire. Flux is applied to the components that need to be soldered only. Smta releases selective soldering 101 online training course. Selective soldering defects and how to prevent them gerjan diepstraten vitronics soltec bv. In principle, the objective was to mimic wavesoldering, but in localised areas. Layout design rules needed to take into account the additional clearances required to accommodate selective soldering, and it was recommended to remove solder mask between pads to eliminate solder balls. Selective soldering selective soldering series part 1 of 3. For years the primary method of soldering a circuit board in production has been to wave solder it. Presented by bob willis who spent many years running the electrovert wave soldering master class, both one and twoday theory and hands on training in europe.
Selective wave and point soldering are both options but what are the realities with leadfree and high temperature solder alloys. Why use selective soldering user experience of selective and wave soldering with leadfree pcb design rules for selective soldering flux requirements for wave and selective soldering compatibility of solder masks and leadfree solder setting up leadfree profiles solder alloy choices cost of leadfree process operation. Design rules for selective soldering assemblies smtnet. The pcb then passes through a molten wave of solder to solder the boards. Many defects can be eliminated in the design phase of the assemblies when specific rules for a robust selective soldering process are applied. Considerations for choosing wave versus selective solder wave soldering all soldering processes require flux, heat, and solder application.
Selective i reflow i wave i handling i aoi i know how. Design rules for miniwave drag selective soldering miniwave drag selective soldering design rules introduction. For wave soldering of surface mount components glued to the bottom of the board, it is necessary to align them parallel to the wave to prevent solder skips. Conformal selective wave solder carriers design rules the design of an exclusion fixture is non trivial.
Select wave andor multi wave soldering process in both leaded and lead free alloy. This can either be done by hand, or it can be done with a selective soldering machine. Wave versus selective soldering aci technologies, inc. The optimally matched solder for every application. There are two automated methods for accomplishing this wave soldering or selective soldering figure 1. Success in selective soldering is critically dependent on choosing a suitable flux, and placing it exactly where it is required. Wave versus selective soldering soldering is a process for attaching electronic components to a printed circuit board pcb to form an electronic assembly.
For more details on board layout please see our design guidelines for selective soldering. Pcb design for defectfree selective soldering general guidelines for snpb and pbfree alloys. The selective solder machine creates a small wave of liquid solder that streams. Pcb design guidelines for wave or dip soldering should be applied. A wave soldering machine combines these steps into a single machine process. Advantages of miniature wave selective soldering over wave soldering.
Wave soldering is a bulk soldering process used in the manufacture of printed circuit boards. When a pcb is designed according to these guidelines, a stable and solid solderprocess can be guaranteed. Selective soldering for high quality throughhole tempo. Selective solder troubleshooting guide ddm novastar inc. Bob still runs his own courses on selective and wave soldering for customers worldwide. Selective soldering defects and how to prevent them. If you want to compare selective soldering machine with wave soldering machine cost, you will be pleased to know that selective soldering will be five times cheaper. New pcb design rules a key goal in selective soldering is to avoid affecting the surfacemount components and other adjacent materials on the board. The guidelines can be applied for select wave andor multi wave soldering process in both leaded and leadfree alloy. All ddm novastar selective soldering machines are compatible with both lead and lead free solder.
Why use selective soldering pcb design rules for selective soldering flux requirements for selective soldering compatibility of solder masks and leadfree solder. When a pcb is designed according to these guidelines, a stable and solid solder process can be guaranteed. The name is derived from the fact that the process uses a tank to hold a quantity of molten solder. We are experiencing problems while soldering with a 700 degree f iron tip, and are thinking of changing this process to a selective wave soldering. It is critical to selective solder a heavily populated board. Selective soldering is also useful for soldering odd size components. During wave soldering the underside of a board is fluxed, preheated, immersed in molten solder and subsequently cooled. Wave height set too high or hot, air knife is set incorrectly excess turbulence in the wave increased surface tension due to nitrogen definition. These design attributes do not support the use of full board wave soldering and the added cost of its usage cannot be balanced against its speed. Other soldering techniques beside wave and reflow soldering, other techniques are used in special applications. This document describes general guidelines and attention points for pcb design regarding selective soldering.
Selective solderingselective i reflow i wave i knowhow recommendations for the design of assemblies to be soldered selectively selective miniwave soldering the following data is based on projects which already were realized. Book traversal links for design guidelines for selective wave soldering. Key requirements for selective fountain type soldering are. We recommend to book a seho engineer or a trained engineer of the seho. Wave soldering troubleshooting guide soldering solutions. Soldering and mounting techniques on semiconductor.
The surface mount technology association smta announced the recent release of selective soldering 101, the latest in a series of online training courses on the fundamentals of electronics assembly. For details, please refer to chapter 4 and chapter 5. Saline lectronics offers every type of pcb soldering solution available including wave soldering, selective soldering, hand soldering and robotic soldering in order to ensure proper connection of the components used on your pcb assembly. Pcb design for defectfree selective soldering general. Additional free space might be required to address product tolerances. Recommendations for the design of assemblies to be soldered. How to use the right flux for the selective soldering application. Apr 03, 20 welcome to this defect of the month video on soldering support wires, this series of videos were produced for and featured as part of the nplipc video library and examples are taken from the npl. Wave solderingthe ultimate guide to effective soldering.
The fixture, which is fabricated by milling cavities in a high temperature composite, is designed so that it covers all of the surface mount components while exposing all of the throughhole components. Nov 11, 2019 design guidelines for selective wave soldering bruce mon, 11112019. Selective soldering workshops introductory and advanced 2day selective soldering workshops compresses learning curve for those new to selective or advances indepth knowledge more than 195 people from over 100 companies have attended previous workshops taught by independent industry specialists combined classroom and handson. Selective wave pallet exposed center pins less complex insert more space. However, some boards still require throughhole pins. This process is designed primarily for thruhole parts, although with the correct preparation it will.
Before we get into laser soldering dfm discussion, let us briefly discuss the laser soldering process, since it is relatively new. Apr 16, 2018 design rules for miniwave drag selective soldering miniwave drag selective soldering design rules introduction. With wave soldering, many years were needed to optimize the process and apply relevant design rules. Free space requirements for selective soldering multi wave. Laser soldering uses diode lasers to heat the component lead and pth pad while automatically feeding solder wire to achieve the desired fillet. The test vehicle was chosen to represent a realistic but challenging product design for pbfree selective wave solder. Selective soldering in the first two articles on selective soldering, we discussed the different processes making selective soldering work for yo u, september 2002 and how to keep track of the quality of the process ensuring reproducibility in selective solder ing, october 2002. The high melting points of the leadfree solders and the fact that the solder is only supplied.
Shorting can occur due to poor fluxing, incorrect heat or wave separation. Design rules for miniwave drag selective soldering blog. Selective soldering is the process of selectively soldering components to printed circuit boards, molded modules, etc. Recommendations for the design of assemblies to be. A small sphere of solder adhering to a laminate, resist, or conductor surface generally occurring after wave or reflow soldering. General this document describes general guidelines and attention points for pcb design regarding selective soldering. How to use the right flux for the selective soldering. In selective wave soldering of thruhole components when surface mount components are reflow soldered on both top and bottom sides, adequate space between surface mount and thruhole. It is especially useful for avoiding damage to components that are sensitive to the heat of a reflow oven in a traditional smt assembly process. This soldering technique can be very successful, but is also sensitive to some typical defects. They should be placed far enough from solder side smt components to meet the clearance and aspect ratio requirements shown below. They should be placed far enough from solder side smt components to meet the clearance and aspect ratio. The pcb soldering process for your circuit board design. The course will be useful for equipment operators, technicians, and engineers new to the industry that want to understand more about the soldering.
Soldering quality problems, throughput too low or inconsistent resultsan existing robotic system that may need replacingwearing out, poor results, lack of factory supportselective soldering that cant be easily done with typical bottom side selective soldering systemspost wave or reflow hand soldering that is better done with a robot. Selective wave soldering is a process used for the soldering of through hole components and requires addition design rules to protect other components. Selective wave soldering requires a custom, sitespecific fixture for each pcba design. Wave soldering th pins cte caused separation on layer 2 and lifted pads restoring nfp on th pins eliminated opens. This poses a small problem because throughhole pins cannot be soldered in a reflow oven and must be soldered separately. Wave soldering t e n s i l e s t r e n g t h n v80cmmin vcmmin v180cmmin 300 250 200 150 100 50 tense li strength leadfree solder joint sac305 wave soldering poor hole filling at high belt speed result in lower tensile strength. As well as checking the process suitability, calculations need to be done to ensure. Design and development of optimized selective soldering process for thruhole aerospace. Design guidelines for selective wave soldering bruce mon, 11112019. Throughhole components are still in use and wave soldering is undoubtedly the fastest technique to solder a large number of components quickly and may be the best method depending on your design. Layout design rules needed to take into account the additional. Pcb support during wave or selective soldering youtube.
Assembly and joining handbook developed by the assembly and joining subcommittee 735 of the product assurance committee 730 of ipc users of this publication are encouraged to participate in the development of future revisions. All shorting can be decreased through good design rules with reduction in pad size and component lead length. As a general rule bare board cleanliness should not exceed 1. Although, the application of other soldering methods, such as selective soldering, are steadily increasing there are advantages to wave soldering. Itw eae support center this document describes general guidelines and attention points for pcb design regarding selective soldering. Design improvements for selective soldering assemblies. We develop and produce highpurity electronic solders, smd solder pastes and solder fluxes for the electronics industry. The first involves the use of a single nozzle, for either a single drag wave soldering process or a dip soldering process. Orient parts close to throughhole pads orthogonal to the nozzle path. Wave soldering and selective soldering a wave soldering system that is used to selectively solder smaller areas of the bottom of a printed circuit board are used to solder through hole components and some active smt components and smt passives, such as chip resistor and capacitors. The footprint for the semiconductor packages must be the correct size to ensure proper solder connection interface between the board and the package. Two different soldering principles apply to selective soldering. Heres a brief snapshot of the different soldering process your pcb design will go through.
It will be because of less electricity requirement, less flux and solder consumption, no cleaning, less rework, and no protective taping. Wave soldering wave soldering is a largescale process by which electronic components are soldered to a pcb to form an electronic assembly. General recommendations for assembly of infineon packages. Reduce production costs, while improving quality and consistency, with the tr2 benchtop system or the standalone neol. The design of fluxes for a selective soldering applications pose unique problems due to the localization of the soldering proboth tcess. While hand soldering is slow, costly, and not always accurate, selective soldering allows a manufacturer to solder throughhole pins and work around delicate smt packages by targeting specific areas on the board. Parts shall be mounted in such a manner that, at a minimum, the markings are visible in the following order of precedence. Felder the technology for soldering in electronics production. The guidelines can be applied for select wave andor multi wave soldering process in both leaded and lead free alloy. Conformal selective wave solder carriers design rules.
Business business, international computers and office automation alloys design and construction circuit printing materials handling equipment and supplies materials handling equipment printed circuit boards printed circuits. Dont place smt parts too close to throughhole pads. Mastering selective soldering processing and manufacturability. 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. Pbfree selective wave solder guidelines for thermally. Design rules for miniwave drag selective soldering blog rps. Similarly, new design rules must be created for selective. A copy of the slides presented during the webinar are provided at the end of the event. Some suggestion allows for greater design density and reduce the possibility of product failure. Selective soldering, which is a type of wave soldering that targets specific components or regions of the board, is the solution for smaller boards with congested or mixed throughhole and smd. The guidelines can be applied for the different selective process for both. Pallet design guidelines introduction due to the never dying, mix technology of doublesided printed circuit boards required for assembly and the ever decreasing real estate in which to place these components, there is an ever increasing demand for a reliable selective soldering process. Design guidelines for selective wave soldering macaos.
They should be placed far enough from solderside smt components to meet the clearance and aspect ratio requirements shown below. Why use selective soldering user experience of selective and wave soldering with leadfree pcb design rules for selective soldering flux requirements for wave and selective soldering compatibility of solder masks and leadfree solder setting up leadfree profiles solder alloy choices cost of. Follow these selective soldering pcb design guidelines. They should be placed far enough from solderside smt. Smt parts on the solderside of the board should not be too close to the selectivesoldered pads. To prevent thermal shock the board is slowly preheated before soldering. Selective wave for small lcd an lcd glass display with 44 pins, 22 per side is soldered to the pcb using a manual soldering process. Guideline orientation standard for multiconnection package design rules for tape and reel. We are experiencing problems while soldering with a 700 degree f iron tip, and are thinking of changing this process to a selective wave soldering process.
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