Selective Soldering - A Cost Effective Alternative to Wave Soldering

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SELECTIVE
SOLDERING
By Suntronic Inc.
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WHAT IS SELECTIVE SOLDERING?
Selective Soldering is the process of soldering
components to the PCB. The components are
selected based on a program that uses PCB
images. Selective Wave Soldering machines help
to achieve consistent quality and process
control when assembling boards that have multiple
grounds, power planes, or dense populations of
SMT components on both sides. Our equipment is
also set up to support both Tin/Lead processes
and lead-free processes with interchangeable
solder pots.
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STEPS OF SELECTIVE SOLDERING
Step 1 - Program the selective soldering machine
using centroid files which are derived from
Gerber Files. Step 2 - Boards that are to be
soldered are kept on the conveyor belt and
inserted in the machine. Step 3 - Flux is
applied on the board to remove the oxidized metal
layer. Which is then activated by heating the
boards at 100 degrees. Step 4 - Each and every
through-hole components are soldered on the board
with the help of solder fountain.
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FACTORS TO CONSIDER FOR SELECTIVE SOLDERING
PROCESS

• Size of PCB
• Solder Type
• Nozzles
• Nitrogen supply
• Solder Pots
• Solder Flux

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ADVANTAGES FOR SELECTIVE SOLDERING

• Selective soldering allows the operator to
  program the exact spots for applying the molten
  solder.
• Machine operators can easily set the temperature
  and solder amount.
• Selective Soldering produces reliable solder
  joints.
• Different parameters are set for each component
  to ensure effectiveness.
• It requires no expensive wave solder pallets.
  The overall process is cost-effective.

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WHAT IS WAVE SOLDERING?

• Wave soldering is the automated PCBA soldering
  process. It is also known as flow soldering, it
  is usually performed in a closed protective gas
  atmosphere. In this process the board passes over
  a wave of solder.
• The wave soldering process has following
  advantages
• Easy Setup
• Rapid Process
• Low Costs

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DISADVANTAGES OF WAVE SOLDERING?

• Higher consumption of solder, flux and
  electricity
• Sensitive points on PCBs needs to be masked
• Post-wave solder rework increased
• Additional cleaning of wave solder aperture
  pallets or masks

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WHY CHOOSE SELECTIVE SOLDERING OVER WAVE
SOLDERING?

• It is generally recommended to choose selective
  soldering over wave soldering for through-hole
  assemblies for the following reasons
• If tall components are involved then, they may
  stop the wave from soldering the board properly.
• Manual soldering becomes difficult when boards
  with thick copper layers for ground and power
  planes are involved.
• It becomes difficult to solder through-hole pins
  if placed in dense configuration.
• Wave soldering can produce excessive consumption
  of Nitrogen if Nitrogen is run during the
  process.

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CONTACT US

• Suntronic has been providing expert PCB assembly
  services. Feel free to contact us today to know
  more about our selective soldering capabilities
  and other PCB assembly capabilities. Our experts
  would be happy to answer your queries regarding
  the services we offer and make the right
  decision regarding choice of components.
• www.suntronicinc.com info_at_suntronicinc.com
  [phone]