PCBSINO has a
comprehensive lead-free solder program and is the industry
leader in lead-free solder technology. Our team has
studied every aspect of lead-free solder, including
solder alloy selection, solder paste evaluation, wave
solder flux evaluation, process optimization, design
rules, component evaluation, reliability, equipment
evaluation, quality, inspection and test, and cost.
Pcbsino has worked actively with industry consortia
and standard organizations to facilitate the industry-wide
transition to lead-free products.
----Pcbsino
offers a full range of services including printed circuit
board assembly and test, materials procurement, inventory
management, final system assembly (box build) and test,
packaging and distribution.
----Pcbsino
is a provider of advanced electronics manufacturing
services to original equipment manufacturers (OEMs)
in the telecommunications, networking, computer, consumer
electronics, and medical device industries.
RoHS prototype
assembly
----Lead free pcb assembly
at PCBSINO, an innovator in prototype circuit board
assembly, offers leading edge lead-free pcb assembly
(Pb-Free) and RoHS-compliant circuit board assemblies.
Lead-Free pcb assembly
includes:
Lead-Free
Rigid or Flexible Circuit
Lead
Free Rework
Lead
Free Printed Circuit Boards
Lead
free Board Assembly (SMT or THT/PHT)
Lead
Free Wave Soldering
Lead–Free
Materials Analysis
----Our Lead free pcb assembly
service utilizes special assembly procedures to assure
compliance with Lead-Free and RoHS pcb assembly standards.
In addition to leadfree pcb assembly, PCBSINO also provides
support to help you transition to lead-free and RoHS
compliant circuit boards. We are lead free pcb assembly
experts.
----PCBSINO
not only assembles your lead-free boards — we can also
assist you if you need help in determining if the materials
in your Bill-of-Materials meet lead free pcb manufacturing
requirements. We can even research lead-free components
for you and send you a Bill-of-Materials with the appropriate
components as part of our Turn-Key lead free proto assembly
service.
RoHS Electronic
Assembly Process
----Our RoHS
manufacturing and lead free prototype assembly processes
meet lead-free and RoHS standards. We use IPC 610D soldering
standards.
If components arrive in invalidated moisture
packets and your components need to be baked to reduce
excess moisture, then 72 hours is required to bake the
components. The assembly time does not start until the
components are baked.
The lead
free SMT Assembly Process
----The RoHS pcb assembly
process requires that none of the hazardous materials
listed in the RoHS Directive are used in the board,
components or solder. Bare circuit boards used in the
typical “leaded process」 are often coated with a lead-tin
finish, so the finish on the board must be modified
significantly to be compliant with lead-free and RoHS
standards.
----The lead-free
prototype process also requires that boards be assembled
at higher temperatures—usually 30-50 degrees C higher.
The higher temperature may require that the substrate
of the circuit board itself and various components be
modified to withstand the higher temperatures in the
oven. In addition, the IC moisture sensitivity level
that indicates how long the board can be exposed to
the air is approximately 2 classes higher for lead-free
boards, so there can be increased moisture sensitivity.
The shelf life of the materials used in lead-free boards
may also be shorter.
Profiling:
To ensure proper oven reflow temperature profiling,
we ask for one additional lead free pcb along with an
extra set of any temperature critical parts; i.e. BGAs,
heat slug parts, etc. These can be actual parts, non-functional
actual parts or thermally equivalent dummy parts. Most
manufacturers of large and expensive components can
supply non-functioning "Mechanical Samples"
specifically for this purpose. Additionally, suppliers,
such as Practical Components provide thermally equivalent
parts specifically for this purpose.
Inspection:
Due to the metallic composition of lead-free solder,
the visual appearance may differ significantly from
that of a standard leaded solder joint. Frequently,
a first look will give the impression of a cold solder
joint. Our inspection technicians are trained to IPC-610D
standards to ensure that the solder joints are solid
and of high quality.
Bill-of-Materials,
Board Finish and Components Analysis: It is
the customer’s responsibility to verify that the Bill-of-Materials
is correct for lead-free parts. We can also consult
with you if you need help in determining if your board
and components meet the requirements. If the components
arrive in invalidated moisture packed and we determine
there might be excess moisture issues, we will notify
you that we think your components need to be baked prior
to assembly.
Applying
Board Stencil and Solder Paste: PCBSINO begins
the assembly process using a lead-free compatible circuit
board and applying a stencil to the board. A lead-free
compatible solder paste alloy called SAC305 is applied.
The SAC305 solder alloy is used in SMT, Wave Solder
and Wire (Hand) soldering processes. After soldering,
the board is visually inspected for solder coverage
and manufacturing acceptability.
Placement
of Components: The next step is placement of
parts using a Pick-and-Place machine. The parts that
are placed are based on the supplied Bill-of-Materials.
Each part has a unique part number assigned to it. When
a product is programmed to run on the SMT equipment,
the part is assigned and the machine will then pick
the correct part. Any component on the board must be
lead-free process compatible. These components must
be able to withstand the higher solder and manufacturing
process temperatures.
Thru
Hole and Manual Solder: PCBSINO can also perform
Thru Hole and Hand / Wire soldering of lead-free boards.
Lead-Free Pass Thru and Hand soldering will be performed
in areas with no leaded parts. We will use lead-free
solder and a lead-free soldering iron.
Placing
Board in the Reflow Oven: The final step is
placing the board in the oven where the solder paste
is melted to form a metallic bond between the component
and the circuit board trace. Lead-free and RoHS compliant
boards must be processed at higher temperatures in the
reflow oven. The process margin (window) is smaller
which makes thermal profiling more important for lead-free
circuit boards. It is helpful for profiling to have
the following: board thickness, board finish, size of
the board, and layer count. Screaming Circuit uses ECD’s
SuperM.O.L.E.? Gold, WaveRIDER?, and OvenRIDER? thermal
profiling products to control the higher temperature
reflow soldering processes and track thermal profiles
required for lead-free boards.
Testing:
PCBSINO performs a visual inspection right after soldering
looking for manufacturing defects. PCBSINO uses the
IPC 610D soldering acceptability standard. Solder that
is “unleaded」 looks different after the manufacturing
process. PCBSINO has trained its staff how to evaluate
lead-free solder joints.
Packaging:
Fully assembled lead-free Boards are packaged individually
in ESD bags for shipment.
|