----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. |
