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ROHS Compliance
Printed Circuit Boards |
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PCB Express Inc., Printed Circuit
Board Manufacturer use standard, high temperature and special application
materials including, but not limited to, FR-4, FR-406, FR-408, IS410,
Getek, Teflon, Rogers, Arlon, Nelco and Thermagon. Printed Circuit
Boards Manufacturer’s products are RoHS compliant surface
finishes include Hard Gold and Soft Gold applications. Circuit Board
Manufacturer US specializes in ENIG (Electroless Nickel / Immersion
Gold), Immersion Silver, Immersion White Tin, ENTEK OSP, and Lead
Free Solder. PCB Manufacturer can also supply PCBs with Standard
Tin/Lead HASL (Hot Air Solder Leveling). Blind vias, Buried vias,
Controlled Impedance, Aluminum backed and heavy copper boards are
not a problem here at PCB Express Inc. |
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PCB Express
Inc is a manufacturer of RoHS Compliant Printed Circuit Boards,
Motherboard PCB and Prototype Circuit Board in Illinois, US. |
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PCB Express Inc is a manufacturer
of RoHS
Compliant Printed Circuit Boards, Motherboard
PCB and Prototype
Circuit Board in Illinois, US. We offer a comprehensive
Printed Circuit Board Prototype PCB Service, ensuring you get what
you want, when you want it. PCB Express Inc is a Custom manufacturer
of Restriction of Certain Hazardous Substances (RoHS) compliant
& leaded printed circuit board (PCB) assemblies. We provide
high quality PCBs at the most competitive prices. Our PCB
manufacturing facilities suit your design needs in a
very wide range. As an ISO certified PCB manufacturer, we commit
to our customers a variety of unique services from small quantity
prototype PCB to volume PCB Production. |
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We can provide you with UL approved RoHS
compliant PCB's boards with a variety of final finishes. |
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Our RoHS compliant boards are
produced using laminate materials of varying decomposition temperatures
with a number of different final finishes. We can provide you with
a lead-free solder finish using SN100CL - a lead free alloy of 99.3%
tin/ 0.6% copper with a trace of nickel. It is an alternative to
more expensive finishes and makes a flatter pad than its leaded
counterpart. We can also finish plate your boards with either electro-plated
or immersion gold. We just recently added Electro-less Nickel Immersion
Gold (ENIG) and Immersion Silver to our production floor. And of
course we offer a standard "hard" electro-plated gold
finish over electro-plated nickel. The laminate materials that we
are processing RoHS products on are capable of withstanding temperatures
between 260º and 288º C for 20 seconds or more depending
on the laminate selected. |
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Prototype and Production PCB's That
Meet the Rohs Directive |
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PCB Express, Inc.is currently
producing both Prototype and Production PCB's that
meet the RoHS Directive. To reach that goal it is important that
our circuit boards not only be lead free but also meet the restricted
concentration levels for mercury, cadmium, hexavalent chromium,
polybrominated biphenyls and polybrominated diphenyl ethers. We
are using raw materials and processes that enable us to meet those
restrictions. PCB Express, Inc.is using a Tin Copper alloy as our
lead free solder finish. It is Nihon Superior's SN100CL, a solder
that has been in use in Asia for a number of years. It is made up
of 99.3% Tin, 0.6% Copper and a number of additional proprietary
elements including Nickel. It is not PCB Express, Inc' intent to
replace our tin lead solder process at this time. It will continue
to run in tandem with the lead free process until the use of leaded
solder becomes untenable. ENIG and Immersion silver have just recently
been added to our "in-house" capabilities. We are now
able to offer electro-less nickel immersion gold plating as an alternative
to the lead-free solder finish. Immersion silver was included in
our new immersion plating line so we have yet another "in-house"
option for a final plated finish. |
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ROHS Compliant |
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Currently any printed circuit
board that we produce does not contain any mercury, cadmium, hexavalent
chromium, polybrominated biphenyls or polybrominated diphenyl ethers.
Boards we produce that are not processed using leaded solder for
a final finish will meet all of the RoHS' restrictions. These products
would include those that have lead free solder, electro less nickel
immersion gold, immersion silver, electroplated gold, white tin
or finishes other than tin-lead solder. |
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Laminates |
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PCB Express, Inc.can supply you
with a RoHS compliant board using laminate materials that can be
matched up with the exposure to high temperatures during your assembly
processes. It is important to keep in mind that some lead free assembly
processes will require the laminate base material to withstand temperatures
in excess of 260 degrees C or 500 degrees F for extended periods
of time. To resolve this, we have high temperature laminates in
our inventory so that our customers will be able to meet the higher
temperature cycling requirements of some lead free assembly applications.
PCB Express, Inc.can supply high thermal capacity materials manufactured
by Isola/Polyclad and Nelco among others. These materials met the
UL testing for 130°C maximum operating temperature, solder limits
of 288°C for 20 seconds, 94-V0 flame rating and direct support
of current carrying parts. Each of these laminate systems meets
the minimum requirements for IPC 4101B specification sheets 26,
28, 121, 124 or 129. Individual manufacturer's material types may
exhibit variations in electrical, thermal and physical properties.
Normally a single manufacturer's material will be stocked for use.
If you have specific questions please contact your PCB Express,
Inc.sales representative |
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Lead Free Solder |
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PCB Express, Inc. currently process
all of our Standard Spec panels using the lead-free solder in addition
to the production Custom Spec panels that require it. This
particular solder is 99.3% tin and 0.6% copper with a small amount
of nickel added. This lead free alloy allows us to process panels
at approximately the same temperature as leaded solder. We ran a
series of processing tests to assure the best possible coverage
and surface characteristics and the results were excellent. We found
the coverage to be excellent and the finish has exhibited exceptional
co planarity for a HASL process. We have sample boards available
for your evaluation; just contact your sales representative. |
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Electro-less Nickel Immersion Gold |
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The electro less nickel is an
auto-catalytic process that deposits nickel on the palladium catalyzed
copper surface. The process requires continuous replenishment of
the nickel ion and the reducing agent. Good process control (constituent
concentration, temperature and pH) is the key to a consistent reproducible
deposit. It is very important that the nickel be able to plate
a surface with consistent phosphorus levels. Most prefer a
middle range of 6 - 8% P, too low would easily corrode/too high
makes subsequent soldering of parts more difficult. Immersion golds
are replacement chemistries. This means that they attach themselves
to the nickel by replacing atoms of nickel with atoms of gold.
The purpose of the immersion gold layer is to protect the nickel
surface until such time as it is soldered to. The recommended gold
thickness is 2 - 4 uin. As the purpose of the gold layer is to maintain
the solderability of the nickel surface, it is necessary that it
be thin (two to four micro inches is preferred) and pore-free.
ENIG is a very versatile surface finish, it is a solderable surface,
it is aluminum wire bondable, and is an excellent electrical contacting
surface. It has excellent shelf life, in excess of 12 months, and
is easy to inspect (visual) and the thickness is easily verified
by non-destructive measurement. Immersion silver is deposited directly
on the copper surface by a chemical displacement reaction. Immersion
silver processes available in the industry co-deposit an organic
anti tarnish with the immersion silver. The reaction is fast approximately
1-2 minutes and does not require the relatively high temperatures
of ENIG. This makes this process very conducive to conveyorized
processing. IPC specification 4553 covers Immersion silver and when
issued will specify 8 - 12 uins on a pad size of 60 X 60 mils or
equivalent. The pad size was specified because the thickness of
the deposited silver varies with pad size, the smaller pads plate
thicker than the ground plane areas. The primary use of IAg is as
a solderabilty preservative. During assembly the immersion silver
dissipates into the solder and allows the formation of a Cu/Sn intermetallic.
All indications are that IAg will transition readily into LF assembly.
This is to be expected since the SAC alloy contains a relatively
high percentage of silver in the alloy. |
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Electrolytic Nickel Gold |
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Electrolytic plating of gold
over a nickel base, commonly referred to as hard gold, is also available
from PCB Express, Inc.as a final finish. Copper and gold tend to
undergo solid state diffusion into each other and the process is
accelerated by increased temperature. Copper on the surface can
oxidize resulting in increased contact resistance and copper migrating
into the gold can cause the gold to tarnish and corrode. This can
be minimized by plating a barrier layer between the copper and gold.
Nickel is commonly used as a barrier layer to prevent the gold migrating
into the copper. The nickel barrier helps to reduce the porosity
compared with plating gold directly over the copper base. The nickel
protective coating provides several benefits. It serves as a backing
to the gold for extra hardness as well as providing an effective
diffusion barrier layer between gold and copper. The nickel/gold
provides a finish that is heat and corrosion resistant, environmentally
stable, solderable and durable the nickel under plate enhances the
wear characteristics of gold. Traditionally, nickel/gold plating
has been applied over copper features used for keyboard contacts,
push pads or edge fingers to provide the conductive, corrosion resistant
coating. But at higher frequencies the presence of the nickel layer
can produce additional signal loss. Thicknesses in the range of
125 to 150 micro inches of Nickel are typically plated onto the
copper followed by 25 to 30 micro inches of gold. This type of gold
plating is not recommended for solderable pads although it will
work well with aluminium wire bonding. The intention is to cover
features that will experience some wear and tear throughout the
life of the circuit board. Gold plating over 15 to 18 micro inches
will "contaminate" the solder joint and can cause fracturing
and joint failures. |
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