Circuit Services welcomes the opportunity
to meet your SMT requirements for assembly. In order to save time
and therefore offer our best pricing we request that our customers meet
certain requirements to avoid additional charges and delays.
Bill of Materials to include: manufacturer’s
part number, type of part2,
type of packaging3,
topside or bottomside assembly, component locations listed by reference
designators and quantity. (download an "Excell"
including any change notices.
Dimensional specifications for non-standard5
Solder paste stencil file in "Gerber"
Circuit board requirements:6
Electronic "Centroid data" in ASCII format.
This is the "X" & "Y" coordinates for the location of the parts on
the board. These coordinates should reflect the location of the center
of the component body referenced to the same zero point. This information
should also include the respective component designations as well as the
component rotation. The preferred format for coordinates is in millimeters.
(please call for info if you are unfamiliar with this)
Circuit board designs shall provide for
marks to be used for registration of boards or panels. Fine pitch components
with spacing of 25 mils or less should include 2 fiducials for placement
verification. One should be in the center and the other should be diagonally
placed to the outside edge of the component.
All panel arrays or boards must have a
minimum of two tooling holes diagonally opposing in the corners of the
There must be a minimum of 0.25" space
clearance from any edge of the panel to the edge of the nearest component
Circuit boards must meet bow and twist
specifications of IPC–D-600.
Maximum board or panel accepted for assembly
is 12" x 14".
When boards are small, it is advised that
the boards be arrayed in panel form and scored whenever possible in order
to cut down on the handling time and cost.
The finish on the surface mount pads must
exhibit a property of flatness to allow for proper placement of SMT components.
This property becomes more critical as the pitch becomes smaller. Examples
of a preferred flat finish would be Ni/Au(immersion gold over electroless
nickel), OSP(Organic Solderability Preservatives) or Electroless Palladium(recommended).
Soldermask should cover all traces and exhibit good registration.
SOIC components should be supplied in
either tubes or on tape and reel. PLCC components should be supplied in
trays, tubes or on tape and reel. QFP components are to be packaged in
trays. To prevent damage to QFP’s, do not remove from original provided
trays and do not break hermetic seal. Tape and reel are preferred
for all components whenever possible.
All SMT components provided on tape and
reel should have a factory-attached leader approximately 12" long before
the first component.
First Article Assembly:
Please provide 5% attrition for all parts
provided on tape and reel and 2% attrition for all other forms of packaging.
Unused parts will be returned after completion of assembly.
All prices quoted are budgetary and based
on customer meeting the above requirements. Prices are subject to change
until after final review and receipt of all supplied parts and/or boards
for assembly. Delivery times are after receipt and final review of all
supplied components and/or boards. Set-up charges quoted are also based
on the above requirements. Set-up charges include: Solder paste film and
stencil, custom tooling or fixtures, kit audit and verification, programming
for pick and place, feeder preparation, solder paste stencil preparation
and product specific thermal profile for solder paste reflow.
The first time we set-up a new assembly
for SMT, it is both important and necessary that we verify solder paste
stencil set-up, placement programming, feeder set-up and optimization,
placement accuracy and oven profile for proper reflow of the solder paste
with the components mounted. It is not recommended that these parameters
for proper assembly be learned "on the fly". The multitudes of possible
problems encountered during this exercise are far too numerous to list.
These potential problems must be identified and corrected before the production
order is run through the entire sequence of events required for proper
SMT assembly. It may often be required that we build 1 or 2 assemblies
for purposes of proofing the set-up. It is possible that these boards may
or may not be usable after this exercise. We will not mount components
identified as expensive for this proofing and we request that if you are
the supplier of the boards, please send any extra bare boards that you
may have on hand. These bare boards may be scrap due to damage or defects
in manufacturing, extras, or possibly an older revision that has become
obsolete, but please identify them as scrap to be used for test purposes
Questions concerning the above requirements
or the manufacturing capabilities of Circuit Services can be answered by
calling 504-468-9714, faxing 504-468-9726 or email questions to email@example.com.
We welcome you to visit our website at www.circuitservices.com
Documentation may be supplied as a "WORD" file, "EXCEL" file or hard paper
An example of a "type of part" is: SOIC-8 pin, QFP-160 pin, PLCC-84 pin,
An example of a "type of packaging" is tube, waffle tray, 8mm tape, 12mm
tape, bulk, etc.
Drawings may be supplied as "Gerber" files, "DXF" files or hard paper copies.
Non-standard SMT components are defined as connectors, headers, sockets,
transformers, LEDs, etc.
Circuit board requirements apply for circuit boards supplied by customer
and not manufactured at CSI.
Fiducial marks are isolated targets placed on the board for the purpose
of verifying registration of the board, panel or component location during
assembly. Board/panel fiducials are usually placed diagonally opposing
on two of the outside corners. There should be a minimum soldermask clearance
Component requirements apply for all components supplied by customer and
not supplied by CSI.