SMT PCB assembly Requirements
Documentation Requirements (electronic)
The following information is required for all component purchasing / receiving / verification / inspection / programming the pick & place equipment and PCB assembly work instructions creation.
- Component Description
- Reference Designator
- Manufacturer Part Numbers
- Indicate any “no load / do not install” (DNI) locations.
- If you are supplying components, please identify as “Customer supplied”
- Reference designator
- X / Y – Centroid location (mils / in)
- Layer / Board side / (top / bottom – component mounting not silkscreen)
- Redline drawing for conformal coating
- Gerber files
- Assembly Drawings
- Component layout (top / bottom), polarity marking, special assembly instructions or any components that require special handling or processing, some examples may include
- Non- washable (Moisture sensitive) components – switches, sensors, modules
- Special prep / specific height / placement requirements
- Lead length / trim – make sure to include +/- tolerances
- Rework wires (pin to pin routing)
- Component mounting (top /bottom – opposite of silkscreen – polarity)
- Labeling / Serialization – (format / location / type)
CAM Specific PCB Assembly Requirements
Please note that we require the following information to complete the pcb assembly process, or you job will be delayed at your expense. (Note 1: Our CAM team must be notified up front that if this information is not received, the job cannot be assigned to the production floor).
The customer must provide us with PCB Silk Screen polarity mark information on all
polarized parts (cathode, anode, pin number and what the dot or plus sign indicate.
Polarized components are Capacitors, Connectors, Diodes, LED’s, IC’s, Switches,
Antennas, Filters, Modules, Crystals, Oscillators, Battery Clips, and Transformers).
Polarity marks indicate the following:
* DOT: A "Dot (0)" on or near a lead does not represent anything unless the meaning of
the dot is clarified as being a "Cathode", "Anode" or a "Pin Number Indicator".
* + (Plus): The (+) Plus symbol on or near a lead does not represent anything unless the
meaning of the dot is clarified as being a "Cathode", "Anode" or a "Pin Number Indicator".
* K: The "K" symbol indicates the "Cathode".
* A: The "A" symbol indicates the "Anode ".
* Diode Symbol: The Diode symbol (looks like an arrow head hitting a target) should have
the Anode near the components anode, and the Cathode near the components cathode.
* 1: The number (1) indicates the "Pin 1" of the component.
* Other Symbols: All other symbols on or near a lead must be clarified as to what it
The Customer must provide us with special assembly instructions when required, such as:
Height of components, Adhesive placement, Reflow profile for temperature sensitive
The customer must provide us with how they want us to handle polarity issues (DNI, Place
as is, Call or Email for instructions). (Note 2: We must make it clear that if we are not
provided this information, their job will be delayed or shipped without the parts in question.
In doing this, we place the responsibility on the customer when their assembly issues, and
any rework will need to be paid for by them. Our sales team, website, or the CAM team
can provide customers with the checklist via email when they go over CPL, Files, and
Technical Question inquiries).
The customer must provide the CAM team with all drawings needed to complete the
Customer Supplied / Consignment - Component Requirements
Lead time will be impacted if proper attrition is not supplied. We will always work with our customers when it comes to customer supplied components; the following is our standard guidelines. If you have expensive or a minimum quantity of any component on hand please contact the assembly sales team for details.
SMT components, not supplied on reels, are required to be on one continuous strip of tape. Resistors, Capacitors, Diodes (0603, 0805, 1206, 2225, SOT, SOD, MELF – packages) require a minimum of 50 pcs and/or has to exceed the required quantity by 30 pcs. (Example: build req. 40 pcs – we will require 70 pcs – this meets our minimum required 50 pcs plus 30 pcs above build requirement) Resistors, Capacitors, Diodes (0201, 0402, mini-melf, miniature packages) require a minimum of 100 pcs and/or has to exceed the required quantity by 50 pcs. (Example: build req. 80 – we will require 130 – this meets our minimum required 100 pcs plus 50 pcs above build requirement).
An overview of the PCB Assembly Manufacturing can be found here: Turnkey pcb assembly