The PCB supply chain encompasses multiple components, raw materials, and
the PCB itself. PCBs and PCB assemblies (PCAs) are often the most technically complex
components that are purchased for electronic assemblies and products, and they form the
center of an electronic product’s universe. The complexity of modern PCBs leads to
several challenges for a supply chain management (SCM) team that may be significantly
different when compared with other commodities the team manages.
Anatomy of the PCB Supply Chain
The supply chain for PCBs and PCBAs encompasses a range of raw materials
vendors, manufacturers, and of course, the components that appear on a finished PCB.
Each step along the supply chain from design concept to finished product draws resources
from multiple areas:
Bare board core and laminate materials, some of which may have
compatible swaps as defined in slash sheets; these draw resources from their
supply chain in terms of chemicals and raw materials.
Tooling and materials used in production of bare boards and
assembly of PCBAs, spanning across solder materials, coatings, plating
precursors, cleaning materials, and other consumables.
Semiconductors and other components that are mounted to the PCB
give the device its functionality. PCBAs require a broad range of components
support the desired functions and capabilities in a given product, which
create risk if not selected with an eye towards sustainability.
Packaging and enclosure materials, or pre-formed enclosures,
will house the finished assembly and enable connectivity with other systems.
Part of the challenge in managing the PCB supply chain
is to ensure new products are manufacturable at the desired scale and over the desired
product lifetime. For example, ensuring a long-term sustainable supply chain is less
important when producing QTY 1 of a complex system, whereas it could be much more
difficult when producing a forecasted quantity of millions over a 10+ year period. This
is also an important consideration in product lifecycle management as product lifetimes
will end once raw materials and components go EOL.
Who Manages a Product’s Supply Chain?
Once a product’s requirements are defined and engineering starts to work, it is the
design of the PCB and selection of components that will start a Value Chain of
Events.The layout of the printed is the first physical representation of that product.
Design for manufacturing (DFM) is required as a way of optimizing performance and cost,
yet also to ensure a design can be manufactured at the desired scale given a
manufacturer’s fabrication and assembly capabilities. The challenge of managing the
information, documentation, and transfer in order to specify the design requirements and
other expectations for the suppliers.
Procurement: Unless an OEM is one of the few that is vertically
endowed with manufacturing, the general considerations for PCB and PCA
sourcing decisions, and the criteria that should be used to evaluate and
select suppliers is turned over to purchasing.
Supplier selection and qualification: Others are involved in
the business considerations and selection criteria described to evaluate and
qualify suppliers, including processes to perform technical assessments of
samples provided by the supplier.
Process control, monitoring, and inspection: An ongoing task in
managing the electronics supply chain is the monitoring of quality assurance
methodology, often based on best quality practices like six sigma
principles, with specific recommendations for process control, testing, and
inspection of PCBs and PCAs at the supplier.
Product acceptance and feedback: Finally, processes must be in
place for design qualification, lot acceptance, and ongoing inspection of
received PCBs and PCBAs. It also includes recommendations for long-term
supplier management that minimize the internal management cost while
maintaining a high level of performance.