Standards Used In PCB Assembly Process
The best
manufacturer will be those who are well-versed in the industry standards for
PCB Assembly. Some of these standards are those which are published by IPC, the
Association Connecting Electronics Industries. In these standards, you can find
detailed information on how a PCB should be manufactured, and how the
manufacturing of the board should be documented. To be a best manufacturer it
is necessary to incorporate those standards into all aspects of their
operations.
IPC
Standards Used in the Manufacturing of PCB
IPC is the official name of the
association which produces PCB-related standards. The association was formerly
called the Institute for Printed
Circuits (hence the acronym "IPC"), but is presently called the
Association
Connecting Electronics
Industries.
There are IPC
standards for almost every phase of the PCB production process. To give you an
idea of what these standards entail, here are a few examples.
F
IPC-2581: IPC-2581 is a generic standard used when sending
information between a PCB designer and a manufacturer or assembly company. It
provides a standardized format for exchanging design data that helps ensure
consistent production results.
F IPC-2221: IPC-2221 is a generic standard for the design of PCBs. Within the 2220
series, there are also specifications for specific types of PCBs such as rigid,
flex and MCM-L. It addresses topics like design layout, parts lists, materials,
mechanical and physical properties, electrical properties, thermal management
and more.
F IPC-4101C: IPC-4101C covers requirements for base materials, typically called laminate,
mostly for use with rigid or multilayer boards. It deals with the materials
used, their dimensions and their properties.
F IPC-6012B: The Specification
IPC-6012BThe specification establishes qualification and
performance requirements for the fabrication of rigid PCBs. It offers
requirements for the various types of product classes in areas such as
structural integrity, solder ability and conductor spacing.
F J-STD-001: IPC J-STD-001 describes the materials,
methods and other criteria for creating high-quality soldered interconnections.
It focuses on process control and lays out requirements for a range of
electronic product types.
F IPC-TM-650: IPC has also published a test methods manual, IPC-TM-650, which
provides guidelines for assessing various aspects of PCBs. For example, test method IPC-TM-650 2.6.14.1 describes methods for
testing a board’s propensity for surface electrochemical migration. The
test measures resistance to the flow of current across a
PCB substrate surface. IPC-TM-650-2.3.25.1 describes
a method for ionic cleanliness testing of bare printed wire boards, which is
important because ionic contamination can cause issues that make a PCB
defective.
F IPC-A-600G: IPC-A-600G sets the acceptance criteria for PCBs. It
describes which observable conditions of a board are acceptable and
non-conforming — as well as the target conditions — for all parts of the PCB,
from gold fingers to copper plating. It is the visual
representation of the requirements put forward in other specifications
F IPC-A-610: IPC-A-610, Acceptability of Electronic Assemblies, provides
criteria for the acceptance of end products. It is the most widely used
standard the IPC publishes.
F IPC-A-620: IPC-A-620 provides criteria for acceptability of cable, wire
and harness assemblies and can serve as a stand-alone document for purchasing products.
F IPC/WHMA-A-620C: Requirements and
Acceptance for Cables and Wire Harness Assemblies. This is used in the
manufacturing of cables used in conjunction with your PCB assemblies.
F IPC-A-630: Acceptability Standard
for Manufacture, Inspection, and Testing of Electronic Enclosures. This standard is used when
your CM assembles and inspects box builds.
F IPC 7711/7721C:
Rework, Modification, and Repair of Electronic Assemblies. To repair and rework PCBAs
to IPC standards, your manufactures will use the information from this
document.
F
IPC-5704: Cleanliness
Requirements for Unpopulated Printed Boards, now addresses board cleanliness. It defines the recommended requirements for the cleanliness of
unpopulated single, double-sided and multilayer printed boards.
There are
many other IPC specifications that apply to the assembly of printed
circuit boards, but these are the primary ones that should be used Manufactures
to ensure success on your boards.
Image given below shows a complete picture of IPC standards from start
to finish.
IPC standards are the electronics-industry-adopted standards for design,
PCB manufacturing, and electronic assembly.
There are
several categories of printed circuits boards depending upon their uses, and
speaking of Product Classes, IPC has adopted the following three classes:
F Class 1 – General Electronic Products: Includes products suitable
for applications where the major requirement is the function of the completed
assembly.
F Class 2 – Dedicated Service Electronic Products: Includes products
where continued performance and extended life is required, and for which
uninterrupted service is desired but not critical. Typically, the end-use
environment would not cause failures.
F Class 3 – High Performance Electronic Products: Includes products
where continued performance or performance-on-demand is critical, equipment
downtime cannot be tolerated, and end-use environment may be uncommonly harsh,
and the equipment must function when required, such as life support systems and
other critical systems.
To achieve
high-quality, reliable products that meet customer expectations, it’s essential
for companies involved in the production of PCBs and the products that use them
to commit to quality through the use of IPC standards for printed circuit
boards.
Complying with IPC standards can
help a company improve its processes and products in numerous ways. Here are
four of the leading benefits.
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