A Complete Guide To PCB Assembly Process

best pcb assembly manufacturers

PCB mechanics, which entails several processing phases, is useful to create PCBs. Before the circuit board can be useful, however, additional processing, including PCB assembly, is needed. The bare board will construct from fiberglass, copper lines, and other metal components. Epoxy glue will hold it all together, and a solder mask will serve as insulation. The bottom surface glows green due to the solder mask.

A PCB may be constructed with electronic elements and components after being prepared. Additionally, a few electronic components will be put on the PCB. This board may be used to make electrical items and is known as a PCBA. Therefore, PCB assembly, or PCBA for short, refers to the manufacturing process of soldering electronic components to printed circuit boards.

How Is A PCB Assembled?

Adding solder paste to the board, selecting and arranging components, soldering, inspecting, and testing are all steps in the PCB assembly process. To guarantee that the greatest quality of items is generated, the entire assembly process must be watched carefully. (PCB prototype assemblies are early versions of goods created only for the aim of evaluating the viability of design concepts.)

What Are The Steps In PCB Assembly?

Several automatic and manual processes are in the straightforward PCB construction process. The most fundamental PCB unit is where the PCBA process always begins:

  • A thorough inspection is necessary for PCB SMT, BGA, and other assembly processes. includes electrical and bare board inspections when assembling components.
  • The smooth operation by quality pcb manufacturer of the ensuing assembly process can take place via real-time inspection. Visual inspection, AOI (Automated Optical Inspection), X-ray inspection, and ICT (In-Line Inspection) are a few of the frequently essential primary inspections and testing.
  • Checking for size and appearance Aspect ratio, space and tolerance, and PCB edge measurements are among the bare board size check criteria. PCB inspectors can identify it by looking at the inner and outer layers of multilayer PCBs, as well as single- and double-sided PCBs, and by looking for flaws including open circuits, short circuits, abrasion, line width, tracking, and other issues.
  • Warpage check: To measure the PCB warpage manually, measure the distance from the fourth corner to the tabletop while firmly pushing the remaining portion of the circuit board against the surface.
  • Solderability testing includes edge immersion testing, rotating immersion testing, wave immersion testing, and solder ball testing. SMT solderability inspection addresses pad and plating through-hole inspection.
  • Checking for internal flaws: Microsection technology is frequently used to find flaws in PCBs, such as the thickness of tin-lead alloy copper, the alignment between conductive layers, lamination, etc.

What Standards Apply to PCB Assembly?

Almost at every level of the PCB fabrication process, IPC standards are accessible. The following lists a few IPC standards that directly impact PCB assembly in the hopes of assisting you.

IPC-2221 is a normative manual for PCB design.

There are two IPC standards for rigid and MCM-L PCBs in the 2220 series, as well as one for flexible PCBs. Design layout, materials, mechanical and physical qualities, electrical properties, thermal management, and other subjects cover in IPC-2221. All bare board standards should be uniform to facilitate PCB assembly in the future.

Materials, techniques, and other standards for producing high-quality welded interconnects are described in IPC J-STD-001. It emphasizes process control and provides specifications for many kinds of electronics.


The IPC-A-620 serves as a benchmark for the acceptability of cable, wire, and harness assemblies and can be useful independently when making product purchases.


It offers instructions for assessing several facets of PCBs. For instance, test method IPC-TM-650 outlines a procedure for evaluating the propensity for electrochemical migration on a circuit board’s surface. This test evaluates the current’s resistance as it passes through the PCB substrate’s surface.

What Kinds Of PCB Assembly Are There?

When assembling prototype boards for testing and usage, electronic designers frequently face several difficulties. Consequently, they need to be knowledgeable about PCB assembly services and technology. High-quality PCBs that satisfy the specifications may produce with the appropriate assembly and technology. Here, we’ll quickly go through several PCB assembly services and technologies.

Surface Mount Technology (SMT Assembly)

It is a technique for securely attaching electrical components to a PCB’s surface. A small quantity of molten solder paste is useful in this procedure to join the component leading to a pad on the PCB surface. Automated tools are typically useful in SMT assembly to find and install components on the PCB.

BGA (Ball Grid Array) Assembly

BGAs, or ball grid arrays, are another type of surface mount technology. This kind of technology is typically useful in ICs, which contain several pins. Due to the precise component positioning, BGA is a low-cost packaging method that is perfect for creating some of the greatest circuit boards.

Technology Mix

PCB boards with only one type of component are no longer able to handle the complexity of today’s more sophisticated electronics, which calls for more sophisticated, integrated, and compact PCB boards. As a result, a board with mixed technologies that includes both SMD and through-hole components is now necessary.

This kind of board includes SMD and through-hole assemblies, necessitating the integration of through-hole and surface mount technologies. But soldering is a challenging operation.

Through-hole Construction

Through-hole Assembly describes the precise installation of leads, which you place into the printed circuit board holes after they have been drilled and soldered on the opposite side of the pad. This procedure can carry out manually or mechanically.

Mechanical Installation

PCB mechanical assembly includes putting PCB parts together in a production line. Additionally, it describes an assembled component or item created in this manner. It combines best PCB assembly manufacturers to carry out particular tasks.

Box-Build Construction

System integration is another name for box-build assembly. A PCB component in a wire-filled cabinet, a compact enclosure, or a fully integrated electromechanical system with electrical and pneumatic components are all examples of boxes.

A sturdy packaging is necessary. Make sure your manufacturer is utilizing the right packaging if you want your PCB to operate correctly.

Leave a Reply

Your email address will not be published. Required fields are marked *