Circuit Card Assembly

Assembled circuit boards are referred to as Circuit Board Assembly (PCBA) or Circuit Card Assembly (CCA).

Both Printed Circuit Board Assembly (PCBA) and Printed Circuit Assembly (PCA), more casual names that are frequently used in the industry, are also known as Circuit Card Assembly (CCA), according to the Intellectual Property Constituency (IPC).

Circuit Card Assembly Method Selection:

there are three common circuit card assembly methods: Through-Hole Technology (THT): , Ball Grid Array (BGA) , Surface Mount Technology (SMT). which assembly is best? Befor select them, you should understand their different first.

Through-Hole Technology (THT)

Through holes drilled in the circuit board, components with leads or wires are connected using this method. On the other side of the board, the extra lead component is soldered manually or with the aid of a wave soldering machine.

THT might be most effective for prototype or low-volume production. Additionally, it works better with front connectors. However, it might be constrained for multilayer boards.

Ball Grid Array (BGA)

Surface-mount components that need to be permanently mounted using a grid of solder balls on pins under the components are typically packaged as BGAs, or ball grid arrays. BGA boards can accommodate smaller, higher-density boards like those seen in mobile phones and CPUs because they have more connections than traditional PCBs.

BGA packages are appropriate when placing electrical components more densely, such as integrated circuits, requiring a thinner assembly.

Surface Mount Technology (SMT)

SMT is a method used in industrial production. The surface mount devices (SMD) are picked up by an automated machine, placed on the board’s surface, and then soldered in a reflow oven. SMDs take up less space on the circuit board than SMT, which makes it simpler to produce PCBs that are more compact. SMT allows components to be placed on both sides of the board.

SMT is typically the best option for big volume manufacture. SMDs can be picked and placed automatically and take up less room on a board. Component placement on both sides of the PCB is also possible with SMT.

Why Turnkey Circuit Card Service is Popular?

There are several advantages of using turnkey circuit card assembly service:

Bill of Materials (BoM) costs are reduced and shipping costs are eliminated when all procedures are carried out on site.

With several vendors, mistakes made at one step might not get reported to the next, resulting in end product quality problems. Who is at fault can result in a time-consuming finger-pointing contest that frequently has no obvious victor—and, as a result, no clear plan of action to correct the situation. Usually, this results in higher expenses. By taking on all responsibilities and ensuring quality at every stage while rectifying problems before moving on to the next, a single organization may prevent this dilemma.

In addition to ironing out kinks, having a single point of contact fosters greater communication between the design, engineering, and testing teams.
There is better collaboration, more control over quality, open communication, and no transition time between phases when working with a single partner.

Circuit Card Assembly Testing

There are three types of circuit card assembly testing methods:

Manual Checks:

Despite the approaching development trend of automated and intelligent manufacturing, PCB assembly still relies on manual checks. An in-person visual examination by a designer is an efficient way to guarantee the quality of a PCB following the reflow process for smaller quantities. However, as the number of inspected boards rises, this process becomes more and more inefficient and inaccurate. Over an hour of looking at such tiny components can cause eye fatigue, which reduces the accuracy of examinations.

Automatic Optical Inspection:

For larger batches of circuit card assembly, automatic optical inspection is a better inspection technique. An AOI machine, also known as an automatic optical inspection machine, employs a number of powerful cameras to “see” PCBs. To view solder connections, these cameras are set up in various configurations. A lower-quality solder can be identified by the AOI because different types of solder connections reflect light differently. The AOI processes a large number of PCBs in a brief amount of time thanks to its extremely fast processing speed.

X-ray Inspection:

X-rays are yet another inspection technique. This less popular inspection technique is most frequently utilized for PCBs that are more intricate or have multiple layers. An observer can visualize lower layers and see through layers with the help of an X-ray to find any potential problems that may be concealed.

Circuit Card Assembly Manufacturing Process

circuit card assembly manufacturing process involves steps:

Step 1: Solder Paste printing

The first step involves applying solder paste to specific board locations where mounting electronic components is required. The majority of the solder paste is made up of tin, which makes up roughly 96.5% of it, along with other metals including silver and copper. Additionally, flux must be added to the solder paste in order for it to melt and adhere to the board. CCA makers typically utilize mechanical fixtures to hold the circuit boards and solder stencil in order to apply solder paste in the exact locations and proper amounts. Apply the appropriate quantity of solder paste to the specified area using the applicator, and when the stencil is removed, the solder paste will be in the proper location.

Step 2: Pick and Place Component

After the solder paste has been appropriately put to the board, a pick and place procedure is required. Surface mount components should be taken off a reel and placed where they are needed on the board. Additionally, the adhesive strength of the solder paste is sufficient to hold these components in place. This procedure can be carried either manually or automatically, but since a machine completes the full process, it is currently preferred by most manufacturers because it increases accuracy and production efficiency. Additionally, automatic select and place guarantees PCBA consistency from batch to batch.

Step 3: Reflow Soldering and solified component on board

Reflow soldering is a process used by circuit card assembly makers to harden the solder paste used to link the surface mount components to the board after the components have been mounted. So how does it function? The board would first be moved to a conveyor belt and moved through a sizable reflow oven. In the oven, there are several heaters that heat the boards to a temperature of roughly 250 °C until the solder transforms into solder paste. The board would then be put through a series of coolers that can cool down the molten solder paste to form a permanent solder bond, allowing for a snug fit of surface mount components on the board.

Step 4: Inspection

After reflow soldering, it is possible for circuit boards to have issues like poor connection quality or short circuits; as a result, at this process, manufacturers employ a variety of techniques to inspect the CCA and test the board’s performance. The following two CCA testing techniques are listed:

Optical Inspection: Automatic optical inspection is better appropriate for inspecting large volumes of CCA orders than manual inspection since it can quickly and accurately discover mistakes and defects in the board. An autonomous optical machine that is outfitted with powerful cameras that can examine the connection from various angles plays a crucial part in the optical inspection process. Additionally, the machine can examine the various light intensities reflected from solder connections to check the quality of connections.

X-ray inspection: This technique employs x-rays to examine circuit card assembly and is ideal for complicated and stacked circuit boards. We can look through the layers and identify all board flaws, including those in the lower layer, by using x-rays. Prior to the final functional test, which verifies the board is fully functioning, these two checks are carried out.

Step 5: Plated Through Hole Components

Electronic components must be utilized with different types of circuit card assembly, and in addition to surface mount components, PTH (Plated Through Hole) components are also frequently employed. To allow components to transmit signals from one side of the circuit board to the other during PTH assembly, holes are drilled into the board. Additionally, there are two different PTH soldering methods:

All components are manually put into the board during manual soldering. This is how it works: one person is in charge of placing one sort of component in the required location, after which the board is moved to another workstation, another person places another type of component, and so on, until all of the holes have the proper components in them.

Another well-liked soldering technique for through-hole printed circuit assemblies is wave soldering. A conveyer would move the board through a pumped wave or cascade of solder when the PTH components were placed on the board. In order to establish reliable mechanical and electrical connections, the solder coats the board’s exposed metallic regions.

Step 6: Functional Test

Final inspection, or functional testing, of every CCA is the last stage of circuit card assembly manufacture. The PCBA would undergo testing under conditions similar to those in which the circuit would function. To test the board’s electrical components, simulated signals and power signals would pass through the PCBA. The board failed the test if the fluctuations of these properties were greater than what was permitted.

As a top circuit card assembly manufacturer, INTOPCB possesses extensive knowledge and experience in circuit card assembly production. We are your first pick if you’re seeking for a dependable CCA fabrication partner. From the design and manufacture of circuit boards through the sourcing of components, circuit card assembly prototype, assembly, and testing, we provide end-to-end PCBA services.

INTOPCB, as a circuit board assembly manufacturer, specializing in manufacturing circuit card assembly parts since 2000.