assembled pcb

What is an assembled PCB?

assembled pcb is a procedure of put electronic components to connect with PCB wiring trace and soldering them together to be a functional board.

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What are the types of PCB assembly?

There is several types of PCB assembly technology, such as Plated through-hole technology (PTH), Surface Mount Assembly (SMT), Mixed assembly, Electro-mechanical assembly etc. They are for different types of PCB product.

Plated through-hole technology: This process involves attaching components with leads to a printed circuit board hole. The PCBs must come with holes. The lead of the components would be inserted into the hole of PCB and soldered on the board.

Surface Mount Assembly: using automatic machine to place SMD components to surface of the PCB and solidified them on the surface of the PCB board by reflow soldering machine.

Mixed Assembly: Combined the surface mount and through hole technology together to meet special PCB Board assembly requirement.

Electro-mechanical assembly: This method is commonly referred to as box-build assembly. It involves using various components such as wire harnesses, cable assemblies, molded plastics, and custom metalwork.

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How a PCB is assembled?

Assembled PCB process would involve several steps as following:

Step 1. Solder Paste: The first step in the process of PCB assembly is the application of solder paste, which is different from THT. This is because SMT involves both the printing and application of paste.

Step 2. Component Placements: The next step in the process of assembling PCBs involves placing the components on the board. In the traditional process, this can be done manually or with the help of machinery. In the THT assembly process, components are placed manually, which requires a high degree of accuracy. On the other hand, in the SMT process, robotic systems are used to place components.

Step 3. Reflow: The next step in the process of assembling PCBs is reflow. This process involves remelting the solder and then resolidifying it. After the solder has been melted, the components move through an oven to liquify it. Once the connections are made, the solder is cooled.

Reflow soldering is also carried out during this process. The board is sent through a process that involves melting the solder paste. This process allows the board to flow as it needs to, and it seals the components in place. The temperature inside the cooling system gradually lowers, which then solidifies the solder and prevents it from melting.

Step 4. Inspection: Inspection of the PCB board, soldering, and components, if any error.

Step 5. Through-Hole components Insertion: Manual insert the through hole components and soldering by manual or wave soldering.

Step 5. inspetion and clean: Inspect the the components, soldering points, and PCB board, clean out the excess or debris on the board.

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assembled pcb SMT

The surface-mounted technology is assembled pcb with SMD components, also known as SMT, is a type of component assembly process that involves connecting and attaching components to a printed circuit board using a batch solder-reflow process.

Unlike other process types, such as PWB, which involves placing component leads into through-holes, SMT involves wave-soldering the components from the bottom.

Compared to the traditional through-hole insertion process, which involves placing components into a hole, SMT offers various advantages, such as higher packaging densities and lower cost. It is mainly used for low-cost electronic assemblies.

assembled pcb surface mount and SMD components relationship

The concept of surface mount technology involves the use of various components in a circuit board. Usually, the assembly method known as SMT is more efficient and faster than the traditional method. On the other hand, surface mount devices (SMD) are real components that are assembled using a specific method on PCB board surface.

People often confuse the two things: the SMD and the mounting process. However, these two are very different. The SMD is the one that’s used in the assembly process, while the mounting process is the one that involves selecting and arranging the SMD components. The selection and arrangement of the components are the main factors that affect the efficiency of the assembly process.

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How much does SMT assembly cost?

PCB SMT assembly cost can be from $1 to $500 per units. The price can be so far different just because PCB SMT assembly cost effect by a lot of factors as below:

PCB size: The large PCB size it is, it would consume more material and its price would be more expensive.

Components: the more components consume in the SMT process, the PCB cost would be higher. and if the components are special price would be higher too.

Labor: The PCB assembly involve more labor work, that would consume more cost. Through hole need more manual labor work, so cost higher than SMT technology.

Turnaround time, The lead time shorter, manufacturing operation cost would be higher, so SMT cost would be higher.

Quantity order: The more quantity you order, average cost would be cost on each PCB. Mass production can make the cost lowdown.

PCB material: Different PCB material cost is different, that would make your PCB assembly cost different too.

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