Concerned about the expense of PCB assembly? Precise PCB assembly estimations are crucial. Being aware of this can lower your expenses.
You can use this advice to make well-informed judgments on cutting PCB assembly costs.

1.  8 Key Factors Influencing PCBA Cost

1.1 PCB complexity

（1） PCB layers

Single-layer and double-layer PCBs are the least expensive. Due to increased material prices and routing complexity, multilayer PCBs are more costly.. According to the general belief, PCBs cost increases with increasing layers.

（2） Dimensions PCB

The size of the PCB determines its cost. The more space there is on the PCB, the easier it will be to add components and circuits for the intended purpose. Larger PCBs are more expensive because they can be used for large and medium devices. Smaller PCBs need fewer parts and are less expensive. As the PCB grows in size, the assembly costs increase.

（3） PCB minimum hole diameter

Drilling requires a drill bit. Compared to drill bits with lower diameters, standard drill bits are less costly. Drilling costs go up when the hole diameter is smaller.

（4）Trace Width

To get smaller gaps or traces, we’ll need to employ laser drilling or certain etching methods. Additionally, production and tooling costs will rise..

（5） PCB Thickness

The cost of assembly increases with board thickness. Drilling holes in large boards requires precision and complex equipment. The cost of custom-made assembly panels for PCBs with non-standard sizes will increase.

（6） PCB Substrate Material

The material of the PCB substrate may have a significant effect. Materials such as FR-4 are extensively used and reasonably priced. Those substrates that are more expensive include ceramics and flexible materials.

Flexible PCB                        FR-4 PCB

 

（7） PCB Solder Mask Color

Standard colors like green are the least costly. Custom colors cost more.

（8） Surface Finishes on PCBs

The cost of various PCB surface treatment techniques varies.

• HASL: An inexpensive method that is less accurate.
• Impression tin/silver: This is reasonably priced. The boards have a limited shelf life, which can affect inventory and assembly time.
• ENIG: The gold plating is what gives ENIG its highest rating. This is perfect for wire bonding or high-reliability applications. The thickness of immersion gold increases its cost.

HASL      Immersion tin      ENIG

1.2 components and bill of materials (BOM)

The choice of components and the bill of materials are crucial determinants of PCB assembly costs.

(1) Purchase Price of Components

During shortages, we could have to spend extra money on components. The cost of BOM will rise sharply.

It’s possible that components from well-known brands cost more than those from other brands. They are more reliable and safer. Orinew products are original.

(2) Density and Quantity of Components

Each additional component will increase the time it takes to pick and place. Boards with a lot of components may require more programming time and even nozzle replacement. Depreciation and increased labor costs are the outcomes.

Densely packed components are subject to stricter design and placement guidelines. As a result, there is more rework and less yield.

(3)Component Type & Packaging

• Surface Mount Device (SMD). Assembly costs Through Hole Device (THD). assembly costs

SMD component assembly can be cheaper. The automatic placement machine increases manufacturing efficiency by processing a large number of components rapidly. Wave soldering and manual soldering are both used to solder through-hole components. Lead must be inserted into the holes, among other procedures. These need more time and effort.

THT VS SMD

• Package Complexity and Assembly difficulty

BGA/LGA/Flip Chip: Precise placement, X-ray inspection of the solder junction, and underfilling are necessary for these high-density packagings. Boards can have higher inspection costs or special processes.

Some components that do not conform to standard shapes require manual positioning or even special tooling. The result is increased setup costs and slower production.

1.3 Order Quantity

The quantity of boards you order determines the pricing per PCB.

• We can expect to pay a lot if we only need a few prototypes. There will be additional setup fees. For small batches,Orinew charges RMB 200–300; for medium batches, RMB 300–400; and for large batches, RMB 500.
• The unit price for bulk orders will be lower. The engineering fee is not required. The cost per unit will go down as we produce more units.

1.4 Assembly Processes Technology

(1) SMT Process Cost

• Stencil Costs and Model Costs: It is important to know that stencil fabrication costs are also included. When we place large purchases, we will be billed for the cost of the models and test fixtures.
• SMT placement cost: The cost of the patch is determined by the quantity of soldering sites. The amount of soldering needed increases with price. In the long term, machine placement is cheaper.

(2)Cost of DIP post-welding processing

The quantity of holes has an impact on the cost as well. The more holes there are, the higher the price. There are two distinct pricing situations.

• Wave soldering: The circuit board is capable of handling temperatures as high as 250 degrees. Soldering machines can be used by operators.
• Manual Soldering: The circuit boards cannot handle the high temperatures generated by wave soldering. Soldering the circuit board’s components by hand is required. The labor cost is high. Wave soldering, in comparison, is cheaper.

 

(3) Cleaning of PCB

It may be more cost-effective to leave the residues. Residues can raise the cost of rework and interfere with testing. However, cleaning the PCB will result in short-term cost increases. It is still beneficial to inspect later. It can also reduce the rate of rework.

 

(4) Input Program Testing

We sometimes provide our own software for testing to the assembly plants. This includes the loading of software, functional verification, and system debugging. For the test, it could be required to recruit extra workers or buy more equipment. Costs of equipment and labor will increase.

1.5 Inspection and Testing

PCB assembly is not possible without testing and inspection, which are expensive. We mention X-Ray, AOI, and power-on tests, as well as other essential testing. Testing can help you find problems faster and save a lot of time later.

 

1.6 Hidden Fees

(1)PCB Depaneling Price

Separating PCBs from panel structures also incurs a cost. Board thickness is one of several elements that affect the cost of removing PCBs from the panel structure.

• Depaneling costs are generally higher for PCBs with thicker substrates.
• Standard layouts are typically less expensive to depanel than complex shapes.
• Depaneling standard PCB substrates is generally less expensive than depaneling high-performance substrates.
• Low-volume production typically costs more per unit than high-volume batches.

(2)Package Price

Anti-static bags and other protective packaging solutions are also expensive. Customized packaging is usually more expensive for large orders. Sorting and labeling, whether manual or automated, will incur additional costs. Costs are associated with developing packaging that meets industry standards (e.g., IPC Standards).

 

(3)Expenses for logistics

Costs of logistics include both domestic and foreign transportation. Multiple factors influence prices, including distance, weight, and volume.

(4)Lead time Costs

Orders with normal processing times are subject to standard pricing. Rush orders often incur additional charges due to the accelerated handling.

 

2.Five Proven Strategies for Reducing PCB Assembly Costs

We now know the breakdown of PCB Assembly costs. We will now explore ways to cut costs without compromising on quality.

2.1 DFM Optimizer

(1) Optimization of Layers: Streamline the circuit design by minimizing PCB layers. To achieve cost-effectiveness, balance functionality and layer count.

(2) Avoid exotic features: Limit blind/buried vias, controlled impedance, or HDI to critical areas. Standard FR-4 should be preferred over specialty substrates wherever feasible.

(3)Component Uniformity: Choose standard SMD package dimensions. Reduce stencil complexity during assembly and reduce changeover costs.

(4)Ensure Adequate Spacing: Ensure that components are spaced enough apart. There is less soldering, AOI inspection, and rework.

(5)Panel design: Increase the number of panels and improve material use. Costs will be cut as well.

 

2.2 Controlling Costs for Bill of Materials (BOMs).

(1)Dual Source Strategy: Qualify 1-2 alternative suppliers of critical components. This can reduce price fluctuations and supply-chain disruptions caused by sole-source vendors.

(2) Optimization of Tolerance: Select passive parts with a larger tolerance when performance allows. This can lower component costs.

(3)Standardization of BOM: Reduce component diversity through the use of common parts. It can simplify procurement and reduce overhead.

(4)Bulk Procurement: Aggregate the material requirements across all projects to meet MOQs. It is possible to get volume discounts by centralizing purchasing.

2.3 Process Enhancement

(1)Assembly Simplification:

Where possible, opt for SMT components over THT designs. Reduce labor costs by eliminating manual/wave soldering.

(2)No-clean Soldering:

Lead-free solder paste can be used to eliminate the need for post-soldering cleanup. Production times and cleaning expenses can be decreased.

(3)Standardize test fixtures:

Replace ICT fixtures that are custom-made with universal test platforms. Reduces the upfront costs of test setup and speeds up debugging.

• Risk-Based Testing:

For products with low risk, test AOI instead of 100% on samples. Quality assurance and cost-efficiency should be balanced.

 

2.4 Work with Full-Service Manufacturers

Understanding the drivers of PCB assembly costs is crucial. Assembling PCBs with the best PCB assemblers will ensure quality and timely delivery. Selecting a reliable, experienced assembly partner is crucial to success.

(1)One-stop service advantage: Prioritize PCB and PCBA manufacturers that offer integrated fabrication. The quality-controlled processes that they offer reduce the risk of product failures or rework.

(2) Sourcing Strategically: Chinese manufacturers offer cost-effective options for high-volume orders. Orinew provides affordable prices without sacrificing quality. Local suppliers can minimize costs and lead times for small or urgent orders.

 

2.5 Packaging and Logistics Optimization

(1)Packaging Standardization: Replace customized trays with generic ESD bags for PCBs that are not fragile. Packaging costs are reduced without compromising ESD safety.

(2)Strategic Shipping: Choose rail or sea freight instead of air for large orders. For goods that are not urgent, it is an excellent method to lower transit expenses.

 

3.Mitigating Common Risks

(1)Overlook Hidden Costs: Don’t underestimate costs like certification and compliance. These “invisible costs” often exceed 15 percent of the total assembly fees.

(2)Quality-Cost Tradeoffs: Defect rates from low-cost vendors may raise long-term costs.  Give preference to suppliers with established quality control systems.

(3)BOM accuracy: To prevent delays, make sure the bill of materials (BOM) is complete. Use automatic BOM verification tools to cut down on errors.

(4)Process optimization: Avoid excessive automation for small batches. Manual assembly is more cost-effective. Mixed SMT+THT board setups require two lines, which can cause 2+ hours of downtime per day.

 

4.PCB Assembly Costs FAQs

1) Are suppliers able to source PCB assembly components?

Suppliers can manage component procurement, but this will increase costs. We can also source the parts ourselves, provided they are compatible with solder.

2) What is the cost of a PCB prototyping assembly?

The cost of a prototype depends on the number of layers, the complexity of design, and types components.

3) What can be done to minimize the amount of waste components during PCB assembly?

Organise the components in accordance with the sequence of assembly. It reduces the number of errors made during testing and placement, reducing material waste.

4) How to avoid hidden charges in PCBA quotations?

Testing or expediting charges are often hidden costs. Request quotes that include detailed BOM breakdowns, and compare component prices across suppliers to avoid any surprises.

5) How does solder paste affect PCB assembly cost?

Yes. Solder paste of high quality reduces the number of defective solder joints and the rate of rework, which has an indirect effect on overall costs.

6) Are through-hole components soldered with SMT machines?

No. No. SMT equipment was designed only for surface-mounted parts. THT is required for through-hole components.

7) In China, why are PCB assemblies cheaper than in the US?

China’s competitive advantage is due to its lower labor costs, reduced compliance costs, and efficient equipment usage.

8) Does any PCB assembly manufacturer offer free testing

Some suppliers offer complimentary functional testing with large-volume orders.

9) How do manufacturers calculate initial PCB

Three main inputs are required by suppliers. Gerber files are required to determine the design complexity. To price components, they need a BOM (Bill of Materials). They should also be aware of any special instructions regarding lead times, testing specifications, or compliance requirements.

 

5.Summary

Keep in mind that the greatest option isn’t usually the one with the lowest price. Costs should be weighed against delivery deadlines, quality standards and long-term performance. We may use this tool to make well-informed decisions on our project. We wish you success in your PCB assembly projects, now and for the future!