What Affect PCB Assembly Cost?

16 Factors Affecting PCB Assembly Cost

PCB Assembly Cost , Every electronic engineer or designer want to know , How Do you get the best PCB Assembly quote , and how do you what price will affect PCB assembly cost . Here is some tips to guide you how to control PCB assembly price .

First ,Clear understanding of attributes to the cost of PCB assembly (PCBA). Some of the biggest cost drivers include :

1.  Assembly Type

Surface mount (SMT)    ( SMD Components )
Through hole                    (DIP )
Mixed (both)

2. Components Place

Request Only Top Layer assembly

Request  Doulbe sided assembly

3.  Total numbers of electronic components  (SMD + DIP )

4.  Package Size of components

1206
0804
0603
0402
0201

01005

5.  Components Package    ( reel is priority )

Reel
Tube
Tray
Cut strip with or without a leader
Loose in a bag

6.Processes Required

SMT pick and place
Through hole auto insertion
Through hole slide line
Wave solder
Automated Optical Inspection (AOI)
X-ray
Selective solder
Hand solder
General assembly

7.  Quantity and Batch Size(s)

“Keep Panelization Flexible to your manufacturer’s needs.”

ou want to make sure that panelization is optimized to the needs of the PCBA manufacturer.

8. Special Part Preparation Requirements

(i.e. lead length, height min/max, spacing)

9. Total Cost of the Complete Bill of Materials (BOM)

10. Bare Board (PCB) Layer Count and Material Used

Flexible PCB Assembly’s cost is higher than Rigid PCB board’s

11. Coating Requirements

medical or military normally request full coating or selective coating 

Spray or brush
Number of coats
Coverage tolerances
Specified keep out areas

12. Potting Requirements (if any)

13. Assembly Compliance Requirements

RoHS (lead free)
Non-RoHS (leaded)
IPC-A-610D Class I, II or III
ITAR

14. Test Requirements 

( RayMing prefer to test all PCBA Board before ship , We would like you can show us how to test )

Power up
Functional
In Circuit Test (ICT)
Thermal cycling
No test (visual inspection only)

15. Shipping Requirements

Standard ESD (electrostatic discharge) bags
Non-standard/special containers

16. Delivery

( RayMing provide quick turn pcb assembly services )

Standard turn with no expedite requirements
Expedited quick turn (labor and material costs are affected)

Those 16 tips will affect the pcb assembly price , so you can choose the best one to save the cost , When you source parts , You can Provide Multiple Component Sources for Each Component , is easy to control some cost , not only from digikey, some agent also have strong price support one some one components ,

Qualify Lower Cost Sources More Quickly

Set up a process to qualify lower cost sources between your Design Engineering and Purchasing departments. This is easier said than done. Conflicting priorities between Design Engineering and Purchasing can impede the process.

One solution is to set up Material Cost Reduction Committees. Management partners up with Purchasing and Engineering to identify high-value cost reduction opportunities. They also work to determine strategic components that need multiple sources to assure continuous production.

5 Aspects Of cut PCB assembly cost breakdown

PCB assembly cost calculation is currently almost at a transparent stage, and the algorithm for how much is per point is simple. But first, we need to clarify the concept of “point.” Different companies use different algorithms, but the final PCB assembly cost is the same for a PCB board.

The primary purpose of SMT assembly processing is to mount the electronic components on the PCB soldering pads. Some companies count one pad as one point, but there are also cases where two pads are counted as one point. For ease of understanding, this article will count one pad as one point. You only need to calculate the number of all the pads on the PCB. However, some special components, such as inductors, large capacitors, ICs, etc., require additional calculations. The specific experience method is as follows: For example, the inductor can be counted as 10 points, IC is discounted in half according to the number of pins (a 40-pin IC counts as 20 points). According to the above method, you can easily calculate the total number of solder points of the entire circuit board.

The solder point’s unit price is different in the current market, ranging from 0.01 to 0.08 ¥ per solder joint. This depends on the process difficulty of SMT assembly and the quality control requirements and capabilities of SMT manufacturers.

1.Unit price according to PCB assembly process:

A.Leaded solder paste – SMT costis relatively cheap.

B.Lead-free SMT solder paste – SMT costis relatively high.

C.Red adhesive environmental protection – SMT cost is relatively low.

D.Both process of solder paste and red glue – SMT processing cost is high, and the process is relatively complex.

2.According to the quantity of the order

A.The common PCB assembly for 3-20 pieces prototypes will charge engineering fees and will not be calculated by multiplying the number of points by the unit price.

B. Small batch SMT assembly and production of 1,000 pieces or less will charge a start-up fee and points multiplied by the unit price.

C.Mass production SMT assembly is calculated by multiplying the count points by the unit price.

3. Start-up fee: The assembly cost for a single batch of less than 2,000 ¥ is a small batch order. The small batch SMT assembly order is calculated according to the number of points. Depending on the type of components, the time to debug the placement machine, and the difficulty of making the first piece,will add a start-up fee ranging from 800 to 3,000 ¥.

4.PCB prototypes PCB Assembly cost: SMT prototypeorder is for around 100 pieces. The engineering fee ranges from 1,000 ¥ to 5,000 ¥, which is determined by the difficulty of the board and the effort to write the program and transfer it to the machine.

5. Solder stencil cost: Different types of stencilscan be done according to the size of the PCB board. Depending on the precision of the chips on the PCBA board, laser stencil or ordinary stencil can be chosen. The cost of different types of stencils ranges from 200 ¥ to 800 ¥. Of course, customers can also provide their custom

What does the PCBA cost include?

The PCB assembly cost estimator is composed of the following parts:

– PCB charge (If you provide bare PCB yourself, then there is no charge).

– Components purchase cost (There is no charge if you provide this).

– SMT assembly cost (SMD+DIP).

– PCBA test and install fee.

1.PCB Charge

If you want to find a PCB manufacturer to do this for you, you have to provide the PCB file and BOM list. Then the PCB manufacturer will help you manufacture the bare PCB board according to your PCB file. At this time, the first part of the cost will be incurred: the PCB board. The difficulty of the board determines the cost of the PCB board. For example, 4-layer board, 8-layer board, aluminum substrate, carbon ink board, the prices of these boards are different. Of course, you can also find a PCBA factory for processing independently. The price is definitely not low. After all, there are advantages to long-term cooperation.

2.Component Purchase Cost

The second part of PCBA assembly costs is the component purchase costs. The manufacturer purchases the components you need according to the BOM. When the components are purchased, it needs to cover about 5% of the material loss. This is due to the tray-loading, such as resistors and capacitors and SMT patch loss, jumping on the wrong board, the failure to clear the tape. The PCBA manufacturers have long-term cooperation with component manufacturers so that the price will be lower.

3.PCB Assembly Cost (SMD+DIP)

When calculating the SMT assembly fee, it first depends on your order quantity. If it is more than 2000 pcs, there is no engineering fees. Otherwise, engineering fees will be charged.

• PCBA Test and Install Fee

The PCBA test fee is generally calculated at 2 ¥ per board. PCBA install and packaging costs are around 0.8 ¥ per piece. This is the fourth part of the cost.

Now, add up the cost of the above four parts. It is the PCBA assembly cost!

A calculator list of PCBA assembly costs:

1：Detailed list of point pricing

1. SMD components two pins as 1 point.

0402 components are calculated at CNY 0.018 per point.

0603-1206 components are calculated at CNY 0.015 per point.

2. DIP material 1 pin is 1 point,calculated according to CNY 0.015 for each point.
3. The socket type has 4 pins as 1 point; each point is calculated as CNY 0.015.
4. Ordinary IC, 4 pins are 1 point; calculated as CNY 0.015 per point.
5. Close-pin IC, 2 pins are 1 point; calculated as CNY 0.015 per point.
6. BGA2 pins equals 1 point; each point is calculated as CNY 0.02.
7. Machine-mounted largematerials are calculated according to the volume of the components doubled.
8. The additional fee is calculated at CNY 30 per hour.
9. This quotation does not include testing fees.

2：Calculation method of component points and special expenses

1. Understand the SMT production process and the content of each process:

Loading–Printing solder paste –SMD components–Visual inspection–Pass reflow oven–Ultrasonic cleaning–Cutting board–Visual inspection–Package (some products require IC programming and PCBA function test)

2. Calculate the number of SMD components points:

SMT assembly fee is generally calculated based on the number of component points, one pin (resistor, capacitor, diode) counts as one point, and one transistor counts as 1.5 points.

If IC pins are less than 50, two pins count as one point. IC with more than 50 pins, 4 pins count as one point and count all the patch points of PCB.

3. Calculate cost

Processing fee = points * unit price of 1 point (processing fee includes: red glue, solder paste, washing water, and other accessories)

4. Others cost

The test fixture, stencil, and other expenses agreed upon by both parties need to be calculated separately.

3: Take the mobile phone board and calculate the specific quotation of SMT assembly as an example

Each trial production of mobile phone boards is calculated at CNY 10,000, and the trial production quantity is less than 300 pieces.

(Any mobile phone board that is trial-produced in the RAYMING SMT assembly workshop for the first time is called a new model and belongs to the trial production stage.)

Remarks:

1. The above quotation is only applicable to the assembly trial production stage.
2. The above quotation is in CNY.
3. The above includes stencil, accessories, bottom fill,and other expenses.

Board PN   Type  Qty ”Unit price” Subtotal ”Amount per PCS” Total

SUB_U311  0402  8     0.018    0.144        1          0.2340603

Component (included) and above 0 0.016 0.000    , Socket (PIN Qty) 20 0.02 0.1

BGA (ball number) 0 0.028 0.000   0.200 BGA bottom filling 0.200 0.200 0.2 Total: 0.234

Board PN component type

Quantity ”Unit price” Subtotal ”Amount per piece” Total “SUB_U311SUB ” 0402  0.018  0.144 1  0.2340603 components (inclusive) and above 0 0.016 0.000, Socket (PIN Qty) 20 0.02 0.1    BGA (ball number) 0 0.028 0.000       0.200   0.200      0.200 Total: 0.234

1. The above quotation is only applicable to the mass production stage of assembly.
2. The above quotation is in CNY.
3. According to the currentassembly outsourcing manufacturing price, 0402 components are 0.028CNY/component, 0603 components are 0.026CNY/component.
4. The IC and connector calculation method counts one component per 4PIN, and the BGA calculation method countsone component per 4 balls.
5. A Soldier stencil cost confirmed by the stencil supplier will be deducted from the assembly processing fee after the order of the same product exceeds 100K pieces.
6. The above is the quotation for none- RoHS RoHS products will increase by 20% based onthis quotation.

If the mass production quantity is less than 350 pieces, the minimum assembly fee is ¥7000/time. The above quotation is for mass production quantity exceeds 350 pieces.

These are just reference.

SMT Factory Cost Control

As an essential part of the electronics industry, the most critical and direct content of the SMT electronics manufacturing industry is cost, quality, and delivery time.

Therefore, we talk about the importance of controlling costs in SMT assembly. So, let’s do a cost analysis first, waste factors, and then improve it.

1. Cost structure in the SMT assembly process

The production cost is the sum of the direct materials, direct labor, and other direct or indirect costs consumed by the company in the production process. This also includes costs due to product quality problems.

The proportion of SMT production cost has the general breakdown: Equipment and maintenance account for 40% to 43%, material loss accounts for 19% to 22%, and product repair and maintenance costs account for 17% to 21%. The labor costs account for 15% to 17% of the total cost of SMT. Lastly, other expenses account for 2%.

SMT production costs are mainly concentrated in assets such as equipment, repair, maintenance, raw material loss and scrap, and SMT production material costs.

SMT production costs are generally divided into manufacturing costs and quality costs. Product manufacturing cost refers to the materials, labor, and other expenses directly consumed by the enterprise in producing products and providing labor services. In SMT production, direct materials refer to electronic components, printing templates, soldering materials, dispensing materials, and cleaning materials. Direct labor is the salary, labor fee, bonus allowance, overtime pay of SMT production workers. Other manufacturing expenses refer to all costs associated with the manufacturing process, excluding materials and labor. This includes the various items consumed in the workshop, the cost of materials used in the maintenance of machinery and equipment, the water and electricity used in production, lighting, air conditioning, office expenses. Quality cost is the enterprise’s cost to ensure satisfactory quality and losses caused by deficiency.

Prevention cost is the cost to prevent quality defects. Appraisal cost refers to the expenses on testing and product quality inspection. Internal and external defect cost refers to the loss caused by the product’s failure to meet the specified quality requirements before and after delivery, respectively. The cost of external quality assurance refers to the cost incurred in providing objective evidence, demonstration, and certification to meet the quality assurance requirements stipulated in the contract.

2. Waste in SMT production

Waste refers to an operation that does not add value or resource used exceeds the breakeven point. The breakeven point is the production level at which the costs of production equal the revenues for a product. In the SMT production process, operations that transform materials add value to the production process, such as welding and assembly. However, inventory, handling, and inspection do not add value. Activities that do not add value but increase costs are not economical. For production companies, we believe that profit = price-cost. At present, the price of SMT production is unchanged, but the cost can be controlled. The only way for companies to increase profits is to reduce costs and eliminate production losses.

The waste in SMT production includes:

1. The waste of equipment includesthe inefficient operation rate of the assembly machines, low utilization rates, accelerated wear of equipment due to poor maintenance, idle equipment, and maintenance costs caused by equipment failure.
2.  The waste of materialsincludesdiscarding parts of the assembly machine, loss and damage of chips, small components, and PCB board It also includes scraps and incorrect calculation of solder paste usage, poor storage conditions, and deteriorations.
3.  The waste of repair and maintenance refers to the waste of time, workforce,and material resources required due to defective products in production. This type of waste includesloss of materials, defective products, loss of equipment, personnel, working hours, loss of additional repair, identification, and additional inspection.
4. Human waste refers to activities that do not add value to theproductionIf there are too many processes, the production line is unreasonable, unbalanced, and uneconomical; It is not a streamlined operation. This also includes bottleneck processes that cause product backlogs, idle personnel, inadequate personnel arrangements, and staff turnover in key positions.
5.  Waste of work methods is caused byunbalanced workallocation and improper production planning. The lack of operating procedures, standard operations, and chaotic processes are also contributing factors.
6. Production managementand support staff, office expenses, air-conditioning, water, electricity, and lighting expenses are considered other expenses.

3. How to reduce PCB Assembly cost?

3.1 Reduce costs from the five major cost compositions

After understanding the cost composition of production, waste in production, and bottlenecks, we can control and manage it in a targeted manner to reduce costs.

1. 1. Equipment- Equipment is for a company to produce products and provide services.From the above survey, SMT manufacturers’ most serious problem is equipment cost, and equipment cost is vital. In production, equipment operation efficiency should be improved so that large orders can operate around the clock. The SMT machine should use non-stop reloading methods to reduce downtime caused by reloading. All equipment on each production line should be reasonably arranged and optimized to avoid bottlenecks. One streamline operation improves overall efficiency. Also, proper equipment maintenance can reduce parts wear, extend the life of the equipment, save additional repair costs, improve the integrity and utilization, reduce the failure rate, and reduce the loss of electricity, lubricating oil, parts, and operating materials during the operation of the equipment. For some vulnerable parts, such as the suction nozzle of the assembly machine and solenoid valves, spare parts should accessible to prevent damage to the equipment and machinery from being unusable. It is also necessary to train engineers to promptly repair the machines to reduce downtime and maintenance costs, and improve economic benefits.

There is another mode, that is, the international model of “equipment leasing.” You don’t need to spend too much money on leasing new equipment, keep the technological leadership, and replace the newer equipment after leasing for 1 to 3 years. This model has a successful example in some international leading semiconductor factories, and it is also an excellent cost-saving solution.

2. 2. Material aspect: In SMT production, solder pasteand glueare relatively expensive. Dispensing and printing must be controlled as separate processes. The cost of solder paste and lead-free implementation is steadily increasing. Therefore, it is necessary to reduce loss and waste and accurately calculate the weight of each batch of products using solder paste. On the premise of ensuring quality, its consumption is least controlled. The storage conditions, usage methods, and working environment of solder paste must be strictly controlled to prevent deterioration and scrapping. At present, the price of solder paste on the market has a wide range.

We use exceptional solder paste for products. For example, some low-demand consumer electronics use cheap solder paste to reduce costs. The impurity content of wave soldering and anti-oxidation must be strictly controlled. Tin, with high-quality ingredients, cannot be mixed. If mixed, it will cause a decrease in welding quality, and the impurity content increases. As a result, the whole pot is not useable, which will significantly increase the cost. PCB boards should reduce the number of scraps such as scratches, falls, and burns. Damp PCB boards should be baked to prevent cost increases de to quality problems. The assembly machine’s throwing rate should be controlled to below 0.2%, and the damage and loss rate of the components should also be controlled. Several quotas were issued for expensive materials such as chips.

For materials, the recycling method can be used to recover part of the cost.

3. Quality cost: Includesthe cost of repair and maintenance. Quality costs are mainly composed of prevention, appraisal, internal defect, and external defect costs. A large amount of statistical data shows that the current proportions of the four quality costs in the total quality cost are as follows:

Internal defect cost  25 ~ 40%

External defect cost  20 ~ 40%

Appraisal cost  10 ~ 45%

Prevention cost  0.5 ~ 5%

Statistics prove that if prevention is focused and quality management is strengthened, quality accidents can be reduced. Although prevention costs may increase by 3% to 5%, total quality costs may decrease by 30%. Under normal circumstances, as the cost of identification and prevention increases, the product’s quality will increase, and defective products will greatly reduce. As a result, the total quality cost will decrease. Take precautions in SMT production, strengthen process control, reduce the cost of faults and defects, reduce the probability of repair and maintenance needed, and reduce the total quality cost.

4. Labor cost: Remove roles and positions that do notadd value, including indirect personnel, redundant management personnel, and SMT auxiliary personnel. It is ideal to appoint competent engineers and technical experts. “Cancel, merge, rearrange and simplify” existing production personnel, production processes, and site layouts that are unreasonable, uneconomical, and unbalanced. Employees use a shift system to work because overtime pay is higher than regular hours pay. Also, meal expenses, transportation expenses, and shift pay is not calculated as overtime.

In the production process, personnel is the most unstable factor. People’s mentality and responsibility are also a factor that affects production costs.

If more inducements are given, it will increase the employees’ responsibility and significantly reduce the scrap rate of production. Therefore, a good incentive for workers is also a way to reduce costs.

5. Operation method: Make a sound production plan, formulate standard working hours, standard operations,and centralprocesses must have manufacturing regulations or work instructions. Workers must operate strictly in accordance with instructions documents. Technology instruction documents are controlled, and current useful versions of documents can be obtained at the Technology instruction documents and materials should be as follow: the font is neat, filling and changing are standardized, conclusive and timely. The technological process must be scientific, reasonable, and firmly operational. Elimination of blind operations and non-compliance with process regulations, thereby reducing quality problems and reducing production costs.

3.2 Reduce costs from the production workshop

The SMT production site is the main location for cost consumption. Therefore, it is necessary to eliminate excessive resource consumption from the production site to reduce costs. You can also implement the following six measures at the same time to reduce production costs:

1. Improve production quality to reduce costs. Improved quality in the production process at the production site will reduce product errors, fewer unqualified products, causes fewer reworks, shorten delivery time, reduce resource consumption, reduce quality costs, andreduce total production costs.
2. To improve productivity. Productivity is improved when the same product “output”is produced with less (resource) “input,” or more “output” is produced with the same “input.” The “inputs” refer to the workforce, equipment, and materials for production. “Output” refers to the semi-finished or finished electronic products and the value they bring. Use the IE technique to optimize the number of people on the production line, and try to be as streamlined as possible. This reduces costs and reduces quality problems because a decrease in the workforce means fewer opportunities for human error. When productivity increases, costs fall.
3. Reduce inventory. SMT foundry is the inventory and backlog of WIP when manufacturing. Suppose one process of the production line is a bottleneck. In that case, there will be a backlog of products in this area for sometime, which causes unused inventory. As a result, components cannot be supplied to the next process. Inventory occupies production space, and with inventory “sitting” in the production site or warehouse, it will not generate any added value. On the contrary, they will deteriorate in quality and increase management and removal costs. Therefore, it is necessary to implement a balance production line, balance all the production processes, adjust operating load, achieve a streamlined production, and reduce inventory to reduce the total cost.
4. Shorten the production line. In production, a longer production line requires more operators. The more people on the production line, the more human errors and other defects can occur, which will cause quality problems, increase quality costs, and increase labor costs.
5. Reduce machine downtime. Machine downtime will interrupt production operation, resulting in excessive work in progress, excessive inventory,and excessive repair work, compromising quality. All of these factors increase production costs. A new employee, without proper training, is assigned to the production line to operate the machine. The consequences of delays in work are equivalent to the cost of machine crashing. Therefore, it is necessary to do a good job in maintaining the machine, reducing the failure rate, strengthening the skills training of the equipment operators, and eliminating the minor equipment failures in time to reduce the loss caused by the shutdown.
6. Reduce workplaces. Implementing the5S in the workshop, release excess space, avoid waste of workplaces, improve useful utilization, shorten production lines, merge separate workstations into the main production line, reduce inventory, and reduce removal. All these improvements reduce space requirements.

3.Reduce SMT costs from the production process

In the SMT production process, the more the components go to the next process, the more the cost will increase. According to statistics, in SMT production, 60% to 70% of the quality problems are related to solder paste printing. Therefore, cost reduction has to start from the first few process, and the problem of process defects should be resolve in the initial stages. If problems are not resolved in earlier stages, the cost will be higher at later stages. Many companies allow defective assembly boards to go to the next process. They think the defective boards will be sent back for repair when caught during the inspection process. This is a great mistake. Defective products should be promptly found and resolved to avoid the problem; Avoidance produces more defective products, which increase repair and maintenance costs. A proper quality resolution could reduce costs from the production process.

To SMT assembly manufacturers, if they strictly implement the above methods, I believe they will become more competitive.