PCB Manufacturing Cost Breakdown & Analysis

“You get what you pay for” is a common workplace adage cautioning against expenditures that outweigh the quality of a product or service received in return. Unfortunately, there are far too many transactions that elicit this proverbial response. For enterprise executives and managers, consistently making regrettable investments can have dire consequences, primarily when operating in competitive industries where the profit margins require high efficiency.

Optimizing costs is an objective when developing PCBAs, as well. For circuit board manufacturing, three primary factors inform cost-effectiveness:

1. Time: What is the turnaround time for the board construction process?
2. Board quality: What is the structural integrity, which includes the quality of materials and components, precision of component-footprint alignment and reliability of soldering techniques used of the boards?
3. Process quality: What is the yield rate for a board’s production?

These factors are predominant in determining a CM’s manufacturing process’s value and weighed when considering costs. Let’s take a look at the time, quality and cost for the different board building stages. The goal is to establish guidelines to utilize a PCB manufacturing cost breakdown best, optimizing board development.

PCBA Manufacturing Cost Considerations

The actual physical manufacturing of a circuit board is a two-stage process, consisting of the fabrication of the bare board or PCB and the adding and soldering of components or PCB assembly (PCBA). These two stages are typically outsourced to a fab house and then an assembly facility or a single contract manufacturer for turnkey PCBA manufacturing. According to a recent survey on the state of PCBA manufacturing, most board developers, OEMs and others prefer working with a single CM.

For turnkey, the responsibility of procuring components rests with the CM, except when your design requires exotic electronic components. The advantages here are that your CM can make suggestions for component selection and implement manufacturing techniques to help avoid common component failures. They add more comprehensive services such as digital manufacturing and employ automated testing equipment that provides high-resolution inspection and functional testing to accelerate board bring-up. The most advanced PCBA manufacturing services consist of fabrication, component procurement, assembly and testing stages. Each of these impacts the time and quality of board manufacturing and are instrumental for PCB manufacturing cost breakdown analysis.

Fabrication

The costs of board fabrication depend upon several factors. These include the types of materials, whether the board is rigid, flex or rigid-flex (hybrid), the number of PCB stackup layers, the incorporation of high-density interconnects (HDI), and Every Layer Interconnect (ELIC). Cost and time comparisons for some of these considerations are shown in Fig. 1, below.

Fig. 1 Cost and time considerations for board fabrication

As shown above, the more complex the fabrication process, the longer the turnaround time and the higher the cost.

Components

Fig. 2 Costs comparisons for different component package types

As shown in Fig. 2, there is no appreciable increase in time associated with a component type. However, the cost for through-hole components and specific high pin count surface mount component packages is higher than the more standard SMD types. Those increases are due to the additional fabrication steps required or the complexity of the process. For example, BGAs may require via-in-pad routing, which some manufacturers won’t perform or guarantee the results.

Assembly

The cost and process time for assembly is typically consistent for many designs, as shown in Fig. 3 below.

Fig. 3 Assembly time and cost comparisons

As shown above, through-hole technology (THT) implementation takes longer and is more costly.

Testing

There are essentially three types of PCB testing: manufacturing, functional and regulatory. Some CMs can assist with your PCB functional testing needs, but it will increase turnaround time and cost. From a cost-efficiency perspective, it’s best to rely on your CM for manufacturing testing as opposed to functional and/or regulatory testing. The number and types of testing may vary by CM, so you should determine the quality control (QC) testing procedures that are standard and which are considered additional before selecting a CM to build your boards. A comparison of standard and further testing is displayed in Fig. 4 below.

Fig. 4 Time and cost comparisons for manufacturing QA tests

Using the PCB Manufacturing Cost Breakdown to Optimize Board Development

Almost all aspects of PCBA design will impact the cost and turnaround time for your boards. Fortunately, a set of guidelines broadly utilized with a CM’s PCB manufacturing cost breakdown will achieve the ideal balance between costs and value.

Guidelines for Controlling Costs and Optimizing Board Quality

• Match design complexity to functional requirements complexity and avoid unnecessary costly design features.
• Acquire and follow your CM’s DFM and DFA rules.
• Have your board built to meet applicable classification standards and avoid driving up costs to adhere to those that are irrelevant to your design.
• If necessary, only use THT when a component’s not available as an SMD or installation environment requires that components be more resistant to movement or vibration.
• Choose a CM with a robust standard QA process.
• Collaborate with your CM.

The most critical factor for achieving the best quality, fastest turnaround and optimal cost efficiency is the CM you select for their standard and additional capabilities for building PCBAs.