PCB Teardown Benchmarking & Cost Reduction Insights
PCBs make up over 15% of the Bill of Materials (BOM) cost in electric vehicles (EVs). Considering the recent fluctuations in the cost of electronic components, it is crucial to focus on studying PCBs. This blog aims to provide an in-depth understanding of the PCB teardown and benchmarking process and how it can generate insights for cost reduction and target setting. Our proprietary SaaS platform, xcPEP, ensures high-quality data mapping with zero errors and analyses them to determine target costs for PCBs in EVs.
PCB teardown and benchmarking involve a detailed analysis of the components, materials, and manufacturing processes used in a PCB. This information is used to compare and improve the design and quality of PCBs. Through this blog, we will delve into the PCB teardown and benchmarking process, methods used, and the potential outcomes that can be achieved through these analyses.
At ASI, we employ a variety of activities to ensure accurate and comprehensive benchmarking of PCBs which includes the following:
- Generating the Bill of Materials (BOM) for the PCB
- Mapping the data for electronic child parts
- Creating an architecture diagram for the PCB
- Identifying the layers of the PCB.
- Determining the cost of electronic child parts.
- Calculating the process costs involved in PCB manufacturing
- Generating ideas for PCB cost reduction
- Conducting should costing for the PCB board
- Conducting should costing for the PCB transformer
- Analysing the utilization of the PCB area
In this technical blog, we will discuss deeper into each of these activities and how they contribute to the benchmarking process.
- Single Sided: PCBs with components on one side only.
- Double Sided: PCBs with components on both sides.
- Multi Layered: PCBs with multiple layers of copper and insulating material sandwiched together.
- Aluminium Base: PCBs with a base layer made of Aluminium, used for heat dissipation.
- Flexible: PCBs with a flexible base material, used in applications with tight or irregular spaces.
- Ceramic Base: PCBs with a base material made of ceramic, used for high-temperature applications.
- High Frequency: PCBs designed to operate at high frequencies, with specialized materials and construction techniques to minimize signal loss and interference.
During the teardown of Printed Circuit Boards (PCBs) to accurately assess Electronic Child Parts, the use of specialized equipment is crucial. The LCR meter, microscope, and hot gun are among the commonly used equipment in this process. The LCR meter provides inductance, capacitance, and resistance measurements of the PCB components, allowing for the identification of their characteristics and value of capacitance, inductance of the child part. The microscope is used to identify small electronic child parts. To remove Electronic Child Parts like transformer, Choke coil inductor from PCB, a desoldering pump or hot air rework station is typically used. These tools utilize heat and suction to remove the parts while minimizing the risk of damage to the surrounding components and PCB traces. By utilizing specialized equipment during PCB teardown, accurate assessment of Electronic Child Parts can be achieved, leading to a more thorough understanding of the PCB’s.
When mapping BOM parameters for a Printed Circuit Board (PCB), it is important to consider several key factors. These parameters include:
- Description: This parameter provides detailed information about the component, including its purpose and specifications.
- Quantity: This parameter indicates the number of components present on the PCB.
- Aluminium Base: PCBs with a base layer made of Aluminium, used for heat dissipation.
- Image: This parameter includes a child part image, allowing for easy identification of the component.
- Location of Component: This parameter defines the side of the PCB where the component is located (top or bottom).
- Type: This parameter identifies whether the component is surface mount (SMD) or through-hole (THD).
- Component Size: This parameter specifies the dimensions of the component, such as the size of resistors or capacitors.
- Component Type: This parameter identifies whether the component is active (such as transistors) or passive (such as resistors and capacitors).
- MFR: This parameter identifies the manufacturer of the child part.
- MPN: This parameter identifies the manufacturer part number or order number of the child part.
- Designator: This parameter identifies the component class according to its name.
- Datasheet: This parameter provides detailed information about the component, including its specifications and performance characteristics.
By mapping these BOM parameters, it is possible to gain a better understanding of the PCB and its components, enabling accurate benchmarking and assessment.
A PCB layout diagram is a visual representation of the physical PCB, including all child components and their specifications. This diagram provides a clear overview of the PCB and allows for easy visualization of how the various components are connected and interact with one another. By creating a PCB layout diagram, it is possible to gain a better understanding of the overall design of the PCB and identify any potential areas for improvement. Additionally, a PCB layout diagram can be used as a reference tool for future modifications or repairs, as it provides a clear visual guide to the physical layout of the PCB and its components. Overall, a PCB layout diagram is an essential tool for accurate assessment and benchmarking of PCBs, as it allows for a detailed understanding of the physical structure and components of the PCB.
Cross-sectional analysis is a commonly used method for identifying the layers of a PCB. This involves cutting a section of the PCB and examining it under a microscope to identify the copper layers, prepreg, and core thickness. Microscopic images are taken to determine the layer stack-up of the PCB. In addition, copper thickness measurement is often performed using a scanning electron microscope (SEM) to obtain accurate results. By using these techniques, we can gain a better understanding of the PCB’s layer composition and determine any potential issues with the layers or copper thickness.
PCBs can be broadly classified into several types, each with its own specific construction and layer stack-up.
- Single-sided PCBs consist of a single conductive layer and are commonly used in simple circuits where cost is a major concern.
- Double-sided PCBs have two conductive layers separated by an insulating layer and are used in more complex circuits.
- Multi-layer PCBs consist of multiple conductive layers separated by insulating layers and are used in very complex circuits with a high density of components.
- Aluminum base PCBs are used for applications where heat dissipation is a major concern, such as in LED lighting systems.
- Flexible PCBs are made from flexible plastic materials and are commonly used in devices that require bending or shaping.
- Ceramic base PCBs are used in high-temperature and high-power applications due to their excellent thermal conductivity.
- High-frequency PCBs are used in high-speed digital circuits and have a specialized layer stack-up to ensure optimal performance at high frequencies.
PCB Chemical Composition
PCB Chemical Composition
PCB Copper Layer Thickness
PCB costing is a crucial step in the PCB manufacturing process as it allows the manufacturer to assess the total cost of the PCB, including the cost of raw materials, electronic child parts, and assembly. The cost estimation is done in three stages: Bare Board cost estimation, electronic child parts costing, and Assembly costing.
The first stage, Bare Board cost estimation, involves assessing the cost of raw materials used to manufacture the PCB, including the copper clad laminate, copper foil, and solder mask. The cost is calculated based on the size and thickness of the board, as well as the number of layers.
Second stage is electronic child parts costing, is the most challenging stage as it involves identifying the exact electronic child parts used in the PCB, their data sheet, and whether they are obsolete or not. Once the correct electronic child part is identified, its cost is estimated based on its value chain. PCB manufacturers buy electronic child parts from distributors or direct OEMs such as NXP, Infineon, etc. If the electronic child parts are purchased from distributors, certain discounts are considered based on the spot buy sites’ data such as Digi-Key, Mouser, Octa Part, etc. If the electronic child parts are bought directly from the manufacturers, the distributor discounts are to be considered.
- Surface finish improves PCB’s flatness, assembly compatibility, electrical performance, and protects against oxidation and corrosion.
- Different surface finishes are available for PCBs, each with advantages in terms of solderability, corrosion resistance, cost, and assembly process compatibility.
- Common surface finishes include HASL, ENIG, Immersion Tin, OSP, Immersion Silver, and Hard Gold.
- HASL is cost-effective and widely used but may not be suitable for fine-pitch components due to an uneven surface.
- ENIG provides excellent solderability and a flat surface but is more expensive.
- Immersion Tin offers good solderability for lead-free processes and a flat surface but is susceptible to oxidation.
- OSP is environmentally friendly, cost-effective, provides good solderability and a flat surface but has lower resistance to handling and environmental factors.
- Immersion Silver provides excellent conductivity and solderability but is more prone to tarnishing.
- Hard Gold offers excellent corrosion resistance and durability but is expensive.
- Solder mask is a protective layer applied to PCB surface to insulate and shield copper traces and pads.
- Solder mask is available in various colours such as green, red, blue, black, white, and yellow.
- The choice of solder mask colour is based on personal preference or specific application requirements.
- Green is the most traditional and widely used colour, while red, blue, black, white, and yellow offer aesthetically pleasing and distinctive looks for PCBs.
The final stage is Assembly costing, which involves estimating the cost of the assembly process, including the cost of labour, test equipment, and overheads. Labour cost is based on location and complexity of the assembly process.
In conclusion, benchmarking PCBs involves a variety of activities, including PCB teardown, understanding the different types of PCBs, using specialized equipment for PCB study, mapping PCB BOM parameters, and creating a PCB architecture diagram. These activities are essential for accurate and comprehensive benchmarking of PCBs, which is critical in ensuring optimal functionality in modern electronic devices.
A reduction in PCB size from a PCB component study led to a 7% cost reduction in the client’s PCB used in the electric drive of a vehicle.
The cost savings were identified through the following steps:
- Identification and determination of components in the client and competitor’s PCBs.
- Data mapping in xcPEP
- Analysis of the PCB BOM data
- The client’s PCB consisted of three boards – one mainboard and two smaller secondary boards
- The competitor’s PCB did not have a similar arrangement, and the rectifier and filter circuits were integrated into the main PCB.
- The smaller secondary boards in the client’s PCB were used for rectifier and filter circuits, respectively.
- The competitor’s board utilization was high due to a square layout, while the client’s intricate and complex shape layout resulted in lower PCB utilization.
Cost Reduction by Reducing PCB Interface Connections from Architecture Study: Cost-saving of 4% was achieved in the client PCB by analyzing the PCB schematic and architecture. This study also provided insights into the PCB component spacing, component layout, and cooling provisions for components. The study involved the following steps:
- Teardown of the PCB from the housing
- PCB BOM mapping under a digital microscope.
- Capturing high-quality images of the PCB and components.
- Connection study and
- schematic mapping
- Schematic analysis
Comparison of client and competitor PCBs (ref. image 2.1 and 2.2):
- The architecture study revealed that the client PCB used bus bars for interconnections.
- In contrast, the competitor PCB used regular wired connections for the interface connections of the systems.
- It was proposed to eliminate the busbars and use wired connections, resulting in a cost-saving of 4%.
LED lights generate heat during operation and excessive heat can lead to performance degradation or even failure. Aluminum PCBs are preferred over FR4 PCBs for LED applications due to their efficient heat dissipation, lightweight and cost-effectiveness, mechanical stability, and good electrical performance. These characteristics make aluminum PCBs a better choice for LED manufacturers.
It was found that company A was using FR4 base and we recommended them to use aluminum base helping them increase the component’s reliability and reduce cost by 6% at the same time.
