What is Design for Manufacturing in PCB Assembly?

DFM     |      2021-10-16 17:21

Introduction

 

i. Design for Manufacturing:

Today, organizations are spending more time on design instead of manufacturing. After the industrial revolution 4.0, the industries are spending more effort in product design and development. DFM means optimization (best) of products, parts, and components, to produce cheap and quality product by reducing waste such as non-value-added services.

ii. Difference between PCB & PCBA:

In the printed board circuit, all the electronic components are connected electrically using pads, conductive traces from copper foil. This copper foil is laminated on the non-conductive substrate. There are various modules of the printed circuit board such as single-sided, double-sided, and multi-sided. In single-sided, there is only one copper layer, and so on. In a multi-layer printed circuit board, there are multiple layers and there are a more complex design and high density. Printed circuit board analysis (PCBA), is the final product in which all the electronic components have been installed using soldering or some other processes and now it is ready to use for the purpose or function for which it is designed.

printed circuit board

iii. DFM in PCBA:

In the manufacturing of printed circuit boards, there is high complexity and stress. So, in the printed circuit boards, there is a need to optimize the design as it includes multiple electronic components. A good design can really help in achieving the cheap printed circuit board. DFM can help in reducing the desired components of it.

Design for Manufacturing in PCBA

iv. Why We Need DFM in PCBA:

Design for manufacturing is very important in the manufacturing of printed circuit boards. DFM is the simplification as well as optimization of a prototype during its preparation for its manufacturing. About 80% of the cost of a product is based on its design. DFM can allow one to produce integrated, optimized, and cost-competitive printed circuit boards. For example, now the organization wants to dispatch its printed circuit board that can perform certain functions. But in the end, the organization faces multiple errors in the fabrication or assembly process. Now, the organization will invest both money and time in analyzing that where are the issues. Either the issue is in product material, or in PCB layout. Are the prototypes are matched with the main process and development files. So, the product will cost too much and need more time to dispatch to the market. So, there is a need for proper design in order to minimize the chances of high cost, and more lead time (time from order to customer delivery). As in PCB, there are multiple components, so, DFM can reduce the production time as well as components by reducing waste (non-value-added services or operations). Now, the extra time can be induced to fit value-added services in the manufacturing of PCB.

 

How DFM Works in PCBA:

In PCBA, after the idea of a conceptual design or prototype, concept of DFM is used. The necessary resources and components are listed that are required in the development of product after the idea. The required components and amount is listed and the process is called Bill of Material (BOM). Following is the working of DFM in the manufacturing of printed circuit board:

i. Reduced Number of Components:

In development and design of PCB, the main aim is to reduce the number of components as it requires a lot of components. This goal will not only help in reducing the cost but also reduce the complexity in the assembly or fabrication process. Therefore, there will be lesser cycle time and there will be more productivity. Suppose there is a machine that is used in the assembly of PCB. It can support only flow of limited components per pass. So, a lesser number of components can reduce the machine pass. It will result in lesser cost and more production. Moreover, the availability time of the machine will also be increased.

ii. A Module Design:

Using tools of DFM, PCB’s single model will be made. will be made in order to check the integration, optimization, and flexibility of the production process. It is because when the customer orders more, the cost per PCB reduces. So, there is a need for optimization in the production of PCB. Therefore, a single module is prepared as a model for the manufacturing of other PCBs. This will result in reducing cycle time, there will be more productive and lesser breakdowns.

Module Design

iii. Nourish Usage of Standardized Components:

Usage of standard components can dramatically reduce the design development cost as well as time. The use of simple and common components can simplify the supply chain of products. Moreover, if the organization uses the standardized components, their footprints can easily be verified before the usage of components in PCB design.

Lesser Components PCB

iv. Select Multifunctional Components:

Using DFM knowledge, there is a need to use multifunctional parts that can serve more than one function in PCB. It will optimize the usage of components in PCB. For example, usage of the standoff in PCB.

Multifunctional Components such as ICS

v. PCB Material:

To reduce cost and production time, select the suitable material for the manufacturing of PCB. For example, the paint at the end can cost too much. But selecting a material that is naturally painted or does not need paint can reduce the cost and time. Assembly Optimization: The components of the PCB should be made with lesser tolerances. Because more tolerance in components can increase the stress level during the assembly or fabrication process.

vi. Components Replacements:

The PCBs must be designed in such a way that their mounting issues should be reduced. To reduce mounting errors, there must be high dimensional tolerance at components end. High levels of placement tolerance can heavily reduce the failure rate of the fabrication process.

Repositioning and Replacement of PCB Components

 

 

Advantages of DFM in PCBA:

Following are the advantages of design and development of printed circuit board analysis:

⋄ Handling and documentation of a lesser number of parts

⋄ Reduction of the bill of material (BOM) cost

⋄ Repositioning and handling cost can be reduced

⋄ More workers’ productivity

⋄ Lesser input (energy) from labor is required

⋄ Reduced cycle and lead time

⋄ High reliability and flexibility

⋄ Lesser complexity and stress levels

⋄ More competitive products due to lower cost

⋄ High margins can be gained

 

Conclusion:

DFM is very necessary for development and design. Similarly, in PCBA, it is very necessary to optimize the design to decrease the overall cost and lead time. So, with the help of DFM more time will be spent on design and product development, after that lesser time will be invested in production. Further, the product will be competitive and reliable.