PCB Blog - What are the advantages of the soft and hard combination design of PCB

This is an era of rapid change. In addition to creativity and design ability, today's PCB design  also face many limitations. They need to face more and more complex designs - a series of peripherals connected through IO. Moreover, today's design is increasingly pursuing the miniaturization, low cost and high speed of products, which are particularly reflected in the mobile device market. In recent years, a large number of high-performance and multi-function devices have emerged one after another, and the market has developed rapidly, which makes smart consumers dizzy. Bringing these products to the electronic design market requires a tight design process, which usually involves high-density electronic circuits, and PCB design also considers reducing manufacturing time and cost.

One solution to help designers and design teams meet these challenges is to use the combination of hardware and software design technology, that is, the combination of hardware and software design of printed circuit board (PCB). Although this is not the latest technology, the comprehensive factors of many parties show that this technology is universal and can reduce costs. From the traditional rigid PCB connected by cables to today's soft and hard combination board technology, from the cost perspective, it is feasible to connect two hard boards and flexible cables for short-term design; However, this requires connectors to be installed on each board, and the connectors need to be assembled to the circuit board and cables - all of which add to the cost. In addition, rigid PCBs connected by cables are prone to electrical false soldering, which will lead to failures. In contrast, the combination of soft and hard circuits can eliminate these solder joints, make them more reliable, and provide higher overall product quality.

Let's take a closer look at the total cost. Figure compares the simulation manufacturing cost of rigid PCB with traditional cable connection and 3D software hardware combination design. The traditional design consists of a rigid board using flexible cables and connectors. The soft and hard combination design is embedded in the soft and hard board, with two built-in soft layers in the middle. The overall structure is a group of four layers of printed circuit boards. The manufacturing cost of both designs is based on the quotation of PCB manufacturer, including assembly cost. In addition, the cost of two separate four layer circuit boards, connectors and cables in the traditional design factors need to be added.

What are the advantages of the soft and hard combination design of PCB

Figure 1: Comparison of rigid PCB assembly cost between soft and hard combination design and cable connection.

It can be seen from the figure that when the manufacturing number is more than 100 sets, the combination of software and hardware design will save more time and improve efficiency compared with the traditional design scheme. The main reason is that the soft and hard combination circuit does not contain any connector components/cables, so connector assembly is not required. Not only that, they have reliable performance and excellent technology. And this is just the tip of the iceberg.

With the combination of hardware and software technology, designers can interconnect multiple PCBs in a single package without using connectors, wires and cables Because the soft and hard bonding plates do not require cable assembly, the overall assembly consumption and test complexity are reduced, both of which help to reduce costs. In addition, fewer components need to be purchased, which reduces the bill of materials, thus reducing the supply chain risk and cost. The soft and hard combination board makes the maintenance of the product more convenient and saves the cost in the whole product life cycle.

The cost of manufacturing, assembly, testing and logistics is a factor that cannot be ignored for any project, design and cost control that uses a combination of hardware and software design technology. The combination of hardware and software design often requires a mechanical team to assist in flexible design and PCB integration of the final product. This process is time-consuming, costly, and error prone.

What's worse, PCB design tools often ignore the folding and assembly problems of hardware and software combined design. The combination of hardware and software requires designers to think and work with 3D thinking. The flexible part can be folded, twisted and rolled to meet the mechanical design requirements. However, traditional PCB design tools do not support 3D PCB design or bending and wrinkle simulation of rigid design parts, or even the definition of different stack design parts, including flexible design parts.

Because of this, designers who combine hardware and software are forced to manually convert the rigid and flexible parts of 3D design into planar and 2D production formats. Later, the designer also needs to manually record the soft design area, and carefully review to ensure that no components or vias are placed between the rigid and flexible areas. This process is also constrained by many other rules, most of which are not supported by PCB design software.

In general, compared with the standard rigid PCB designed with traditional PCB software, which is in a weak competitive position, more efforts are needed to design a combination of hardware and software PCB. Fortunately, modern design tools with advanced 3D functions can support the bending definition and simulation of flexible design parts, as well as the definition of different design parts and different layer stacks. These tools largely eliminate the dependence on mechanical CAD tools when dealing with flexible parts, saving designers and design teams time and money.

Through the use of modern PCB design tools, developers and circuit board manufacturers timely coordinate to promote the time-saving and efficiency of the combination of hardware and software technology. The combination of hardware and software design, compared with the traditional rigid circuit board and cable design, requires closer cooperation between designers and manufacturers. The successful production of soft and hard bonded boards requires designers and manufacturers to jointly develop design rules, including the number of layers in the design, material selection, through hole size, bonding method and size control. With appropriate design tools, we can clearly define and balance at the early stage of design, so as to optimize the soft and hard combination board and further reduce the overall cost.

It is undeniable that the current industry development trend and consumer demand are constantly driving designers and design teams to challenge the design limit and to develop new electronic products to meet market challenges. 

These challenges,  rigid PCB especially the demand for mobile devices today, have promoted the combination of hardware and software technology to become the mainstream of the design industry step by step, and have gained higher commercial value in extensive applications, especially those projects starting from hundreds of sets. Modern PCB design tools support the necessary definition and simulation of 3D product development, early cooperation and all software hardware integration, greatly reducing the trouble of software hardware integration design, making its solution more attractive; In addition, it is cheaper than the rigid PCB design for cable connection. For the design team, PCB design different choices mean that the success or failure of the product lies in the front line.