Virtual Product Development

Almost all product designers are considering the concept of a product at the stage of integrating a solution of their own expertise into the final product. Unfortunately, design is often done through a traditional product development process where designers bring out the best of their ideas to integrate into the product. These ideas are reviewed and based on the reviews, a decision is made to order a physical prototype. The physical prototype is measured in a variety of quantities, and any findings and their repairs are transferred to the next prototype. This process continues until the device meets e.g. EMC requirements and is ready for the market. This process usually involves many prototypes, depending on the product, up to hundreds of hours in laboratories, and numerous, often complicate technical solutions that can be difficult to integrate into a product.

However, there is an alternative workflow to the above description. Virtual Product Development - where the product is mainly designed using simulations from all possible technical fields.

Please find attached a draft concept drawing of the ANSYS SpaceClaim direct modeler for a coffee maker. Usually, an industrial designer submits a draft concept for product development. This draft can be used to test various technical solutions. The model can be used to analyze the effects of materials, such as antenna performance or product surface temperatures on different material combinations. However, in this example, I will focus on ESD and the circuit board grounding solution.

The simulation model of the IEC 61000-4-2 ESD test environment is modeled using the ANSYS SpaceClaim direct modeler. The mechanical model from the coffee maker has been transferred as a project to the same model as the test environment. As a result, all model updates to the coffee machine are directly transferred to the actual virtual testing model. This way, the model does not need to be constantly updated, but always remains up to date when the mechanics are changed.

The same ANSYS SpaceClaim model has been transferred to a 1:1 ANSYS HFSS simulator. The HFSS model is linked to SpaceClaim, and as the mechanics change, the HFSS model is also updated if desired. The model uses the correct material parameters. The table is not included in the model because its impact on the indirect ESD test is very small.

Indirect ESD discharge is applied to the Vertical Coupling Plane (VCP) in the simulation model. The model includes a voltage port and an ESD gun ground wire. The model includes all assumed components, circuit boards, cables, flexible PCB's, display driver areas, antennas, etc. All materials have real material properties.

The animation shows how the ESD pulse field is distributed in the test environment. The field is also visible inside the product where all the electronics are located. An external electric field can be connected to cables, flexes, circuit board components, and display drivers inside the product.

Non-grounded Solution

Grounded solution

The above result shows the voltage caused by the indirect ESD discharge connected to the display driver interface. In the Non Grounded situation, the circuit boards are not grounded to the metal body of the device, and the circuit boards are not galvanically interconnected except through terminals. In a grounded situation, the same circuit boards are grounded to each other and one circuit board to the device body. This shows a relative difference between different grounding solutions. It is generally known that the display interface is susceptible to interference, and a 6 Vpp voltage pulse at this interface poses a high probability of display interference or freezing in the ESD test. Therefore, based on the simulation results, it can be concluded which grounding solution reduces the potential risk of disturbance.

This is simple example how to analyze a virtual prototype in really early phase.