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Corporate InformationResearch & Development

September 5, 2014

Report from Presenter

The IEEE International symposium on Electromagnetic Compatibility (EMC) 2014 was held in Raleigh, North Carolina, United States between Aug. 3rd and 8th. The symposium was one of the biggest conferences on EMC including more than 250 presentations. Yokohama Research Laboratory, Hitachi Ltd., made a presentation entitled "Model-Based Analysis of Screw Locations to Reduce Radiation from a PCB-Chassis Structure".

Fig. 1 Radiation Behavior from PCB-Chassis

Recently the number of wireless portable devices such as smart-phone and/or tablet as well as electric vehicle or electrified automotive is increasing in the market. The technology for the electromagnetic compatibility (EMC) is getting more important in order to avoid the interferences between the devices.

Such complex devices sometimes encounter the electromagnetic interference problem at integrated system-level even the PCB is designed properly and achieved low noise.

We focused on the screw which connects the PCB with other parts such as chassis and it is considered as the source of electromagnetic noise from the PCB-chassis structure. The analytical calculation model of PCB-chassis structure has been created and the guideline to lower the screw current was then revealed using the model.

Fig. 2 Created PCB-chassis model

Fig. 3 Correlation between impedance and
screw current


The results obtained from the study realize the design for lower electromagnetic noise. We, Yokohama Research Laboratory, continue developing such design technologies for more reliable products.

(By FUNATO Hiroki)

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