EMI reduction in power modules through the use of integrated capacitors on the substrate level
AssigneeBallard Power Systems Inc.
InventorsDouglas Maly, Sayeed Ahmed, Scott Parkhill, Fred Flett
Life of this patent
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Abstract
A high frequency, low impedance network is integrated into the substrate level of a power module for the reduction of electromagnetic interference (“EMI”). In one embodiment, capacitance is electrically connected to at least one of the positive conducting layer in a substrate or the negative conducting layer in a substrate and a ground. Integrating a capacitive network of low stray inductance in a substrate of a power module allows relatively small, inexpensive capacitors to be used.
Claims4
A power module for reducing inductance in transferring power between a power source and a motor, the power module comprising:
- a lead frame for supporting the power module and for providing interconnections to the motor and the power source;
- a substrate connected to the lead frame comprising a high side substrate and a low side substrate;
- high side switches proximate to the high side substrate;
- low side switches proximate to the low side substrate;
- a positive conducting layer in the high side substrate of the power module configured for connection to a positive bus;
- a negative conducting layer in the low side substrate of the power module configured for connection to a negative bus;
- and
- a high frequency, low impedance network comprising a ground.
A power module for reducing inductance in transferring power between a power source and a motor, the power module comprising:
- a lead frame for supporting the power module and for providing interconnections to the motor and the power source;
- a substrate connected to the lead frame comprising a high side substrate and a low side substrate;
- high side switches proximate to the high side substrate;
- low side switches proximate to the low side substrate;
- a positive conducting layer in the high side substrate of the power module configured for connection to a positive bus;
- a negative conducting layer in the low side substrate of the power module configured for connection to a negative bus;
- and
- a high frequency, low impedance network comprising a ground and a surface mount capacitor surface mounted to the ground and to at least one of the positive conducting layer or the negative conducting layer.
Dependencies are inferred from the claim text.