EMI reduction in power modules through the use of integrated capacitors on the substrate level

• US 6,636,429 B2
• Filed: 09/20/2001
• Issued: 10/21/2003
• Est. Priority Date: 09/20/2000
• Status: Expired due to Term

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Ballard Power Systems Corporation (Superior Plus Corporation)
• Inventors: Maly, Douglas, Flett, Fred, Ahmed, Sayeed, Parkhill, Scott
• Primary Examiner(s): Martin, David
• Assistant Examiner(s): BUI, HUNG S
• Application Number:
  US09/957,001
• Publication Number:
  US 20020126465A1
• Time in Patent Office: 761 Days
• Field of Search: 361/818, 361/819, 361/288, 361/715, 361/723, 361/752, 361/724, 361/800, 361/816, 315/194, 257/584, 257/587, 257/666, 257/700, 174/35
• US Class Current: 361/818
• CPC Class Codes: H01L 2223/665 Bias feed arrangements
• CPC Class Codes: H01L 23/50 for integrated circuit devices, e.g. power bus, number of leadsH01L23/482 - H01L23/498 take precedence
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 25/072 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/01039 Yttrium [Y]
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H05K 1/0215 Grounding of printed circuits by connection to external grounding means
• CPC Class Codes: H05K 1/0231 Capacitors or dielectric substances
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2201/09345 Power and ground in the same plane; Power planes for two voltages in one plane
• CPC Class Codes: H05K 2201/10446 Mounted on an edge soldering edge mounted components H05K3/3405; edge terminals H05K2201/1034
• CPC Class Codes: H05K 2201/10636 Leadless chip, e.g. chip capacitor or resistor
• CPC Class Codes: H05K 2203/049 Wire bonding
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

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.

Claims

1. 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.

2. 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.

3. The power module of claim 2, further comprising:

a via connection; and

a ground layer in the substrate, the ground electrically connected to the ground layer by the via connection.

4. The power module of claim 2, wherein the ground is

an electrically isolated layer in the substrate, and further comprising:

a grounded area in the lead frame; and

a wire bond from the electrically isolated layer in the substrate to the ground connection mounted in the lead frame.