METHOD AND APPARATUS FOR ATTACHMENT OF INTEGRATED CIRCUITS

• US 20130215591A1
• Filed: 12/17/2012
• Published: 08/22/2013
• Est. Priority Date: 02/20/2012
• Status: Active Grant

• Current Assignee: TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Babala, Mike, Theissen, Jesse
• Granted Patent: US 9,635,794 B2
• Time in Patent Office: Days
• US Class Current: 361/808
• CPC Class Codes: H01L 22/14 for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
• CPC Class Codes: H01L 22/34 Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line switching, multiplexing, gating devices G01R19/25; process control with lithography, e.g. dose control, G03F7/20; structures for alignment control by optical means G03F7/70633
• 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: H05K 1/0268 for electrical inspection or testing
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 13/0465 by soldering H05K13/0469 takes precedence
• CPC Class Codes: H05K 2201/10151 Sensor
• CPC Class Codes: H05K 2201/10727 Leadless chip carrier [LCC], e.g. chip-modules for cards

Abstract

Method and apparatus for bonding an electrical circuit component onto a substrate. A first electrically conductive bonding pad is formed on the component, and a second electrically conductive bonding pad is formed on the substrate. One of said first and second bonding pads is physically split into at least two parts, with electrical discontinuity between the two parts. An electrically conductive bond is formed between the first and second bonding pads such that electrical continuity is established from one part of the one bonding pad, through the other of the bonding pads, and through the second part of the one bonding pad. The integrity of the electrically conductive bond is evaluated by testing electrical continuity between the at least two parts.

Claims

1. Apparatus for bonding an electrical circuit component onto a substrate, comprising

a first electrically conductive bonding pad fixed to said component,

a second electrically conductive bonding pad fixed to said substrate,

wherein one of said first and second bonding pads is divided into at least two parts, with electrical discontinuity between said at least two parts, and

an electrically conductive bond between said first and second bonding pads such that electrical continuity is established from a first part of said one bonding pad, through the other said bonding pad, and through a second part of said one bonding pad,

whereby the integrity of the electrically conductive bond may be evaluated by testing electrical continuity between said first and second parts.

2. Apparatus as set forth in claim 1, wherein said electrical circuit component includes an integrated circuit having multiple pins for electrical connection to other components on said substrate.

3. Apparatus as set forth in claim 2, wherein said first bonding pad is not directly connected to said multiple pins.

4. Apparatus as set forth in claim 1, wherein said electrical circuit component includes an inertial sensor having multiple pins for electrical connection to other components on said substrate, and at least one of said other components includes a microprocessor device.

5. Apparatus as set forth in claim 4, wherein said inertial sensor is packaged in a leadless chip carrier, said multiple pins are located around the edges of said leadless chip carrier, and said first electrically conductive bonding pad is at least partially located on the bottom surface of said leadless chip carrier between said edges.

6. Apparatus as set forth in claim 5, wherein said first electrically conductive bonding pad is a single continuous pad, said second electrically conductive bonding pad is divided into at least two parts with electrical discontinuity between said at least two parts, and wherein each of said at least two parts is soldered to said first electrically conductive bonding pad, whereby electrical continuity is established between said first and second parts through said first electrically conductive bonding pad and the respective solder connections.

7. Apparatus as set forth in claim 4, wherein said microprocessor device is programmed to test the electrical continuity between said first and second parts.

8. Apparatus as set forth in claim 1, wherein said apparatus further comprises circuit traces adapted for connection to a power source, one of said first and second parts is connected to one of said circuit traces, and the other of said first and second parts is connected to a test landing pad to allow an external tester to check for a good connection from said test landing pad through the first and second electrically conductive bonding pads to said circuit trace.

9. Apparatus as set forth in claim 8, wherein said circuit trace to which said one of said first and second parts is connected to an electrical ground.

10. Apparatus as set forth in claim 1, wherein said first electrically conductive bonding pad is split into said first and second parts and further wherein said electrical circuit component includes testing circuitry for testing electrical continuity between said first and second parts.

11. Apparatus as set forth in claim 10, wherein said electrical circuit component comprises at least one inertial sensor.

12. A method for evaluating the bond between an electrical circuit component and a substrate, comprising the steps of fixing a first electrically conductive bonding pad to said component, fixing a second electrically conductive bonding pad to said substrate, splitting one of said first and second bonding pads into at least first and second parts so as to have electrical discontinuity between said first and second parts,

forming an electrically conductive bond between said first and second bonding pads such that electrical continuity is established from said first part of said one bonding pad, through the other said bonding pads, and through said second part of said one bonding pad, and

testing electrical continuity between said at least two parts so as to thereby evaluate the integrity of the electrically conductive bond.

13. A method as set forth in claim 12, wherein the electrical circuit component to which said method is applied is an integrated circuit and said method further includes the step of forming multiple pins on said integrated circuit for electrical connection to other components on said substrate.

14. A method as set forth in claim 13, wherein said steps of fixing said first electrically conductive bonding pad to said component is performed such that said first electrically conductive bonding pad is not directly connected to said multiple pins.

15. A method as set forth in claim 12, wherein the electrical circuit component to which said method is applied is an inertial sensor, and said method further includes the step of forming multiple pins on said inertial sensor for electrical connection to other components on said substrate, and connecting a microprocessor device to said inertial sensor pins.

16. A method as set forth in claim 15, wherein the inertial sensor to which said method is applied is packaged in a leadless chip carrier, said step of forming multiple pins on said inertial sensor includes the step of forming multiple pins around the edges of said leadless chip carrier, and wherein said step of fixing said first electrically conductive bonding pad to said component comprises the step of fixing said first electrically conductive bonding pad to said inertial sensor such that said pad is at least partially located on the bottom surface of said leadless chip carrier between said edges.

17. A method as set forth in claim 16, further including the step of testing for short circuits between one of said pins and one of said first and second electrically conductive bonding pads.

18. A method as set forth in claim 16, wherein the step of fixing said first electrically conductive bonding pad includes the step of forming said first electrically conductive bonding pad as a single continuous pad, wherein the step of fixing said second electrically conductive bonding pad includes the step of forming said second electrically conductive bonding pad as at least first and second parts with electrical discontinuity between said first and second parts, and wherein said step of forming said electrically conductive bond comprises the step of soldering each of said first and second parts of said second electrically conductive bonding pad to said first electrically conductive bonding pad, whereby electrical continuity is established between said first and second parts through said first electrically conductive bonding pad and the respective solder connections.

19. A method as set forth in claim 15, and further comprising the step of programming said microprocessor device to test the electrical continuity between said two parts.

20. A method as set forth in claim 12, wherein said apparatus further comprises circuit traces adapted for connection to a power source, and wherein said method further comprising the step of connecting said first part to one of said traces and said second part to a test landing pad whereby an external tester may be used to check for a good connection from the test landing pad through the first and second electrically conductive bonding pads to said trace.

21. A method as set forth in claim 20, and further comprising the step of connecting an external tester between said landing pad and said trace and checking for a good connection from said test landing pad to said trace with said tester.

22. A method as set forth in claim 12, wherein said step of fixing said first electrically conductive bonding pad comprises the step of forming said first electrically conductive bonding pad in first and second parts and wherein said method further includes the step of testing for electrical continuity between said first and second parts with electrical circuitry contained in said electrical circuit component.