Methods to utilize ultrasonic energy to reduce the initial contact forces in known-good-die or permanent contact systems

• US 6,619,532 B2
• Filed: 07/15/2002
• Issued: 09/16/2003
• Est. Priority Date: 02/23/1998
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Farnworth, Warren M., Hembree, David R., Wood, Alan G., Hess, Michael E., Jacobson, John O.
• Primary Examiner(s): Dunn, Tom
• Assistant Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US10/196,666
• Publication Number:
  US 20020179681A1
• Time in Patent Office: 428 Days
• Field of Search: 228/103, 228/1.1, 228/110.1, 228/173.3, 228/44.7, 228/179.1, 228/180.1, 228/6.2, 156/73.1, 156/73.2, 156/580.1, 156/580.2
• US Class Current: 228/103
• CPC Class Codes: B23K 20/10 making use of vibrations, e.g. ultrasonic welding
• CPC Class Codes: B23K 2101/38 Conductors

Abstract

A machine and method for bonding puncture-type conductive contact members of an interconnect to the bond pads of a bare semiconductor die includes the use of one or two ultrasonic vibrators mounted to vibrate one or both of the die and interconnect. A short axial linear burst of ultrasonic energy enables the contact members to pierce hard oxide layers on the surfaces of the bond pads at a much lower compressive force and rapidly achieve full penetration depth.

Claims

1. A method for forming bonds between a semiconductor die having at least one bond pad on a first surface thereof and an interconnect having at least one contact member on a connection surface thereof, said at least one contact member for penetrating a layer of material on an outer surface of said at least one bond pad for connecting said at least one contact member to said at least one bond pad of said semiconductor die, said method comprising:

aligning said semiconductor die and said interconnect;

bringing together said connection surface of said interconnect having said at least one contact member aligned proximate said at least one bond pad on said first surface of said semiconductor die;

providing a force to at least one of said semiconductor die and said interconnect;

engaging said semiconductor die and said interconnect using said force; and

substantially ultrasonically vibrating one of said semiconductor die and said interconnect using vibrational energy having said at least one contact member of said interconnect penetrating a portion of said at least one bond pad of said semiconductor die, forming an electrical connection.

2. The method of claim 1, whereby said engaging and said substantially ultrasonically vibrating are continued having said at least one contact member penetrating said portion of said at least one bond pad to a predetermined depth.

3. The method of claim 2, wherein said predetermined depth comprises a range of about 0.3-0.8 of a thickness of said at least one bond pad.

4. The method of claim 2, wherein said substantially ultrasonically vibrating is conducted to achieve a vibrational amplitude in a range of about 5 to about 30 percent of said predetermined depth.

5. The method of claim 1, wherein said substantially ultrasonically vibrating is conducted in a range of about 5 to about 200 milliseconds.

6. The method of claim 2, further comprising:

detecting penetration of said at least one bond pad to said predetermined depth by detection/feedback apparatus.

8. The method of claim 1, wherein said electrical connection comprises a nonpermanent electrical connection between said at least one bond pad and said at least one contact member.

9. The method of claim 1, wherein said electrical connection comprises a permanent electrical connection between said at least one bond pad and said at least one contact member.

10. The method of claim 1, further comprising:

retracting said semiconductor die and said interconnect from each other during application of a linear axial ultrasonic vibrational force to one of said semiconductor die and said interconnect, said retracting for disconnecting said semiconductor die from said interconnect.

7. A method for forming bonds between a semiconductor die having at least one bond pad on a first surface thereof and an interconnect having at least one contact member on a connection surface thereof, said at least one contact member for penetrating a layer of material on an outer surface of said at least one bond pad for connecting said at least one contact member to said at least one bond pad of said semiconductor die, said method comprising:

aligning said semiconductor die and said interconnect;

bringing together said first surface of said semiconductor die and said connection surface of said interconnect having said at least one contact member aligned proximate said at least one bond pad on said first surface of said semiconductor die;

providing a force to at least one of said semiconductor die and said interconnect;

engaging said semiconductor die and said interconnect using said force;

substantially ultrasonically vibrating one of said semiconductor die and said interconnect using vibrational energy having said at least one contact member of said interconnect penetrating a portion of said at least one bond pad of said semiconductor die, forming an electrical connection, said substantially ultrasonically vibrating continuing to have said at least one contact member penetrating said portion of said at least one bond pad to a predetermined depth;

detecting penetration of said at least one bond pad to said predetermined depth by detection/feedback apparatus; and

terminating said penetration of said at least one bond pad to said predetermined depth by said detection/feedback apparatus.