Method for identifying a compound using an acoustic microscope

• US 5,834,648 A
• Filed: 02/14/1997
• Issued: 11/10/1998
• Est. Priority Date: 03/07/1996
• Status: Expired due to Term

• Current Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Original Assignee: Integrated Device Technology Incorporated (Renesas Electronics Corporation)
• Inventors: Wang, Willy C., Sue, Steve Kun
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US08/799,947
• Time in Patent Office: 634 Days
• Field of Search: 73/597, 73/599, 73/602, 73/606
• US Class Current: 73/606
• CPC Class Codes: G01N 2291/101 one transducer
• CPC Class Codes: G01N 2291/2698 Other discrete objects, e.g. bricks
• CPC Class Codes: G01N 29/0681 by acoustic microscopy, e.g. scanning acoustic microscopy
• CPC Class Codes: G01N 29/07 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 29/30 Arrangements for calibrating or comparing, e.g. with standard objects

Abstract

A non-destructive method of identifying a type of compound in a sample using an acoustic microscope, particularly, identifying the type of compound used in an integrated circuit package by comparing attributes of the tested molding compound with known attributes of known compounds to identify the compound being evaluated. The attributes that are compared include voltage, attenuation, peak frequency, average frequency, and the velocity of reflected sound.

Claims

1. A method for identifying a compound in an integrated circuit package comprising the steps of:

examining an integrated circuit package with an acoustic microscope;

determining at least one attribute of a compound in said integrated circuit package with the acoustic microscope; and

comparing the at least one attribute of the compound in said package with at least one attribute of a known compound to identify the compound of said package.

2. The method of claim 1 wherein the at least one attribute comprises voltage, peak frequency, attenuation, average frequency or velocity of reflected sound.

3. The method of claim 1 wherein the at least one attribute comprises peak frequency, average frequency, voltage, attenuation or velocity of reflected sound.

4. The method of claim 1 wherein the at least one attribute comprises attenuation.

5. The method of claim 4 wherein the at least one attribute further comprises peak frequency, average frequency, or velocity of reflected sound.

6. The method of claim 1, wherein at least one attribute comprises voltage.

7. The method of claim 6, wherein at least one attribute further comprises peak frequency, average frequency or velocity of reflected sound.

8. A method for identifying a compound in an integrated circuit package comprising the steps of:

placing the integrated circuit package adjacent a transducer of an acoustic microscope;

transmitting sound waves into the integrated circuit package with the transducer;

determining at least one attribute of the compound in the integrated circuit package with the acoustic microscope; and

comparing the at least one attribute of the compound in said package with at least one attribute of a known compound to identify the compound in the integrated circuit package.

9. The method of claim 8 wherein the at least one attribute comprises voltage, peak frequency, attenuation, average frequency or velocity of reflected sound.

10. The method of claim 8 wherein the at least one attribute comprises peak frequency, average frequency, voltage, attenuation or velocity of reflected sound.

11. The method of claim 8 wherein the at least one attribute comprises attenuation.

12. The method of claim 11 wherein the at least one attribute further comprises peak frequency, average frequency, or velocity of reflected sound.

13. The method of claim 8, wherein at least one attribute comprises voltage.

14. The method of claim 13, wherein at least one attribute further comprises peak frequency, average frequency, or velocity of reflected sound.

15. A method for identifying a compound comprising the steps of:

examining an integrated circuit package with an acoustic microscope;

determining a plurality of attributes of a compound in said integrated circuit package with the acoustic microscope; and

comparing the plurality of attributes of the compound in said package with attributes of known compounds to identify the compound of said package;

wherein said attributes include frequency and velocity of reflected sound.

16. The method of claim 15, wherein the frequency attribute comprises peak frequency or average frequency.

17. The method of claim 15, wherein the plurality of attributes further comprises voltage, or attenuation, or a combination thereof.