Shape and height measurement of solder bumps using focus measure difference

Akira Ishii; Jun Mitsudo; Shinsuke Mizushima

doi:10.1117/12.515014

30 September 2003 Shape and height measurement of solder bumps using focus measure difference

Akira Ishii, Jun Mitsudo, Shinsuke Mizushima

Proceedings Volume 5264, Optomechatronic Systems IV; (2003) https://doi.org/10.1117/12.515014
Event: Photonics Technologies for Robotics, Automation, and Manufacturing, 2003, Providence, RI, United States

Abstract

This paper describes a technique, based on the shape-from-focus method, to measure the shapes and heights of an array of solder bumps through visually inspecting an IC chip-size package (CSP). We devised a focus measure difference method for detecting the horizontal section of a bump quickly and precisely. This was where we selected bump image pixels that had the same focus measure at two specified focal points along the height axis. The selected pixels corresponded to the contour points of the section at the mid-height between the two focal points. We applied it to measuring the height of an array of 208 bumps that were 260 μm high arranged at intervals of 500 μm. By measuring the area of the horizontal section at a specified height and using it to fit a sphere in the bump, the height of the bump top was efficiently estimated to match the sphere top. This sphere fitting achieved a height measurement accuracy of 8 μm (2σ) at a resolution of 3.4 μm pixels on the bump using a 2/3-inch high resolution CCD camera with 1300 × 1030 pixels. The accuracy was sufficient to inspect the coplanarity of an array of solder bumps.

Citation Download Citation

Akira Ishii, Jun Mitsudo, and Shinsuke Mizushima "Shape and height measurement of solder bumps using focus measure difference", Proc. SPIE 5264, Optomechatronic Systems IV, (30 September 2003); https://doi.org/10.1117/12.515014

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available