Noncontact electrical test of a ball grid array substrate that uses the electro-optic probing technique

Area of Science:

• Materials Science
• Electrical Engineering
• Semiconductor Device Testing

Background:

• Ball Grid Array (BGA) packages are critical in semiconductor packaging.
• Ensuring the integrity of BGA substrates is essential for device reliability.
• Existing testing methods may lack the required spatial resolution for detecting subtle defects.

Purpose of the Study:

• To investigate a new electro-optic (EO) probing technique for BGA substrate testing.
• To assess the capability of EO probing for detecting open circuits with high spatial resolution.
• To demonstrate the practical application of EO probing on a real BGA substrate.

Main Methods:

• Development and implementation of an experimental setup for EO probing.
• Utilizing a probe tip fabricated from Lithium Niobate (LiNbO3) crystal.
• Performing measurements on a functional BGA package substrate.

Main Results:

• The EO probing technique successfully detected open circuits within the BGA substrate.
• High spatial resolution was achieved, enabling precise localization of defects.
• Measurement results from a real BGA substrate validated the technique's efficacy.

Conclusions:

• Electro-optic probing presents a viable and high-resolution method for BGA substrate testing.
• This technique offers a promising alternative for non-destructive detection of open circuits.
• Further research can explore optimization and broader application of EO probing in semiconductor testing.