Ultrasonic Scanning Microscope Solution for Semiconductor Industry

Ultrasonic Testing Principle

Ultrasonic transducer generates ultrasonic pulse which reaches DUT through the coupling medium (water).

Due to the difference of acoustic impedance, ultrasonic wave reflect at the interface of different materials.

Ultrasonic transducer receives the reflected echo and converts it to electrical signals.

Computer processes the electrical signal and display waveform or image.

Scanning form

A scan: waveform at a certain point;

The horizontal axis indicates the time when the waveform appears;

The vertical axis indicates the waveform amplitude.

C scan: transverse cross-sectional scan;

The horizontal and vertical axes indicate the physical dimensions;

The color indicates the waveform amplitude.

B scan: longitudinal cross-sectional scan;

The horizontal axis indicates the physical dimensions;

The vertical axis indicates the time when the waveform appears;

The color indicates the waveform amplitude and phase

Multi-layer scanning: multi-layer C scanning is performed in the depth direction of the sample.

Transmission scanning: receivers are added to the bottom of the sample to collect the transmitted sound waves to generate images.

Advantages and limitations of detection

Advantages:

1. Ultrasonic detection is applicable to a wide range of materials, including metals, non-metals, and composite materials;

2. It can penetrate most materials;

3. It is very sensitive to interface changes;

4. It is harmless to the human body and the environment.

Limitations:

1. The waveform selection is relatively complex;

2. The shape of the sample affects the detection effect;

3. The position and shape of the defect have a certain influence on the detection result;

4. The material and grain size of the sample have a great influence on the detection.

Welding quality inspection during the wafer loading process

Monitoring during the wafer loading machine startup and debugging process to intuitively discover abnormalities in various equipment parameters and states.

Height and angle of the suction head;

Oxidation and temperature of the solder;

Material of the lead frame and chip material

Welding quality inspection during chip loading

Monitoring during the startup and debugging of the chip loading machine can intuitively find abnormalities in various equipment parameters and states

Height and angle of the suction head;

Oxidation and temperature of the solder;

Material of the lead frame and chip

Voids in the chip welding process will cause insufficient heat dissipation during the use of the device, affecting its service life and reliability. Using ultrasonic testing methods, welding void defects can be quickly and effectively identified.

Detection of package delamination defects after the plastic encapsulation process

Ultrasonic scanning phase detection mode to accurately identify delamination defects between resin plastic and metal frame

The oxidized area after peeling is basically the same as the red area

Void detection and multi-layer detection of thinner packages

Detection case TO series

Test the whole board

Test a single chip

Typical application case: memory chip package pores

Typical application case: memory chip layering defect

Other test cases