Since 1963, R&D Magazine has presented annual awards to the 100 greatest technological achievements of the year.  This includes the most advanced new technologies, processes, materials, and software with commercial potential.  During this 40^th annual competition of the R&D 100 Awards, R&D Magazine saw entries from many of the most prestigious companies, research organizations, and universities in the world.  

Simpex Technologies, Inc. has been selected by R&D Magazine as a 2002 R&D 100 Award winner for its Laser Ultrasonic Bond Detection System.  This system is a high speed, non-contact, non-destructive method of determining bonding integrity of materials at micro-level.  This Micro Laser Ultrasonic Technology combines a pulse laser and a continuous wave laser detector forming a cause-and-effect sensing device. This technology has many potential applications, one being in the semiconductor industry.

As the demand for smaller, lighter and denser circuitry increases, new manufacturing technologies have been developed to keep up with the pace. Unfortunately, methods and techniques for bond integrity testing have remained dormant or with minor adaptation.  The current methods for bond integrity testing are the bond pull and bond shear methods, both of which are contact types, time consuming, labor intensive and rely on high degree of human judgment. In addition, the bond shear test is destructive; therefore, the quality of production units is based on the inspection results of test coupons and not on the actual product.

Simpex’s approach applies tightly controlled light pulse(s) onto the top of the interconnection (such as a ball bond), causing a thermal elastic propagation.  These propagation waves travel through the bond interface onto the surface of the base material.  At a distance, the surface wave displacements are measured with a continuous wave laser beam. Knowing the amount of light energy applied and the response of the materials to the energy pulses, the bond integrity of the interconnection can be determined.  This technique, is much improved from the traditional contact type techniques - no direct contact is made with the object, the excitation is much gentler than that required in a contact test and the speed of testing is much faster than any automated assembly machines, allowing for real-time process control.   

The Laser Ultrasonic Bond Detection System combines a broad spectrum of technologies including custom optics, structured illumination, image processing algorithms, laser ultrasonics, and high-speed computer controlled sensors.  There is no special surface preparation required, and the induced propagation from the object of interest can be extremely gentle. Since the sensor is a beam of light focused to a small point, it measures a true local response rather than an average over the area of interest. It offers a non-contact test technique whenever optical access to the material surface is available, including locations with tight curvatures such as corners and edges. This fact allows its use in many processing environments where contacting the material surface is not possible or desired. Lasers are used for both generation and detection of the elastic waves. This allows the technique to be used in environments or where components of interest are so fragile that contact sensing is inappropriate.

Simpex Technologies, Inc. is located in Chino, California, and has worked with Idaho National Engineering and Environmental Laboratory, Johns Hopkins University, Applied Physics Laboratory, and National Institute of Standards and Technology in creating its Laser Ultrasonic Bond Detection System.