Electronic packaging

About: Electronic packaging is a research topic. Over the lifetime, 3977 publications have been published within this topic receiving 48510 citations.

New packaging of chip-on-board by unique printing method

Abstract: A novel printing method which has been found to be successful in making the chip-on-board (COB) packaging for ICs has been developed. Using this technique, it has become possible to achieve less than mm height, uniform thickness, and all-in-one operation. This method is more economical than the transfer-molding method. In addition, the cost of packages is much reduced, and it is more suited to mass production. One-component epoxy-resin, called NPR-150, has been developed which is suitable for printing. Deformation of gold wires was not observed, and reliability test results showed excellent levels, comparable to the formal transfer-molding packaging. >

Online-offline laser ultrasonic quality inspection tool for multi-layer chip capacitors

Abstract: The advent of surface mounted devices has allowed continued size decreases in electronic packages. However, the decrease in device size has led to other manufacturing problems. Therefore, as devices decrease in size, inspection technology must be developed to maintain consistent levels of quality without increasing manufacturing process time. The focus of most inspection technology is on finding defects with solder joint interconnects, but some devices, such as multi- layer chip capacitors (MLCCs), have failures not relating to the solder connection. Defects in MLCCs, known as flex cracks, are commonly caused by manufacturing processes, and no current means of detection exists, unless the cracks cause a device to fail a functional test. A laser ultrasonic and interferometric system, providing a non-contact, nondestructive and online approach for microelectronic package quality inspection, is designed and presented. A pulsed infrared laser excites a specimen into vibration through laser-generated ultrasound, and the vibration displacement is measured using an interferometer. Differentiation between acceptable and unacceptable devices is achieved using signal-processing techniques that compare waveforms between two devices. Results are presented or a case study involving MLCCs that have intentionally induced flex cracks, causing the devices to fail. The system has the capability of detecting open connections and flex cracks in the MLCC packages.

Increasing the lifetime of electronic packaging by higher temperatures: Solders vs. silver sintering

Abstract: Increasing the temperature in power electronic applications usually causes a decreasing lifetime and reliability. This study shows that packaging materials and technologies like silver sintering or gold germanium solders can easily deal with temperatures above 150°C. Furthermore the power cycling capability at increased temperatures can be much better than at room temperature. Active power cycling tests with 240 devices offered more cycles to failure at 120°C cooling temperature than at 40°C. The three tested sample groups consisted of silicon carbide diodes which were soldered (gold germanium/ tin lead) or silver sinter to copper-ceramic-substrates (DBCs). The reason behind this effect is the decreasing of Young's modulus, yield strength and ultimate strain over temperature. The materials are getting much more ductile and robust against load cycling at higher temperatures. The three mentioned material properties were measured by nano-indentation and tensile tests up to 200°C. In summary, packaging materials and their properties should be adopted to the intended application and its requirements, starting with a temperature-dependent analysis.

Advanced mixed-mode bending test: A rapid, inexpensive and accurate method for fracture-mechanical interface characterisation

Abstract: This paper presents a comprehensive method for obtaining urgently required critical interface delamination data of material pairings used in electronic packaging. The objective is to thereby enable rapid, inexpensive and accurate lifetime prediction for that failure mode. A new testing method is presented which allows maximum mode-angle range and enhanced throughput testing under multiple loading conditions, the coverage of which is usually a rather lengthy and resource-demanding procedure. The approach is specimen-centred in the sense that the accent is put on test-specimens which are easily manufacturable industrially, rather than having to adapt them to a special testing machine. The concept is also scalable, i.e. it has potential to work also for smaller samples cut from real devices. We show the first version of a newly developed test-stand and discuss the obtained results for copper-molding compound interfaces in the light of the current state of the art used for delamination testing in electronic packaging.