COB ICs

The quest to fabricate more and more devices in a minimum Silicon space has been ON since J. K and R. Noyce invented the first ICs. This quest has enabled scientific community to cross various technological frontiers. Sustained efforts to put more and more transistors on a wafer have led us to nanotechnologies.

 

In the commonly used electronic technology, the semiconductor chips (also known as bare-dice) are individually mounted on a package, and wire-bonded to its I/O pins. This package is then mounted on a Printed Circuit Board (PCB). However, not only does packaging of single chip ICs cost more than the cost of the chips they contain, packaging of a chip take relatively large amount of physical space. Using a conventional single chip package and circuit board interconnect strategy, the package and interconnects took up over 50% of the timing budget as well.

 

However, there is an emerging technology where several bare die chips are mounted on a single package. This technology is known as Multi-Chip Module (MCM) technology. It can be used for both standard and ASIC chips. The resulting package can then be soldered on a PCB.

 

Although different from MCM, Chip-on-Board (COB) and Flip-Chip technologies are generally considered as related technologies. In COB technology, a semiconductor chip is placed directly on a PCB, eliminating the packaging step thereby, COB comprises of bare dice on organic laminate substrates, such as FR4, along with other SMT devices, both packaged devices and discrete components.  

 

In the Flip-Chip technology, the chip is mounted upside-down (metal contacts down), providing a direct electrical connection to the I/O pads, eliminating the wirebonding step.

CMOS Image Sensors

Advent of CMOS technology in eighties led to the phenomenal growth in semiconductor industry. Transistors have become smaller, faster, consume less power, and are cheaper to manufacture. It is CMOS technology which has enabled very high integration on the chips leading to modern high performance, miniaturized integrated circuits.

 

Apart from the valuable contribution in miniaturization of integrated circuits, CMOS technology found applications in sensing applications. CMOS technology has been adopted to design sensors, especially in the field of imaging. Due to the wide usage of CMOS based image sensors, CMOS sensors are often considered to be a synonym of CMOS based image sensors and have emerged as a competitor to CCD based image sensors.

 

Until recently, Charge Coupled Devices (CCDs) dominated most of the image sensing systems, i.e., cameras, camcorders, etc. CCDs have been in use in astronomical cameras, video camcorders and scanners. However of late, CMOS Imaging have emerged as an alternative to CCD imagers and it also offers better features.

 

Subsequent sections will discuss both CCD and CMOS sensor based imagers, their pros and cons, and also their applications. Further, other applications of CMOS technology in the field of sensing will be discussed.

gesture recognition technology

“Have you seen the remote?” “I left it on the table after watching my matinee show”. “It is not here, I will miss the news again because of you!!!” In the near future, such heated discussions over remote control won’t disturb the harmony of the house. Not because they will place it correctly but because soon remote controls will be the objects of the past. Technology has finally reached that dimension when our hands will take over the job and replace them by directly communicating with the computer or television. For instance, in order to delete a folder or file from the computer, place your palm on it, and throw it like a paper in a dustbin. Even while using the microwave oven to bake a cake, waving our hands in the air like a magician would serve as a command for the oven. While some of us might be thinking of it being a futuristic vision, some of us have already experienced it through what we call “Gesture Recognition Technology”

 

Since the time that the computer revolution started, human computer interaction has always been attempted to improve. Computers have now become an integral part of our lives and hence their usage should be as trouble-free as talking to someone is. Earlier the way humans interacted with this smart machine was either through keyboard or a mouse. But now attempts are being made to make the man-machine interaction as natural as possible. Fulfilling this requirement is the popular touch screen technology which is soon expected to be replaced by the gesture recognition technology.