IC Package Types and Definitions

IC (Integrated Circuit) means an assemblage of electronic components such as resistors, transistors, capacitors, etc. All these are crammed into a very small chip and attached with each other to acquire a common objective.

The IC package is what encases the die of integrated circuit and extends it out into a device we can more conveniently attach to. Every external connection on the die is linked via a very small piece of gold wire to a pad or pin on the packaging. The silver, extruding terminals on an IC are the pins. These pins carry out the work to link to different components of a circuit. These are of highest significance to us whereas they are what will go on to connect to the remaining elements and wires in a circuit.

Every IC is polarized and each is pin is distinctive in case of both position and operation. For this reason, it is necessary for the package to have some way to impart which pin is which. For most ICs, a dot or a notch (in some cases, both or sometimes anyone of them) designates the first pin. If you can recognize the first pin, the rest of the pin numbers increase according to the sequence as you move counter-clockwise around the chip.

The way how the IC packages mount to a circuit board is one of the primary distinguishable package type characteristics. Mainly there are two mounting types: through-hole (PTH) or surface-mount (SMD or SMT). All packages fall into one of these two mounting types. Usually through-hole packages are bigger in size and much simpler to work with. They are designed especially to be pierced through one side of a board and dredged to the other side.

Surface-mount packages can be small to minuscule in size. They are all intended to be installed on one side of a circuit board and be dredged to the surface. Most of the times, the pins of a SMD package thrust out the side. These also steep to the chip, or are sometimes set out in a matrix on the bottom of the chip. ICs with surface mount packages are not very suitable to assemble with hands. Generally special tools are needed to assist in the process.

There are numerous varieties of IC packages, each of which has distinctive measures, mounting styles, and/or pin-enumerations. These packages are batched into three major categories: Dual In-line Packages, Grid Arrays and Chip Carriers. Each package, regardless of the category has a body style that scales with pin count. The number of pins determines the physical dimension of the package, the name of the package does not.

1. Dual In-line Packages [DIP], or Dual In-Line [DIL] packages are packages with two rows of leads on two sides of the package. DIP ICs may be through-hole [PDIP or CERDIP] or SMT package [SOJ or SOIC].

2. Quad Flat Packs or Chip Carriers are square packages [or nearly square], with leads on all four sides Chip Carriers, as in PLCCs and other variants are strictly Surface Mount Technology (SMT).

3. Grid Arrays are those type packages that have their pins arranged in a grid. The pin grid may consist of Leads, pads, or solder balls on an area array. The through hole variant is called a PGA, while the SMT variant might be called LGA or BGA.

Integrated Circuit Designs and Extensions

Dependability on semiconductor devices by the electronic systems is increasing day-by-day because the integration level is growing quicker than ever and it is necessary to pack more circuitry in the smallest packages. Various circuit components, which are required to complete computer systems such as, capacitors, transistors, resistors, etc, can be installed on an individual silicon die.

When a package holds individual silicon (silicon germanium for RF circuits, or gallium arsenide for microwave frequency circuits) that builds up either portion of a bigger electronic circuit or system or an entire electronic system in its own right is called an Integrated Circuit (IC). When a full electronic system is created by the IC, it is generally mentioned as a SoC (System on a Chip). Present-day communication ICs are of SoC designs.

MCM (Multichip Module) comprises more than one dies and it is an extension to the IC; we can say for example, circuits and sensors are to be accommodated in an individual package but which is not possible to be set up on an individual die. The MCM was mentioned as a hybrid circuit at the beginning, which consists of multiple ICs and inactive components on a common circuit base that are unified by conductors set up within that base. Complications related to size reduction and signal degradation can be alleviated by implementing MCM.

An extension to the IC is the multichip module (MCM), which contains multiple dies; for example, when sensors and circuits are to be housed in a single package but which cannot be fabricated on a single die. Originally referred to as a hybrid circuit, the MCM consists of two or more ICs and passive components on a common circuit base that are interconnected by conductors fabricated within that base. The MCM helps with size reduction problem and helps alleviate signal degradation.

Devices are piled vertically on system in a package (SiP), which is an extension to the MCM. Wire bonding to the substrate is usual. An extension to the SiP is the package on a package (PoP).

Home Diagnostic Tests Could Be Enabled By Microfluidic Integrated Circuit

Microfluidic integrated circuits have been originated by the researchers of University of Michigan as a technique to make simple lab-on-a-chip devices that could offer faster, low-cost and more portable medical tests.

These microfluidic circuits control the flowing of fluid through their devices without directions from outside systems. This process is similar to the computer chips where electronic circuits intelligently route the flow of electricity without external controls

A paper on the technology is recently disclosed online in Nature Physics.

A microfluidic device, or lab-on-a-chip, combines more than one laboratory operations onto one chip only centimeters in size. The devices make allowance for the researchers to experiment with very small sample sizes, and also to perform multiple experiments on the same material at the same time. They can be cut out to simulate the human body more nearly than the Petri dish does. They could lead to on-the-spot home tests for illnesses, food contaminants and toxic gases are major among other advances.

"In most microfluidic devices today, there are essentially little fingers or pressure forces that open and close each individual valve to route fluid through the device during experiments. That is, there is an extra layer of control machinery that is required to manipulate the current in the fluidic circuit," said Shu Takayama, the principal investigator on the project. Takayama is an associate professor in the U-M Department of Biomedical Engineering.

That's same to how electronic circuits were manipulated a century before. Then, with the improvement of the integrated circuit, the "thinking" became embedded in the chip itself -- a technical step forward that enabled personal computers, Takayama said.

"We have literally made a microfluidic integrated circuit," said Bobak Mosadegh, a doctoral student in Takayama's lab who is first writer of the paper.

The outer controls that power today's microfluidic devices may be inconvenient. Every valve on a chip (and there could be dozens of them) needs its individual electromechanical push from an off-chip actuator or pump. This has made it hard to shrink microfluidic systems to palm- or fingertip-sized diagnostic devices.

The Takayama lab's innovation is a step in this direction. His research group has devised a strategy to produce the fluidic counterparts of key electrical components including transistors, diodes, resistors and capacitors, and to efficiently network these components to automatically regulate fluid flow within the device.

Because of the use of conventional techniques in the making of these components, they are suitable for all other microfluidic components such as mixers, filters and cell culture chambers.

"We've made a versatile control system," Mosadegh said. "We envision that this technology will become a platform for researchers and companies in the microfluidics field to develop sophisticated self-controlled microfluidic devices that automatically process biofluids such as blood and pharmaceuticals for diagnostics or other applications.

"Just as the integrated circuit brought the digital information processing power of computers to the people, we envision our microfluidic analog will be able to do the same for cellular and biochemical information."

The university is pursuing patent protection for the intellectual property, and is seeking commercialization partners to help bring the technology to market.