Thick Film technology is ideally suited when quick turnaround is required for complex, high density multi-layer, low cost, high volume applications. It is also extremely effective for development work, quite often surpassing PCB turnaround. The ability to print resistors, capacitors, and inductors on ceramic based substrates allows for increased package density and reliability.

Thick Film Technology has the advantages of circuit miniaturization together with increased reliability, low weight and Low cost. By using a Thick Film circuit instead of a PCB many benefits are gained – reduced component count, lower assembly costs, and quicker assembly/test times along with increased reliability. The characteristics of Thick Film Technology make it highly applicable to Commercial, Industrial, Scientific and Military applications.

Thick Film Technology achieves this with the ability to produce integrated resistors of small size, planar 2D construction, with high reliability, high power density and high stability.  This means that resistors can be made as small as 1mm square with no significant thickness. Components can be mounted on top of resistors to save space. Reliability is high since the resistors are integrated into the supporting substrate (ceramic) along with the terminations and conductor lines; hence there are no solder joints to fail under harsh conditions. Another added bonus is that the resistors are not limited to preferred values. Almost any value is possible from less than 1Ω to greater than 100 MΩ with tolerances as tight as 0.1% depending on value. The temperature stability is also very good with 100ppm/deg C being typical.

Miniature components

A wide range of miniature components in various forms can be assembled onto a Thick Film circuit to make a Thick Film Hybrid Circuit. These components can be unpacked silicon circuits to packed surface mount components. Conductive epoxy, eutectic and Solder attachment methods may be used. It is possible to combine these methods on one circuit.

CUSTOM SUBSTRATE PRODUCTS
	SINGLE LAYER THICK FILM HYBRID SUBSTRATES
	MULTI-LAYER THICK FILM HYBRID SUBSTRATES
	RF AND MICROWAVE HYBRID SUBSTRATE ASSEMBLIES
	SPECIAL CUSTOM HYBRID ASSEMBLIES
	POWER HYBRID CIRCUIT SUBSTRATES
	POWER LASER DIODE BLOCKS

PASSIVE PRODUCTS
	CHIP RESISTORS
	RESISTOR ARRAYS
	CUSTOM RC NETWORKS
	CUSTOM RC NETWORKS

SERVICES
	DESIGN AND DEVELOPMENT OF MULTI-LAYER SUBSTRATES
	DESIGN AND DEVELOPMENT OF SPECIALTY HYBRID PRODUCTS
	THICK FILM METALIZATION
	PROTOTYPE QUICK RESPONSE AND TURN-AROUND
	HIGH VOLUME CONTRACT MANUFACTURING

Process

Fabrication of thick film hybrid microcircuits is done by the screen printing of conductive, dielectric and resistive pastes on to 96% alumina substrates. These pastes, when fired at temperatures in the range of 8000 to 10000C, become an integral part of the substrate and form the basic structure of the hybrid microcircuit. Out of tolerance resistors can be trimmed to desired values upto 1% accuracy or more, by using air abrasive / laser technique. Functional trimming is utilised where circuit function is of prime importance compared to specific value of resistance and tolerance. Discrete components, both active and passive, are added to the substrate with the generated basic structure to complete the circuit, and finally hermetically sealed into customer desired packages.

Hybrid Circuit

A hybrid circuit is a device that performs all or part of an electronic function by combining and interconnecting several passive and active semiconductor devices into a single package.

The base material of the hybrid consists of a substrate -- Alumina (Al2O3), Aluminum Nitride (AlN) or Beryllia (BeO) -- with screen printed thick film resistors and conductor patterns. The printed pastes are then fired in temperature controlled, multi-zone furnaces -- fusing the pastes to the base material and becoming an integral part of the circuit. Passive and active semi-conductor packages are reflowed onto the printed substrate. Bare die are then attached with epoxy and interconnected with gold or aluminum wire bonds to the printed substrate.

International Sensor Systems' hybrid circuits provide superior circuit density, performance, and reliability, with relatively low development and tooling costs.

Packages Available for Hybrid Thick Film Assembly:
	Single-Inline-Package (SIP), Dual-Inline-Package (DIP)
	Ceramic, Metal or Plastic covers with adhesive seal
	Silicone or epoxy junction coatings (glob top) to protect wire bonds
	Protective circuit assembly epoxy conformal coatings
	Hermetic and non-hermetic

Features of Hybrid Thick Film Technology from ISSI:
	Further space savings over Surface Mount Technology and Chip-On-Board
	Alumina (AL2O3), Aluminum Nitride (AlN), and Beryllia (BeO) base material available
	Very compact with low profile and low mass
	Provides reliable performance in extreme temperature operating range
	Superior Base Material Power Dissipation
	Alumina (AL2O3) High Level ~ 1 Watt per inch per degree C
	Aluminum Nitride (AIN) Higher Level ~ 7 Watts per inch per degree C
	Printed thick film resistors range in value from 0.1 ohm to 300 megohm
	Temperature Coefficient Resistance (TCR) as low as 50 ppm with tracking TCR's to 20 ppm
	Power ratings range one-sixteenth (1/16) to five (5) Watts
	Automated Laser Trimming of Resistors
	Precision Resistors to one-tenth of one percent (0.1%)
	Ratio Matching to one-tenth of one percent (0.1%)
	Epoxy and eutectic semi-conductor die attach
	Gold and aluminum thermosonic and ultrasonic wire bonding with wire diameters from 0.0007 inch to 0.003 inch
	Reflow soldered passive component attachment
	Wide selection of solder/paste available
	In-process testing and inspection procedures of Hybrid Thick Film Circuits in accordance with MIL-STD-883
	(Test Methods & Procedures for Microelectronics)
	Improved signal to noise ratio over laminate technologies