Thick Film Integrated Circuit Flexible Design And Convenient Process
Thick Film Integrated Circuit and its application
Thick Film Integrated Circuit is a integrated circuit made of semiconductor integrated technology and thick film technology, the film is used to make thick film elements and their interconnects on the substrate, and the discrete semiconductor chips, monolithic integrated circuits or miniature components are assembled in the same substrate, and then encapsulated. Compared with the discrete component circuit, the hybrid integrated circuit has the characteristics of large assembling density, high reliability and good electrical properties. Compared with the monolithic integrated circuit, it is flexible in design, convenient in process, and convenient for many varieties of small batch production, and the parameter range is wide, the precision is high, the stability is good, can withstand the high voltage and the big power.
Characteristics of 1 Thick Film Integrated Circuit
Thick Film Integrated Circuits are in many respects superior to the status and characteristics of semiconductor integrated circuits:
(1) Low noise circuit
(2) High stability Passive network
(3) High frequency linear circuit
(4) High-precision linear circuit
(5) Microwave circuit
(6) High voltage circuit
(7) High power circuit
(8) Modular circuit mix
Thick-film hybrid integrated circuits are usually printed on ceramic substrates by printing technology and formed by high temperature sintering of passive networks. Manufacturing processes include:
(1) Graphic design of circuit graphics: logic design. Circuit conversion. Circuit segmentation. Layout design. Planar component design. Discrete component selection. The consideration of parasitic effect under high frequency. Consideration of thermal performance under high power. Noise considerations for small signals.
(2) The production of printed boards: The graphic design of the development of the method of production in stainless steel or nylon on the web.
(3) The choice of the circuit substrate and slurry: making Thick Film Integrated Circuit usually chooses 96% alumina ceramic substrate (special circuit can choose other substrate), the slurry generally selects the American DuPont Company.
(4) Screen printing: Using a printing press to make a variety of slurry through the production of circuit graphics screen printing on the substrate.
(5) High-temperature sintering: The printed substrate in high-temperature sintering furnace sintering, so that the slurry and substrate formed a good fusion and network interconnection, and the thick film resistance stability.
(6) Laser resistance: the use of thick-film laser drag-resistance machine will be sintered on the circuit substrate on the printed thick film resistance to adjust to the required requirements.
(7) Surface mount: The use of automatic mounting machine will be affixed to the various components and connector assembled on the circuit substrate, and the reflow soldering furnace to complete the welding, including the welding lead wire.
(8) Circuit testing: the welding intact circuit on the test bench for a variety of functional and performance parameters of the test.
(9) Circuit encapsulation: The test of qualified circuit according to the requirements of appropriate packaging.
(10) test of finished product: retest the qualified circuit.
(11) Warehousing: The retest of the qualified circuit register.
In the Thick Film Integrated Circuit, the substrate plays the role of thick film components, interconnect, external components and encapsulation, in high-power circuits, the substrate also has the role of heat dissipation. Thick film circuit requirements for substrates include: flatness. High smooth finish, good electrical properties, high thermal conductivity, heat expansion coefficient matching with other materials, good mechanical properties, high stability, good processability and low price. Usually, the thick film circuit chooses 96% alumina ceramic substrates, and if the substrate with better heat dissipation conditions is needed, the beryllium oxide substrate can be selected.
In the Thick Film Integrated Circuit, the passive network is mainly on the substrate to the various pastes through the printing into the graph and through the high-temperature sintering. Materials used include: conductor slurry. Medium slurry and resistance slurry.
Thick film conductor is an important part of Thick Film Integrated Circuit, and the interconnection of active devices is established. Multilayer wiring. Capacitor electrodes. The lead welding area of the external component. Resistor end-head material. Low resistance resistor. Thick film Microstrip and other functions. In the conductor slurry, the usual thick-film hybrid integrated circuit uses palladium-silver material, which is used in some military circuits and high-precision circuits, and is a silver slurry used in some of the less demanding circuits.
Thick film resistance slurry is one of the most important components in Thick Film Integrated Circuit, and thick film resistor made of thick film resistance slurry is one of the most widely used and most important components. Thick film resistance slurry is composed of functional groups. Bonding Group. Organic carrier and modifier composition, general selection of the United States DuPont company resistance slurry.
Thick film medium slurry is in order to realize thick film external paste capacitance thick film. The multi-layer of the step conductor and the performance parameters of the thick film resistance are not affected by the external environment. including capacitance medium slurry. Cross and multi-layer dielectric pastes and encapsulation media slurry.
With the development of technology, the application of Thick Film Integrated Circuit is expanding, which is mainly used in aerospace electronic equipment. Satellite communications equipment. Computer。 Communication systems. Automotive industry. Audio equipment. Microwave equipment and household appliances. Thus, Thick Film Integrated Circuits have penetrated many industrial sectors. In Europe, the application of thick-film hybrid integrated circuits in computers is the dominant, and then the remote communication. Communication。 Military and aviation departments. In Japan, a large number of consumer electronics products using Thick Film Integrated Circuits. The United States is mainly used in aerospace. Communications and computers, with the highest share of communications.
In the aerospace industry, thick-film hybrid integrated circuits are characterized by its structural and design flexibility, miniaturization, lightweight, high reliability, impact resistance and vibration, and radiation resistance, in airborne communication, radar and fire control systems. The missile guidance system, as well as satellite and various types of spacecraft communication, television, radar, remote sensing and telemetry system to obtain a large number of applications. In the military industry, thick film circuit is generally used for high stability, high-precision, small volume module power supply, sensor circuit, preamplifier circuit, power amplifier circuit and so on. In other fields, thick-film multi-layer step-line technology has been successfully used in the decoding of digital display tubes. Driving circuit, transparent thick film is also used for cold cathode discharge type. Liquid crystal digital display tube electrode. In addition, thick film technology in many emerging and electronic technology in the interdisciplinary edge of the development potential, the relevant categories are: magnetic and superconducting membrane devices. Acoustic surface wave devices. Membrane-sensitive devices (thermal sensitivity). Photosensitive。 Pressure sensitive. Gas sensitivity. Sensitive)-membrane solar cells. Integrated optical path.
At present, thick-film hybrid integrated circuits are also threatened by great competition. The continuous improvement of printed circuit boards pursues the development of Thick Film Integrated Circuits. In the case of rapid change and fierce competition, we must further explore the problems of Thick Film Integrated Circuits and the corresponding measures taken:
(1) To develop a variety of low-cost quality of new substrate materials. Slurry and encapsulation materials, such as SIC substrates. Porcelain glaze Base plate. G-10 Epoxy Resin board, base metal series slurry. Resin slurry, high-temperature stability of good packaging materials and glass low-temperature encapsulation materials.
(2) using a variety of new chip components, such as micro-package structure devices (SOT), power miniature molded tubes, high-power transistors, a variety of semiconductor integrated circuit chips, chip resistors, capacitors, inductors and various chip-type adjustable devices, r network, c network, RC network, diode network, transistor network.
(3) Development and application of multi-layer wiring. High-density assembly and three-dimensional circuit, the development of large-scale thick-film hybrid integrated circuit with unit system function.
(4) Give full play to the thick film mixed integrated circuit of the specialty, continue to multi-function. High-power direction, and continuous improvement of materials and processes to further improve product stability and reliability, reduce production costs to enhance the vitality of Thick Film Integrated Circuits and the competitiveness of the electronic products market.
(5) in the use of thick film integration technology, the comprehensive use of surface assembly technology, thin film integration technology. Semiconductor micro-processing technology and a variety of special processing technology, the preparation of multiple varieties, multi-function, high-performance, Low-cost micro-circuits, such as thick film micro-chip circuit, Thick Film Integrated Circuit. Thick film sensors and a variety of other new circuits.
Promotion of CAD. The application of CAM and cat technology in the design and manufacture of thick-film hybrid integrated circuits, the production process is gradually mechanized and semi-automatic. Automatic direction of transition, and continuously improve production efficiency, reduce production costs and improve the reliability of Thick Film Integrated Circuits.
With the increasing scale of semiconductor IC chip, it provides high density and multi-function external components for large scale and Thick Film Integrated Circuit. Using thick-film multi-layer wiring technology and advanced assembly technology for mixed integration, the multi-functional large-scale hybrid integrated circuit is the current and future development direction. A large-scale thick-film hybrid integrated circuit can be a subsystem, even a whole system.