Thick Film Integrated Circuit Design Flexibility, Convenient Process
Thick Film Integrated Circuit and Its Application
The Thick Film Integrated Circuit is an integrated circuit made by combining the semiconductor integrated process and the thick film process. The thick film element and its interconnection line are formed by film forming method on the substrate, and the discrete semiconductor chip , Monolithic integrated circuits or micro-components mixed assembly, and then add the package made. Compared with the discrete component circuit, the hybrid integrated circuit has the characteristics of high assembly density, high reliability and good electrical performance. Compared with monolithic integrated circuits, it is designed to be flexible, easy to process, easy to multi-species small batch production; and component parameters range, high precision, good stability, can withstand higher voltage and higher power.
1 Thick Film Integrated Circuit characteristics
Thick Film Integrated Circuits in many ways, are maintained better than 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) modulo circuit mix
Thick Film Integrated Circuit is usually the use of printing technology in the ceramic substrate printed on the graphics and high temperature sintering to form a passive network. The manufacturing process includes:
(1) planar design of circuit graphics: logic design. Circuit conversion. Circuit segmentation. Layout design. Planar element design. Discrete component selection. Consideration of parasitic effects at high frequencies. Considerations on Thermal Performance at High Power. Considerations of Noise under Small Signal.
(2) the production of printed circuit board: the graphic design of the graphic with the development method of stainless steel or nylon mesh.
(3) circuit substrate and the choice of slurry: the production of Thick Film Integrated Circuit usually choose 96% of the alumina ceramic substrate (special circuit can choose other substrates), the general choice of the United States DuPont slurry.
(4) Screen printing: Use a press to print a variety of slurries on a substrate by making a good screen pattern.
(5) high temperature sintering: the printed substrate in the high temperature sintering furnace sintering, so that the slurry and the substrate between the formation of a good fusion and network interconnection, and the resistance of the thick film resistance stability.
(6) laser resistance: the use of thick film laser dampers will be sintered circuit board printed thick film resistance resistance to the specified requirements.
(7) surface mount: the use of automatic placement machine will be posted on the various components and connectors assembled on the circuit substrate, and reflow soldering furnace to complete the welding, including welding leads and so on.
(8) circuit test: the welding of the circuit in the test bench on a variety of functions and performance parameters of the test.
(9) circuit package: the test should be qualified circuit as required to the appropriate package.
(10) finished product test: the package will be qualified to re-test the circuit.
(11) storage: the re-test of qualified circuit registration.
In the Thick Film Integrated Circuit, the substrate plays the role of carrying thick film elements, interconnection, external components and encapsulation, etc., in the high-power circuit, the substrate also has the role of heat dissipation. Thick film circuit on the substrate requirements include: flatness. High thermal conductivity; good electrical performance; high thermal conductivity; good thermal performance with other materials; good mechanical properties; high stability; good processing performance; cheap. Usually thick film circuit to select 96% of the alumina ceramic substrate, if you need better heat dissipation conditions can choose beryllium oxide substrate.
In the Thick Film Integrated Circuit, the passive network is mainly in the substrate will be printed on a variety of paste into a graphic and high temperature sintering. Materials used include: conductor paste. Media slurry and resistance slurry.
Thick film conductor is an important part of Thick Film Integrated Circuit, in the circuit from the active device interconnect. Multi-layer wiring. Capacitor electrode. The solder pad area of the external component. Resistor terminal material. Low resistance resistor. Thick film microstrip and so on. In the conductor paste, the usual thick-film hybrid integrated circuit uses a palladium-silver material. In some military circuits and high-precision circuits, gold paste is used, and silver is used in some of the less demanding circuits.
Thick film resistive slurries are also an important part of Thick Film Integrated Circuits. Thick film resistors made from thick film resistive slabs are one of the most widely used and most important components. The thick film resistive slurry is composed of functional components. Bonding component. Organic carrier and modifier composition, the general use of the United States DuPont resistance slurry.
Thick film media slurry is in order to achieve thick film paste the thick film. The multilayer of the step conductor and the performance parameters of the thick film resistors are not affected by the external environment. Including the capacitor medium slurry. Cross the multi-layer media slurry and encapsulate the media slurry.