A hybrid circuit is a circuit where two or more technologies are "mixed". This means that in principle a hybrid circuit can be any mixture of SMD technology, ASIC technology, flexible circuit technology etc., but hybrid circuits have gradually become synonymous with circuits where one of the technologies is thick film technique. With this technique tracks and resistors are printed on a ceramic substrate and fired at high temperature. When these circuits are combined with SMD technique, we have what is normally understood by a hybrid circuit. As regards the advantages of using such circuits a number of questions typically arise. They can be answered in the following way:


Why choose a hybrid circuit ?

A well-designed hybrid circuit has much smaller dimensions than a corresponding printed circuit. Besides, the ceramic-based circuit gives possibilities of higher insulation resistance, impedance level, power, and temperature range than other circuits, and finally the reliability for hybrid circuits is better than for traditional printed circuits.

Is a hybrid circuit a competitive technology ?

The production technique is simple and efficient, and although the materials are more expensive than those used for traditional printed circuits, hybrid circuits will in many cases be a very competitive technology.

Can the supplier of hybrid circuits ensure confidentiality ?

Most hybrid circuit suppliers regard the circuits they design as the customer's property. Confidentiality agreements about the information received in connection with the development of the circuit is normally a matter of course.

What about certainty of supply and price stability ?

In Northern Europe there are approximately 30 suppliers of hybrid circuits. Eachsupplier has his own design rules, but a circuit can almost always be transferred from one supplier to another at a very modest expense. This means that after having paid development costs to one supplier a customer can at a marginal expense transfer the circuit to other suppliers and thereby get certainty of supply and price stability.

What information is required before a quotation can be made ?

In order to make a quotation it is necessary to have the customer's circuit diagram, parts list, and information on requested dimensions and terminal position. On the basis of this information it is possible to establish the size of the circuit, the number of layers to print, whether printing is to be made on both sides of the circuit, and whether there are to be components on both sides. All these questions affect the production costs. Naturally the production quantity is also of great importance.