Thin film circuit integrating thick film resistors thereon

Abstract

A method of fabricating printed circuit boards integrating thick film resistor components and thin film circuit portions thereon is disclosed. This is a two-phase process, where the first phase is to create multiple thick film resistors, and the second phase is to create a thin film circuit portion on the substrate with thick film resistors in existence, involving the printing of the electrodes and the resistive coating for the thick film resistors, and the printing of a low temperature passivation layer over the resistors; and the thin film circuit is formed by titanium and copper layers over the substrate, and electroplating of interconnections to form copper plated circuit. The present fabrication process does not require drilling of holes nor electroplating of leads to the resistors, thus the whole process can be automated to a greater extent than with conventional techniques.

1 . A printed circuit board integrating thick film resistor components and a thin film circuit portion thereon, comprising: 
 an insulating substrate, where multiple thick film resistors and thin film circuit portions are formed thereon, wherein each thick film resistor having:    pairs of electrodes printed at predetermined positions on the substrate to act as end terminals of the thick film resistors;    a resistive layer being placed in between the pairs of electrodes of the thick film resistors; and    a passivation layer being formed over the thick film resistor layer by a low temperature process;    whereby each thick film resistor on the substrate is connectable to corresponding junctions on the thin film circuit to form an electrical circuit.    
   
   
       2 . The printed circuit board as claimed in  claim 1 , wherein the resistive coating in between each pair of electrodes to form a thick film resistor is a rectangular block.  
   
   
       3 . The printed circuit board as claimed in  claim 1 , wherein the resistive coating in between each pair of electrodes to form a thick film resistor is a continuous winding section.