초록 ▼

A thin-film metal resistor (44) suitable for a multilayer printed circuit board (12), and a method for its fabrication. The resistor (44) generally has a multilayer construction, with the individual layers (34, 38) of the resistor (44) being self-aligned with each other so that a negative mutual ind

A thin-film metal resistor (44) suitable for a multilayer printed circuit board (12), and a method for its fabrication. The resistor (44) generally has a multilayer construction, with the individual layers (34, 38) of the resistor (44) being self-aligned with each other so that a negative mutual inductance is produced that very nearly cancels out the self-inductance of each resistor layer (34, 38). As a result, the resistor (44) has a very low net parasitic inductance. In addition, the multilayer construction of the resistor (44) reduces the area of the circuit board (12) required to accommodate the resistor (44), and as a result reduces the problem of parasitic interactions with other circuit elements on other layers of the circuit board (12).

대표청구항 ▼

1. A method for manufacturing a printed circuit board having a two-layer thin-film metal resistor, the method comprising the steps of:forming a first electrically-resistive film and a first electrically-conductive layer on a substrate so that the first electrically-conductive layer overlies the firs

1. A method for manufacturing a printed circuit board having a two-layer thin-film metal resistor, the method comprising the steps of:forming a first electrically-resistive film and a first electrically-conductive layer on a substrate so that the first electrically-conductive layer overlies the first electrically-resistive film; etching the first electrically-conductive layer so as to define first and second metallic terminations on the first electrically-resistive film; depositing a positive-acting photodielectric material on the first electrically-resistive film and the first and second metallic terminations; forming a second electrically-resistive film and a second electrically-conductive layer on the positive-acting photodielectric material so that the second electrically-conductive layer overlies the second electrically-resistive film; etching the second electrically-conductive layer so as to define a mask that exposes a first portion of the second electrically-resistive film and masks a second portion of the second electrically-resistive film; using the mask to etch the second electrically-resistive film so as to remove the first portion of the second electrically-resistive film and expose a first portion of the positive-acting photodielectric material, the second portion of the second electrically-resistive film remaining between the mask and a second portion of the positive-acting photodielectric material; using the mask to expose and develop the positive-acting photodielectric material so as to remove the first portion of the positive-acting photodielectric material and expose the first and second metallic terminations and a first portion of the first electrically-resistive film, the second portion of the positive-acting photodielectric material remaining between the mask and a second portion of the first electrically-resistive film so as to define a dielectric layer; using the mask to etch the first electrically-resistive film so as to remove the first portion of the first electrically-resistive film and so that the second portion of the first electrically-resistive film remains between the mask and the substrate; etching the mask so as to define third and fourth metallic terminations on the second electrically-conductive layer; and then forming a plated via so as to electrically interconnect the second and third metallic terminations and thereby define a resistor path that starts at the first metallic termination, follows the first electrically-resistive film to the second metallic termination, continues to the third metallic termination through the interconnecting means, and then follows the second electrically-resistive film to the fourth metallic termination.