PCB Droplet Actuator Fabrication

Abstract

Alternative approaches to fabricating printed circuit boards for use in droplet actuator operations are provided. In one embodiment, a method of manufacturing a droplet actuator for conducting droplet operations includes positioning a dielectric material between a first metal layer configured to include an electrode and a second metal layer configured to include an interconnect pad. The method additionally includes forming a connection between the first and second metal layers. Droplet actuators and methods of fabricating and supporting printed circuit boards of droplet actuators are also provided.

We claim: 
     
         1 . A method of manufacturing a droplet actuator for conducting droplet operations, the method comprising:
 (a) positioning a dielectric material between a first metal layer configured to include an electrode and a second metal layer configured to include an interconnect pad; and   (b) forming a connection between the first and second metal layers.   
     
     
         2 . The method of  claim 1  further comprising applying a photoresist layer onto the first metal layer. 
     
     
         3 . The method of  claim 1  further comprising stripping a photoresist layer from the first metal layer. 
     
     
         4 . The method of  claim 1 , wherein forming the connection further comprises forming a via connection between the first and second metal layers. 
     
     
         5 . The method of  claim 1 , wherein forming the connection further comprises forming an opening through both the dielectric material and the second metal layer through to the first metal layer. 
     
     
         6 . The method of  claim 5  further comprising applying a photoresist layer onto the second metal layer in such a manner as to leave the opening exposed. 
     
     
         7 . The method of  claim 6  further comprising applying a metal plating into the opening to form the connection. 
     
     
         8 . The method of  claim 7  further comprising stripping the photoresist layer from the second metal layer. 
     
     
         9 . The method of  claim 1  further comprising forming the electrode from the first metal layer. 
     
     
         10 . The method of  claim 1  further comprising forming the interconnect pad from the second metal layer. 
     
     
         11 . The method of  claim 1  further comprising laminating a rigid structure onto the second metal layer using a bonding layer. 
     
     
         12 . The method of  claim 1  further comprising attaching a rigid structure onto the second metal layer. 
     
     
         13 . The method of  claim 12 , wherein attaching the rigid structure further comprises attaching a glass structure to the second metal layer. 
     
     
         14 . The method of  claim 1  further comprising applying an electrowetting layer onto the first metal layer. 
     
     
         15 . The method of  claim 14 , wherein applying the electrowetting layer to the first metal layer further comprises applying a dielectric substance onto the first metal layer. 
     
     
         16 . The method of  claim 14 , wherein applying the electrowetting layer onto the first metal layer further comprises applying at least one of a liquid photoimageable soldermask and a non-florescent material onto the first metal layer. 
     
     
         17 . The method of  claim 1  further comprising applying a photoresist layer onto the second metal layer. 
     
     
         18 . The method of  claim 1  further comprising stripping a photoresist layer from the second metal layer. 
     
     
         19 . The method of  claim 1  further comprising forming the dielectric material from non-florescent material. 
     
     
         20 . The method of  claim 1  further comprising positioning a first plate proximate a second plate comprising the first and second metal layers, the dielectric material and the connection to form a gap between the two plates that provides a fluid flow path for a droplet operations. 
     
     
         21 . The method of  20  further comprising forming the first plate. 
     
     
         22 . A droplet actuator for conducting droplet operations, comprising:
 (a) a first plate that includes:
 (i) a first metal layer comprising an electrode; 
 (ii) a second metal layer comprising an interconnect pad; 
 (iii) a dielectric material positioned between the first and second metal layers; and 
 (iv) a via connecting the electrode to the interconnect; and 
   (b) a second plate proximate the first plate and forming a gap therebetween that provides a fluid flow path for the droplet operations.   
     
     
         23 . The droplet actuator of  claim 22  further comprising an electrowetting layer positioned on at least one of the first and second metal layers proximate the gap. 
     
     
         24 . The droplet actuator of  claim 22 , wherein the via comprises metal applied in a hole formed through the second metal layer and the dielectric material. 
     
     
         25 . The droplet actuator of  claim 24 , further comprising a photoresist layer protecting the second metal layer from the applied metal. 
     
     
         26 . A method of fabricating and supporting a printed circuit board of a droplet actuator for conducting droplet operations, the method comprising:
 (a) providing a core printed circuit board by positioning a dielectric material between a first metal layer configured to include an electrode and a second metal layer configured to include an interconnect pad;   (b) applying a photoresist layer onto the first metal layer and forming one or more openings in the dielectric material and the second metal layer;   (c) applying a photoresist layer onto the second metal layer and plating the one or more openings to form one or more blind vias, thereby forming a connection between the first and second metal layers;   (d) stripping the photoresist layer from both the first metal layer and the second metal layer;   (e) patterning the features on both the first metal layer and the second metal layer;   (f) applying an electrowetting dielectric layer to the first metal layer; and   (g) bonding a rigid support structure to the second metal layer.