Test plate for ceramic surface mount devices and other electronic components

Abstract

A test plate for holding miniature electronic circuit components on a component testing system as a part of batch processing for parametric testing purposes, including passive, two-terminal, ceramic capacitors, resistors, multilayer inductors, inductor beads, varistors, thermistors, fuses, sensors, actuators, and the like, or another type of device under test (DUT), includes a DUT-holding plate having an upper side, a lower side, and a rotational axis. The DUT-holding plate defines a plurality of DUT-engaging holes extending through the DUT-holding plate from the upper side to the lower along central axes of the DUT-engaging holes that are not parallel to the rotational axis. With the DUT-holding plate oriented so that the rotational axis is not vertical, the DUT-engaging holes change orientation relative to vertical as they orbit the rotational axis. According to a separate aspect, the DUT-holding plate includes upper and lower layers that are bonded together to form the DUT-holding plate. The lower layer defines vacuum passageways for coupling a vacuum source on a vacuum plate portion of the component testing system in fluid communication with each of the DUT-engaging holes. The lower layer is fabricated to include the vacuum passageways and then it is attached to the upper layer in order to enable use of circuit board fabrication techniques instead of machine shop type operations.

What is claimed is: claims  
     
         1 . A test plate, comprising: 
 a DUT-holding plate having an upper side, a lower side, and a rotational axis;    the DUT-holding plate defining a plurality of DUT-engaging holes that extend through the DUT-holding plate from the upper side to the lower side;    each of said DUT-holding holes having a central axis that extends between the upper side and the lower side; and    each of said DUT-engaging holes being so disposed that the central axis of each DUT-engaging hole is not parallel to the rotational axis.    
     
     
         2 . A test plate as recited in  claim 1 , wherein the central axes of the plurality of DUT-engaging holes are inclined outwardly from the upper surface toward the rotational axis.  
     
     
         3 . A test plate as recited in  claim 1 , wherein the central axes of the plurality of DUT-engaging holes are inclined relative to the rotational axis angles that have sizes within a range of one degree to eighty-nine degrees.  
     
     
         4 . A test plate as recited in  claim 1 , wherein the DUT-holding plate has at least two layers that are bonded together to form the DUT-holding plate.  
     
     
         5 . A test plate as recited in  claim 4 , wherein the DUT-holding plate has at least one conductive layer composed of an electrically conductive material in order to enable use of the conductive layer as a guard layer for electrical testing purposes has at least two layers.  
     
     
         6 . A test plate for use atop a vacuum plate portion of a component testing system, the test plate comprising: 
 an upper layer and a lower layer that are bonded together to form a DUT-holding plate having an upper side, a lower side, and a rotational axis;    the DUT-holding plate defining a plurality of DUT-engaging holes that extend through the DUT-holding plate from the upper side to the lower side;    the upper layer defining an upper section of each of the DUT-engaging holes that provides a close fit for a DUT; and    the lower layer defining a lower section of each of the DUT-engaging holes and a plurality of vacuum passageways that function as means for coupling a vacuum source from the vacuum plate portion of the component testing system to the plurality of DUT-engaging holes.    
     
     
         7 . A test plate as recited in  claim 6 , wherein: 
 the lower layer includes first and second lower sub-layers that are bonded together to form the lower layer;    the first lower sub-layer defines a first segment of the lower section of each DUT-engaging hole and a first segment of each vacuum passageway; and    the second lower sub-layer defines a second segment of the lower section of each DUT-engaging hole that provides a close fit for a DUT in order to help support the DUT, while also defining a second segment of each vacuum passageway such that the second segments of the vacuum passageways are spaced apart from the DUT-engaging holes.    
     
     
         8 . A test plate as recited in  claim 6 , wherein the upper layer of the DUT-holding plate has at least one conductive upper sub-layer composed of an electrically conductive material in order to enable use of the conductive upper sub-layer as a guard layer for electrical testing purposes.  
     
     
         9 . A method for fabricating a DUT-holding plate, the method comprising: 
 providing upper and lower DUT-holding plate layers such that the upper and lower DUT-holding plate layers have DUT-engaging holes and vacuum passageways formed in them; and    bonding the upper and lower DUT-holding plate layers together to form a DUT-holding plate.