Accurate Positioning and Alignment of a Component During Processes Such as Reflow Soldering

Abstract

One or more channels are provided in the surface of a conductive layer of a PCB substrate in an area on which a component is to be placed. The channels can help reduce or prevent shifting of the component during reflow soldering through surface tension/capillary forces of the solder paste material in the channels. Such channels also can be used, for example, by an image processing system to facilitate accurate positioning and/or alignment of the component. The image processing system can use the location of the channels alone, or in combination with other features such as a solder mask or other alignment marks, to position and/or align the component with high accuracy.

1 . An apparatus comprising:
 a substrate including a conductive layer over an insulating base layer, wherein the conductive layer includes one or more channels in its surface; and   an electronic or optoelectronic component bonded to the conductive layer by a solder material, wherein the component is disposed at least partially over the one or more channels in the surface of the conductive layer.   
     
     
         2 . The apparatus of  claim 1  wherein some of the solder is in the one or more channels and some of the solder is on the surface of the conductive layer. 
     
     
         3 . The apparatus of  claim 1  wherein the one or more channels include a plurality of channels. 
     
     
         4 . The apparatus of  claim 1  wherein each of the one or more channels is a narrow groove in the surface of the conductive layer. 
     
     
         5 . The apparatus of  claim 1  wherein each of the one or more channels extends substantially entirely through a thickness of the conductive layer. 
     
     
         6 . The apparatus of  claim 1  wherein the conductive layer is a conductive pad that covers part of the base layer. 
     
     
         7 . The apparatus of  claim 1  wherein the conductive pad comprises copper. 
     
     
         8 . The apparatus of  claim 1  wherein the base layer comprises a ceramic or fiberglass material. 
     
     
         9 . The apparatus of  claim 1  wherein the one or more channels extend beyond a footprint of the component. 
     
     
         10 . The apparatus of  claim 1  further including a solder mask on the surface of the conductive layer, wherein the solder mask substantially surrounds a perimeter of the component. 
     
     
         11 . The apparatus of  claim 1  further including one or more alignment features on the surface of the conductive layer, wherein the alignment features are different from the one or more channels. 
     
     
         12 . A method of bonding an electronic of optoelectronic component to a printed circuit board substrate, the method comprising:
 depositing solder paste on a surface of a conductive layer of the printed circuit board substrate, wherein the conductive layer includes one or more channels in its surface and wherein some of the solder paste is in the channels and some of the solder paste is on the surface of the conductive layer;   placing the component on the conductive layer in contact with the solder paste such that the component is disposed at least partially over the one or more channels in the surface of the conductive layer; and   performing a reflow soldering process to bond the component to the conductive layer.   
     
     
         13 . The method of  claim 12  wherein the one or more channels include a plurality of channels. 
     
     
         14 . The method of  claim 12  any one of  claims 12 - 13  wherein presence of the solder paste in the one or more channels prevents or reduces movement of the component during the reflow soldering process. 
     
     
         15 . The method of  claim 12  including:
 obtaining an image of the surface of the conductive layer including the one or more channels; 
 comparing the image to a previously-stored image or data; 
 determining a positioning and/or alignment for the component based on the comparison of the image to the previously-stored image or data; and 
 placing the component on the conductive layer based on the determined positioning and/or alignment. 
 
     
     
         16 . The method of  claim 12  wherein there is a solder mask on the surface of the conductive layer, the method including:
 obtaining an image of the surface of the conductive layer including the solder mask; 
 comparing the image to a previously-stored image or data; 
 determining a positioning and/or alignment for the component based on the comparison of the image to the previously-stored image or data; and 
 placing the component on the surface of the conductive layer based on the determined positioning and/or alignment. 
 
     
     
         17 . The method of  claim 12  wherein there are one or more alignment features on the surface of the conductive layer, the alignment features being different from the channels, the method including:
 obtaining an image of the surface of the conductive layer including the one or more alignment features; 
 comparing the image to a previously-stored image or data; 
 determining a positioning and/or alignment for the component based on the comparison of the image to the previously-stored image or data; and 
 placing the component on the surface of the conductive layer based on the determined positioning and/or alignment. 
 
     
     
         18 . An apparatus comprising:
 a printed circuit board including a conductive pad on a base layer, the base layer being composed of a ceramic or fiberglass material, wherein the conductive pad includes a plurality of channels in its surface; and   an electronic or optoelectronic component bonded to the conductive pad by a solder material,   wherein the component is disposed at least partially over the channels in the surface of the conductive pad, and wherein some of the solder is in the channels and some of the solder is disposed between the component and the surface of the conductive pad.   
     
     
         19 . The apparatus of  claim 18  wherein the channels extend beyond an outer perimeter of the component. 
     
     
         20 . The apparatus of  claim 18  wherein each of the channels has a depth of at least tens of microns.