Image sensor circuit, system, and method
A process of forming optical sensors includes sealing an imaging portion of each of a plurality of optical sensors on a sensor wafer with a transparent material. The operation of sealing leaves a bonding portion of each of the optical sensors exposed. The process further includes cutting the wafer into a plurality of image sensor dies after sealing the optical sensors such that each image sensor die includes one of the optical sensors sealed with a corresponding portion of the transparent material.
1. A method, comprising:
sealing an imaging portion of each of a plurality of optical sensors on a sensor wafer with a portion of a transparent material wafer while leaving a bonding portion of each of the optical sensors exposed; and
cutting the sensor wafer into a plurality of image sensor dies after sealing the optical sensors such that each image sensor die includes one of the plurality of optical sensor sealed with a corresponding portion of the transparent material wafer;
wherein the sealing comprises:
patterning the transparent material wafer to facilitate subsequent formation of the portions of the transparent material wafer on the respective image sensor dies, wherein the patterning includes removing portions of the transparent material wafer prior to dicing the transparent material wafer; and
forming a glue layer on one of the wafers;
wherein the transparent material wafer has a circular shape and wherein patterning the transparent material wafer includes forming a plurality of transparent material segments arranged to correspond to an arrangement of the optical sensors on the sensor wafer and forming a grid of parallel slits in the transparent material wafer, the grid comprising:
a first set of parallel slits, each slit having a variable length and ends extending proximate the edge of the transparent material wafer with the position within the grid determining the length of the slit; and
a second set of parallel slits orthogonal to the slits in the first set, each slit in the second set having ends extending proximate an edge of the transparent material wafer with the position within the grid determining the length of the slit,
wherein the slits in either the first or second set have projections that extend over a width of the slits while the slits in the other set have no such projections.
2. The method of claim 1 wherein the slits of the first and second sets are uniformly spaced.
3. A method, comprising:
forming a grid of linear slits extending through a transparent material wafer to facilitate subsequent attachment of portions of the transparent material wafer to respective image sensor dies on a sensor wafer, the forming of the grid of linear slits including removing portions of the transparent material wafer prior to cutting the transparent material wafer, the grid comprising:
a first set of parallel slits of variable length; and
a second set of parallel slits of variable length, orthogonal to the slits in the first set, the first and second sets of parallel slits extending proximate the edge of the transparent material wafer;
sealing an imaging portion of each of a plurality of the image sensor dies with a corresponding portion of the transparent material wafer while leaving a bonding portion of each image sensor die exposed; and
cutting the sensor wafer into a plurality of image sensor dies after sealing the imaging portion.
4. The method of claim 3 wherein each of the sensors includes a CCD sensor.