Abstract:
A process for separating image sensor dies and the like from a wafer in which pairs of separation grooves separating each row of dies are formed in the active side of the wafer, with the tab between each groove pair being substantially equal to the width of the dicing blade, cutting a single bottom groove in the inactive side of the wafer opposite to and spanning each pair of separation grooves, and aligning the dicing blade with the midpoint of the wall of one groove in each pair of grooves so as to cut between the rows of dies. In a second embodiment, a two-pass separation process is enabled in which the tab between separation grooves is slightly larger than the width of the dicing blade, with the dicing blade first aligned with the midpoint of one separation groove to cut one row of dies from the wafer together with part of the tab, with the blade realigned with the midpoint of the other separate groove to cut a second row of dies and the remainder of the tab.
Abstract:
The present disclosure relates that constraining a substrate into a convex arc prior to mounting and affixing of any chips, allows those chips to achieve exemplary final chip-to-chip abutment when the substrate is released and allowed to return to stasis. This is particularly of use where there are any intervening thermal cycles, and the thermal temperature coefficients of expansion for the chip/die and any substrate/mount are significantly different. This will allow the utilization of otherwise more desirable materials for the substrate in spite of some mismatch in thermal coefficients that may exist between the substrate and chips.
Abstract:
Semiconductor chips, such as photosensor arrays for a full-page-width scanner or printhead chips for a full-page-width ink-jet printer, are mounted on a substrate to maintain reasonably consistent spacing among adjacent chips. To remove a defective chip from the array, the substrate is urged evenly against a work surface defining a convex bow. Alternately, back-cuts are provided along abutting edges of the chips, and the silicon around these back-cuts can be sawed away to space defective chips from neighboring good chips.
Abstract:
A process for manufacturing semiconductor chips, such as photosensor arrays for a full-page-width scanner or printhead chips for a full-page-width ink-jet printer, mounted on a substrate to maintain reasonably consistent spacing among adjacent chips. Before chips are tacked onto the substrate with uncured epoxy, the substrate is urged evenly against a work surface defining a concave bow. The radius of curvature of the concave bow is calculated as a function of the desired spacing between adjacent chips. When the substrate having chips tacked thereon is released form the work surface, neighboring chips have parallel adjacent surfaces of the desired spacing.
Abstract:
Semiconductor chips, such as photosensor arrays in a full-width scanner, are mounted on a substrate to maintain reasonably consistent spacing among chips regardless of temperature conditions during use. After chips are tacked onto the substrate with uncured epoxy, the assembly is brought to a low temperature prior to the heating of the curing step. The technique permits design of the assembly to compensate for differences between the thermal coefficient of expansion of the chips and that of the substrate, while also minimizing mechanical stresses on the chips caused by heating in the course of use.
Abstract:
An improved process for forming individual dies having faces that allow the dies to be assembled against other like dies to form one and/or two dimensional scanning arrays with minimal chipping and fracturing wherein the active side of a wafer is etched to form separation grooves with the wall of the grooves adjoining the die presenting a relatively wide surface to facilitate sawing, wide grooves are cut in the inactive side of the wafer opposite each separation grooves, and the wafer cut by sawing along the separation grooves, the saw being located so that the side of the saw blade facing the die is aligned with the midpoint of the wide wall so that on sawing the bottom half of the wall and the remainder of the grooves are obliterated leaving the top half of the wall to prevent cracking and chipping during sawing.