Angularly offset stacked die multichip device and method of manufacture
AssigneeMicron Technology, Inc.
InventorsRich Fogal, Michael B. Ball
Life of this patent
Estimating the term…
Abstract
An offset die stacking arrangement having at least one upper level die having a width which is less than the distance separating the opposing bonding sites of the underlying die. The upper die is suspended above the lower die on one or more pillars and rotated within a plane parallel to the lower die through an angle which insures that none of the bonding sites of the lower die are obstructed by the upper die. Once the dice are fixed in this manner, the entire assembly is subjected to the wire bonding process with all of the bonds being made in the same step.
Claims25
A method for manufacturing a multichip module comprising the acts of:
- affixing a lower die to a substrate, the lower die having two opposing side edges each including bonding sites therealong, a base surface and an upper surface, the lower die being attached to the substrate with the lower die's base surface facing the substrate;
- orienting an upper die having a width less than the perpendicular distance separating any two opposing bonding sites along the opposing side edges of the lower die, this perpendicular distance being defined as W, the upper die further having a base surface and an upper surface, by rotating the upper die in a plane substantially parallel to the upper surface of the lower die, through an angle defined as the minimum offset angle, .alpha., which is at least equal to the value given by the formula ##EQU3## where L is equal to the maximum distance between two outermost edges of any two bonding sites along one of the sides of the first die;
- and
- attaching the upper die above the lower die with the upper die's base surface facing the upper surface of the lower die in this orientation using a pillar interposed between and affixed to the upper die and the substrate.
A method of stacking a plurality of die, comprising:
- mounting an upper die on at least one pillar, wherein said upper die is over a lower die;
- defining a first angular offset between said upper die and said lower die;
- and
- allowing access to a bonding site on said lower die with said first angular offset.
A method of manufacturing a multichip module, comprising:
- forming a stack of at least two die;
- at least partially supporting one die of said at least two die with a pillar;
- defining an offset angle with two of said at least two die;
- and
- bonding wire to said stack.
A method of mounting a plurality of die to a substrate, comprising:
- coupling a first die to said substrate at a first orientation, wherein said first die has a bonding site;
- providing at least one pillar on said substrate;
- coupling a second die at a second orientation to said at least one pillar;
- defining an offset angle between said first orientation and said second orientation;
- and
- encompassing said bonding site within said offset angle.
A method of stacking a plurality of chips, comprising:
- spiraling said purality of chips around an axis perpendicular to said plurality of chips;
- supporting said purality of chips with a plurality of columns, wherein at least one column corresponds in height to each chip of said plurality of chips;
- and
- ensuring bond pad clearance to said each chip.
A method of stacking a plurality of die on an electronic surface, comprising:
- mounting a first die on said electronic surface, wherein said first die comprises at least one bonding area;
- providing a first support over said electronic surface;
- and
- mounting a second die on said first support in a configuration wherein said second die extends over said first die and clears said at least one bonding area.
Dependencies are inferred from the claim text.