Methods of thinning microelectronic workpieces
AssigneeMicron Technology, Inc.
InventorTongbi Jiang
Life of this patent
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Abstract
Microelectronic device assemblies are provided with reduced-thickness dies. In certain methods of the invention, a die is connected to a mounting surface of a support and the back surface of the die is ground to reduce the die thickness. In certain embodiments, a portion of the mounting surface of the substrate remains exposed, permitting other devices to be electrically coupled directly to the substrate. In other embodiments, a second die is electrically coupled to the ground back surface of the first die via an intermediate layer, enabling a reduced profile stacked die assembly without requiring direct connection to the support.
Claims34
A method of assembling a stacked microelectronic device assembly from a microelectronic device subassembly, the microelectronic device subassembly including a support having a first electrical contact and a first die attached to and electrically coupled to the support, the method comprising:
- thinning the first die of the microelectronic device subassembly while the first electrical contact is exposed;
- connecting a second die to the first die after thinning the first die, leaving the first electrical contact exposed;
- and
- thereafter, electrically coupling the second die to the exposed first electrical contact.
A method of reducing a thickness of a microelectronic device assembly including a support and a first die electrically coupled to the support, the first die being attached to a mounting surface of the support, the method comprising grinding an exposed back surface of the first die with a support contact carried by the mounting surface of the support exposed, thereby reducing a thickness of the first die;
- connecting a facing surface of a second:
- die to the ground back surface of the first die;
- and, thereafter, electrically coupling a die contact to the support contact, the die contact being carried on an outer face of the second die.
A method of assembling a microelectronic device assembly, comprising:
- connecting a first die to a support;
- filling at least a portion of an underfill gap defined between an active surface of the first die and a mounting surface of the support with an underfill material in a manner that leaves a portion of the mounting surface adjacent to the die exposed;
- reducing the thickness of the first die after filling;
- physically attaching a second die to the first die, the second die having an outer surface carrying a second die contact;
- and
- electrically coupling the second die contact to a support contact on the mounting surface by a bonding wire.
A method of assembling a microelectronic device assembly including a support, a first die, and a second die;
- the support having a rear surface bearing a first contact and a mounting surface bearing a second contact;
- the first die having an active surface bearing a third contact;
- and the second die having an outer surface bearing a fourth contact;
- the method comprising:
- mechanically supporting the active surface of the first die with respect to the mounting surface of the support;
- electrically coupling the first contact to the third contact;
- reducing the thickness of the first die;
- connecting the second die to the first die after reducing the thickness of the first die, the second die being connected such that its outer surface and the fourth contact are exposed;
- and
- electrically coupling the second contact to the fourth contact.
A method of assembling a stacked microelectronic device assembly from a microelectronic device subassembly, the flip chip assembly including a support and a first die attached to and electrically coupled to the support, the method comprising:
- grinding an exposed back surface of the first die, thereby reducing a thickness of the first die and leaving an electrical element exposed on the ground back surface;
- attaching an intermediate layer to the ground back surface of the first die;
- and
- connecting a second die to the intermediate layer and electrically coupling the second die to the exposed electrical element of the first die via the intermediate layer.
A method of assembling a microelectronic device assembly, comprising:
- mechanically supporting an active surface of a first die with respect to a mounting surface of a support;
- electrically coupling the first die to the support;
- reducing a thickness of the first die;
- after reducing the thickness of the first die, physically connecting a second die to the first die;
- and
- after physically connecting the second die to the first die, electrically coupling the second die to the support.
Dependencies are inferred from the claim text.