Die package with guard structure to reduce or prevent material seepage into air cavity, and related fabrication methods
Bare die package with guard to reduce or prevent material seepage into an air cavity, and related fabrication methods. In exemplary aspects, to avoid or reduce material (e.g., an encapsulation material such as a mold material and/or a coating material) from entering or seeping into the air cavity in the active filter region of a filter, the die package includes a guard structure. The guard structure is a structure on or adjacent to the die operable to be used in a filter that redirects or reduces material from entering the gap between the die and the substrate. The guard structure reduces or prevents the material entering the air cavity of the die so as to avoid such material affecting the acoustic performance of the air cavity of the filter.
1 . A die package, comprising:
a substrate comprising a first surface;
a filter, comprising:
a die operable to be used in the filter, comprising:
a second surface; and
a plurality of die edges adjacent to the second surface;
a plurality of metal bumps coupled to the second surface and coupled to the first surface of the substrate forming a gap between the first surface and the die; and
an air cavity in the gap between the first surface and the die; and
one or more guard structures each adjacent to the gap and each adjacent to a first die edge of the plurality of die edges;
wherein the one or more guard structures comprise one or more channels in the gap and adjacent to the first die edge;
wherein the one or more channels are disposed between a plurality of channel structures parallel to each other and extending beyond the first surface of the substrate in the gap.
2 . The die package of claim 1 , wherein:
the substrate comprises one or more metallization layers parallel to each other in a first direction; and
the one or more guard structures are between the first die edge and at least one metal bump of the plurality of metal bumps in the first direction.
3 . The die package of claim 2 , wherein:
the die further comprises:
an inactive region in the gap between the plurality of metal bumps and the plurality of die edges in the first direction;
an active filter region adjacent to the air cavity such that the plurality of metal bumps is between the active filter region and the plurality of die edges in the first direction; and
the one or more guard structures are between the plurality of metal bumps and the plurality of die edges in the first direction.
4 . The die package of claim 1 , wherein:
the substrate comprises one or more metallization layers parallel to each other in a first direction; and
each guard structure of the one or more guard structures extends to the first die edge in the first direction and intersects a first plane of the first die edge in a second direction orthogonal to the first direction.
5 . The die package of claim 1 , wherein the one or more guard structures comprise at least one guard structure extending adjacent to each die edge of the plurality of die edges.
6 . The die package of claim 1 , wherein the one or more guard structures are comprised of a material comprised from the group consisting of a metal material, a dielectric material, a photoresist film, and a passivation layer.
7 . The die package of claim 1 , wherein the one or more guard structures comprise a plurality of channels parallel to each other.
8 . The die package of claim 1 , wherein:
the substrate comprises one or more metallization layers parallel to each other in a first direction; and
the one or more channels are between the first die edge and at least one metal bump of the plurality of metal bumps in the first direction.
9 . The die package of claim 1 , wherein the one or more channels extend continuously in a closed pattern adjacent to each die edge of the plurality of die edges.
10 . The die package of claim 1 , wherein the one or more channels are non-continuous.
11 . The die package of claim 1 integrated into a device selected from the group consisting of: a set top box; an entertainment unit; a navigation device; a communications device; a fixed location data unit; a mobile location data unit; a global positioning system (GPS) device; a mobile phone; a cellular phone; a smart phone; a session initiation protocol (SIP) phone; a tablet; a phablet; a server; a computer; a portable computer; a mobile computing device; a wearable computing device; a desktop computer; a personal digital assistant (PDA); a monitor; a computer monitor; a television; a tuner; a radio; a satellite radio; a music player; a digital music player; a portable music player; a digital video player; a video player; a digital video disc (DVD) player; a portable digital video player; an automobile; a vehicle component; avionics systems; a drone; and a multicopter.
12 . A die package, comprising:
a substrate comprising a first surface;
a filter, comprising:
a die operable to be used in the filter, comprising:
a second surface; and
a plurality of die edges adjacent to the second surface;
a plurality of metal bumps coupled to the second surface and coupled to the first surface of the substrate forming a gap between the first surface and the die; and
an air cavity in the gap between the first surface and the die; and
one or more guard structures each adjacent to the gap and each adjacent to a first die edge of the plurality of die edges;
wherein the one or more guard structures comprise one or more die recesses in the die, wherein the one or more die recesses are adjacent to the first die edge.
13 . The die package of claim 12 , wherein:
the substrate comprises one or more metallization layers parallel to each other in a first direction; and
the one or more die recesses extend to the first die edge in the first direction and intersect a first plane of the first die edge in a second direction orthogonal to the first direction.
14 . The die package of claim 12 , wherein the one or more die recesses extend continuously in a closed pattern adjacent to each die edge of the plurality of die edges.