US-12628694-B2 - Integrated bare die package, and related fabrication methods

US12628694B2US 12628694 B2US12628694 B2US 12628694B2US-12628694-B2

Abstract

Integrated bare die packages, and related fabrication methods are disclosed. To provide for the integration of a bare die filter into the bare die package while maintaining an acoustic cavity for the bare die filter and conserving package size, the bare die filter is vertically-integrated with a second component (e.g., another die, a second bare die filter, a passive electrical device(s)). In examples, the bare die filter is vertically-integrated with the second component in a second direction (e.g., vertical direction) orthogonal to the first direction on a first side of a package substrate of the bare die package. The bare die filter and the second component each intersect a common plane in the second direction. In this manner, the expansion in size of the bare die package through the integrated of bare die filter is minimized, while also maintaining the acoustic cavity of the bare die filter.

Inventors

Yeng Kwan Hoo
Anna Katharina Krefft
Emre Topal

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260512
Application Date: 20221215

Claims (18)

1 . A bare die package, comprising: a package substrate comprising one or more metallization layers parallel to each other in a first direction; a first bare die filter coupled to a first surface of the package substrate and adjacent to the first surface of the package; and a second component coupled to the first surface of the package substrate; wherein the first bare die filter and the second component each intersect a common first plane in a second direction orthogonal to the first direction; wherein the first bare die filter is between the first surface of the package substrate and the second component in the second direction.
2 . The bare die package of claim 1 , wherein the first bare die filter comprises: a first filter die comprising a second surface adjacent to the first surface of the package substrate, a third surface opposite the second surface; and a plurality of first metal interconnects coupled to the first surface of the package substrate such that a first air cavity is formed between the second surface of the first filter die and the first surface of the package substrate.
3 . The bare die package of claim 1 , further comprising a plurality of extension metal interconnects coupled to the package substrate and extending in the second direction; and the second component is coupled to the plurality of extension metal interconnects.
4 . The bare die package of claim 3 , wherein at least one first extension metal interconnect of the plurality of extension metal interconnects is adjacent to the first bare die filter in the first direction.
5 . The bare die package of claim 3 , wherein: a second surface of the first bare die filter adjacent to the first surface of the package substrate is disposed a first height from the first surface of the package substrate; and the plurality of extension metal interconnects extend in the second direction to a second height that is equal to or greater than the first height.
6 . The bare die package of claim 1 , further comprising a first redistribution layer (RDL) coupled to a first extension metal interconnect of the plurality of extension metal interconnects and the second component.
7 . The bare die package of claim 1 , wherein the second component comprises a second bare die filter.
8 . The bare die package of claim 7 , wherein the second bare die filter comprises a second filter die comprising: a sixth surface adjacent to the first surface of the package substrate; a seventh surface opposite the sixth surface; and a plurality of second metal interconnects coupled to the sixth surface and the first surface of the package substrate such that a second cavity is formed between the sixth surface of the second filter die and the first surface of the package substrate.
9 . The bare die package of claim 1 , wherein the second component comprises a second die.
10 . The bare die package of claim 1 , wherein the second component comprises at least one second passive electrical device.
11 . The bare 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 method of fabricating a bare die package, comprising: providing a package substrate comprising one or more metallization layers parallel to each other in a first direction; electrically coupling a second component to a first surface of the package substrate; and electrically coupling a first bare die filter to a first surface of the package substrate and adjacent to the first surface of the package; wherein the first bare die filter and the second component each intersect a common first plane in a second direction orthogonal to the first direction; wherein the first bare die filter is between the first surface of the package substrate and the second component in the second direction.
13 . The method of claim 12 , further comprising: placing a second surface of the first bare die filter adjacent to the first surface of the package substrate; and placing the second component adjacent to a third surface of the first bare die filter opposite of the second surface.
14 . The method of claim 13 , further comprising forming a plurality of extension metal interconnects coupled to the package substrate and extending in the second direction; wherein electrically coupling the second component to the first surface of the package substrate comprises coupling the second component to the plurality of extension metal interconnects.
15 . The method of claim 14 , further comprising a first redistribution layer (RDL) coupled to a first extension metal interconnect of the plurality of extension metal interconnects and the second component.
16 . The method of claim 15 , further comprising: disposing a first overmold layer on the first bare die filter and the plurality of extension metal interconnects; and grinding down the first overmold layer to the third surface of the first bare die filter; wherein forming the RDL further comprises forming the RDL adjacent to the third surface of the first bare die filter.
17 . The method of claim 16 , further comprising forming a second overmold layer adjacent a fifth surface of the second component.
18 . The method of claim 13 , wherein electrically coupling the first bare die filter to the first surface of the package substrate comprises coupling a plurality of first metal interconnects of the first bare die filter to the first surface of the package substrate such that a first air cavity is formed between a first filter die of the first bare die filter and the first surface of the package substrate.

Description

BACKGROUND I. Field of the Disclosure The field of the disclosure relates to integrated circuit (IC) packages that incorporate die filters, including bare die filter module packages (BDMPs) and systems-in-a-package (SiPs). II. Background Mobile wireless device manufacturers pack ever-increasing capabilities into hand-held sized packages. Increasing capability means that more electronic components must fit into the package. This trend drives a size reduction of electronic components used for radio-frequency (RF) signal processing. A challenge to miniaturizing electronic components is finding a way to provide the same function in a physically smaller electronic device. Another challenge to miniaturizing electronic components is created by a physically smaller device dissipating the same or similar amount of power, leading to the same or similar heat generation. Heat generated within a physically smaller device leads to higher operating temperatures in a smaller package, which increases the potential to affect device performance and its life span. Thus, there is a desire to find ways for more effectively dissipating heat when reducing the device size. One device that has been employed in RF signal processing circuits (e.g., RF front end (RFFE) circuits) provided in smaller electronic devices for signal filtering is an acoustic wave (AW) filter, such as a surface AW (SAW) filter, or bulk AW (BAW) filter. The AW filter removes or reduces the energy in one or more bands of frequencies from an input analog signal. An AW filter filters frequencies by transforming electromagnetic wave propagation into mechanical wave propagation on the surface of a substrate material. AW filters can be implemented as a die filter in a systems-in-a-package (SiPs) and bare die module packages (BDMPs). In a SiP, a filter circuit can be incorporated as a die filter that is coupled to a package substrate like an integrated circuit (IC) die. The die filter is encapsulated in the SiP. In a BDMP, a die filter is coupled to a package substrate and is also encapsulated, but an air cavity as an acoustic cavity is preserved between the die filter and the package substrate free of encapsulation material. SiP and BDMP technology has been significant in the reduction of mobile device sizes. However, there is continued need to decrease SiP and BDMP size, especially when integrated into mobile devices. Double-sided BDMPs have been developed where a filter die(s) and IC die(s) are coupled on both sides of a package substrate to avoid or mitigate increase in vertical height of the packages. However, package design rules may limit the integration dies on both sides of a package substrate to provide a double-sided SiP or BDMP. SUMMARY OF THE DISCLOSURE Aspects disclosed herein include an integrated bare die package. Related fabrication methods are also disclosed. A bare die package is an integrated circuit (IC) package that includes at least one bare semiconductor die (“die”). A bare die is a die in an IC package that has an area free of encapsulation between a side of the die and a coupled surface (e.g., a surface of a package substrate) adjacent to the die side. The area that is free of encapsulation between the die and the coupled surface provides an air cavity between the die and the coupled surface. For example, a bare die package may include a bare die filter that is a cavity filter that has an area free of encapsulation between an active side of a filter die and a coupled surface to maintain an air cavity that acts a cavity resonator to filter and pass RF signals at particular frequencies. The bare die package includes a package substrate that includes one or more metallization layers disposed in parallel with each other in a first direction (e.g., horizontal direction). The metallization layers include metal interconnects to provide external signal routing to one or more included semiconductor dies (“dies”) and/or between dies. The die(s) is electrically coupled to the package substrate. In exemplary aspects, to provide for the integration of a bare die filter into the bare die package such that the acoustic cavity for the bare die filter is maintained and package size is conserved, the bare die filter is vertically-integrated with a second component (e.g., another die, a second bare die filter, a passive electrical device(s)). The bare die filter is vertically-integrated with the second component in a second direction (e.g., vertical direction) orthogonal to the first direction on a first surface of the package substrate. In this regard, the bare die filter is coupled to a first surface of the package substrate through metal interconnects coupled to package substrate. The second component is also coupled to the first surface of the package substrate through metal interconnects coupled to package substrate. The bare die filter and the second component each intersect a common plane in the second direction (e.g., vertical direction) such that the