Interconnection structure with liquid metal and surface pins and removable magnet or guideposts aligment around package substrate
A substrate to printed circuit board (PCB) interconnect with liquid metal and surface pins. A thin dielectric sheet with drilled openings is adjacent to the bottom of a system on chip or CPU package substrate. Holes in the dielectric sheet have a liquid metal (LM) therein, the holes correspond to landing metal pads on the package substrate. The PCB includes surface pins in an arrangement to match the LM filled holes. A pick and place assembly of the package substrate to the PCB can be done without needing a reflow step. A magnet ring can be positioned on the polyimide sheet and configured to pair with a metal plate on the PCB. Guideposts around the periphery of the package substrate may be used to assist in alignment during assembly.
1 . An apparatus comprising:
a dielectric layer comprising an upper surface and a lower surface, the dielectric layer having a plurality of holes from the upper surface to the lower surface;
individual holes of the plurality of holes having a liquid metal (LM) therein, the LM extends from the lower surface to the upper surface;
a package substrate having metal pads, the metal pads to be electrically coupled to the LM at the upper surface of the dielectric layer; and
a magnet located on the upper surface of the dielectric layer and at least substantially surrounding a perimeter of the package substrate.
2 . The apparatus of claim 1 , further comprising a guidepost extending downward from the lower surface.
3 . The apparatus of claim 2 , wherein the guidepost is a first guidepost and further comprising a second guidepost extending from the lower surface.
4 . The apparatus of claim 1 , further comprising:
a die coupled to the package substrate.
5 . The apparatus of claim 4 , further comprising:
a thermal interface material (TIM) located on the die; and
a cap enclosing the die and TIM on a top surface of the package substrate.
6 . The apparatus of claim 1 , wherein the LM comprises gallium.
7 . The apparatus of claim 1 , wherein the LM comprises indium, tin, or zinc.
8 . The apparatus of claim 1 , wherein the dielectric layer comprises a thickness in a range of 250 to 400 microns.
9 . The apparatus of claim 1 , further comprising:
a printed circuit board (PCB) having a plurality of surface pins, the PCB located adjacent to the lower surface of the dielectric layer; and
individual surface pins of the plurality of surface pins extending into a respective hole, thereby establishing an electrical connection with a respective metal pad.
10 . The apparatus of claim 9 , further comprising an integrated circuit component attached to the PCB.
11 . The apparatus of claim 9 , further comprising:
a metal plate, the metal plate located on the PCB; and
the magnet paired to the metal plate.
12 . The apparatus of claim 1 , wherein the dielectric layer is a polyimide layer.
13 . An assembly, comprising:
a package comprising a package substrate, a die coupled to a top surface of the package substrate, and a dielectric layer located under the package substrate, the dielectric layer comprising a plurality of holes having a liquid metal (LM) therein;
a printed circuit board (PCB) having a plurality of surface pins;
the package located on the PCB, with individual surface pins of the plurality of surface pins inserted into respective holes in the package; and
a magnet removably attached to an upper surface of the dielectric layer.
14 . The assembly of claim 13 , further comprising:
a metal plate located on the PCB and magnetically attached to the magnet.
15 . The assembly of claim 13 , further comprising a guidepost having a first end inserted into the dielectric layer and having a second end inserted in the PCB.
16 . The assembly of claim 13 , wherein the dielectric layer is a polyimide layer.
17 . The assembly of claim 13 , wherein the dielectric layer comprises a thickness in a range of 250 to 400 microns.
18 . The assembly of claim 13 , wherein the plurality of surface pins comprises copper.
19 . A system, comprising:
a printed circuit board (PCB) having a plurality of surface pins arranged in a pinout;
an integrated circuit component attached to the PCB;
a package comprising a package substrate, a die coupled to a top surface of the package substrate, and a layer located under the package substrate, the layer comprising polyimide, wherein a plurality of holes are arranged in the pinout, the plurality of holes having a liquid metal therein;
the package is attached at a lower surface of the layer to the PCB, such that individual surface pins of the plurality of surface pins are inserted into a respective hole in the package; and
a magnet located on an upper surface of the layer and at least substantially surrounding a perimeter of the package substrate.
20 . The system of claim 19 , further comprising:
a metal plate located on the PCB and paired with the magnet.
21 . The system of claim 19 , further comprising a guidepost having a first end inserted into the layer and having a second end inserted in the PCB.
22 . An apparatus comprising:
a layer comprising polyimide, an upper surface, and a lower surface, the layer having a plurality of holes from the upper surface to the lower surface;
individual holes of the plurality of holes having a liquid metal (LM) therein that extends from the lower surface to the upper surface;
a package substrate including a backside adjacent to the upper surface of the layer; and
an alignment means removably attached to the layer and located at a periphery of the package substrate, the alignment means configured to provide alignment reference in assembly.
23 . The apparatus of claim 22 , wherein the alignment means comprises a magnet or a guidepost.
24 . The apparatus of claim 22 , wherein the alignment means comprises both a magnet and a guidepost.
25 . The assembly of claim 13 , wherein the magnet at least substantially surrounds a perimeter of the package substrate.