Paddle card optimization
A paddle card includes a printed circuit board (PCB), a shielded cable, and an electromagnetic interference (EM) shield. The PCB includes a first metal layer on a top surface of the PCB, a second metal layer within the PCB, and a cavity in the top surface of the PC. The cavity exposes the second metal layer. The first metal layer includes a first ground pad. The second metal layer includes a signal pad located within the cavity. The shielded cable includes a signal conductor coupled to the first signal pad. The EMI shield is coupled to the ground pad and covers the cavity.
1 . A paddle card, comprising:
a printed circuit board (PCB) including a first metal layer on a top surface of the PCB, a second metal layer within the PCB, and a first cavity in the top surface of the PCB, wherein the first cavity exposes the second metal layer at a first location, wherein the first metal layer includes a first ground pad and the second metal layer includes a first signal pad located within the first cavity;
a first shielded cable including a first signal conductor coupled to the first signal pad; and
a first electromagnetic interference (EMI) shield coupled to the first ground pad and covering the first cavity.
2 . The paddle card of claim 1 , wherein the first shielded cable includes a shield layer surrounding the first signal conductor.
3 . The paddle card of claim 2 , wherein the shield layer is coupled to the first EMI shield.
4 . The paddle card of claim 1 further comprising:
a resin epoxy that fills the first cavity.
5 . The paddle card of claim 4 , wherein the first EMI shield is affixed atop the resin epoxy.
6 . The paddle card of claim 1 , wherein the second metal layer includes a second signal pad, and the first shielded cable further includes a second signal conductor coupled to the second signal pad.
7 . The paddle card of claim 6 , wherein the first signal conductor and the second signal conductor carry a differential signal.
8 . The paddle card of claim 1 , wherein:
the PCB further includes a second cavity in the top surface of the PCB, wherein the second cavity exposes the second metal layer at a second location, wherein the first metal layer further includes a second ground pad and the second metal layer further includes a second signal pad located within the second cavity; and
the paddle card further comprises:
a second shielded cable including a second signal conductor coupled to the second signal pad; and
a second EMI shield coupled to the second ground pad and covering the second cavity.
9 . The paddle card of claim 1 , wherein the ground pad is coupled to a ground plane of the PCB.
10 . The paddle card of claim 1 , wherein the first signal pad is coupled to a signal trace within the second metal layer.
11 . The paddle card of claim 1 , wherein the ground pad is coupled to a ground plane of the PCB.
12 . A method for assembling a paddle card, the method, comprising:
providing, on the paddle card, a printed circuit board (PCB);
including on the PCB, a first metal layer on a top surface of the PCB, a second metal layer within the PCB, and a first cavity in the top surface of the PCB, wherein the first cavity exposes the second metal layer at a first location;
providing, on the first metal layer, a first ground pad;
providing, on the second metal layer, a first signal pad located within the first cavity;
providing, on the paddle card, a first shielded cable including a first signal conductor;
coupling the first signal conductor to the first signal pad;
providing, on the paddle card, a first electromagnetic interference (EMI) shield;
coupling the first ground pad to the first EMI shield; and
covering the first cavity with the first EMI shield.
13 . The method of claim 12 , wherein the first shielded cable includes a shield layer surrounding the first signal conductor.
14 . The method of claim 13 , further comprising:
coupling the shield layer to the first EMI shield.
15 . The method of claim 12 further comprising:
filling the first cavity with a resin epoxy.
16 . The method of claim 15 , further comprising:
affixing the first EMI shield atop the resin epoxy.
17 . The method of claim 12 , wherein:
the second metal layer includes a second signal pad, and the first shielded cable further includes a second signal conductor; and
the method further comprises coupling the second signal conductor to the second signal pad.
18 . The method of claim 17 , wherein the first signal conductor and the second signal conductor carry a differential signal.
19 . The method of claim 12 , wherein:
the PCB further includes a second cavity in the top surface of the PCB, wherein the second cavity exposes the second metal layer at a second location;
the method further comprises:
providing, on the first metal layer, a second ground pad;
providing, on the second metal layer, a second signal pad located within the second cavity;
providing, on the paddle card, a second shielded cable including a second signal conductor;
coupling the second signal conductor to the second signal pad;
providing, on the paddle card, a second electromagnetic (EMI) shield;
coupling the second ground pad to the second EMI shield; and
covering the second cavity with the second EMI shield.
20 . A paddle card, comprising:
a printed circuit board (PCB) including a first metal layer on a top surface of the PCB, a second metal layer within the PCB, and a cavity in the top surface of the PCB, wherein the cavity exposes the second metal layer, wherein the first metal layer includes a ground pad and the second metal layer includes a first and second signal pads located within the cavity;
a first shielded cable including a first signal conductor and a second signal conductor, wherein the first signal conductor is coupled to the first signal pad, and the second signal conductor is coupled to the second signal pad;
an electromagnetic interference (EMI) shield coupled to the ground pad and covering the cavity; and
a resin epoxy that fills the cavity.