Memory module assembly including heat-sink plates with heat-exchange fins attached to integrated circuits by adhesive
A memory module assembly includes a heat-sink plate attached to one or more of the integrated circuits (e.g., memory devices) of a memory module PCBA by adhesive. The heat-sink plate includes an elongated base structure, a first contact plate extending away from the base structure such that a step-like positioning surface is defined therebetween, and heat-exchange fins extending from the opposite side of the base structure. An optional upper heat-sink plate is secured to a second side of the PCBA by a second adhesive layer, and contacts the lower heat-sink plate to facilitate heat transfer to the heat-exchange fins. The adhesive is either heat-activated or heat-cured. The adhesive is applied to either the memory devices or the heat-sink plates, and then compressed between the heat-sink plates and memory module using a fixture. The fixture is then passed through an oven to activate/cure the adhesive.
1. A memory module assembly comprising:
a memory module printed circuit board assembly (PCBA) including:
a substrate having opposing first and second surfaces, a plurality of wiring traces formed on the first and second surfaces, at least some of the wiring traces being connected to metal contact pads formed along a connector edge of the substrate, the substrate having a second edge disposed opposite to the connector edge, and
a plurality of first integrated circuit (IC) devices mounted on the first surface of the substrate such that an upper surface of each of the plurality of first IC devices faces away from the substrate;
a first heat-sink plate mounted on the memory module PCBA, the first heat-sink plate including:
an elongated first base structure,
a first contact plate having a fixed edge connected to the base structure and a free edge disposed away from the base structure, the first contact plate having a first outer surface and an opposing first underside surface, wherein the first contact plate is disposed such that a step-like positioning surface is defined by the base structure and the first underside surface of the contact plate, and
a plurality of heat-exchange fins extending from the first base structure; and
at least one adhesive portion sandwiched between the first underside surface of the first heat-sink plate and the upper surface of an associated IC device of said plurality of first IC devices,
wherein the memory module PCBA is positioned such that the second edge of the substrate contacts the positioning surface, and the connector edge of the substrate extends beyond the free edge of the contact plate,
wherein the memory module PCBA further includes a plurality of second IC devices mounted on the second surface of the substrate such that an upper surface of each of the plurality of second IC devices faces away from the substrate,
wherein the memory module assembly further comprises:
a second heat-sink plate having a second outer surface and an opposing second underside surface; and
at least one second adhesive portion sandwiched between the second underside surface of the second heat-sink plate and the upper surface of an associated IC device of said plurality of second IC devices,
wherein the elongated base structure of the first heat-sink plate defines an elongated engaging groove, and
wherein the second heat-sink plate includes an elongated engaging protrusion extending from the underside surface and received in said elongated engaging groove
2. The memory module assembly according to claim 1 , wherein the plurality of heat-exchange fins comprises a first row of said heat-exchange fins and a second row of said heat-exchange fins separated by an elongated air gap.
3. The memory module assembly of claim 1 , wherein each of said first and second adhesive portions comprise a heat-activated adhesive material exhibiting a first, relatively low adherence when heated to a first, relatively high temperature, and exhibiting a second, relatively high adherence when subsequently cooled to a second, relatively low temperature.
4. The memory module assembly according to claim 1 , wherein each of the first and second adhesive portions comprises one of a high thermal conductive adhesive film and a thermal-bond adhesive film.
5. The memory module assembly according to claim 1 , wherein the memory module PCBA comprises a dynamic random access memory (DRAM).