# US 2014/0197505 A1 · Shields for magnetic memory chip packages > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197505 A1 - Document ID: US20140197505A1 - Status: Published application - Kind: A1 - Application number: 13/740,180 - Filed: 2013-01-12 - Published: 2014-07-17 - Earliest claimed: 2013-01-12 - Assignees: Avalanche Technology, Inc. - Applicants: Avalanche Technology Inc. - Inventors: Yuchen Zhou; Bernardo Sardinha; Rajiv Yadav Ranjan; Ebrahim Abedifard; Roger Klas Malmhall; Zihui Wang; Yiming Huai; Jing Zhang - Web page: https://patentgrep.com/patent/US20140197505A1 ## CPC - H10W 42/20: protecting against electromagnetic or particle radiation, e.g. light, X-rays, gamma-rays or electrons - H10W 42/287: {materials for magnetic shielding, e.g. ferromagnetic materials} - H10W 70/655: Fan-out layouts - H10W 72/884: {Die-attach connectors and bond wires} - H10W 74/15: on active surfaces of flip-chip devices, e.g. underfills - H10W 90/724: {between a chip and a stacked insulating package substrate, interposer or RDL} - H10W 90/734: {between a chip and a stacked insulating package substrate, interposer or RDL} - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract Chip packages are described with soft-magnetic shields that are included inside or attached externally to the package containing a MRAM chip. In one group of embodiments a single shield with vias for bonding wires is affixed to the surface of the MRAM chip having the contact pads. The limitation of shield to chip distance due to bonding wire is eliminated by VIA holes according to the invention which achieves minimal spacing between the shield and chip. A second shield without vias can be positioned on the opposite side of the chip from the first shield. In one group of embodiments a hardened ferro-fluid shield can be the only shield or the structure can include a shield with or without vias. One group of embodiments includes an external shield with vias for solder access to the package contact pads affixed to the outer surface of the package. ## Claims ### Claim 1 A chip package including: an MRAM chip with a set of chip contact pads on a first surface of the MRAM chip; a set of package contact pads disposed on an exterior surface of the package; a set of bonding wires connecting the chip contact pads to the package contact pads; and a first soft-magnetic shield disposed inside the package adjacent to the first surface of the MRAM chip, a surface of the first shield confronting the MRAM chip being larger than the first surface of the MRAM chip and extending beyond the MRAM chip on opposing sides, the first shield having at least one via with at least one bonding wire passing through the via. ### Claim 2 (depends on 1) The chip package of claim 1 wherein the first soft-magnetic shield is a homogeneous material that is an alloy of Fe and/or Co and any of the following Ni, Mn, Ir, Mg, Al, Ta, Ti, Pt, Pd, Ru, Cr, Cu, Hf, Zr, Si, C, Ge, W, Nb, Nd, Zn, Au, Ag, Cu, Mo, V, Ru, O and N. ### Claim 3 (depends on 1) The chip package of claim 1 wherein the first soft-magnetic shield includes magnetic particles in a non-magnetic matrix. ### Claim 4 (depends on 3) The chip package of claim 3 wherein the non-magnetic matrix is a non-magnetic metal or alloy, polymer, oxide, carbide, nitride, silicide, carbonate, sulfate, or silicon. ### Claim 5 (depends on 3) The chip package of claim 3 wherein the magnetic particles are composed of an alloy of Fe and/or Co and any of the following Ni, Mn, Ir, Mg, Al, Ta, Ti, Pt, Pd, Ru, Cr, Cu, Hf, Zr, Si, C, Ge, W, Nb, Nd, Zn, Au, Ag, Cu, Mo, V, Ru, O and N. ### Claim 6 (depends on 3) The chip package of claim 3 wherein the magnetic particles are ferromagnetic. ### Claim 7 (depends on 3) The chip package of claim 3 wherein the magnetic particles are ferri-magnetic. ### Claim 8 (depends on 3) The chip package of claim 3 wherein the magnetic particles are super-paramagnetic. ### Claim 9 (depends on 3) The chip package of claim 3 wherein the magnetic particles have a particle size less than one hundred microns. ### Claim 10 (depends on 3) The chip package of claim 3 wherein the magnetic particles have an approximate particle size from 5 nm to 500 nm. ### Claim 11 (depends on 1) The chip package of claim 1 wherein the first soft-magnetic shield is laminated and includes layers of soft magnetic material separated by non-magnetic spacer layers. ### Claim 12 (depends on 11) The chip package of claim 11 wherein the first soft-magnetic shield includes at least one layer of metallic magnetic foil. ### Claim 13 (depends on 1) The chip package of claim 1 wherein the first soft-magnetic shield is flexible. ### Claim 14 (depends on 1) The chip package of claim 1 wherein the first shield has a thickness equal to or greater than a thickness of the MRAM chip measured along a selected line passing through the first shield and the MRAM chip. ### Claim 15 (depends on 1) The chip package of claim 1 wherein the first shield is bonded to the MRAM chip. ### Claim 16 (depends on 1) The chip package of claim 1 further comprising a second soft-magnetic shield disposed inside the chip package adjacent to a second surface of the MRAM chip opposite to first surface the MRAM chip, a surface of the second soft-magnetic shield confronting the MRAM chip being larger than the second surface of the MRAM chip and extending beyond the MRAM chip on opposing sides. ### Claim 17 (depends on 1) The chip package of claim 1 wherein the first shield is disposed adjacent to an outer wall of the chip package. ### Claim 18 (depends on 1) The chip package of claim 1 wherein the MRAM chip is disposed adjacent to an outer wall of the chip package and first surface of the MRAM chip with the set of chip contact pads faces away from the outer wall of the chip package and toward the first shield. ### Claim 19 (depends on 18) The chip package of claim 18 wherein a set of bonding wires extend out through vias in the first shield and pass through an interior area of the chip package before connecting to the set of package contact pads. ### Claim 20 (depends on 1) The chip package of claim 1 further comprising a magnetically-soft, hardened ferro-fluid shield formed inside the chip package over a structure that includes the MRAM chip and the first soft-magnetic shield. ### Claim 21 (depends on 1) The chip package of claim 1 wherein the via is formed without corners. ### Claim 22 (depends on 1) The chip package of claim 1 wherein the first soft-magnetic shield is formed by two or more pieces of shield material juxtaposed to form the via. ### Claim 23 (depends on 1) The package of claim 1 wherein the first soft-magnetic shield is formed from a ferro-flu id. ### Claim 24 (depends on 23) The chip package of claim 23 wherein the ferro-fluid includes a polymer. ### Claim 25 (depends on 23) The chip package of claim 23 wherein the ferro-fluid includes oil, water, epoxy, silicone, or glue. ### Claim 26 (depends on 23) The chip package of claim 23 wherein the ferro-fluid is deposited as a flowing liquid and subsequently hardens. ### Claim 27 (depends on 25) The chip package of claim 25 wherein the ferro-fluid is hardened by heating or exposure to light. ### Claim 28 (depends on 1) The chip package of claim 1 further comprising a second soft-magnetic shield disposed inside the chip package adjacent to a second surface of the MRAM chip, the second surface being opposite to the first surface of the MRAM chip, a surface of the second soft-magnetic shield confronting the MRAM chip being larger than the second surface of the MRAM chip and extending beyond the MRAM chip on opposing sides. ### Claim 29 (depends on 28) The chip package of claim 28 wherein the second soft-magnetic shield has at least one via with at least one bonding wire passing through the via. ### Claim 30 (depends on 28) The chip package of claim 28 wherein the second soft-magnetic shield has a thickness greater than a thickness of the MRAM chip measured along a selected line passing through the second soft-magnetic shield and the MRAM chip. ### Claim 31 A package including: an MRAM chip with a set of chip contact pads on a first surface of the MRAM chip; a set of package contact pads disposed on a first exterior surface of the chip package; a set of bonding wires connecting the chip contact pads to the chip package contact pads; and a first soft-magnetic shield attached to the first exterior surface of the chip package, the first shield having vias corresponding to the package contact pads disposed on a first exterior surface of the chip package, the vias providing access for solder connection to the package contact pads. ### Claim 32 (depends on 31) The chip package of claim 31 wherein a surface of the first shield confronting the first exterior surface of the chip package is larger than the first surface of the MRAM chip and extends beyond the MRAM chip on opposing sides. ### Claim 33 (depends on 31) The chip package of claim 31 wherein the first soft-magnetic shield is a homogeneous material that is an alloy of Fe and/or Co and any of the following Ni, Mn, Ir, Mg, Al, Ta, Ti, Pt, Pd, Ru, Cr, Cu, Hf, Zr, Si, C, Ge, W, Nb, Nd, Zn, Au, Ag, Cu, Mo, V, Ru, O and N. ### Claim 34 (depends on 31) The chip package of claim 31 further comprising a second soft-magnetic shield magnetically-soft formed inside the chip package over the MRAM chip, the second soft-magnetic shield being formed from a ferro-fluid including magnetic particles. ### Claim 35 (depends on 34) The chip package of claim 34 wherein the second soft-magnetic shield includes magnetic particles in a non-magnetic matrix and wherein the non-magnetic matrix is a non-magnetic metal or alloy, polymer, oxide, carbide, nitride, silicide, carbonate, sulfate, or silicon. ### Claim 36 (depends on 34) The chip package of claim 34 wherein the ferro-fluid includes oil, water, epoxy, silicone, or glue. ### Claim 37 (depends on 34) The chip package of claim 34 wherein the ferro-fluid is deposited as a flowing liquid and subsequently hardens. ### Claim 38 (depends on 37) The chip package of claim 37 wherein the ferro-fluid is hardened by heating or exposure to light. ### Claim 39 (depends on 34) The chip package of claim 34 wherein the magnetic particles in the second soft-magnetic shield are composed of an alloy of Fe and/or Co and any of the following Ni, Mn, Ir, Mg, Al, Ta, Ti, Pt, Pd, Ru, Cr, Cu, Hf, Zr, Si, C, Ge, W, Nb, Nd, Zn, Au, Ag, Cu, Mo, V, Ru, O and N. ### Claim 40 (depends on 34) The chip package of claim 34 wherein the magnetic particles are ferromagnetic. ### Claim 41 (depends on 34) The chip package of claim 34 wherein the magnetic particles are ferri-magnetic. ### Claim 42 (depends on 34) The chip package of claim 34 wherein the magnetic particles are super-paramagnetic. ### Claim 43 (depends on 34) The chip package of claim 34 wherein magnetic particles have a particle size less than one hundred microns. ### Claim 44 (depends on 34) The chip package of claim 34 wherein the magnetic particles have an approximate particle size from 5 nm to 500 nm. ### Claim 45 (depends on 31) The chip package of claim 31 wherein the first soft-magnetic shield is laminated and includes layers of soft magnetic material separated by non-magnetic spacer layers. ### Claim 46 (depends on 31) The chip package of claim 31 wherein the first soft-magnetic shield includes at least one layer of metallic magnetic foil. ### Claim 47 (depends on 31) The chip package of claim 31 wherein the first soft-magnetic shield has a thickness equal to or greater than a thickness of the MRAM chip measured along a selected line passing through the first soft-magnetic shield and the MRAM chip. ### Claim 48 (depends on 31) The chip package of claim 31 further comprising a second soft-magnetic shield disposed inside the chip package adjacent to a second surface of the MRAM chip opposite to first surface the MRAM chip, a surface of the second soft-magnetic shield confronting the MRAM chip being larger than the second surface of the MRAM chip and extending beyond the MRAM chip on opposing sides. ### Claim 49 (depends on 31) The chip package of claim 31 wherein the vias are formed without corners. ### Claim 50 (depends on 28) The chip package of claim 28 wherein the second soft-magnetic shield has a thickness greater than a thickness of the MRAM chip measured along a selected line passing through the second soft-magnetic shield and the MRAM chip.