# US 5,703,350 A · Data carriers having an integrated circuit unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,350 A - Document ID: US5703350A - Status: Granted - Kind: A - Application number: 08/551,241 - Filed: 1995-10-31 - Granted: 1997-12-30 - Earliest claimed: 1995-10-31 - Assignees: Lucent Technologies Inc. - Inventors: Ephraim Suhir - Web page: https://patentgrep.com/patent/US5703350A ## CPC - G06K 19/07728: {the record carrier comprising means for protection against impact or bending, e.g. protective shells or stress-absorbing layers around the integrated circuit} - G06K 19/07745: {Mounting details of integrated circuit chips} - G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS ## Abstract Integrated circuits embedded in cards are known in the industry as "Smart Cards". The present invention discloses a novel design for housing an integrated circuit(IC) within a card unit. The integrated circuit is first made thin and placed in the midplane of the card. This lessens the tensile stress in the IC when the Smart Card is subjected to bending. In addition, it is suggested that the IC chip is then placed in a relatively long and wide enclosure. This second measure reduces the stress on the IC by compromising between the competing objectives of making a rigid cavity for IC protection, versus making a more compliant cavity for overall card strength. Lastly, the cavity is made out of a material that typically has a Young's modulus that is higher than the Young's modulus of the card but lower than Young's modulus of the integrated circuit. This once again increases Smart Card reliability by utilizing a harder cavity material to protect the IC. ## Claims ### Claim 1 A data carrier, comprising: a card composed of a material having a Young's modulus, said card including a horizontal midplane therein, a cavity filled with a material having a Young's modulus and including a length, and a thickness, wherein said cavity is positioned by said thickness in said horizontal midplane of the card, and an integrated circuit composed of a material having a Young's modulus, said integrated circuit including a length and a thickness of less than 12 mils, located in said cavity and positioned by said thickness in the horizontal midplane of said card, wherein said Young's modulus of said cavity material is higher than the Young's modulus of said card and lower than the Young's modulus of said material in said integrated circuit. ### Claim 2 (depends on 1) A data carrier as claimed in claim 1 wherein said integrated circuit is centered by said thickness in the horizontal mid-plane of said card. ### Claim 3 (depends on 1) A data carrier as claimed in claim 1 wherein said cavity is centered by said thickness in the horizontal midplane of said card. ### Claim 4 (depends on 1) A data carrier as claimed in claim 1 wherein said integrated circuit is off center by no greater than said thickness of the integrated circuit. ### Claim 5 (depends on 1) A data carrier as claimed in claim 1 wherein said cavity is off center. ### Claim 6 (depends on 3) A data carrier as claimed in claim 3 wherein said integrated circuit is centered by said thickness within the horizontal mid-plane of the card. ### Claim 7 (depends on 1) A data carrier as claimed in claim 1 wherein said cavity is centered by said length and by said thickness in the horizontal midplane of said card. ### Claim 8 (depends on 7) A data carrier as claimed in claim 7 wherein said integrated circuit is centered by said length and by said thickness in said cavity. ### Claim 9 (depends on 1) A data carrier as claimed in claim 1 wherein a ratio of the length of said cavity to the length of said integrated circuit is between about 2:1 to about 6:1. ### Claim 10 (depends on 1) A data carrier as claimed in claim 1 wherein, a ratio of the thickness of said cavity to the thickness of said integrated circuit is between about 1.5:1 to about 6:1. ### Claim 11 (depends on 9) A data carrier as claimed in claim 9 wherein said ratio is between about 2:1 to about 4:1. ### Claim 12 (depends on 10) A data carrier as claimed in claim 10 wherein said ratio is between about 2:1 to about 4:1. ### Claim 13 (depends on 6) A data carrier as claimed in claim 6 wherein the length of said cavity is three times greater than the length of said integrated circuit and the thickness of the cavity is five times greater than the thickness of said integrated circuit. ### Claim 14 (depends on 1) A data carrier as claimed in claim 1, wherein the Young's modulus of said cavity material is between about 0.4.times.10.sup.6 psi and about 7.5.times.10.sup.6 psi. ### Claim 15 (depends on 1) A data carrier as claimed in claim 1 wherein said material of said card is a multi-layer composite. ### Claim 16 (depends on 1) A data carrier as claimed in claim 1 wherein said material in said cavity is an epoxy resin. ### Claim 17 (depends on 1) A data carrier as claimed in claim 1 wherein said integrated circuit material is silicon. ### Claim 18 A data carrier, comprising: a card composed of a material having a Young's modulus and including a horizontal midplane therein, a truncated cavity filled with a material having a Young's modulus and including a thickness, wherein said truncated cavity is positioned by thickness in the horizontal midplane of said card, and an integrated circuit located in said truncated cavity and including a thickness of less than 6 mils wherein said integrated circuit is positioned by thickness in the horizontal midplane of said card and wherein said Young's modulus of said truncated cavity material is higher than the Young's modulus of said card and lower than the Young's modulus of said material in said integrated circuit. ### Claim 19 (depends on 18) A data carrier as claimed in claim 18 wherein said integrated circuit is centered by said thickness in the horizontal mid-plane of said card. ### Claim 20 (depends on 19) A data carrier as claimed in claim 19 wherein said integrated circuit is off center by no more than said thickness of the integrated circuit. ### Claim 21 (depends on 20) A data carrier as claimed in claim 20 wherein said truncated cavity is centered by thickness in the horizontal mid-plane of said card. ### Claim 22 (depends on 21) A data carrier as claimed in claim 21 wherein said integrated circuit is centered in the horizontal mid-plane of the card. ### Claim 23 (depends on 18) A data carrier as claimed in claim 18 wherein said truncated cavity is truncated at about 1.backslash.4. ### Claim 24 (depends on 18) A data carrier as claimed in claim 18 wherein said truncated cavity is truncated at about 2/3. ### Claim 25 (depends on 18) A data carrier as claimed in claim 18 wherein said truncated cavity is truncated at about 1/2. ### Claim 26 (depends on 22) A data carrier as claimed in claim 22 wherein said truncated cavity is three times the length of said integrated circuit and five times the thickness of said integrated circuit. ### Claim 27 A data carrier, comprising: a card including a thickness of 0.9144 mm, a length of 7.62 mm, Young's modulus of 0.4.times.10.sup.6 psi, a poisson's ratio of 0.4, and a horizontal midplane therein, a cavity having a thickness and filled with a material having Young's modulus between about 0.1.times.10.sup.6 psi to about 17.5.times.10.sup.6 psi, wherein said cavity is centered by thickness in the horizontal midplane of said card, and an integrated circuit including a thickness of 6 mils, a length of 2.54 mm, a Young's modulus of 17.5.times.10.sup.6 psi and a poisson's ratio of 0.24 k, positioned in said cavity and centered by thickness in the horizontal midplane of said card.