# US 2010/0163608 A1 · Method for depositing solder material on an electronic component part > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0163608 A1 - Document ID: US20100163608A1 - Status: Published application - Kind: A1 - Application number: 12/582,637 - Filed: 2009-10-20 - Published: 2010-07-01 - Earliest claimed: 2005-12-30 - Inventors: Kenneth J. Huth; Lawrence C. Monterulo; John C. Sugrue - Web page: https://patentgrep.com/patent/US20100163608A1 ## CPC - H05K 3/3478: Application of solder preforms; Transferring prefabricated solder patterns - H05K 2203/0113: Female die used for patterning or transferring, e.g. temporary substrate having recessed pattern - H05K 2203/0338: Transferring metal or conductive material other than a circuit pattern, e.g. bump, solder, printed component - H05K 2203/041: Solder preforms in the shape of solder balls - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract A method for accurately depositing a required volume of solder material on a specific area of a lead frame, substrate or other part (4) of an electronic component to be bonded by reflow of solder material to another part into a reliable, void-free connection during a subsequent assembly step comprises the following steps. Minute particles (3) of solder material whose cumulative volume corresponds to the total volume to be deposited are loaded into a cavity (2) cut into a fixture (1) made from a material such as graphite. The cavity delineates the specific area of deposit. The part (4) is then laid upon the fixture and immobilized thereon by a cover (7) made from a material such as graphite. The fixture and its enclosed part are then subjected to solder material melting temperature under a controlled atmosphere in a furnace. The cavity is patterned and dimensioned to accommodate the right number of uniformly dimensioned particles necessary to precisely create the desired deposit of solder material. ## Claims ### Claim 1 A method for accurately depositing a metered volume of solder material of a given melting point on a delineated area of an electronic component part, said method comprising the steps of: providing a fixture having a top surface shaped and dimensioned for intimate contact with said area, and a melting temperature substantially higher than said melting point; carving into said top surface a cavity shaped to be congruent with said area; placing into said cavity a number of particles of said solder material; positioning said part against said top surface and said particles in contact with said area; and exposing said fixture and part to a temperature at least equal to said melting point; whereby the material of said particles melts and adheres to said area. ### Claim 2 (depends on 1) The method of claim 1 which further comprises securing said part upon said fixture with a cover. ### Claim 3 (depends on 1) The method of claim 1, wherein said fixture is made of a material comprising high density graphite. ### Claim 4 (depends on 1) The method of claim 1, wherein said solder material comprises a metal alloy selected from the group consisting of gold alloys, tin alloys, lead alloys, copper alloys, and silver alloys. ### Claim 5 (depends on 1) The method of claim 1, wherein said solder material comprises a metal alloy selected from the group consisting of AuSn, AuGe, AuSi, AuAgCu, AgCu, and PbSnAg. ### Claim 6 (depends on 1) The method of claim 1, wherein said delineated area comprises an electronic package lead frame. ### Claim 7 (depends on 1) The method of claim 1, wherein said delineated area comprises a marginal, peripheral area of a microelectronic package lid. ### Claim 8 (depends on 1) The method of claim 1, wherein said cavity is segmented into a plurality of ditches. ### Claim 9 (depends on 8) The method of claim 8, wherein two of said plurality of ditches are differently dimensioned. ### Claim 10 (depends on 1) The method of claim 1, wherein said particles are laid in a single row into said cavity. ### Claim 11 (depends on 1) The method of claim 1, wherein said particles are substantially uniform. ### Claim 12 (depends on 1) The method of claim 1, wherein said particles are laid in a plurality of rows into said cavity. ### Claim 13 (depends on 1) The method of claim 1, wherein said particles are symmetrical, and have calculated dimensions. ### Claim 14 (depends on 1) The method of claim 1, wherein said particles are spherical, and have a calculated diameter and radius. ### Claim 15 (depends on 1) The method of claim 1, wherein the cumulative volume of said particles is equal to said metered volume. ### Claim 16 (depends on 14) The method of claim 14, wherein said cavity has a constant depth greater than said diameter. ### Claim 17 (depends on 1) The method of claim 1, wherein said step of positioning comprises inverting said fixture and part. ### Claim 18 (depends on 14) The method of claim 14, wherein said cavity has a constant depth lesser than said diameter. ### Claim 19 (depends on 1) The method of claim 1, which further comprises pressing said part against said fixture. ### Claim 20 (depends on 14) The method of claim 14, wherein said cavity has an arcuate bottom of a radius commensurate with the radius of said particles. ### Claim 21 (depends on 14) The method of claim 14, wherein said cavity has a series of spaced-apart bottom separators dimensioned to intimately nest said particles. ### Claim 22 (depends on 21) The method of claim 21, wherein said separators are regularly spaced-apart at a calculated interval.