# US 7,611,040 B2 · Method for forming solder bump and method for mounting semiconductor device using a solder powder resin composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,611,040 B2 - Document ID: US7611040B2 - Status: Granted - Kind: B2 - Application number: 11/579,505 - Filed: 2006-04-25 - Published: 2008-08-21 - Granted: 2009-11-03 - Earliest claimed: 2005-05-24 - Assignees: Panasonic Corporation - Inventors: Takashi Kitae; Seiichi Nakatani; Toshiyuki Kojima; Shingo Komatsu; Yoshihisa Yamashita - Web page: https://patentgrep.com/patent/US7611040B2 ## CPC - H05K 3/3485: Application of solder paste, slurry or powder (using printing techniques to form the desired conductive pattern of the printed circuit by applying conductive material H05K3/12) - H05K 3/3436: {having an array of bottom contacts, e.g. pad grid array or ball grid array components} - H10P 72/74: {using temporarily an auxiliary support} - H10W 70/099: {Connecting interconnections to insulating or insulated package substrates, interposers or redistribution layers} - H10W 72/20: Bump connectors, e.g. solder bumps or copper pillars; Dummy bumps; Thermal bumps - H10W 90/701: {characterised by the relative positions of pads or connectors relative to package parts} - H05K 3/323: {by applying an anisotropic conductive adhesive layer over an array of pads} - H05K 2201/09745: Recess in conductor, e.g. in pad or in metallic substrate - H05K 2201/10977: Encapsulated connections - H05K 2203/0108: Male die used for patterning, punching or transferring - H05K 2203/0113: Female die used for patterning or transferring, e.g. temporary substrate having recessed pattern - H05K 2203/043: Reflowing of solder coated conductors, not during connection of components, e.g. reflowing solder paste - H05K 2203/0465: Shape of solder, e.g. differing from spherical shape, different shapes due to different solder pads - H05K 2203/167: Using mechanical means for positioning, alignment or registration, e.g. using rod-in-hole alignment - H10W 72/01204: {using temporary auxiliary members, e.g. using sacrificial coatings or handle substrates} - H10W 72/01261: {Chemical or physical modification, e.g. by sintering or anodisation (patterning H10W72/01251)} - H10W 72/072: {of bump connectors} - H10W 72/07227: {involving guiding structures, e.g. spacers or supporting members} - H10W 72/07236: {Soldering or alloying} - H10W 72/073: {of die-attach connectors} - H10W 72/241: {Dispositions, e.g. layouts} - H10W 72/251: {Materials} - H10W 72/252: {comprising solid metals or solid metalloids, e.g. PbSn, Ag or Cu} - H10W 72/29: Bond pads specially adapted therefor - H10W 72/923: {Bond pads having multiple stacked layers} - H10W 72/952: {comprising metals or metalloids, e.g. PbSn, Ag or Cu} - H10W 74/012: {of encapsulations on active surfaces of flip-chip devices, e.g. forming underfills} - 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} - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A method for forming solder bumps for realizing high density mounting and a highly reliable method for mounting a semiconductor device is provided. A flat plate having a plurality of projections or recesses thereon is prepared; the flat plate is aligned to oppose an electronic component and a resin composition including a solder powder is supplied to a gap between the flat plate and the electronic component; the resin composition is annealed to melt the solder powder included in the resin composition for growing the solder powder up to the level of the surface of the flat plate by allowing the melted solder powder to self-assemble on terminals, so as to form solder bumps on the terminals; and the flat plate is removed after cooling and solidifying the solder bumps. Thus, the solder bumps having pits corresponding to the projections or having protrusions corresponding to the recesses are formed. ## Claims ### Claim 1 A method for forming solder bumps on terminals of an electronic component having a plurality of terminals on an upper surface of the electronic component, comprising the steps of: preparing a flat plate including a lower surface, the lower surface having a plurality of projections or recesses disposed thereon and a flat portion on which the plurality of projections or recesses are not disposed; supplying a resin composition including a solder powder to the upper surface of said electronic component; aligning the lower surface of the flat plate to oppose the upper surface of said electronic component; bringing the lower surface of the flat plate into contact with the resin so that the flat portion and the plurality of projections or recesses make contact with the resin thereby spreading the resin composition between the upper surface and the lower surface while the flat portion does not contact the upper surface; forming solder bumps on the terminals by melting the solder powder included in the resin composition by annealing of the resin composition and by allowing the melted solder powder to self-assemble on the terminals for growing the melted solder powder up to a level of a surface of said flat plate; and removing the flat plate after cooling and solidifying the solder bumps, wherein in the step of forming solder bumps, the solder bumps having pits corresponding to the projections or protrusions corresponding to the recesses are formed. ### Claim 2 (depends on 1) The method for forming solder bumps of claim 1, wherein said resin composition further includes a convection additive boiled or decomposed for releasing a gas when said resin composition is annealed in the step of forming solder bumps. ### Claim 3 (depends on 1) The method for forming solder bumps of claim 1, wherein the step of supplying a resin composition comprises the steps of: supplying said resin composition onto said electronic component; and allowing said flat plate to come into contact with a surface of said resin composition while opposing said electronic component. ### Claim 4 (depends on 3) The method for forming solder bumps of claim 3, wherein in the step of allowing said flat plate to come into contact with the surface of said resin composition, said flat plate is allowed to come into contact with said resin composition with said projections brought into contact with said terminals. ### Claim 5 (depends on 1) The method for forming solder bumps of claim 1, wherein said electronic component is a wiring board or a semiconductor device. ### Claim 6 (depends on 1) The method for forming solder bumps of claim 1, wherein a metal film having wettability with solder is formed on said projections or recesses of the flat plate. ### Claim 7 (depends on 1) The method for forming solder bumps of claim 1, wherein a mold releasing layer having a mold releasing property with said projections or recesses is formed on said projections or recesses of the flat plate. ### Claim 8 (depends on 1) The method for forming solder bumps of claim 1, further comprising, after the step of removing said flat plate, a step of removing said resin composition. ### Claim 9 (depends on 1) The method for forming solder bumps of claim 1, wherein in the step of forming solder bumps, said resin composition is annealed for allowing said resin composition to self-assemble on said terminals, said resin composition is further annealed to melt said solder powder included in said resin composition, and said melted solder powder is grown up to the level of the surface of said flat plate by allowing said melted solder powder to self-assemble on said terminals, whereby forming solder bumps on said terminals. ### Claim 10 (depends on 1) A method for mounting a semiconductor device on a wiring board, comprising the steps of: forming solder bumps having pits on terminals of one of said semiconductor device and said wiring board; forming solder bumps having protrusions on terminals of the other one of said semiconductor device and said wiring board; and mutually fitting and connecting said solder bumps formed on said terminals of said semiconductor device and said solder bumps formed on said terminals of said wiring board, wherein at least said solder bumps having pits or said solder bumps having protrusions are formed by the method for forming solder bumps of claim 1, ### Claim 11 (depends on 10) The method for mounting a semiconductor device of claim 10, wherein the step of mutually fitting and connecting said solder bumps includes a step of annealing for melting at least either of said solder bumps of said semiconductor device or said solder bumps of said wiring board mutually fit. ### Claim 12 (depends on 11) The method for mounting a semiconductor device of claim 11, wherein said solder bumps of said semiconductor device are made of a different solder material from said solder bumps of said wiring board.