# US 8,785,253 B2 · Leadframe for IC package and method of manufacture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,253 B2 - Document ID: US8785253B2 - Status: Granted - Kind: B2 - Application number: 13/262,709 - Filed: 2010-02-26 - Published: 2012-02-02 - Granted: 2014-07-22 - Earliest claimed: 2009-04-03 - Assignees: Kaixin, Inc. - Applicants: Tunglok Li - Inventors: Tunglok Li - Web page: https://patentgrep.com/patent/US8785253B2 ## CPC - H10W 72/00: Interconnections or connectors in packages - H10W 70/042: {Etching} - H10W 70/457: {of metallic layers on leadframes} - H10W 74/00: Encapsulations, e.g. protective coatings - H10W 74/111: {the semiconductor body being completely enclosed} - H10W 90/756: {between a chip and a stacked lead frame, conducting package substrate or heat sink} - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A leadframe for use in an integrated circuit (IC) package comprising a metal strip partially etched on a first side. In some embodiments, the leadframe may be selectively plated on the first side and/or on a second side. The leadframe may be configured for an IC chip to be mounted thereon and for a plurality of electrical contacts to be electrically coupled to the leadframe and the IC chip. ## Claims ### Claim 1 A method of manufacturing a leadframe for an integrated circuit (IC) package, the method comprising: receiving design criteria for a partially patterned leadframe for use in an IC package, the design criteria including a first number of bonding areas to be disposed on a top surface of the leadframe and a second number of contact areas to be disposed on a bottom surface of the leadframe; providing at a first location a metal strip having a top surface and a generally flat bottom surface; etching at the first location the top surface of the metal strip to define a plurality of bonding areas equal to the number of bonding areas from the design criteria and to define upper portions of a plurality of metal traces, each metal trace extending from the top surface to the bottom surface of the metal strip and coupling a bonding area of the plurality of bonding areas to an area disposed on the bottom surface of the metal strip where a contact area will be defined; wherein at least one metal trace couples a bonding area of the plurality of bonding areas to a contact area laterally remotely disposed from beneath the bonding area; transporting the metal strip from the first location to a second location prior to an IC chip being mounted thereto, the first location being a first manufacturing facility and the second location being a second manufacturing facility remotely disposed from the first manufacturing facility; and wherein the generally flat bottom surface provides support for the metal traces integrally formed therewith during the transporting of the metal strip. ### Claim 2 (depends on 1) The method of claim 1, wherein the second location is a location of a customer sending the design criteria. ### Claim 3 (depends on 1) The method of claim 1 comprising mounting, at the second location, an IC chip to the top surface of the metal strip. ### Claim 4 (depends on 3) The method of claim 3, wherein the IC chip is mounted to at least one metal trace, the at least one metal trace coupling a contact area disposed beneath the IC chip to a bonding area disposed peripherally to the IC chip. ### Claim 5 A method of manufacturing a leadframe for an integrated circuit (IC) package, the method comprising: receiving design criteria for a partially patterned leadframe for use in an IC package, the design criteria including a first pattern of locations of a plurality of bonding areas to be disposed on a top surface of the leadframe and a second pattern of locations of a plurality of contact areas to be disposed on a bottom surface of the leadframe; providing, at a first location, a metal strip having a top surface and a generally flat bottom surface; etching, at the first location, the top surface of the metal strip to define the plurality of bonding areas at the locations of the first pattern and to define upper portions of a plurality of metal traces, the plurality of metal traces coupling the locations of the first pattern of the plurality of bonding areas on the top surface of the metal strip to the locations of the second pattern of the plurality of contact areas on the bottom surface of the metal strip; applying a metal plating to the locations of the first pattern of the plurality of bonding areas and to the locations of the second pattern of the plurality of contact areas on the bottom surface of the metal strip; transporting the etched metal strip to a second location, the first location being a first manufacturing facility and the second location being a second manufacturing facility remotely disposed from the first manufacturing facility; and wherein at least one of the plurality of metal traces electrically couples a bonding area laterally disposed from a contact area such that no line perpendicular to the top surface of the metal strip intersects both the bonding area and the contact area electrically coupled thereto via the metal trace. ### Claim 6 (depends on 5) The method of claim 5 comprising: cleaning the etched metal strip at the first location; and preparing the etched metal strip for transport to a the second location. ### Claim 7 (depends on 6) The method of claim 6, wherein the receiving the design criteria is in conjunction with a customer order. ### Claim 8 (depends on 5) The method of claim 5 comprising mounting, at the second location an IC chip to the top surface of the metal strip. ### Claim 9 (depends on 5) The method of claim 5 comprising transporting the etched metal strip to a location of a customer sending the design criteria of the IC package to the first location. ### Claim 10 A method of manufacturing a leadframe for an integrated circuit (IC) package, the method comprising: performing a first leadframe manufacturing process at a first location, the first manufacturing process comprising: providing a metal strip having a top surface and a generally flat bottom surface; etching a pattern into the top surface of the metal strip defining upper portions of a plurality of metal traces, each metal trace extending from the top surface to the bottom surface of the metal strip and having a bonding area disposed on the top surface thereof and a contact area disposed on the bottom surface thereof; and applying a metal plating to each bonding area to form a leadframe subassembly adapted for transport; transporting the leadframe subassembly from the first location to a second location, the first location being a first manufacturing facility and the second location being a second manufacturing facility remotely disposed from the first manufacturing facility; performing a second manufacturing process at the second location, the second manufacturing process comprising: mounting an IC chip onto the top surface of the metal strip; electrically coupling the IC chip to the plurality of bonding areas; and encapsulating the IC chip in an encapsulation compound; and etching the bottom surface of the leadframe to electrically isolate the metal traces from one another such that at least one of the plurality of metal traces electrically couples a bonding area laterally disposed from a contact area wherein no line perpendicular to the top surface of the metal strip intersects both the bonding area and the contact area electrically coupled thereto via the metal trace. ### Claim 11 (depends on 10) The method of claim 10, wherein the first manufacturing process is performed in at least partial dependence on design criteria of the IC package. ### Claim 12 A method of manufacturing a leadframe for an integrated circuit (IC) package, the method comprising: providing, at a first location, a metal strip having a top surface and a generally flat bottom surface; etching, at the first location, a pattern into the top surface of the metal strip defining upper portions of a plurality of metal traces, each metal trace extending from the top surface to the bottom surface of the metal strip and having a bonding area disposed on the top surface thereof and a contact area disposed on the bottom surface thereof; applying a pattern of metal plating to top surface and the bottom surface, the pattern of metal plating covering each bonding area and each contact area; facilitating transporting the etched metal strip to a second location, the first location being a first manufacturing facility and the second location being a second manufacturing facility remotely disposed from the first manufacturing facility; wherein, when remaining portions of the metal strip disposed between the plurality of metal traces are etched away, the plurality of metal traces are electrically isolated from one another; and wherein at least one of the plurality of metal traces electrically couples a bonding area laterally disposed from a contact area such that no line perpendicular to the top surface of the metal strip intersects both the bonding area and the contact area electrically coupled to the bonding area via the metal trace. ### Claim 13 (depends on 12) The method of claim 12 comprising: transporting the etched metal strip to a location of a customer sending design criteria of the IC package to the first location. ### Claim 14 (depends on 12) The method of claim 12, wherein the pattern is etched into the top surface of the metal strip in at least partial dependence on design criteria of the IC package.