US20050029328A1 - Method for checking the quality of a wedge bond - Google Patents

Method for checking the quality of a wedge bond Download PDF

Info

Publication number
US20050029328A1
US20050029328A1 US10/858,767 US85876704A US2005029328A1 US 20050029328 A1 US20050029328 A1 US 20050029328A1 US 85876704 A US85876704 A US 85876704A US 2005029328 A1 US2005029328 A1 US 2005029328A1
Authority
US
United States
Prior art keywords
capillary
wire
wire loop
bond
connection point
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/858,767
Inventor
Jonathan Medding
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Besi Switzerland AG
Original Assignee
Esec Trading AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Esec Trading AG filed Critical Esec Trading AG
Assigned to ESEC TRADING SA reassignment ESEC TRADING SA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MEDDING, JONATHAN
Publication of US20050029328A1 publication Critical patent/US20050029328A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L22/00—Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L24/85—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a wire connector
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • B23K20/002—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating specially adapted for particular articles or work
    • B23K20/004—Wire welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K31/00—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups
    • B23K31/12—Processes relevant to this subclass, specially adapted for particular articles or purposes, but not covered by only one of the preceding main groups relating to investigating the properties, e.g. the weldability, of materials
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
    • H01L21/60—Attaching or detaching leads or other conductive members, to be used for carrying current to or from the device in operation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/74—Apparatus for manufacturing arrangements for connecting or disconnecting semiconductor or solid-state bodies
    • H01L24/78—Apparatus for connecting with wire connectors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0014—Type of force applied
    • G01N2203/0023—Bending
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/022—Environment of the test
    • G01N2203/0248—Tests "on-line" during fabrication
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/026—Specifications of the specimen
    • G01N2203/0296—Welds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/02—Bonding areas; Manufacturing methods related thereto
    • H01L2224/04—Structure, shape, material or disposition of the bonding areas prior to the connecting process
    • H01L2224/05—Structure, shape, material or disposition of the bonding areas prior to the connecting process of an individual bonding area
    • H01L2224/0554—External layer
    • H01L2224/0555—Shape
    • H01L2224/05552—Shape in top view
    • H01L2224/05554—Shape in top view being square
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805—Shape
    • H01L2224/4809—Loop shape
    • H01L2224/48091—Arched
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481—Disposition
    • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/48245—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic
    • H01L2224/48247—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being metallic connecting the wire to a bond pad of the item
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/484—Connecting portions
    • H01L2224/48463—Connecting portions the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
    • H01L2224/48465—Connecting portions the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/49—Structure, shape, material or disposition of the wire connectors after the connecting process of a plurality of wire connectors
    • H01L2224/491—Disposition
    • H01L2224/4912—Layout
    • H01L2224/49171—Fan-out arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/74—Apparatus for manufacturing arrangements for connecting or disconnecting semiconductor or solid-state bodies and for methods related thereto
    • H01L2224/78—Apparatus for connecting with wire connectors
    • H01L2224/7825—Means for applying energy, e.g. heating means
    • H01L2224/783—Means for applying energy, e.g. heating means by means of pressure
    • H01L2224/78301—Capillary
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L2224/85—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a wire connector
    • H01L2224/852—Applying energy for connecting
    • H01L2224/85201—Compression bonding
    • H01L2224/85205—Ultrasonic bonding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L2224/85—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a wire connector
    • H01L2224/859—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a wire connector involving monitoring, e.g. feedback loop
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/42—Wire connectors; Manufacturing methods related thereto
    • H01L24/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L24/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L24/42—Wire connectors; Manufacturing methods related thereto
    • H01L24/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L24/49—Structure, shape, material or disposition of the wire connectors after the connecting process of a plurality of wire connectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001—Technical content checked by a classifier
    • H01L2924/00014—Technical content checked by a classifier the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01005—Boron [B]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01006—Carbon [C]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01013—Aluminum [Al]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01015—Phosphorus [P]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01018—Argon [Ar]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01033—Arsenic [As]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01039—Yttrium [Y]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01068—Erbium [Er]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/01—Chemical elements
    • H01L2924/01082—Lead [Pb]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/19—Details of hybrid assemblies other than the semiconductor or other solid state devices to be connected
    • H01L2924/1901—Structure
    • H01L2924/1904—Component type
    • H01L2924/19042—Component type being an inductor

Definitions

  • the invention concerns a method for checking the quality of a wedge bond.
  • a Wire Bonder is a machine with which wire connections are made to semiconductor chips after they have been mounted on a substrate.
  • the Wire Bonder has a capillary that is clamped to the tip of a horn.
  • the capillary serves to secure the wire to a connection point on the semiconductor chip and to a connection point on the substrate as well as to guide the wire between the two connection points.
  • the end of the wire protruding from the capillary is first melted into a ball. Afterwards, the wire ball is secured to the connection point on the semiconductor chip by means of pressure and ultrasonics. In doing so, ultrasound is applied to the horn from an ultrasonic transducer.
  • Ball bonding as well as wedge bonding are influenced by various factors. In order to achieve bond connections of a predetermined quality, the adequate values of several physical and/or technical parameters must be determined for a particular process. Examples of such parameters are:
  • the object of the invention is to develop a more suitable test for checking the quality of a wedge bond.
  • the checking of the quality of a wedge bond takes place in that the capillary of the wire bonder is used to push the wire loop formed between a first connection point on a semiconductor chip and a second connection point on a substrate, away at right angles to the longitudinal direction of the wire loop, until the wedge bond takes off or the wire breaks, whereby the capillary is applied close to the second connection point.
  • the test takes place with a method that is characterized by the following steps:
  • the test can be performed immediately after the production of the wire loop. The single steps are now explained in detail:
  • the sensor is for example a force sensor integrated into the bondhead.
  • the force sensor measures the force exerted by the horn at the tip of which the capillary is clamped on the bondhead.
  • the bondhead has two drives which enable the movement of the capillary parallel to the surface of the substrate.
  • One of the two drives can serve as the sensor, whereby the sensor signal is the current flowing through the drive.
  • the movement of the capillary must run orthogonally to the longitudinal direction of the wire loop. It is of advantage to align the longitudinal direction of the wire loop relative to the axis of movement of the bondhead such that only one of the two drives is necessary for moving the capillary orthogonally to the longitudinal direction of the wire loop. In this case only the current flowing through this drive has to be measured and analyzed.
  • either the current flowing through one of the two drives can be used as sensor signal or the currents flowing through the two drives can be measured and a single sensor signal formed from them.
  • FIGS. 1 and 2 show a plan and side view of a wire loop and a capillary of a wire bonder that formed the wire loop and is used in accordance with the invention in order to check the quality of the wire loop, and
  • FIG. 3 shows a plan view and schematically the bondhead of the Wire Bonder and two drives for the movement of the bondhead in the horizontal plane.
  • FIG. 1 shows schematically a plan view of a semiconductor chip 1 with several connection points 2 and a substrate 3 with several connection fingers 4 .
  • a wire loop 5 is formed between a first connection point 2 ′ on the semiconductor chip 1 and a second connection point 4 ′ on one of the connection fingers 4 .
  • the wire loop 5 is attached to the connection point 2 ′ with a ball bond 6 and to the connection point 4 ′ with a wedge bond 7 .
  • the wire loop 5 was formed by means of a capillary 8 that is mounted on a not presented bondhead of a Wire Bonder.
  • the capillary 8 is located to the side of the wire loop 5 at a height at which its tip is below the level of the application point of the capillary 8 on the wire loop 5 .
  • This condition is shown in FIG. 2 , it corresponds to the condition after carrying out step 2 of the process explained above.
  • FIG. 2 also shows the direction of movement 9 of the capillary 8 during step 3 of the process explained above.
  • the capillary 8 is placed next to the wedge bond 7 so that the force exerted by the capillary 8 on the wire loop 5 is transmitted from the wire to the wedge bond 7 so that the wedge bond 7 between the wire and the connection finger 4 ′ tears away and the wire itself is not torn in two.
  • FIG. 3 shows in plan view and schematically the bondhead 10 of the Wire Bonder and two drives 11 and 12 for the movement of the bondhead in the plane 13 .
  • the two drives 11 and 12 are linear motors with movement axes x and y running orthogonally to each other, whereby the linear motors allow also a movement of the bondhead orthogonally to their respective movement axis.
  • the linear motors each consist of a stator and a coil connected to the bondhead.
  • Such a bondhead is known for example from U.S. Pat. No. 5,114,302.
  • the direction of the wire loop 5 ( FIG. 1 ) is advantageously chosen such that the direction of movement 9 of the capillary 8 runs either parallel to the x-axis or parallel to the y-axis.
  • the current flowing through the drive 11 i.e. with this example the current flowing through the coil
  • the invention can also be implemented on any other Wire Bonder, for example on a Wire Bonder with a rotative bondhead according to U.S. Pat. No. 6,460,751.
  • connection on the first connection point is a so-called ball-bond and the connection on the second connection point is a so-called wedge-bond.
  • the bond connection on the first connection point can be any arbitrary bond connection, for example also a wedge-bond.
  • the invention can be used to either testing the quality of the wedge-bond on the first connection point or the quality of the wedge-bond on the second connection point.
  • the capillary 8 has to be placed next to the first connection point and in the second case as described by means of the example above next to the second connection point laterally besides the wire loop 5 .
  • the substrate is given by the application.
  • the substrate is for example a leadframe or a tape or foil with printed circuits or even a semiconductor chip if semiconductor chips are mounted directly on above each other (so-called stagged-die application).

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Wire Bonding (AREA)

Abstract

A method for checking the quality of a wedge bond between a wire loop and a connection point on a substrate, whereby the wire loop was formed by means of a capillary of a Wire Bonder, is characterised by the following steps: Placing the capillary at a side of the wire loop and next to the wedge bond, whereby the tip of the capillary is located below the level of the wire loop. Moving the capillary parallel to the surface of the substrate and orthogonally to the wire loop until the wedge bond tears away from the connection point or the wire breaks, and simultaneously measuring a signal that is a measure for a force exerted by the capillary on the wire loop, and Determining the maximum of the measured signal.

Description

    PRIORITY CLAIM
  • The present application claims priority under 35 U.S.C § 119 based upon Swiss Patent Application No. 2003 1087/03 filed on Jun. 18, 2003, the disclosure of which is herein incorporated by reference.
    • FIELD OF THE INVENTION
  • The invention concerns a method for checking the quality of a wedge bond.
    • BACKGROUND OF THE INVENTION
  • A Wire Bonder is a machine with which wire connections are made to semiconductor chips after they have been mounted on a substrate. The Wire Bonder has a capillary that is clamped to the tip of a horn. The capillary serves to secure the wire to a connection point on the semiconductor chip and to a connection point on the substrate as well as to guide the wire between the two connection points. On making the wire connection between the connection point on the semiconductor chip and the connection point on the substrate, the end of the wire protruding from the capillary is first melted into a ball. Afterwards, the wire ball is secured to the connection point on the semiconductor chip by means of pressure and ultrasonics. In doing so, ultrasound is applied to the horn from an ultrasonic transducer. This process is known as ball bonding. The wire is then pulled through to the required length, formed into a wire loop and welded to the connection point on the substrate. This last process is known as wedge bonding. After securing the wire to the connection point on the substrate, the wire is torn off and the next bond cycle can begin.
  • Ball bonding as well as wedge bonding are influenced by various factors. In order to achieve bond connections of a predetermined quality, the adequate values of several physical and/or technical parameters must be determined for a particular process. Examples of such parameters are:
    • the bond force, that is the normal force which the capillary exerts on the ball bond or the connection point of the semiconductor chip during the bonding process,
    • a parameter, designated herein as ultrasonic variable P, which controls the application of ultrasound to the ultrasonic transducer. The ultrasonic variable is, for example, the amplitude of the alternating current which flows through the ultrasonic transducer of the horn or the amplitude of the alternating voltage which is applied to the ultrasonic transducer, or the power, or another variable,
    • a time duration, designated herein as ultrasonic time T, which indicates the length of time that the ultrasonic variable P is applied to the ultrasonic transducer,
    • the impact velocity of the capillary on the connection point,
    • a binary parameter that indicates whether the ultrasonic variable is already applied to the ultrasonic transducer before the capillary impacts on the connection point.
  • Today, in order to characterise the bond quality in the sense of a quality control as well as to determine the optimum bond parameters, two methods are primarily used namely
    • a) a so-called Pull Test, with which the force is measured at which the bond tears away from the semiconductor chip or substrate when the bond is pulled in vertical direction in relation to the surface of the semiconductor chip or substrate, and
    • b) a so-called Shear Test, with which the force is measured at which the bond tears away from the semiconductor chip or substrate when the bond is pushed away parallel to the surface of the semiconductor chip or substrate by means of a tool.
  • These tests are normally carried out with equipment specially developed for this application. However, from the patent U.S. Pat. No. 5,894,981, a Wire Bonder is known which is set up to carry out a Pull Test. This Wire Bonder concerns a specific method for forming the wire loops with which the wire is not fed by a capillary. With the Pull Test, after forming the wedge bond, the wire is pulled away in a direction running vertically to the surface. The disadvantage with this test is that the check takes place before the bond cycle is completed as the wedge bond is still connected to the wire feed device.
  • From the patent U.S. Pat. No. 5,591,920, a Wire Bonder is known which is set up to carry out a Pull Test with which the maximum current is measured which flows through a motor that raises and lowers the capillary. This test can be carried out for Ball Bonds as well as for Wedge Bonds. When this Pull Test is carried out for a Wedge Bond, then an important disadvantage exists in that, on testing, load is not put on the wedge as with the established Pull Test, but on the piece of wire which is to be torn off in the last stage of the bond cycle, the so-called tail.
    • SUMMARY OF THE INVENTION
  • The object of the invention is to develop a more suitable test for checking the quality of a wedge bond.
  • In accordance with the invention, the checking of the quality of a wedge bond takes place in that the capillary of the wire bonder is used to push the wire loop formed between a first connection point on a semiconductor chip and a second connection point on a substrate, away at right angles to the longitudinal direction of the wire loop, until the wedge bond takes off or the wire breaks, whereby the capillary is applied close to the second connection point. The test takes place with a method that is characterized by the following steps:
    • Placing the capillary at a side of the wire loop and next to the wedge bond, whereby the tip of the capillary is located below the level of the wire loop.
    • Moving the capillary parallel to the surface of the substrate and orthogonally to the wire loop until the wedge bond tears away from the connection point or the wire breaks, and simultaneously measuring a signal that is a measure for a force exerted by the capillary on the wire loop, and
    • Determining the maximum of the measured signal.
    DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • The test can be performed immediately after the production of the wire loop. The single steps are now explained in detail:
      • 1. With a normal bond cycle, a wire loop is formed between a first connection point on the semiconductor chip and a second connection point on the substrate. The bond connection on the first connection point usually is a so-called “ball” bond, the bond connection on the second connection point is a so-called “wedge” bond. After forming the wedge bond, the wire is torn off as usual and a new wire ball is formed on the capillary.
      • 2. The capillary of the Wire Bonder is placed at one side of the formed wire loop without touching the wire loop. The tip of the capillary is located below the level of the wire loop.
      • 3. The capillary is moved parallel to the surface of the substrate and orthogonally, i.e. at right angles, to the wire loop. In doing so, it comes into contact with the wire, pulls and stretches the wire until finally the wedge bond tears away or the wire breaks. During this movement, the signal of a sensor that is a measure for the force exerted by the capillary on the wire loop is measured continually and afterwards the maximum of this signal is determined. This maximum is a measure for the force that was necessary in order to tear off the wire.
  • The sensor is for example a force sensor integrated into the bondhead. The force sensor measures the force exerted by the horn at the tip of which the capillary is clamped on the bondhead.
  • The bondhead has two drives which enable the movement of the capillary parallel to the surface of the substrate. One of the two drives can serve as the sensor, whereby the sensor signal is the current flowing through the drive. The movement of the capillary must run orthogonally to the longitudinal direction of the wire loop. It is of advantage to align the longitudinal direction of the wire loop relative to the axis of movement of the bondhead such that only one of the two drives is necessary for moving the capillary orthogonally to the longitudinal direction of the wire loop. In this case only the current flowing through this drive has to be measured and analyzed.
  • If the longitudinal direction of the wire loop with respect to the movement axis of the bondhead is not aligned specially and if therefore both drives are necessary in order to move the capillary orthogonally to the longitudinal direction of the wire loop then either the current flowing through one of the two drives can be used as sensor signal or the currents flowing through the two drives can be measured and a single sensor signal formed from them.
    • BRIEF DESCRIPTION OF THE DRAWING FIGURES
  • The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate the placing of the capillary in step 2 and its movement in step 3. The figures are not to scale.
  • In the drawings:
  • FIGS. 1 and 2 show a plan and side view of a wire loop and a capillary of a wire bonder that formed the wire loop and is used in accordance with the invention in order to check the quality of the wire loop, and
  • FIG. 3 shows a plan view and schematically the bondhead of the Wire Bonder and two drives for the movement of the bondhead in the horizontal plane.
  • FIG. 1 shows schematically a plan view of a semiconductor chip 1 with several connection points 2 and a substrate 3 with several connection fingers 4. A wire loop 5 is formed between a first connection point 2′ on the semiconductor chip 1 and a second connection point 4′ on one of the connection fingers 4. The wire loop 5 is attached to the connection point 2′ with a ball bond 6 and to the connection point 4′ with a wedge bond 7. The wire loop 5 was formed by means of a capillary 8 that is mounted on a not presented bondhead of a Wire Bonder. The capillary 8 is located to the side of the wire loop 5 at a height at which its tip is below the level of the application point of the capillary 8 on the wire loop 5. This condition is shown in FIG. 2, it corresponds to the condition after carrying out step 2 of the process explained above. FIG. 2 also shows the direction of movement 9 of the capillary 8 during step 3 of the process explained above.
  • With this test, the quality of the wedge bond should be determined. For this reason, in process step 2 the capillary 8 is placed next to the wedge bond 7 so that the force exerted by the capillary 8 on the wire loop 5 is transmitted from the wire to the wedge bond 7 so that the wedge bond 7 between the wire and the connection finger 4′ tears away and the wire itself is not torn in two.
  • FIG. 3 shows in plan view and schematically the bondhead 10 of the Wire Bonder and two drives 11 and 12 for the movement of the bondhead in the plane 13. In this example the two drives 11 and 12 are linear motors with movement axes x and y running orthogonally to each other, whereby the linear motors allow also a movement of the bondhead orthogonally to their respective movement axis. The linear motors each consist of a stator and a coil connected to the bondhead. Such a bondhead is known for example from U.S. Pat. No. 5,114,302. The direction of the wire loop 5 (FIG. 1) is advantageously chosen such that the direction of movement 9 of the capillary 8 runs either parallel to the x-axis or parallel to the y-axis. If the direction of movement 9 of the capillary 8 runs parallel to the x-axis then the current flowing through the drive 11, i.e. with this example the current flowing through the coil, can be used as the sensor signal. The invention can also be implemented on any other Wire Bonder, for example on a Wire Bonder with a rotative bondhead according to U.S. Pat. No. 6,460,751.
  • The invention has been described by means of a widely known standard process with which the connection on the first connection point is a so-called ball-bond and the connection on the second connection point is a so-called wedge-bond. As it is aimed to determine the quality of the wedge bond on the second connection point the bond connection on the first connection point can be any arbitrary bond connection, for example also a wedge-bond. But in this case the invention can be used to either testing the quality of the wedge-bond on the first connection point or the quality of the wedge-bond on the second connection point. In the first case the capillary 8 has to be placed next to the first connection point and in the second case as described by means of the example above next to the second connection point laterally besides the wire loop 5.
  • The substrate is given by the application. The substrate is for example a leadframe or a tape or foil with printed circuits or even a semiconductor chip if semiconductor chips are mounted directly on above each other (so-called stagged-die application).
  • While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art having the benefit of this disclosure that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims and their equivalents.

Claims (2)

1. A method for checking the quality of a wedge bond formed between a wire loop and a connection point on a substrate, whereby the wire loop has been formed by means of a capillary of a Wire Bonder, the method comprising the following steps:
placing the capillary of the Wire Bonder at a side of the wire loop and next to the wedge bond, whereby a tip of the capillary is located below a level of the wire loop,
moving the capillary parallel to a surface of the substrate and orthogonally to the wire loop until the wedge bond tears away from the connection point or the wire breaks, and simultaneously measuring a signal that is a measure for a force exerted by the capillary on the wire loop, and
determining a maximum of the measured signal.
2. Method according to claim 1, wherein the signal is a strength of a current that flows through a drive moving the capillary.
US10/858,767 2003-06-18 2004-06-02 Method for checking the quality of a wedge bond Abandoned US20050029328A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH10872003 2003-06-18
CH20031087/03 2003-06-18

Publications (1)

Publication Number Publication Date
US20050029328A1 true US20050029328A1 (en) 2005-02-10

Family

ID=33515058

Family Applications (2)

Application Number Title Priority Date Filing Date
US10/858,767 Abandoned US20050029328A1 (en) 2003-06-18 2004-06-02 Method for checking the quality of a wedge bond
US10/863,303 Expired - Fee Related US7080771B2 (en) 2003-06-18 2004-06-08 Method for checking the quality of a wedge bond

Family Applications After (1)

Application Number Title Priority Date Filing Date
US10/863,303 Expired - Fee Related US7080771B2 (en) 2003-06-18 2004-06-08 Method for checking the quality of a wedge bond

Country Status (5)

Country Link
US (2) US20050029328A1 (en)
KR (1) KR20040110983A (en)
CN (1) CN100516826C (en)
DE (1) DE102004028397B4 (en)
TW (1) TWI231367B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140103096A1 (en) * 2012-10-15 2014-04-17 Hanmin Zhang Wire bonding machine and method for testing wire bond connections

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006049624B4 (en) * 2006-10-20 2016-07-14 Hesse Gmbh ultrasonic Bonder
CN103149097B (en) * 2013-03-07 2015-05-13 中国空间技术研究院 Tension testing device of pin lead wire of electronic component
CN115356205B (en) * 2022-07-27 2024-04-09 苏州信息职业技术学院 Wire bonding quality test system and test method for semiconductor chip

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3890831A (en) * 1973-01-19 1975-06-24 Us Navy Ultrasonic bond monitor
US4040885A (en) * 1974-07-09 1977-08-09 U.S. Philips Corporation Ultrasonic bonding apparatus
US4373653A (en) * 1981-09-10 1983-02-15 Raytheon Company Method and apparatus for ultrasonic bonding
US4998664A (en) * 1989-12-22 1991-03-12 Hughes Aircraft Company Bond signature analyzer
US5323952A (en) * 1991-09-18 1994-06-28 Hitachi, Ltd. Bonding apparatus and testing apparatus of a bonded portion
US5591920A (en) * 1995-11-17 1997-01-07 Kulicke And Soffa Investments, Inc. Diagnostic wire bond pull tester
US5894981A (en) * 1996-11-27 1999-04-20 Orthodyne Electronics Corporation Integrated pull tester with an ultrasonic wire bonder
US20040226983A1 (en) * 2003-04-04 2004-11-18 Hesse & Knipps Gmbh Method of and apparatus for testing a wire bond connection

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5412997A (en) * 1992-12-11 1995-05-09 Industrial Technology Research Institute Nondestructive testing apparatus and method
NL1001532C1 (en) * 1995-10-31 1997-05-02 Gerold Staudinger Device for testing connections between an (electronic) building element and a carrier provided with conductive tracks.
GB9811795D0 (en) * 1998-06-03 1998-07-29 Dage Precision Ind Inc Test apparatus
US6564115B1 (en) * 2000-02-01 2003-05-13 Texas Instruments Incorporated Combined system, method and apparatus for wire bonding and testing
TWI229397B (en) * 2002-10-16 2005-03-11 Esec Trading Sa Method for determining optimum bond parameters when bonding with a wire bonder

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3890831A (en) * 1973-01-19 1975-06-24 Us Navy Ultrasonic bond monitor
US4040885A (en) * 1974-07-09 1977-08-09 U.S. Philips Corporation Ultrasonic bonding apparatus
US4373653A (en) * 1981-09-10 1983-02-15 Raytheon Company Method and apparatus for ultrasonic bonding
US4998664A (en) * 1989-12-22 1991-03-12 Hughes Aircraft Company Bond signature analyzer
US5323952A (en) * 1991-09-18 1994-06-28 Hitachi, Ltd. Bonding apparatus and testing apparatus of a bonded portion
US5591920A (en) * 1995-11-17 1997-01-07 Kulicke And Soffa Investments, Inc. Diagnostic wire bond pull tester
US5894981A (en) * 1996-11-27 1999-04-20 Orthodyne Electronics Corporation Integrated pull tester with an ultrasonic wire bonder
US20040226983A1 (en) * 2003-04-04 2004-11-18 Hesse & Knipps Gmbh Method of and apparatus for testing a wire bond connection

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140103096A1 (en) * 2012-10-15 2014-04-17 Hanmin Zhang Wire bonding machine and method for testing wire bond connections

Also Published As

Publication number Publication date
US7080771B2 (en) 2006-07-25
CN1573313A (en) 2005-02-02
DE102004028397A1 (en) 2005-01-20
US20040256438A1 (en) 2004-12-23
TWI231367B (en) 2005-04-21
DE102004028397B4 (en) 2008-12-18
TW200506336A (en) 2005-02-16
KR20040110983A (en) 2004-12-31
CN100516826C (en) 2009-07-22

Similar Documents

Publication Publication Date Title
US6247629B1 (en) Wire bond monitoring system for layered packages
EP1486790B1 (en) Mounting method and mounting apparatus of electronic part
EP0368533B1 (en) Quality control for wire bonding
US9620477B2 (en) Wire bonder and method of calibrating a wire bonder
US9899348B2 (en) Wire bonding apparatus and method of manufacturing semiconductor device
KR20190040501A (en) Wire bonding method and wire bonding device
SG192342A1 (en) Method of recovering a bonding apparatus from a bonding failure
US7080771B2 (en) Method for checking the quality of a wedge bond
US6929168B2 (en) Method for determining optimum bonding parameters for bonding with a wire bonder
US20040079790A1 (en) Method for determining optimum bond parameters when bonding with a wire bonder
US11935864B2 (en) Methods of optimizing clamping of a semiconductor element against a support structure on a wire bonding machine, and related methods
JP3724875B2 (en) A wire bonding method, a semiconductor mounting method using the wire bonding method, a wire bonding apparatus, and a semiconductor mounting apparatus including the wire bonding apparatus.
Mayer et al. Ultrasonic bonding: understanding how process parameters determine the strength of Au-Al bonds
KR101548949B1 (en) Ultrasonic bonding typed metal wire bonding apparatus
KR20220005102A (en) Bonding detection method between bonding wire and bonding position of wire bonding machine
US20220270937A1 (en) Methods of determining shear strength of bonded free air balls on wire bonding machines
Mayer In situ Monitoring of Microjoining Processes
JP2002076049A (en) Wire bonding equipment and method for manufacturing electrical component
KR20050043258A (en) Wire boding machine
JP2004048075A (en) Wire bonding apparatus
JPH06326161A (en) Quality discriminator in ultrasonic wire bonder

Legal Events

Date Code Title Description
AS Assignment

Owner name: ESEC TRADING SA, SWITZERLAND

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MEDDING, JONATHAN;REEL/FRAME:015424/0907

Effective date: 20040525

STCB Information on status: application discontinuation

Free format text: EXPRESSLY ABANDONED -- DURING EXAMINATION