US5148964A
Expired / Lapsed
US
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Wire bonding method
Assignee: Toshiba Corp
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Filing: 1991-01-25
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Granted: 1992-09-22
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Expires: 2011-01-25
Abstract
Abstract A wire bonding method for connecting an electrode pad on a semiconductor chip and an inner lead of a lead frame through a metal wire is described. The wire bonding method is performed by moving a bonding tool holding the wire metal. The method comprises the steps of calculating the height difference between the electrode pad and the inner lead, determining a reverse movement amount of the bonding tool according to the height difference, and reversing the bonding tool horizontally at a predetermined level by the determined reverse movement amount while raising vertically the bonding tool. According to the present invention, the amount of reverse movement of the bonding tool may be automatically changed in accordance with the height difference and without reliance on an operator.
Inventors
- 👤 Yasuhiko Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:34
CPC Classifications
B; B23; B23K; B23K20/00; B23K20/10; H; H10; H10W; H10W72/00; H10W72/071; H10W72/0711; H10W72/07141; H10W72/075; H10W72/07521; H10W72/07531; H10W72/07532; H10W72/07533; H10W72/50; H10W72/531; H10W72/536; H10W72/5363; H10W72/5366; H10W72/551; H10W72/552; H10W72/5522; H10W72/5524; H10W72/59; H10W72/90; H10W72/951; H10W72/952; H10W90/00; H10W90/701; H10W90/751; H10W90/756
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
179 words
A wire bonding method for connecting an electrode pad on a semiconductor chip and an inner lead of a lead frame through metal wire, by moving a bonding tool holding the metal wire and providing a loop in the metal wire, comprising the steps of: calculating a height difference between the electrode pad and the inner lead, determining a reverse movement amount of the bonding tool according to said height difference, bonding the metal wire held by the bonding tool to the electrode pad, raising vertically the bonding tool to a predetermined level at which the bonding tool is reversed, reversing horizontally the bonding tool in a direction opposite to the inner lead, to provide a horizontal section of wire, at the predetermined level by the reverse movement amount determined by the determining step, wherein the horizontal section is below a top of the loop to be provided, raising vertically the bonding tool further to a top level, moving the bonding tool from the top level to the inner lead, and bonding the metal wire to the inner lead.
Claim 2
Dependent Claim
179 words
A wire bonding method for connecting an electrode pad on a semiconductor chip and an inner lead of a lead frame through metal wire, by moving a bonding tool holding the metal wire and providing a loop in the metal wire, comprising the steps of: calculating a height difference between the electrode pad and the inner lead, determining a reverse movement amount of the bonding tool according to said height difference, bonding the metal wire held by the bonding tool to the electrode pad, raising vertically the bonding tool to a predetermined level at which the bonding tool is reversed, reversing horizontally the bonding tool in a direction opposite to the inner lead, to provide a horizontal section of wire, at the predetermined level by the reverse movement amount determined by the determining step, wherein the horizontal section is below a top of the loop to be provided, raising vertically the bonding tool further to a top level, moving the bonding tool from the top level to the inner lead, and bonding the metal wire to the inner lead.
Claim 3
Dependent Claim
62 words
The method as claimed in claim 1, wherein the step of calculating the height difference comprises lowering the bonding tool, holding the metal wire until the metal wire comes in contact with the electrode pad and the inner lead respectively, and detecting the contact points between the metal wire and the electrode pad and between the metal wire and the inner lead.
Claim 4
Dependent Claim
32 words
The method as claimed in claim 1, wherein the steps of calculating the height difference and determining the reverse movement amount are performed in sequence for each electrode pad and inner lead.
Claim 5
Dependent Claim
35 words
The method as claimed in claim 3, wherein the steps of calculating the height difference and determining the reverse movement amount are performed by using data based on the preceding electrode pad and inner lead.
Claim 6
Dependent Claim
23 words
The method as claimed in claim 1, wherein the step of determining the reverse movement amount is performed by using an interpolation law.
Claim 7
Dependent Claim
16 words
A method as claimed in claim 1, wherein the determining step uses only the height difference.
Claim 8
Dependent Claim
28 words
The method as claimed in claim 1, wherein the reversing step creates a horizontal section in the loop and a vertical section in the wire below the loop.
Claim 9
Dependent Claim
62 words
The method as claimed in claim 1, wherein the bonding to the electrode pad comprises: lowering the bonding tool toward the chip until a predetermined search height is reached; further lowering the bonding tool at a decelerated speed; detecting an impact of the wire against an electrode pad on the chip; and forming a bond between the wire and the electrode pad.
Claim 10
Dependent Claim
24 words
The method as claimed in claim 8, wherein the forming step is performed by at least one of ultrasonic oscillation and application of heat.
References Cited (Backward Citations)
US4327860A
Cited
US4445633A
Cited
US4610387A
Cited
JPS6342135A
Cited
US4932584A
Cited
JPS6358849A
Cited
JPS63232344A
Cited
US4958762A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-22 | 1996-03-23 | 1996-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-22 | 2000-03-23 | 2000-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-22 | 2004-03-23 | 2004-09-22 | $7700.00 | Window Closed / Lapsed |