Bonding wire and integrated circuit device using the same

A technology for bonding wires and coating layers, which is applied to circuits, electrical components, electrical solid devices, etc., and can solve problems such as cross-sectional shape deviation, short mold life, and partial peeling of coating layers.

Inactive Publication Date: 2008-09-24
SUMITOMO ELECTRIC IND LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0019] However, high-melting point metals are generally difficult to draw, and it has been pointed out that the methods with the above-mentioned excellent characteristics still have the following 1-4 problems, which all need to be improved
[0020] 1. Higher frequency of lead breakage and lower yield compared to gold
[0021] 2. The drawing die is easy to wear, and the life of the die is short
[0022] 3. Although the possibility of delamination of the coating layer is reduced, there is still the possibility that the coating layer may be partially peeled off or the coating layer may be cracked during the wire drawing process
[0023] 4. The diameter of a drawn lead may vary along its length, or the cross-sectional shape of a drawn lead may deviate from a true circle
[0024] Problems 1 and 2 lead to increased production costs, while problems 3 and 4 lead to reduced bonding characteristics (hereinafter, problems 1-4 are referred to as "problems of poor drawability")

Method used

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  • Bonding wire and integrated circuit device using the same
  • Bonding wire and integrated circuit device using the same
  • Bonding wire and integrated circuit device using the same

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0104]A 0.8 μm-thick coating layer was formed by electroplating on a core copper lead having a purity of 99.995% and a diameter of 200 μm. By drawing and annealing the wire, various types of bonding wires having a core diameter of 25.2 μm and a coating layer thickness of 0.1 μm were produced. Using various leads, 100 balls with a diameter of 60 μm were formed by using a bonder (model FB 137 manufactured by Kaijo Co., Ltd.), and the number of occurrences of shape defects in which the center of the ball was displaced from the center of the lead was checked. The results are shown in Table 1 together with the core and coating materials used.

[0105] The wet contact angle when the core material was melted was measured by using high temperature wettability test apparatus WET1200 manufactured by ULVAC-RIKO in the following manner.

[0106] A piece of material produced by compressing 2.5 mm sized balls of core material into an easily mountable shape was placed on a piece of coating ...

example 2

[0112] (1) An approximately 0.04 μm thick gold underplating film was formed by underplating on a copper lead having a purity of 99.995% and a diameter of 200 μm. After that, a 0.8 µm thick palladium plating film was formed. By drawing and annealing the wires, copper bonding wires are produced. The copper core diameter of each bonding wire is 25.2 μm, the thickness of the palladium layer (coating layer) is 0.1 μm, and the thickness of the gold layer (different metal layer) is about 0.005 μm, the elongation is 15%. Samples with various radii of curvature were produced by adjusting the diameter of the guide roll and the tension used to wind the lead wire around the spool. Using various samples, a 208-pin QFP (copper lead frame, silver spot plating) with a loop length of about 4 mm was applied by applying a load of 80 g and ultrasonic energy of 160 using a bonding machine (model EAGLE AB339 manufactured by ASM) Bonding was performed on the board and the defect rate (ppm: the num...

example 3

[0118] A gold underplating film with a thickness of about 0.04 μm was formed by underplating on a copper lead having a purity of 99.995% and a diameter of 200 μm. After that, a 0.8 µm thick palladium plating film was formed. Copper bonding wires with various yield strength values ​​were produced by drawing and annealing the wires. The copper core diameter of various bonding wires was 25.2 μm, the thickness of the palladium layer (coating layer) was 0.1 μm, and the gold layer (different metals) layer) has a thickness of about 0.005 μm. Various copper bonding wires have a radius of curvature of 40mm. Using various wires, bonding was performed on a 208-pin QFP (copper lead frame, silver plating) with a loop length of about 4 mm by applying a load of 80 g and varying ultrasonic energy using a bonder (model EAGLE AB339 manufactured by ASM) and inspected The ultrasonic energy range (good bonding condition range) where the defect rate (ppm: the number of bob-tail defects and non-st...

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Abstract

A bonding wire which has a core material and formed on the core material, a coating layer comprising a metal having a melting point higher than that of the core material and further has at least one of the following characteristics: 1. the wet contact angle of the molten core material with the coating material is 20 degree or more, 2. the curvature radius of a circular arc, which is formed when the bonding wire is allowed to hang down so that the tip thereof contacts with a horizontal plane and the wire is cut at the point being upper from the tip by 15 cm and the cut wire is allowed to fall on the horizontal plane, is 35 mm or more. 3. 0.2 % offset yield strength is 0.115 to 0.165 mN / mum<2>, and 4. the coating layer has a Vickers hardness of 300 or less.

Description

technical field [0001] The present invention relates to a bonding lead for connecting electrodes on an integrated circuit device (IC, LSI, transistor, etc.) to wires on a circuit wiring board (lead frame, ceramic substrate, printed circuit board, etc.) , and also relates to an integrated circuit device using such a bonding wire. Background technique [0002] A ball bonding method using a bonding wire is used as a method of connecting an integrated circuit device to a circuit wiring board. [0003] The ball bonding method is a common implementation process in which one end of a bonding wire guided by a movable capillary (hereinafter referred to as "bonding tool") is melted by an electric discharge between it and an electrode torch to A ball is formed at that end, the ball is then pressed against the first bond point to form a ball bond on it, and then, as the wire is fed out, the bonding tool moves to the second bond point in the same manner (but this time does not form a b...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L21/60
CPCH01L2924/01088H01L24/45H01L2924/0105H01L2224/4321H01L2924/01025H01L2924/01045H01L2224/45673H01L2924/01044H01L2924/01022H01L2924/01028H01L2924/01013H01L2924/20751H01L2224/45015H01L2924/0103H01L2224/4845H01L2924/20753H01L2924/19043H01L2924/01007H01L2924/0104H01L2924/01076H01L2924/01033H01L2924/01078H01L2924/01016H01L2224/456H01L2924/01046H01L2924/01082H01L2924/01004H01L2224/43825H01L2924/01002H01L2924/20752H01L2924/01029H01L2224/4312H01L2924/01027H01L2224/45655H01L2924/01024H01L2224/45147H01L2924/01204H01L24/43H01L2924/01047H01L2224/45644H01L2224/45669H01L2924/01079H01L2224/45139H01L2224/45565H01L2924/14H01L2924/01005H01L2924/01006H01L2224/45664H01L2924/01075H01L2224/45144H01L2924/01012H01L2924/01077H01L2224/43827H01L2224/43H01L2224/43848H01L2224/45H01L2224/45572H01L2924/00011H01L2924/15747H01L2924/01008H01L2924/01026H01L2924/01001H01L2924/00014H01L2924/013H01L2924/00H01L2924/2076H01L2924/01015H01L2924/01049H01L2924/00012
Inventor 改森信吾野中毅井冈正则
Owner SUMITOMO ELECTRIC IND LTD
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