JPH05179376A - Fine gold alloy wire for bonding - Google Patents
Fine gold alloy wire for bondingInfo
- Publication number
- JPH05179376A JPH05179376A JP40892A JP40892A JPH05179376A JP H05179376 A JPH05179376 A JP H05179376A JP 40892 A JP40892 A JP 40892A JP 40892 A JP40892 A JP 40892A JP H05179376 A JPH05179376 A JP H05179376A
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- Prior art keywords
- bonding
- gold
- ppm
- gold alloy
- wire
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- 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
- H01L24/43—Manufacturing methods
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- H01—ELECTRIC ELEMENTS
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- 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
- H01L2224/43—Manufacturing methods
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
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- 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
- H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
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- 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
- H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
- H01L2224/45001—Core members of the connector
- H01L2224/4501—Shape
- H01L2224/45012—Cross-sectional shape
- H01L2224/45015—Cross-sectional shape being circular
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- 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
- H01L2224/44—Structure, shape, material or disposition of the wire connectors prior to the connecting process
- H01L2224/45—Structure, shape, material or disposition of the wire connectors prior to the connecting process of an individual wire connector
- H01L2224/45001—Core members of the connector
- H01L2224/45099—Material
- H01L2224/451—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
- H01L2224/45138—Material with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
- H01L2224/45144—Gold (Au) as principal constituent
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- 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
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- 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
- H01L2924/01004—Beryllium [Be]
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- 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
- H01L2924/0102—Calcium [Ca]
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- H—ELECTRICITY
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- 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
- H01L2924/01028—Nickel [Ni]
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- 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
- H01L2924/01031—Gallium [Ga]
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- 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
- H01L2924/01032—Germanium [Ge]
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
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- 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]
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- 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]
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- 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
- H01L2924/01057—Lanthanum [La]
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- H—ELECTRICITY
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- 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
- H01L2924/01058—Cerium [Ce]
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- H—ELECTRICITY
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- 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
- H01L2924/01066—Dysprosium [Dy]
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- H—ELECTRICITY
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- 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
- H01L2924/01079—Gold [Au]
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- H01L2924/01—Chemical elements
- H01L2924/01082—Lead [Pb]
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- H—ELECTRICITY
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- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/012—Semiconductor purity grades
- H01L2924/01204—4N purity grades, i.e. 99.99%
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- Engineering & Computer Science (AREA)
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- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Wire Bonding (AREA)
- Conductive Materials (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、半導体素子上の電極と
外部リードとを接続するために利用する耐熱性に優れる
金合金細線に関し、より詳しくは接合後の半導体装置組
立作業中における振動疲労による断線を大幅に低減させ
るためにボールネック部強度を向上させたボンディング
用金合金細線に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine gold alloy wire having excellent heat resistance used for connecting electrodes on a semiconductor element and external leads, and more particularly, to vibration fatigue during semiconductor device assembly work after joining. The present invention relates to a gold alloy thin wire for bonding, in which the strength of the ball neck portion is improved in order to significantly reduce the disconnection due to.
【０００２】[0002]
【従来技術】従来、半導体素子上の電極と外部リードと
の間を接続するボンディング線としては、金合金細線が
主として使用されている。金合金細線をボンディングす
る技術としては、熱圧着法が代表的な方法である。熱圧
着法は、金合金細線の先端部分を電気トーチで加熱溶融
し、表面張力によりボールを形成させ、１５０〜３００
℃の範囲内で加熱した半導体素子の電極にこのボール部
を圧着接合せしめた後に、さらにリード側との接続を超
音波圧着接合で行う方法である。2. Description of the Related Art Conventionally, a gold alloy thin wire has been mainly used as a bonding wire for connecting an electrode on a semiconductor element and an external lead. A thermocompression bonding method is a typical method for bonding gold alloy fine wires. In the thermocompression bonding method, the tip portion of the gold alloy thin wire is heated and melted by an electric torch, and a ball is formed by surface tension.
In this method, the ball portion is pressure-bonded to the electrode of the semiconductor element heated within the range of ° C, and then the connection with the lead side is performed by ultrasonic pressure-bonding.
【０００３】近年、ボンディング技術の向上に伴って金
合金細線の特性を向上させる要求が強くなった。例え
ば、ボンディング時にボール直上部が高温に晒される結
果として結晶粒の粗大化が起こり、金合金線の強度が劣
化するために、半導体装置組立時の振動により断線する
という欠陥が生じる。この防止対策としてボンディング
後のプル強度を指標とし、従来の金合金細線よりプル強
度の大なる金合金細線が望まれている。In recent years, there has been a strong demand for improving the characteristics of gold alloy thin wires as the bonding technology has improved. For example, as a result of exposure of the ball just above the ball to a high temperature during bonding, the crystal grains become coarse, and the strength of the gold alloy wire deteriorates, resulting in a defect that the wire breaks due to vibration during semiconductor device assembly. As a measure for preventing this, a gold alloy thin wire having a higher pull strength than that of a conventional gold alloy thin wire is desired, using the pull strength after bonding as an index.
【０００４】また、近年の薄型半導体装置の一般化に伴
い、ボンディング後のループ高さを低くする目的のため
に高純度金に大量の元素を添加せしめた金合金細線が開
発され、使用されている。例えば、カルシウムを５〜１
００重量ppm 含有してなる金ボンディングワイヤー（特
開昭５３−１０５９６８号公報）、あるいはランタン、
セリウム、プラセオヂウム、ネオヂウムおよびサマリウ
ムの１種または２種以上を３〜１００重量ppm とゲルマ
ニウム、ベリリウムおよびカルシウムの１種または２種
以上を１〜６０重量ppm 含有してなる金ボンディングワ
イヤー（特開昭５８−１５４２４２号公報）などがあ
る。しかしながら、ループ高さが低くなることによって
プル強度が低下すること、および合金元素の大量添加に
よってボールの硬さが増大し、ボンディング後の接合強
度を著しく劣化させ、半導体装置の信頼性を低下させる
という問題があるために、従来の比較的ループ高さの高
い金合金細線と同等の接合強度を有した、ループ高さが
低く、高信頼性を有するボンディング用金合金細線が望
まれている。Further, with the recent generalization of thin semiconductor devices, gold alloy fine wires in which a large amount of elements are added to high-purity gold have been developed and used for the purpose of reducing the loop height after bonding. There is. For example, 5 to 1 calcium
Gold bonding wire (Japanese Patent Application Laid-Open No. 53-105968) containing lanthanum,
A gold bonding wire containing 3 to 100 ppm by weight of 1 or 2 or more of cerium, praseodymium, neodymium and samarium and 1 to 60 ppm by weight of 1 or 2 or more of germanium, beryllium and calcium. 58-154242). However, the pull strength is lowered due to the decrease of the loop height, and the hardness of the ball is increased due to the addition of a large amount of alloying elements, the joint strength after bonding is significantly deteriorated, and the reliability of the semiconductor device is lowered. Therefore, there is a demand for a gold alloy fine wire for bonding, which has a bonding strength equivalent to that of a conventional gold alloy fine wire having a relatively high loop height, a low loop height, and high reliability.
【０００５】[0005]
【発明が解決しようとする課題】本発明者等は、これら
の従来提案された種々のボンディング用金合金細線につ
いて検討した結果、これらのボンディング用金合金細線
は、少量の元素添加では、特定の添加元素を含まない高
純度金線に較べて高い引張強度は有しているものの、ボ
ール直上部の結晶粒の粗大化を生じる結果として半導体
装置の薄型化に不適切な高ループになりやすいという問
題があることを確かめた。DISCLOSURE OF THE INVENTION The inventors of the present invention have studied various conventionally proposed gold alloy thin wires for bonding, and as a result, these gold alloy thin wires for bonding are Although it has a higher tensile strength than a high-purity gold wire that does not contain additional elements, it tends to cause a high loop that is unsuitable for thinning semiconductor devices as a result of coarsening of the crystal grains directly above the ball. I confirmed there was a problem.
【０００６】また、ボンディング後のループ高さを低く
するために、金の再結晶温度を高くせしめる元素を大量
添加したボンディング用金合金細線は、ループ高さが低
くなることによって必然的にプル強度が低下すること、
添加元素量の増大に伴いボール形成時に、添加元素の酸
化によってボール表面に酸化物層が生成し、電極との熱
圧着に際して充分な接合ができなくなること、また添加
元素の大量添加でボール部の硬度が増加し、圧着時に金
ボールの塑性変形率が低下すると共にボールの先端に収
縮孔が出来やすくなり、これが半導体素子の電極との接
合面積を低下させることによって、シェア強度を低下さ
せるために、ボンディング後のハンドリング等による振
動に起因して断線が発生したり、樹脂封止時に金合金細
線が受ける封止樹脂の流動抵抗や、その後の各種熱サイ
クルによる半導体装置の構成物質の熱膨張率の差異に起
因する剪断力等で金合金細線が破断する場合があり、結
果として半導体装置の信頼性を低下させるという問題を
有している。In addition, a gold alloy thin wire for bonding, in which a large amount of an element for increasing the recrystallization temperature of gold is added in order to reduce the loop height after bonding, inevitably has a pull strength because the loop height becomes low. Is reduced,
When the ball is formed with an increase in the amount of the additional element, an oxide layer is formed on the surface of the ball due to the oxidation of the additional element, and sufficient bonding cannot be achieved during thermocompression bonding with the electrode. The hardness increases, the plastic deformation rate of the gold ball decreases at the time of crimping, and a contraction hole is easily formed at the tip of the ball, which reduces the joint area with the electrode of the semiconductor element, thereby reducing the shear strength. , Breakage due to vibration due to handling after bonding, flow resistance of the sealing resin that the gold alloy thin wire receives during resin sealing, and coefficient of thermal expansion of semiconductor device constituents due to various thermal cycles thereafter There is a case where the gold alloy thin wire is broken due to shearing force or the like due to the difference, and as a result, there is a problem that the reliability of the semiconductor device is lowered.
【０００７】[0007]
【課題を解決するための手段】本発明者等は、ガリウム
とカルシウムを複合添加させることで、ボールネック部
の強度が高く、かつそのバラツキが少なく、ボールネッ
ク部の結晶粒の細かいボンディング用金合金細線が得ら
れること、その添加量を制御することによって、ループ
高さの低いボンディング用金合金細線を工業的に容易に
製造でき、前述の諸問題点を解消することができること
を確かめた。Means for Solving the Problems The inventors of the present invention, by adding gallium and calcium in combination, have high strength in the ball neck portion and little variation, and a bonding gold with fine crystal grains in the ball neck portion. It was confirmed that a fine alloy wire can be obtained, and by controlling the amount of addition, a fine gold alloy wire for bonding with a low loop height can be easily manufactured industrially and the above-mentioned problems can be solved.
【０００８】すなわち、本発明の要旨とするところは下
記のとおりである。 （１） 高純度金（純度９９．９９５％以上）に、第１
群の元素として、ガリウムを３〜５０重量ppm とカルシ
ウムを３〜３０重量ppm 含有してなるボンディング用金
合金細線。 （２） 第１群の元素に加えて、第２群の添加元素とし
て、イットリウム、ランタン、セリウム、ネオジウム、
ジスプロヂウムおよびベリリウムの１種または２種以上
を３〜３０重量ppm 含有し、かつ第１群の元素と第２群
の添加元素の総量が少なくとも９〜１００重量ppm であ
る前項１記載のボンディング用金合金細線。That is, the gist of the present invention is as follows. (1) High purity gold (purity 99.995% or more)
As a group element, a gold alloy thin wire for bonding containing gallium in an amount of 3 to 50 ppm by weight and calcium in an amount of 3 to 30 ppm by weight. (2) In addition to the elements of the first group, yttrium, lanthanum, cerium, neodymium,
The bonding gold according to the above item 1, which contains 3 to 30 ppm by weight of one or more of dysprosium and beryllium, and the total amount of the elements of the first group and the additive elements of the second group is at least 9 to 100 ppm by weight. Alloy fine wire.
【０００９】以下、本発明の構成についてさらに説明す
る。本発明で使用する高純度金とは、純度が少なくとも
９９．９９５重量％以上の金を含有し、残部が不可避不
純物からなるものである。純度が９９．９９５重量％未
満の場合は、その含有する不純物の影響を受ける。特
に、合金元素の添加量の比較的少ない高ループ用の金合
金細線では、本発明に従った合金元素の添加量での効果
が充分に発揮できない。The structure of the present invention will be further described below. The high-purity gold used in the present invention is gold having a purity of at least 99.995% by weight or more, and the balance being inevitable impurities. If the purity is less than 99.995% by weight, it will be affected by the impurities contained therein. In particular, with a gold alloy thin wire for high loops in which the amount of alloying elements added is relatively small, the effect of the amount of alloying elements added according to the present invention cannot be sufficiently exerted.
【００１０】ガリウムは、金中への固溶限界が大であ
り、従来から再結晶温度を高くする効果が知られている
が、単独の添加では十分な効果がない。高純度金中にガ
リウムと共にカルシウムを複合添加させることにより、
ボールネック部の強度が増大し、プル強度を向上させ、
樹脂封止工程以前の諸振動による断線を減少できる。こ
の効果は、カルシウム添加のもとでガリウム含有量が３
重量ppm 未満であると、ボールネック部の結晶粒が安定
して細粒化せず、効果が充分でない。また、ガリウム含
有量が５０重量ppm を超えると、ボール形成時にボール
が真球にならず、またガリウムとカルシウムとの強固な
酸化物がボール表面に生成し、電極との接合時にボール
と電極の圧着時に双方の新生金属面が出にくくなること
によって接合強度が低下することからガリウム含有量の
範囲を３〜５０重量ppm とした。Although gallium has a large solid solution limit in gold, and it has been conventionally known that gallium has a high recrystallization temperature, but addition of gallium alone does not have a sufficient effect. By adding calcium together with gallium in high-purity gold,
The strength of the ball neck is increased and the pull strength is improved.
The disconnection due to various vibrations before the resin sealing process can be reduced. The effect is that the gallium content is 3 when calcium is added.
If the content is less than ppm by weight, the crystal grains in the ball neck portion are not stably refined and the effect is not sufficient. Further, when the gallium content exceeds 50 ppm by weight, the ball does not become a true sphere at the time of ball formation, and a strong oxide of gallium and calcium is generated on the ball surface, so that the ball and the electrode are not bonded at the time of bonding with the electrode. The bonding strength is reduced by making it difficult for both new metal surfaces to appear during pressure bonding, so the range of gallium content was set to 3 to 50 ppm by weight.
【００１１】カルシウムは、耐熱性を向上させる元素で
あることが知られているが、３重量ppm 未満ではボール
ネック部の結晶の細粒化の効果が得られない。また、３
０重量ppm 超の添加では、ボールネック部の結晶を細粒
化し、耐熱性を向上させるものの、ボール形成時にボー
ル先端部に収縮孔が生じること、ボール形成時の酸化に
よってボール全表面に強固な酸化物を生成し、ボールと
電極との接合界面積が低下することによって、接合強度
（シェア強度）が低下する。また、ボールの硬さがカル
シウム添加量の増大と共に大となり、電極との充分な接
合を確保するに必要な荷重をかけると、電極下部の半導
体素子に割れを生じる場合がある。従ってカルシウムの
添加量は、３〜３０重量ppm の範囲とした。ガリウムと
カルシウムの含有量が、それぞれの上限値でも前述の諸
問題を起こさない。複合添加によって、このような効果
が得られるのは、ガリウムが金中のカルシウムの固溶量
を増大させ、かつ結晶粒界の強度を高くすることによる
ものと考えられる。Calcium is known to be an element that improves heat resistance, but if it is less than 3 ppm by weight, the effect of refining the crystal in the ball neck portion cannot be obtained. Also, 3
Addition of more than 0 ppm by weight makes the crystal in the ball neck finer and improves the heat resistance, but it causes shrinkage holes at the tip of the ball during ball formation, and oxidation during ball formation results in a firm surface on the ball. The bonding strength (shear strength) is reduced by the generation of oxides and the reduction of the bonding interface area between the ball and the electrode. Further, the hardness of the ball increases as the amount of calcium added increases, and if a load necessary to secure sufficient bonding with the electrode is applied, the semiconductor element below the electrode may crack. Therefore, the amount of calcium added was in the range of 3 to 30 ppm by weight. Even if the contents of gallium and calcium are the respective upper limits, the above-mentioned problems do not occur. It is considered that the reason why such an effect is obtained by the combined addition is that gallium increases the solid solution amount of calcium in gold and increases the strength of the crystal grain boundary.
【００１２】第２群の元素の添加目的は、伸線の際に金
合金細線の加工硬化によって、さらに伸線し易くするた
めである。第２群の元素は、単独添加の場合には、大量
添加しないと伸線時の加工硬化による常温強度の向上に
効果がない。しかしながら、第１群の元素と共に添加す
ることによって、伸線時の加工硬化が大となり、伸線時
の金線の引張強度不足による断線を防止できる。さら
に、カルシウム添加による耐熱性を複合添加によりさら
に向上させる効果と共に高温強度を上げる効果があり、
結果としてガリウムとカルシウムとを複合添加した上述
の本発明の効果をさらに向上させることができる。The purpose of adding the elements of the second group is to further facilitate wire drawing by work hardening of the gold alloy thin wire during wire drawing. When the elements of the second group are added alone, unless added in a large amount, there is no effect in improving the room temperature strength due to work hardening during wire drawing. However, by adding together with the elements of the first group, work hardening during wire drawing becomes large, and wire breakage due to insufficient tensile strength of the gold wire during wire drawing can be prevented. Furthermore, it has the effect of further improving the heat resistance due to the addition of calcium as well as the effect of increasing the high temperature strength by the combined addition,
As a result, the effect of the present invention described above in which gallium and calcium are added in combination can be further improved.
【００１３】これらの第２群の元素は、添加量が３重量
ppm 未満の場合には、加工硬化を促進させる効果が不安
定であり、耐熱性を向上させる複合効果も充分でない。
他方、３０重量ppm 超の添加では、第１群の元素のみの
添加量では生成しなかったボール先端部の収縮孔が容易
に発生し、結果としてシェア強度が低下する。従って、
第２群の元素の添加量は、３〜３０重量ppm の範囲とし
た。The addition amount of these elements of the second group is 3% by weight.
If it is less than ppm, the effect of promoting work hardening is unstable and the combined effect of improving heat resistance is not sufficient.
On the other hand, if the addition amount exceeds 30 ppm by weight, shrinkage holes at the tip of the ball, which were not generated by the addition amount of only the elements of the first group, are easily generated, resulting in a decrease in shear strength. Therefore,
The amount of the second group element added was in the range of 3 to 30 ppm by weight.
【００１４】また、第１群と第２群の元素の総量が９重
量ppm 未満では、ボールネック部の結晶粒が安定して細
粒化せず効果が充分でなく、他方、１００重量ppm を超
えると電気トーチによるボール形成時にボールが真球に
ならず、半導体素子上の電極との接合時に充分な接合面
積が得られず、接合強度を著しく低下させ、かつ他の電
極と接触する等の問題を生じることから、第１群と第２
群の元素の総量を９〜１００重量ppm の範囲内とした。When the total amount of the elements of the first group and the second group is less than 9 weight ppm, the crystal grains in the ball neck portion are not stably refined and the effect is not sufficient, while 100 weight ppm is added. If it exceeds, the ball does not become a true sphere at the time of ball formation by the electric torch, a sufficient bonding area cannot be obtained at the time of bonding with the electrode on the semiconductor element, the bonding strength is remarkably reduced, and contact with other electrodes may occur. Because it causes problems, the first and second groups
The total amount of elements in the group was within the range of 9 to 100 ppm by weight.
【００１５】[0015]
【実施例】以下、実施例について説明する。金純度が９
９．９９５重量％以上の電解金を用いて、前述の各添加
元素の含有せる母合金を個別に高周波真空溶解炉で溶解
し、鋳造した。なお、カルシウムとガリウムとを複合添
加した母合金を溶解、鋳造すると、カルシウムの添加歩
留りを向上させる効果がある。EXAMPLES Examples will be described below. Gold purity is 9
Using 9.995% by weight or more of electrolytic gold, the mother alloys containing the above-mentioned additive elements were individually melted in a high-frequency vacuum melting furnace and cast. It should be noted that melting and casting a mother alloy to which calcium and gallium are added together has the effect of improving the calcium addition yield.
【００１６】このようにして得られた各添加元素を含む
母合金の所定量と金純度が９９．９９５重量％以上の電
解金とにより、表１に示す化学成分の金合金を高周波真
空溶解炉で溶解、鋳造し、その鋳塊を圧延した後、常温
で伸線加工を行い、最終線径を２５μｍφの金合金細線
とし、大気雰囲気中で連続焼鈍して金合金細線の伸び値
が約４％になるように調整する。By using a predetermined amount of the mother alloy containing each additive element thus obtained and electrolytic gold having a gold purity of 99.995% by weight or more, a gold alloy having the chemical composition shown in Table 1 was prepared in a high frequency vacuum melting furnace. Melted and cast in, and rolled the ingot, then drawn at room temperature to make a gold alloy fine wire with a final wire diameter of 25 μmφ, and continuously annealed in an air atmosphere so that the elongation value of the gold alloy fine wire is about 4 Adjust so that it becomes%.
【００１７】得られた金合金細線について、常温引張強
度、ループ高さ、振動破断率、ボール形状および接合強
度を調べた結果を表１に併記した。接合のループ高さ
は、高速自動ボンダーを使用して半導体素子上の電極と
外部リードとの間を接合した後に、形成されるループの
頂高と半導体素子の電極面とを光学顕微鏡で８０本測定
し、その両者の距離の差をループ高さとした。Table 1 also shows the results of examining the tensile strength at room temperature, the loop height, the vibration rupture rate, the ball shape and the bonding strength of the obtained gold alloy thin wire. The loop height of the junction is 80 after the electrode on the semiconductor element and the external lead are joined using a high-speed automatic bonder, and then the height of the loop formed and the electrode surface of the semiconductor element are 80 with an optical microscope. The loop height was determined by measuring the difference between the two distances.
【００１８】振動破断率は、半導体素子をマウントする
鉄−４２％ニッケルリードフレーム（ボンディングスパ
ン；２mm、インナーリードピン６４本が四方に配列され
ているＩＣパッケージを６個有するもの）を５枚カセッ
トに収納し、前述の２５μｍφの金合金細線を自動高速
ボンディングによりチップ上の電極とインナーリードと
を金合金細線で接合させ、再びカセットに収納し、該カ
セットを振動試験機に固定し、周波数１００ヘルツ、重
力加速度を１Ｇ、２Ｇ、３Ｇの各水準にて１時間の間振
動させた後に、接合部の断線状況を光学顕微鏡にて検査
を行い、断線本数の占める割合を百分率で評価した。The vibration rupture rate is 5 sheets of iron-42% nickel lead frame (bonding span; 2 mm, having 6 IC packages in which 64 inner lead pins are arranged in four directions) for mounting semiconductor elements in a cassette. Then, the above-mentioned 25 μmφ gold alloy fine wire is bonded to the electrode on the chip and the inner lead with the gold alloy fine wire by automatic high-speed bonding, and then housed again in the cassette. After vibrating the gravitational acceleration at each level of 1G, 2G, and 3G for 1 hour, the state of disconnection at the joint was inspected with an optical microscope, and the ratio of the number of disconnection was evaluated as a percentage.
【００１９】ボール形状は、高速自動ボンダーを使用
し、電気トーチによるアーク放電によって得られる金合
金ボールを走査電子顕微鏡で観察し、ボール形状が異常
なもの、酸化物が生じるもの等、半導体素子上の電極に
良好な形状で接合できないものを×印、良好なものを○
印にて評価した。接合強度は、高速自動ボンディング後
にリードフレームと測定する半導体素子を治具で固定し
た後にボンディング後の金合金細線の中央部を引張り、
その細線破断時の引張強度を１００本測定したプル強度
とそのバラツキで評価した。また、同じく固定した半導
体素子の電極から上に５ミクロン離した位置で半導体素
子と平行に治具を移動させ接合した金ボールを剪断破断
させ、剥離時の最大荷重を１００本測定したシェア強度
とそのバラツキを求めた結果で判定した。The ball shape is determined by observing a gold alloy ball obtained by arc discharge by an electric torch with a scanning electron microscope using a high-speed automatic bonder. Nothing that could not be joined to the electrode in a good shape was marked with X, and good one was ○
It was evaluated by the mark. Bonding strength is measured by fixing the lead frame and the semiconductor element to be measured after a high-speed automatic bonding with a jig and then pulling the central part of the gold alloy thin wire after bonding,
The tensile strength at break of the thin wire was evaluated by the pull strength measured from 100 pieces and the variation. In addition, a shear strength was measured by moving a jig parallel to the semiconductor element at a position 5 μm above the electrode of the semiconductor element, which was also fixed, to shear and rupture the joined gold balls, and to measure the maximum load at peeling 100 pieces. It was judged based on the result of obtaining the variation.
【００２０】表１、２は、本発明の成分組成内で製造し
た金合金細線の評価結果を、表３、４は本発明の成分組
成を外れる添加量を含む金合金細線の評価結果を示し
た。従来の経験から金合金細線の場合は、ループ高さが
低くなるとプル強度が低下する傾向がある。表１〜４の
結果でも同様の傾向を有している。ほぼ同一のループ高
さの金合金細線のプル強度の比較では、表２のプル強度
がいずれも表４の値よりも小さく、かつそのバラツキも
小さい結果となっている。また、過剰の合金元素量を添
加した場合には、シェア強度が低下し、そのバラツキも
大きくなっている。Tables 1 and 2 show the evaluation results of the gold alloy fine wire produced within the composition of the present invention, and Tables 3 and 4 show the evaluation results of the gold alloy fine wire containing the addition amount deviating from the composition of the present invention. It was From the conventional experience, in the case of a gold alloy fine wire, the pull strength tends to decrease as the loop height decreases. The results shown in Tables 1 to 4 have the same tendency. Comparing the pull strengths of the gold alloy fine wires having almost the same loop height, the pull strengths in Table 2 are all smaller than the values in Table 4 and the variations are small. Further, when an excessive amount of alloying element is added, the shear strength is lowered and its variation is increased.
【００２１】振動断線の場合もループ高さが低くなるほ
ど断線発生率が増大する傾向が経験的に知られており、
１Ｇの振動強度で断線する場合は、製造した半導体装置
の信頼性が低く、２Ｇでの振動強度で断線する場合は、
断線発生率が２０％以下であれば半導体装置の信頼性
は、充分満たされる。表２と表４における、ほぼ同一ル
ープ高さの金合金細線での断線発生率は、いずれも本発
明の方が断線発生率が低い結果が得られ、半導体装置の
信頼性も充分である。It is empirically known that, even in the case of vibrational disconnection, the disconnection occurrence rate tends to increase as the loop height decreases.
When breaking with 1G vibration strength, the reliability of the manufactured semiconductor device is low, and when breaking with 2G vibration strength,
If the occurrence rate of disconnection is 20% or less, the reliability of the semiconductor device is sufficiently satisfied. Regarding the occurrence rates of wire breakage in the gold alloy fine wires having almost the same loop height in Tables 2 and 4, the present invention results in a lower wire breakage occurrence rate, and the reliability of the semiconductor device is also sufficient.
【００２２】シェア強度は、通常２５μｍの金合金細線
の場合、５０ｇ以上あれば問題がないとされている。表
２の場合は、いずれも５０ｇ以上の値を満足している
が、表４の場合には５０ｇ未満の場合があり、ボンディ
ング用金合金細線としては不十分である。ボール形状の
評価では、表１に示す本発明範囲内の成分組成の合金細
線では、いずれも正常なボール（表２参照）を形成して
いるが、表３の成分組成の合金細線ではボール先端部に
収縮孔など異常なボール（表４参照）になるものが存在
する。Regarding the shear strength, it is generally considered that there is no problem in the case of a gold alloy fine wire of 25 μm if the shear strength is 50 g or more. In the case of Table 2, all satisfy the value of 50 g or more, but in the case of Table 4, it may be less than 50 g, which is insufficient as a gold alloy thin wire for bonding. In the evaluation of the ball shape, the alloy fine wires having the component composition within the scope of the present invention shown in Table 1 formed normal balls (see Table 2), but the alloy fine wires having the component composition in Table 3 formed the ball tip. Some parts have abnormal balls (see Table 4) such as shrinkage holes.
【００２３】上述のように、本発明の成分組成を外れる
合金細線の場合は、プル強度とシェア強度の接合強度が
不十分で、振動断線の発生率が大であり、製造した半導
体装置の信頼性を低下させることは明らかである。As described above, in the case of the alloy fine wire which deviates from the component composition of the present invention, the joining strength of pull strength and shear strength is insufficient, the occurrence rate of vibration disconnection is large, and the reliability of the manufactured semiconductor device is high. Obviously, it reduces sex.
【００２４】[0024]
【表１】 [Table 1]
【００２５】[0025]
【表２】 [Table 2]
【００２６】[0026]
【表３】 [Table 3]
【００２７】[0027]
【表４】 [Table 4]
【００２８】[0028]
【発明の効果】本発明の金合金細線は、ループ高さのバ
ラツキが小さく、接合強度が高く、かつそのバラツキが
小さく、振動断線の発生率も低く、ボール形状もいずれ
も正常で、安定したボンディングが可能であり、線径が
１８〜３０μｍでも同様な効果が得られたことから、工
業上有用な特性を有するものである。The gold alloy fine wire of the present invention has a small loop height variation, a high bonding strength, a small variation, a low occurrence rate of vibration disconnection, and a normal and stable ball shape. Bonding is possible, and the same effect is obtained even when the wire diameter is 18 to 30 μm, so that it has industrially useful characteristics.
Claims (2)
に、第１群の元素として、ガリウムを３〜５０重量ppm
とカルシウムを３〜３０重量ppm 含有してなるボンディ
ング用金合金細線。1. High-purity gold (purity of 99.995% or more)
In addition, gallium as an element of the first group is 3 to 50 ppm by weight.
A fine gold alloy wire for bonding, which contains 3 to 30 ppm by weight of calcium.
素として、イットリウム、ランタン、セリウム、ネオジ
ウム、ジスプロヂウムおよびベリリウムの１種または２
種以上を３〜３０重量ppm 含有し、かつ第１群の元素と
第２群の添加元素の総量が少なくとも９〜１００重量pp
m である請求項１記載のボンディング用金合金細線。2. In addition to the elements of the first group, one or two elements of yttrium, lanthanum, cerium, neodymium, dysprosium and beryllium are added as an additional element of the second group.
3 to 30 ppm by weight of seeds or more, and the total amount of the elements of the first group and the additive elements of the second group is at least 9 to 100 ppm by weight.
The gold alloy fine wire for bonding according to claim 1, which is m 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04000408A JP3143755B2 (en) | 1992-01-06 | 1992-01-06 | Gold alloy fine wire for bonding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04000408A JP3143755B2 (en) | 1992-01-06 | 1992-01-06 | Gold alloy fine wire for bonding |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05179376A true JPH05179376A (en) | 1993-07-20 |
| JP3143755B2 JP3143755B2 (en) | 2001-03-07 |
Family
ID=11472979
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04000408A Expired - Fee Related JP3143755B2 (en) | 1992-01-06 | 1992-01-06 | Gold alloy fine wire for bonding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3143755B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6103025A (en) * | 1997-07-07 | 2000-08-15 | W. C. Heraeus Gmbh & Co. Kg | Fine wire of gold alloy, method for manufacture thereof and use thereof |
| WO2006057230A1 (en) * | 2004-11-26 | 2006-06-01 | Tanaka Denshi Kogyo K.K. | Au BONDING WIRE FOR SEMICONDUCTOR ELEMENT |
| JP2006190719A (en) * | 2004-12-28 | 2006-07-20 | Tanaka Electronics Ind Co Ltd | Semiconductor device |
| JP2008016550A (en) * | 2006-07-04 | 2008-01-24 | Tanaka Electronics Ind Co Ltd | Au BONDING WIRE FOR SEMICONDUCTOR ELEMENT |
| CN111763845A (en) * | 2020-07-09 | 2020-10-13 | 江西森通新材料科技有限公司 | Gold bonding wire and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6397777U (en) * | 1986-12-15 | 1988-06-24 | ||
| JPH0330671U (en) * | 1989-08-03 | 1991-03-26 |
-
1992
- 1992-01-06 JP JP04000408A patent/JP3143755B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6397777U (en) * | 1986-12-15 | 1988-06-24 | ||
| JPH0330671U (en) * | 1989-08-03 | 1991-03-26 |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6103025A (en) * | 1997-07-07 | 2000-08-15 | W. C. Heraeus Gmbh & Co. Kg | Fine wire of gold alloy, method for manufacture thereof and use thereof |
| WO2006057230A1 (en) * | 2004-11-26 | 2006-06-01 | Tanaka Denshi Kogyo K.K. | Au BONDING WIRE FOR SEMICONDUCTOR ELEMENT |
| JP2006190719A (en) * | 2004-12-28 | 2006-07-20 | Tanaka Electronics Ind Co Ltd | Semiconductor device |
| JP4713149B2 (en) * | 2004-12-28 | 2011-06-29 | 田中電子工業株式会社 | Semiconductor device |
| JP2008016550A (en) * | 2006-07-04 | 2008-01-24 | Tanaka Electronics Ind Co Ltd | Au BONDING WIRE FOR SEMICONDUCTOR ELEMENT |
| CN111763845A (en) * | 2020-07-09 | 2020-10-13 | 江西森通新材料科技有限公司 | Gold bonding wire and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3143755B2 (en) | 2001-03-07 |
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