BONDING WIRE

2023-02-13 来源：钮旅网

(19)

󰀅󰀛&󰀋󰀋󰀍󰀍󰀋󰀓󰀓󰀋󰀌󰀘󰀌󰀅

(11)

EP2 208 801B1

(12)

EUROPEAN PATENT SPECIFICATION

(51)Int Cl.:

C22C5/02(2006.01)H01L23/00(2006.01)B23K35/30(2006.01)H01L21/60(2006.01)of the grant of the patent: 04.04.2012Bulletin2012/14

(45)Date of publication and mention

(21)Application number: 08846565.3(22)Date of filing: 11.09.2008

(86)International application number:

PCT/JP2008/066442

(87)International publication number:

WO2009/060662 (14.05.2009Gazette2009/20)

(54)BONDING WIRE

ABBINDEDRAHTFIL DE CONNEXION(84)Designated Contracting States:

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

•CHIBA, JunKanzaki-gun

Saga 842-0031 (JP)•AMADA, FujioKanzaki-gun

Saga 842-0031 (JP)

(30)Priority:06.11.2007JP 2007289091(43)Date of publication of application:

21.07.2010Bulletin2010/29

(74)Representative: Stona, Daniel et al

Moinas & Savoye S.A. 42, rue Plantamour1201 Genève (CH)

(60)Divisional application:

11004085.4 / 2 369 023

(56)References cited:

(73)Proprietor: Tanaka Denshi Kogyo K.K.

Tokyo 100-6422 (JP)

WO-A1-2006/078076JP-A- 8 127 828JP-A- 8 193 233JP-A- 10 303 235JP-A- 10 303 237JP-A- 59 065 439JP-A- 2000 040 710

GB-A- 2 063 913JP-A- 8 127 828JP-A- 10 233 411JP-A- 10 303 235JP-A- 11 186 314JP-A- 63 145 729JP-A- 2007 266 339

(72)Inventors:

•MURAI, HiroshiKanzaki-gun

Saga 842-0031 (JP)

EP2 208 801B1Note: Within nine months of the publication of the mention of the grant of the European patent in the European PatentBulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with theImplementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has beenpaid. (Art. 99(1) European Patent Convention).

Printed by Jouve, 75001 PARIS (FR)

EP2 208 801B1

Description

FIELD OF THE INVENTION

5[0001]The present invention relates to bonding wire bonding with semiconductor devices and outer leads.

STATE OF THE ART

[0002]When connecting the outside wiring with an electrode of an IC chip, wire-bonding methods wired through awire are known. Among these methods as a manner of bonding with Al electrodes of IC chip, thermo-compression andthermo-sonic bonding are occupied mainstream. Where as thermo-sonic bonding, ball-bonding method is used conven-tionally. Bonding method by ball bonding is explained using the figure illustrated in Reference Patent 1 (Japanese PatentApplication No. 3657087) shown herein after. As shown in the Fig. 1(a), wire 2 is sent from a thin hole of tip of capillarythrough wire hole of capillary 1, electric torch 3 is set against the tip, discharging between wire 2, heating and meltingthe tip of wire 2, ball 4 is formed. Then as shown in the Fig. 1(b), capillary 1 is taken downward, said ball 4 is compressedbonded to Al electrode 5 on the IC chip 6 (the first bonding). Where, it is not illustrated here, ultrasonic vibration throughcapillary 1 is applied and since IC chip 6 is heated at heat block, said ball 4 compressed bonded becomes compressedball 4’. Then as shown in the Fig. 1(c), capillary 1 is tracing a defined locus, it moves to above the outer circuit wire 8 oflead frame, and it goes down. Then, it is not illustrated here, ultrasonic vibration through capillary 1 is applied, since theouter circuit wire 8 is heated at heat block, side wall of wire 2 is thermal compressed and bonded (the second bonding).After bonding, as shown in the Fig. 1(d), clamper 7 goes upward with keeping clamped wire 2, wire 2 is cut at the stateof slightly protrude (called as a tail) from a thin hole of tip of capillary, wiring is finished.

[0003]For wire bonding unit, cylindrical capillary 1 is made of high melting point material such as alumina, zirconia,ruby and sapphire, and there is a diamond coated tip of capillary of these high melting point material for longer life, therepresentative material is alumina. Capillary 1 has a wire lead hole 102 of its inside in order to insert metallic wire forbonding. For example, in the case of using around 25 P meters diameter of metallic wire, the size of wire lead hole 102is selected as the range from 33 P meters to 40 P meters. Outside of bottleneck of capillary 1 has around 10 degreesof taper angle because of bonding interval and shape and size of metallic wire after bonding. In this connection, the holediameter H is 38 P meters, the tip diameter is 152 P meters, and the chamfer diameter CD is 64 P meters.

[0004]Many various bonding wires had been developed so far. For example, it is well known that Au matrix alloy withpartial additive of rare earth elements enhances tensile strength. And, as bonding wire which enhances tensile strengthand shear strength, Au alloy thin wire comprising 1 - 10 wt ppm of Sr, 1 - 20 wt ppm of Be, 1 - 50 wt ppm and residualAu is known in Reference Patent 2 (Japanese Patent Application No. 3059314) here in after described. And 1 wt % Aualloy bonding wire improved bonding stability for long period use is also known. It is considered that these materials arecompletely alloyed in the pure Au matrix, and had not been researched the mischief on sublimation of trace additiveelements so far.

[0005]JP200004071 0 A discloses a Au alloy bonding wire with Au in purity exceeding 99.99 wt% containing 2-50 wtppm of Sn and 1-100 wt ppm of at least one kind of element from among Ti, Zr, Hf, V, Nb, Cr, Mo, W, Mn, Fe, Co, Cu,or Ag or 1-50 wt ppm of at least one kind of element from among Be, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Pm, Sm,Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu. Furthermore, 3-100 wt ppm of at least one kind of element from among Ru, Rh,Pd, Os, Ir, Pt, or/and 2-50 wt ppm of at least one kind of element from among B, Al, Ga, In, Si, Ge, Pb.

[0006]In the bonding process, tip of the capillary 1 is heated to around 200 degrees in Celsius conventionally, and atinitial ball forming process by arc discharge, surface temperature of tip of the capillary 1 rises instantly to higher than1,000 degrees in Celsius. For this reason, as repeating bondings by high speed of ten and several times a second,hundreds of thousands of times under unmanned condition, tip 100 of the capillary 1 is contaminated by transferredmaterials from metallic wire nevertheless material of tip of capillary 1. After all, these contaminated materials are accu-mulated in homogeneously for a moment at tip 100 of the capillary 1. Sooner or later, the contaminated capillary 1 bythese accumulated contaminations is suffered that necessary energy amount for bonding isn’t impressed by disturbanceof transformation of ultrasonic and force at the second bonding. In the case of capillary using conventional bonding wirematerial, by accumlated contaminations such as partial additives elements to tip 100, cutting off of the wire would notwork well on the outer wiring 8 of lead frame after second bonding, or by once of percentage at hundreds of thousandsof times this accumlated contamination is used to come off from tip 100 of capillary 1. A stop of bonding equipmentoccurs frequently by this second bonding defect, a suspended situation of the bonding process had often formed. Moreover, though bonding equipment didn’t come to a stop, but considerable decrease of bonding strength at second bondingoccurred.

[Reference Patent 1] Japanese Patent 3657087[Reference Patent 2] Japanese Patent 3059314[Reference Patent 3] JP2000-40710 A

101520253035404550552

EP2 208 801B1

DISCLOSURE OF INVENTION

ISSUES TO BE SOLVED BY THE PRESENT INVENTION

5[0007]The present invention has been done to provide bonding wire, in view of the past’s above-mentioned circum-stances, which is same as conventinal bonding wire at pull strength and superior roundness, more over repeatingbondings by high speed of ten and several times a second, hundreds of thousands of times, accumlated contaminationdoes not occure at tip of capillary and decrese of the second bonding strength.ISSUES TO BE SOLVED BY THE PRESENT INVENTION

[0008]The inventors of the present invention had made every effort and investigated on Au alloy wires superior atstrength of bonding wire. Consequently the effect that contamination does not accumulate at tip of capillary, though tipof capillary is contaminated by partial additive elements under the appropriate range of partial additives such as Mg, In,Al, and Yb to the purity of 99.99 wt % Au has been discovered and the present invention is accomplished.

[0009]Concretely, according to the present invention, Au alloy bonding wire consisting of: 5 - 100 wt ppm Mg, 5 - 20wt ppm In, 5 - 20 wt ppm Al, 5 - 20 wt ppm Yb, optionally 5 - 20 wt ppm Ca, and/or at least one element selected among5 - 20 wt ppm La, 5 - 20 wt ppm Lu, 5 - 100 wt ppm Sr, the rest being Au having purity greater than 99.99 wt% is provided.[0010]And according to the present invention, Au alloy bonding wire consisting of and 5 - 100 wt ppm Mg, 5 - 20 wtppm In, 5 - 20 wt ppm Al, 5 - 20 wt ppm Yb, and the rest being Au having purity greater than 99.99 wt% is provided.[0011]And according to the present invention, Au alloy bonding wire consisting of: in addition to 5 - 100 wt ppm Mg,5 - 20 wt ppm In, 5 - 20 wt ppm Al, 5 - 20 wt ppm Yb, the rest being Au having purity greater than 99.99 wt% is provided.[0012]And according to the present invention, Au alloy bonding wire consisting of: 5 - 100 wt ppm Mg, 5 - 20 wt ppmIn, 5 - 20 wt ppm Al, 5 - 20 wt ppm Yb, 5 - 20 wt ppm Ca, at least one element selected among 5 - 20 wt ppm La, 5 - 20wt ppm Lu, 5 - 100 wt ppm Sr, and the rest being Au having purity greater than 99.99 wt% is provided.EFFECTS OF THE PRESENT INVENTION

[0013]Au alloy bonding wire of the present invention resolves obstacles of bonding defect and coming off by thecontaminated substances, since at ball forming by micro discharge and at the first bonding, contaminated substancesof oxide of trace additive elements are formed and sublimated, and it does not accumulate and transcript to objectivebonding wire with ultrasonic and thermo-compressed operation at the second bonding.BRIEF DESCRIPTION OF THE DRAWINGS

101520253035[0014]

[Fig. 1] Explanatory schema of bonding method by ball bonding on the present invention[Fig. 2] Cross section of tip of capillary using for bonding on the present invention[Fig. 3] One example of shape of bond at the first bonding on the present invention[Fig. 4] One example of shape of bond at the second bonding on the present invention[Explanation of symbols]

4540[0015]122’344’5678100102

CapillaryWire

Bonded wireElectrode torchBall

Compressed ballIC ChipAl electrodeClamperOuter wiringTip of capillaryLead Hole for wire

50553

EP2 208 801B1

DESCRIPTION OF THE MOST PREFERRED EMBODIMENT

[0016]In the present invention, there is few kind of trace additive elements, the range of components is narrow anddefinitive. Pure Au without any impurity is most superior for the second bondability of bonding wire, but all trace additiveelements of the present invention do not disturb so much the superior second bondability of pure Au. Missing balanceof ratio of trace additive elements of the present invention, shape of bonding portion compressed bonded is affectedconsiderablly at the second bonding.

By the way, in the case of Au alloy system, it is commercially advantageous, since it is available to display as high puritybonding wire more than 99.99 wt %, if the total amount of trace additive elements except Au and impurity elements isless than 100 wt ppm.[Mg]

[0017]In the alloy system of the present invention, Mg is a crucial element for the better second bondability, and it isan effective element for roundness of compressed ball diameter after molten ball. On the other hand, Mg has no effectof enhancing strength of bonding wire, though Ca has it. In the alloy system of the present invention, it is necessary thatamount of Mg should be more than 5 wt ppm. Because of less than this, there is no effect for second bondability. In thealloy system of the present invention, it is preferable that amount of Mg is more than 30 wt ppm in order to make secondbondability of wire stable. On the other hand, in the alloy system of the present invention, in the case of amount of Mgis more than 100 wt ppm Mg, it has wrong effect for second bondability since oxide accumlates at capillary when initialball forming. In the alloy system of the present invention, it is preferable that amount of Mg is less than 70 wt ppm Mgin order to make second bondability stable.[In]

25510152030[0018]In the alloy system of the present invention, In is a crucial element for the better second bondability, and it isan effective element for roundness of compressed ball diameter after molten ball. On the other hand, In has no effectof enhancing strength of bonding wire, though Ca has it. In the alloy system of the present invention, it is preferable thatamount of In is more than 5 wt ppm In in order to make second bondability of wire stable. Because of less than this,there is no effect for second bondability. On the other hand, in the alloy system of the present invention, in the case ofamount of In is more than 20 wt ppm In, it has wrong effect for second bondability since oxide accumlates at capillary.[Al]

35[0019]In the alloy system of the present invention, Al is a crucial element for the better second bondability. On theother hand, Al has no effect of enhancing strength of bonding wire, though Ca has it. In the alloy system of the presentinvention, it is necessary that amount of Al should be more than 5 wt ppm Al. Because of less than this, there is no effectfor second bondability. On the other hand, in the alloy system of the present invention, in the case of amount of Al ismore than 20 wt ppm Al, it has wrong effect for second bondability since oxide accumlates at capillary.[Yb]

[0020]In the alloy system of the present invention, Yb is a crucial element for the better second bondability, andmoreover, it is an effective element for roundness of compressed ball diameter after molten ball. On the other hand, Ybhas no effect of enhancing strength of bonding wire, though Ca has it. In the alloy system of the present invention, it isnecessary that amount of Yb should be more than 5 wt ppm Yb. Because of less than this, there is no effect for secondbondability. On the other hand, in the alloy system of the present invention, in the case of amount of Yb is more than20 wt ppm Yb, it has wrong effect for second bondability since oxide accumlates at capillary.[Ca]

[0021]In the alloy system of the present invention, Ca is the most effective element to improve tensile strength ofwire. However, hence Ca is apt to accumulate oxide on the surface of chamfer at tip of capillary, in the alloy system ofthe present invention, Ca is an optional additive element, and additive amount of Ca is definitive. In the alloy system ofthe present invention, in the case of less than 5 wt ppm Ca, there is no effect for tensile strength, and in the case ofmore than 20 wt ppm Ca, it is apt to accumulate oxide on the surface of chamfer at tip of capillary, it has wrong effectfor second bondability. Therefor additive amount of Ca is within the range of 5 - 20 wt ppm Ca.

404550554

EP2 208 801B1

[La]

[0022]In the alloy system of the present invention, La is an effective element to improve tensile strength of wire.Moreover, La is an effective element for second bondability. Furthemore, it is an effective element for roundness ofcompressed ball diameter after molten ball. However, hence La is apt to accumulate oxide at tip of capillary, in the alloysystem of the present invention, La is an optional additive element, and additive amount of La is definitive. In the alloysystem of the present invention, hence, in the case of less than 5 wt ppm La, there is no effect for tensile strength, andin the case of more than 20 wt ppm La, it accumulate oxide on the surface of chamfer at tip of capillary and it has wrongeffect for second bondability. Therefor additive amount of La is within the range of 5 - 20 wt ppm La.[Lu]

[0023]In the alloy system of the present invention, Lu is an effective element to improve tensile strength of wire.Moreover, Lu is an effective element for second bondability. However, hence Lu is apt to accumulate oxide on the surfaceat tip of capillary, in the alloy system of the present invention, Lu is an optional additive element, and additive amountof La is definitive. In the alloy system of the present invention, hence, in the case of less than 5 wt ppm Lu, there is noeffect for tensile strength, and in the case of more than 20 wt ppm Lu, it accumulate oxide on the surface of chamfer attip of capillary and it has wrong effect for second bondability. Therefor additive amount of Lu is within the range of 5 -20 wt ppm Lu.[Sr]

[0024]In the alloy system of the present invention, Sr is an effective element for second bondability. Moreover, it isan effective element for roundness of compressed ball diameter after molten ball. However, Sr is apt to accumulateoxide on tip surface of capillary, in the alloy system of present invention, Sr is an optional additive element and theadditive amount of it is definitive. In the alloy system of the present invention, it is necessary that amount of Sr is morethan 5 wt ppm Sr. Because of the case of less than 5 wt ppm Sr, there is no effect for second bondability. In the alloysystem of the present invention, it is preferable that Sr is more than 30 wt ppm Sr in order to make second bondabilityof wire stable. On the other hand, in the alloy system of the present invention, in the case of more than 100 wt ppm Sr,such too much, oxide accumulates on the surface of tip at capillary, and it has wrong effect for second bondability. Inthe alloy system of the present invention, in order to make second bondability stable, it is preferable that additive amountof Sr is less than 70 wt ppm Sr.

[0025]On bonding wire of the present invention, second bondability, tensile strength and roundness of compressedball diameter after molten ball have been measured by the following manner.(1) Second bondability

[0026]Second bondability is defined as easiness to bond to lead frame deforming the wire by applying thermo-load-ultrasonic on stitch bonding, while the bonding wire is pressed to Ag plated 42 alloy on lead frame. On second bondability,during 500 thousand repeated bonding test, it has been measured as number of un-bonded.(2) Tesile strength

[0027]It was measured by using conventional tensile testing machine at 4 % elongation. Measurement was done atroom temperature, at 100 mm gauge length, and at 10 mm/min speed, and was calculated from acquired value of loadand elongation as fracture. By the way, elongation was calculated by using next equation from elongation as fracture.

5101520253035404550555

EP2 208 801B1

(3) Compressed diameter after molten ball

[0028]Evaluation of compressed diameter after molten ball was done by followng manner. It was ball bonded at Alelectrode (thickness of Al: around 1 x 10-6 m) on Si chip, then it was wired to Ag plated 42 alloy on lead frame by stitchbonding. Then, it was evalutated under condition of span is 3 x 10-3 m, to optionally selected 50 bonded wires from 200bonded wires. After measuring compressed ball diameters of applied direction of ultrasonic wave and paralell directionand virtical direction, it was shown as in \"Good\" for the ratio range of 0.95 - 1.05, as in \"Fair\" for the ratio range of 0.90- 1.00 (where except 0.95 - 1.05), and as in \"Worse\" for other range.(4) Manufacturing Method of Au alloy wire

[0029]Preferable manufacturing method of Au alloy wire on the present invention is explained. It is casted into ingotafter melting in the vacuum furnace adding prescribed amount of elements into high purity Au. It is applied cold metalforming using ditch roll and drawing mill to said ingot, and intermediate annealing, after getting thin wire which diameteris 25 x 10-6 meters by final drawing, it is conditioned at 4 % elongation by final annealing.(5) Usage

[0030]Bonding wire of the present invention is favorable to the method which bonds IC chip to lead frame. Where,said ball bonding means when wiring with wire and electrode of IC chip, especially Al electrode, and outer lead, andother electrode, it is formed molten ball, but at second bonding, without ball forming, side of wire is compressed. Cor-responding to needs it is impressed ultrasonic wave, and it is heated electrode.EFFECTS OF THE PRESENT INNVENTION

255101520[Effects]

[0031]When using Au alloy bonding wire on the present invention, after several hundreds thousands bonding at suchhigh speed the reason why second bondability is not deteriorated is not exactly known, but it is considered as followingmanner. Namely, oxide of trace additive elements is formed and attached at tip of capillary when ball forming by arcdischarge and at first bonding, it is considered that attached oxide is printed to wire side by each second bonding.Therefore, though there is thin layer of oxide at tip of capillary, it does not form thick contamination accumulated. It isconsidered that such attached oxide is transferred to wire side during second bonding before making thick contaminationaccumulated at tip of capillary. Consequently, it is considered that Au alloy bonding wire on the present invention hassuperior effects for second bonding. Bonding wire of the present invention has properly superior effect for pull strengthand roundness.

DESCRIPTION OF THE MOST PREFERRED EMBODIMENT

403035[Examples]

[0032]It is explained the most prefferred embodiment and compared examples shown in Table 1-1, Table 1-2, Table1-3 and Table 2.

45(Example 1)

[0033]After adding prescribed amount of additive elements to high purity Au of purity of 99.999 wt %, were melted inthe vacum furnace, then Au alloy ingots were gotten, which components shown in Table 1-1 and Table 1-2 and Table1-3 after casting. These ingots were roll formed by ditch roll, and were cold worked by using a drowing mill and inter-mediated annealing, finally finished thin wire was gotten, which diameter is 25 P meters by final drawing, was conditionedat 4 % elongation by final annealing.[0034]

50556

EP2 208 801B1

Table 1-1

No.

5Auresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidual

Pd wt %

Additive element (wt ppm)

Mg4934581690644633404431506825436252375566843560425453386145573947564151

In916111871313146812171014181510161286179139151911118127141019

Al10131769187171271481991516118131916186108111511141210712913

Yb14812917151191013714191261813616818191411151716101217151671311

1181018141691512

149109

1118

5240

117

81513

17126

4452

3768551043583464494690

61713

681092

123

104567

158910

201112*13*14*

251516*17*

30181920

3521222324*

402526*27

4528293031*

503233*34

5535*

EP2 208 801B1

(continued)

No.

5Auresidual

Pd wt %

1.0

Additive element (wt ppm)

Mg32

In11

Al9

Yb14

36*

* comparative examples

[0035]

Table 1-2

No.

1510Auresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidualresidual

Pd wt %

1.01.00.51.01.01.01.01.00.11.01. 01.01.01.00.51.01.01.00.11.01.01.01.01.01.01.00.51.01.01.0

Additive element (wt ppm)

Mg594810783651494619534754465544345945963368633162326638593461

In187131661461314121911151817108128101791398111512714

Al101317199181513616717811714819157111861081114121016

Yb81215616818119101610137141912617181319141115917121715

81214

81416

1211

1610

81017

4153

4635674759

197101315

638022

618458314522

37*38*39*

2040*41*42*43*

2544*45*46*

3047*48*49*50*

3551*52*53*

4054*55*56*

4557*58*59*60*

5061*62*63*

5564*65*66*

EP2 208 801B1

(continued)

No.

5Auresidualresidualresidualresidual

Pd wt %

0.51.01.01.0

Additive element (wt ppm)

Mg47314850

In1019910

Al1291312

Yb1671311

Ca1716914

La1219617

714

Lu19

3363

67*68*69*

1070*

* comparative examples

[0036]

15Table 1-3

No.

Auresidualresidualresidualresidualresidual

1.00.51.0

33110

3122

32022

31622

105

Pd wt %

Additive element (wt ppm)

In20

Ca2

La2

Sr5

20Conventional 1Conventional 2Comparative 1Comparative 2

25Comparative 3

(Note) \"Convetional 1\" in the Table 1-3 corresponds to the Example 29 in Reference Patent 2, and\"Convetional 2\" and \"Comparative 1 - 3\" are comparative examples, which components are out of therange of the present invention. Where, Conventional 1 contains 10 wt ppm Be and 2 wt ppm Sc.

30(500 thousands cycle test)

[0037]These Au alloy wires were examined by 500 thousands cycle test, continuously were ball bonded with ultrasonicwave onto Al electrods on IC chip and onto outer wiring, using ball bonding equipment, which brand name is MaxPmPlus from K&S Corporation. Where, it was done under the condition of ball bonding load is 0.2 N, time of ball bondingis 10 ms, ball bonding power is 0.30 w at ball bonding of IC chip side, and at second bonding of outer wiring, it was doneunder condition of ball bonding load is 0.3 N, time of ball bonding is 10 ms, ball bonding power 0.40 w. From this test,it was counted number of stop of ball bonding equipment by failure of second bonding. The result is shown in Table 2.(3) Roundness of compressed diameter after molten ball

[0038]Evaluation of roundness of compressed diameter after molten ball was done from 700 wires by making samplesmentioned manner herein before, by the way different from 500 thousand cycle test. Namely, masuring compresseddiameters of parallel direction of ultarasonic applied and virtical direction of it, comparing with each data, it was shownas in \"Good\" for the ratio range 0.95 - 1.05, as in \"Fair\" for the ratio range 0.90 - 1.00 (where except 0.95 - 1.05), andas in \"Worse\" for other range. The result is shown in Table 2.[0039]

Table 2 Results of 500 thousands cycle test

No.1

5535404550Number of failure of 2nd

Bonding

2223

Roundness

FairFairFairFair

No.39404142

Number of failure of 2nd

Bonding

3221

RoundnessGoodFairFairGood

234

EP2 208 801B1

(continued)

No.

5Number of failure of 2nd

Bonding

1223212120110201101000101211100222

Roundness

FairFairFairFairFairFairGoodFairFairFairGoodFairFairGoodGoodGoodGoodGoodGoodGoodGoodGoodGoodGoodGoodFairFairGoodFairGoodGoodFairFairFair

No.43444546474849505152535455565758596061626364656667686970

Number of failure of 2nd

Bonding

1122221012111110110001221010

RoundnessGoodGoodGoodFairFairFairGoodGoodFairGoodFairFairFairGoodFairFairGoodGoodGoodGoodGoodFairFairFairGoodFairGoodGood

567

10891011

15121314

2015161718

25192021

3022232425

35262728

4029303132

45333435

Conventional 1Conventional 2Comparative 1Comparative 2Comparative 3

44445

GoodFairFairGoodFair

50363738

55[0040]From the results shown herein before, in Table 1-1, Table 1-2, Table 1-3 and Table 2, Example 1 - 6 have thesame range of component described in the claim 1, and the number of failure of second bonding are 1 - 3 times in 500thousand cycles, and the roundness are \"Fair\". From these results, it is known that effect of additive elements such asMg, In, Al and Yb is greate. More over, in same manner, Example 7 - 9 have the same range of component described

EP2 208 801B1

in the claim 2, decrease number of failure of second bonding and improve roundness by adding Ca as same as saidbefore. In the case of Example 10, 11, 15, 18-21, in same manner herein after, have the same range of componentdescribed in the claim 3, it is recognized that these examples decrease number of failure of second bonding and alsoimprove roundeness by the effect of adding La, Lu, Sn and Sr to the component of Example 1 - 6. Example 22, 23, 25,27-30, 32, 34 have the same range of component described in the claim 4, these show the effect of adding Ca. Examples36-70 are not in accordance with the present invention. Furthermore conventional 1 and conventional 2 are lack of therange of additive elements, though roundness were good, but occurred 4 times of second bonding failures for the 500thousands bonding cycles. Comparative 1 - 3 show the case of out of the range on the present invention, which meanless and over. In these cases, roundness is good as same as described before, but it shows tendency of deteriorationsuch as 4 - 5 times of second bonding failures, it is shown that it is important to keep the range of component.

As described herein before, each bonding wire of the present invention considerably decreases bonding failures at 500thousands bonding cycle test.POSSIBILITY FOR INDUSTRIAL USE

15510[0041]According to bonding wire of the present invention, Au alloys of prescribed additive elements of Mg, In, Al, Yboptionally added Ca and optionaly added at least one trace additive element selected among La, and Sr are superior atsecond bondability, more over, have superior effect of pull strength and second bondability as same as conventionalbonding wire so far, it is effective to improve reliability of semi conductor devices.

20Claims1.

25Au alloy bonding wire consisting of:

5 - 100 wt ppm Mg,5 - 20 wt ppm In,5 - 20 wt ppm Al,5 - 20 wt ppm Yb,

optionally 5 -20 wt ppm Ca and/or at least one element selected among 5 - 20 wt ppm La, 5 - 20 wt ppm Lu, 5- 100 wt ppm Sr,

the rest being Au having a purity greater than 99.99 wt %.

30352.Au alloy bonding wire according to claim 1 consisting of:

5 - 100 wt ppm Mg,5 - 20 wt ppm In,5 - 20 wt ppm Al,5 - 20 wt ppm Yb,5 -20 wt ppm Ca,

the rest being Au having a purity greater than 99.99 wt %.

40453.Au alloy bonding wire according to claim 1 consisting of:

5 - 100 wt ppm Mg,5 - 20 wt ppm In,5 - 20 wt ppm Al,5 - 20 wt ppm Yb,

at least one element selected among 5 - 20 wt ppm La, 5 - 20 wt ppm Lu 5 - 100 wt ppm Sr,the rest being Au having a purity greater than 99.99 wt %.

50554.Au alloy bonding wire according to claim 1 consisting of:

5 - 100 wt ppm Mg,5 - 20 wt ppm In,

EP2 208 801B1

5 - 20 wt ppm Al,5 - 20 wt ppm Yb,5 -20 wt ppm Ca,

at least one element selected among 5 - 20 wt ppm La, 5 - 20 wt ppm Lu, 5 - 100 wt ppm Sr,

5the rest being Au having a purity greater than 99.99 wt %.

Patentansprüche

101.Bonddraht-Goldlegierung, bestehend aus:

5 - 100 Gew.-ppm Mg,5 - 20 Gew.-ppm In,5 - 20 Gew.-ppm Al,5 -20 Gew.-ppm Yb,

wobei wahlweise 5 - 20 Gew.-ppm Ca und / oder mindestens ein Element ausgewählt ist aus 5 - 20 Gew.-ppmLa, 5 - 20 Gew.-ppm Lu, 5 - 100 Gew.-ppm Sr,

wobei der Rest Gold ist, das eine Reinheit größer als 99,99 Gew.-% aufweist.

15202.Bonddraht-Goldlegierung nach Anspruch 1, bestehend aus:

5 - 100 Gew.-ppm Mg,5 - 20 Gew.-ppm In,5 - 20 Gew.-ppm Al,5 - 20 Gew.-ppm Yb,5 - 20 Gew.-ppm Ca,

wobei der Rest Gold ist, das eine Reinheit größer als 99,99 Gew.-% aufweist.

25303.Bonddraht-Goldlegierung nach Anspruch 1, bestehend aus:

5 - 100 Gew.-ppm Mg,5 - 20 Gew.-ppm In,5 - 20 Gew.-ppm Al,5 - 20 Gew.-ppm Yb,

wobei mindestens ein Element ausgewählt ist aus 5 - 20 Gew.-ppm La, 5 - 20 Gew.-ppm Lu, 5 - 100 Gew.-ppm Sr,wobei der Rest Gold ist, das eine Reinheit größer als 99,99 Gew.-% aufweist.

35404.Bonddraht-Goldlegierung nach Anspruch 1, bestehend aus:

5 - 100 Gew.-ppm Mg,5 - 20 Gew.-ppm In,5 - 20 Gew.-ppm Al,5 - 20 Gew.-ppm Yb,5 - 20 Gew.-ppm Ca,

wobei mindestens ein Element ausgewählt ist aus 5 - 20 Gew.-ppm La, 5 - 20 Gew.-ppm Lu, 5 - 100 Gew.-ppm Sr,wobei der Rest Gold ist, das eine Reinheit größer als 99,99 Gew.-% aufweist.

4550Revendications

551.Un fil de connexion en alliage d’Au constitué de:

5 à 100 ppm en poids de Mg,

EP2 208 801B1

5 à 20 ppm en poids d’In,5 à 20 ppm en poids d’Al,5 à 20 ppm en poids d’Yb,

éventuellement 5 à 20 ppm en poids de Ca et/ou d’au moins un élément choisi parmi: 5 à 20 ppm en poids deLa, 5 à 20 ppm en poids de Lu, 5 à 100 ppm en poids de Sr,

le reste étant de l’Au ayant une pureté supérieure à 99,99 % en poids.

105Le fil de connexion en alliage d’Au selon la revendication 1, constitué de:

5 à 100 ppm en poids de Mg,5 à 20 ppm en poids d’In,5 à 20 ppm en poids d’Al,5 à 20 ppm en poids d’Yb,5 à 20 ppm en poids de Ca,

le reste étant de l’Au ayant une pureté supérieure à 99,99 % en poids.

153.Le fil de connexion en alliage d’Au selon la revendication 1, constitué de:

5 à 100 ppm en poids de Mg,5 à 20 ppm en poids d’In,5 à 20 ppm en poids d’Al,5 à 20 ppm en poids d’Yb,

au moins un élément choisi parmi: 5 à 20 ppm en poids de La, 5 à 20 ppm en poids de Lu, 5 à 100 ppm enpoids de Sr,

le reste étant de l’Au ayant une pureté supérieure à 99,99 % en poids.

20254.Le fil de connexion en alliage d’Au selon la revendication 1, constitué de:

5 à 100 ppm en poids de Mg,5 à 20 ppm en poids d’In,5 à 20 ppm en poids d’Al,5 à 20 ppm en poids d’Yb,5 à 20 ppm en poids de Ca,

au moins un élément choisi parmi: 5 à 20 ppm en poids de La, 5 à 20 ppm en poids de Lu, 5 à 100 ppm enpoids de Sr,

le reste étant de l’Au ayant une pureté supérieure à 99,99 % en poids.

30354045505513

EP2 208 801B1

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the Europeanpatent document. Even though great care has been taken in compiling the references, errors or omissions cannot beexcluded and the EPO disclaims all liability in this regard.Patent documents cited in the description••

JP 3657087 B [0002] [0006]JP 3059314 B [0004] [0006]

•

JP 2000040710 A [0005] [0006]

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