JP6410692B2 - Copper alloy bonding wire - Google Patents

Description

The present invention relates to a copper alloy bonding wire suitable for connecting an IC chip electrode used in a semiconductor device and a substrate such as an external lead.

Generally, a method called ball bonding is used for the first bonding between a copper bonding wire and an electrode, and a method called wedge bonding is used for wedge bonding between a copper bonding wire and a wiring on a semiconductor circuit wiring board. In the first joining, a true sphere called a free air ball (FAB) is formed at the tip of the wire by applying arc heat from the torch electrode to the tip of the wire by an electron frame off (EFO) method. Then, an ultrasonic wave is applied to the aluminum pad heated within the range of 150 to 300 ° C. while pressing the FAB with a capillary to bond the bonding wire and the aluminum pad.

Next, the capillary is raised while feeding out the bonding wire, and the capillary is moved to the wedge bonding point while drawing a loop toward the lead.
To explain with reference to the drawings, in the wedge bonding by the capillary, the bonding wire (1) is wedge-bonded to the lead (3) as shown in FIG. At this time, the end of the wedge-bonded bonding wire (1) is crushed by the tip of the capillary (2), so that the area of the wire at the bonding location is minimized as shown in FIG. Further, the bonding wire (1) is then cut off. This is because when the bonding wire (1) is grasped by the wire clamper (4) at the upper part of the capillary (2) and pulled upward, the wire is easily formed at the tip of the remaining bonding wire (1) as shown in FIG. It is supposed to be cut.

Next, although not shown, the capillary is moved to the first joining point. Then, spark discharge is performed at the position of the discharge torch, a molten ball (FAB) is formed at the tip of the bonding wire, and the bonding wire and the aluminum pad are first bonded. Such bonding cycle is repeated, and the pad and the lead (3) are sequentially connected through the bonding wire (1).

Since the bonding wire (1) is crushed by the tip of the left capillary (2) in FIG. 1, the bonding wire (1) to be cut is deformed according to the inherent Young's modulus. This deformed shape is different between gold (Au) and copper (Cu). In the case of a gold bonding wire, although it is soft, the fine structure is firm, so that a J-shaped deformed shape as described later does not become a problem.

Even in the case of a noble metal bonding wire having a double core structure, there is no problem as well. Furthermore, a bonding wire using the property that the cross-sectional structure easily forms a double-core wire has been proposed. For example, claim 4 of Japanese Patent Laid-Open No. 59-48948 (Patent Document 1 to be described later) states that “the fiber structure (111) is formed in the core of the wire and the fiber structure (100) is formed in the surface layer of the wire. A gold bonding wire is disclosed.

On the other hand, when a wire made of a pure metal of copper (Cu) or a copper (Cu) alloy is continuously drawn after continuous casting, different fiber structures are formed at the outer peripheral portion and the central portion according to the total cross-section reduction rate, and the cross section The structure makes it easier to form a double core wire. When the total cross-section reduction rate is 96 to 99%, the preferred orientations are <111> and <100> (1990, Japan Society for Technology of Plasticity “Drawing” (non-patent document 1 described later), page 85). This is because the stacking fault energy plays an important role (N. Brown Trans. Met. Soc. AIME, Vol. 221, 1961, p. 236). For this reason, a wire made of pure copper or a copper alloy is usually subjected to intermediate annealing. The time of intermediate annealing is important. Generally, “the allowable limit of primary drawing is considered to be about 95%,” “the {hkl} <111> orientation is the initial stage of secondary processing. It is said that it is important to insert an intermediate annealing process that does not occur in Japan ”(Naoji Inazuna et al., Journal of the Japan Institute of Metals, Vol. 47, No. 3 (1983), p. 266 (non-patent document to be described later) Reference 2)).

Further, in claim 1 of JP2013-139635A (Patent Document 2 described later), it is selected from one of the group consisting of a silver-gold alloy, a silver-palladium alloy, and a silver-gold-palladium alloy. An alloy wire made of a material having a polycrystalline structure with a face-centered cubic lattice and comprising a plurality of crystal grains, wherein the center portion of the alloy wire has an elongated crystal grain or an equiaxed crystal grain. The other part of the alloy wire is made of equiaxed crystal grains, and the number of the crystal grains including annealing twins is 20% or more of the total amount of the crystal grains of the alloy wire. It is disclosed.

Further, in claim 1 of the republished patent 2013/111642 (Patent Document 3 described later), “a bonding wire having a core material mainly composed of copper and a palladium stretched layer, In addition, a bonding wire characterized in that copper has a fibrous structure extending in the axial direction is disclosed.

Further, claim 1 of Japanese Patent Application Laid-Open No. 2004-31469 (Patent Document 4 to be described later) states that “in the crystal grain structure of the longitudinal cross section of the bonding wire, R is the radius of the wire and R / The area of a crystal grain having a [111] orientation with respect to the area of the crystal grain having a [100] orientation among the crystal orientations in the wire longitudinal direction at the center when the portion up to 2 is the outer periphery. And the ratio Rs of the area of the crystal grain having the [111] orientation to the area of the crystal grain having the [100] orientation out of the crystal orientation in the wire longitudinal direction at the outer peripheral portion, the absolute value of the difference ratio between the two | 1-Rc / Rs | × 100 (%) is 30% or more ”, which discloses a“ gold bonding wire for a semiconductor device ”.

Further, in claim 1 of Japanese Patent Application Laid-Open No. 2009-140942 (Patent Document 5 to be described later), “a core material made of a conductive metal and a thin material mainly composed of a metal different from the core material on the core material. A bonding wire for a semiconductor device having a stretched layer, wherein the metal of the thin stretched layer is a face-centered cubic crystal, and the crystal orientation <hkl> in the longitudinal direction in the crystal plane of the surface of the thin stretched layer is < 111> and <100> are both less than 50%, and there is a proposal of “bonding wire for semiconductor device”, which is disclosed in Japanese Patent Application Laid-Open No. 2009-158931 (Patent Document 6 described later). 1 includes a “bonding wire for a semiconductor device having a core material made of a conductive metal and a thin stretch layer mainly composed of a metal different from the core material on the core material, Layer metal face A bonding wire for a semiconductor device, which is a cubic crystal, wherein the proportion of <111> in the longitudinal crystal orientation <hkl> in the crystal plane of the surface of the thin stretched layer is 50% or more. The proposal is seen.

However, when the copper (Cu) bonding wire is wedge-bonded and then the wire is cut, there is a problem that it may be bent lightly into a J-shape as shown in FIG.

In addition, when the wire diameter was as thick as 25 μm even with the copper bonding wire, such a wire deformed into a J-shape was hardly found. However, when the wire diameter of the bonding wire became smaller than 20 μm, became thin, and the bonding speed increased, the wire deformed into a J shape began to appear. When such a tip portion exists in the bonding wire, the loop shape is distorted when the loop is drawn. Further, since the spark current does not strike the tip of the bonding wire well, it may cause a flat deformed ball due to FAB. Further, when the J-shaped deformation becomes severe, the Z-shaped deformation as seen in the prior art becomes a cause of clogging of the capillary.

In addition, in a copper alloy bonding wire made of 10 to 500 ppm of phosphorus (P) and the balance of copper (Cu) having a purity of 99.9% or more, a concentrated layer of phosphorus (P) is easily segregated on the surface of the bonding wire. Another problem is that it is difficult to obtain uniform mechanical properties (Japanese Patent Laid-Open No. 7-122564).

In order to solve such a problem, the conventional attempts have been made to improve the bonding apparatus, but such a method has not been successful. That is, in the prior art, after the wedge bonding, the wire clamper is closed and the bonding wire is pulled slightly upward. As a result, the wire clamper is opened once with the reduced diameter portion formed on the bonding wire. Next, the wire clamper is closed and the wire is strongly pulled again to cut the bonding wire from the reduced diameter portion (Japanese Patent Laid-Open No. 2007-66991 (Patent Document 7 described later)). Conventionally, such a problem of the mechanical properties of the bonding wire has been solved by the operation of the wire clamper.

However, in the improvement by the conventional bonding apparatus, the extra wire clamper work lengthens the time of one bonding cycle, so that particularly in the case of a small-diameter bonding wire of 20 μm or less, the work efficiency of bonding is remarkably deteriorated. Met.

1990, Japan Society for Technology of Plasticity, "Drawing", page 202 Naoji et al., Journal of the Japan Institute of Metals, Vol. 47, No. 3 (1983), p. 266

JP 59-48948 JP 2013-139635 A Republished patent 2013/111642 JP 2004-31469 A JP 2009-140942 A JP 2009-158931 A JP 2007-66991 A

The present invention is made to solve the problem that the tip of the wire is deformed into a J-shape in the wedge bonding step of the second bond in which the copper alloy bonding wire is pulled up as it is and then cut within the shortest time after the wedge bonding. It is a thing. An object of the present invention is to provide a copper alloy bonding wire in which the cut ends are not deformed into a J shape by aligning the crystal grain size and making it non-oriented.

The reason for the deformation to the J-shape can be understood as follows with reference to FIG. After wedge bonding the bonding wire (1) to the lead (3), the capillary (2) is raised. Then, the bonding wire (1) is fed out to the tip of the capillary (2). After a predetermined length of the bonding wire (1) is extended to the tip of the capillary (2), the wire clamper (4) above the capillary (2) is closed to connect the bonding wire (1). Hold the wire clamper (4) and capillary (2) together.

Then, the bonding wire (1) stretches according to the Young's modulus, and the bonding wire (1) is torn off by the further rise. By this cutting, the elastic energy of the bonding wire (1) is released. At this time, if there is a weak mechanical strength in the bonding wire (1) between the wire clamper (4) and the cut part, the energy concentrates on the weak part and the wire bends lightly into a J shape ( There is a springback). The present inventors have noticed that this is the reason why the bonding wire (1) is bent lightly into a J-shape.

The copper alloy bonding wire for solving the problems of the present invention has 50 to 250 crystal grains of the copper alloy per cross-sectional area, the maximum particle diameter is 1/3 or less of the diameter of the bonding wire, and Specific orientations such as <111> and <100> are all non-azimuths of 40% or less. Here, the specific orientation in the present invention refers to a case where the angle is within an allowable angle of ± 20 ° with respect to the orientation in a certain orientation.

One of the embodiments of the present invention is that the copper alloy has a gold (Au) of 100 mass ppm to 3,000 mass ppm, a silver (Ag) of 10 mass ppm to 1,000 mass ppm, phosphorus (P ) Is 5 mass ppm or more and 500 mass ppm or less, the total amount of other impurity elements is 100 mass ppm or less, and the balance is copper (Cu).

In another embodiment of the present invention, the copper alloy has a nickel (Ni), palladium (Pd) or platinum (Pt) content of 0.02 mass% or more and 1 mass% or less, and phosphorus (P). 5 mass ppm or more and 500 mass ppm or less, the total amount of other impurity elements is 100 mass ppm or less, and the balance is copper (Cu).

In another embodiment of the present invention, the core material of the copper alloy is coated with a palladium (Pd) stretched layer.

In another embodiment of the present invention, the core material of the copper alloy is covered with a palladium (Pd) stretched layer and a gold (Au) thin stretched layer.

Another embodiment of the present invention is characterized in that the number of crystal grains is 80 to 200.

In another embodiment of the present invention, the maximum particle diameter is 1/5 or less of the diameter of the bonding wire.

In another embodiment of the present invention, the specific orientation is non-azimuth that is 38% or less.

In the present invention, the number of crystal grains of the copper alloy per cross-sectional area is determined to be 50 to 250, even if a double-core structure is formed in the longitudinal direction of the bonding wire. This is to facilitate tearing along the grain boundaries. When the number of crystal grains is less than 50, coarse crystal grains are easily formed in the bonding wire in the final tempering heat treatment. If the number of crystal grains exceeds 250, the bonding wire becomes hard and the loop shape is not stable. It is preferable that there are 80 to 240 crystal grains. More preferably, the number of crystal grains is in the range of 100 to 220.

In the present invention, the reason that the maximum grain size of the crystal grains is 1/3 or less of the diameter of the bonding wire is that if there are huge crystal grains, the wire is easily bent at that location. Bending of the bonding wire causes leaning defects, loop formation defects and wire flow. The maximum particle size is preferably 1/5 or less of the diameter of the bonding wire. More preferably, it is 1/8 or less.

In the present invention, the reason why all the specific orientations are non-azimuths of 40% or less is to prevent a double core structure from being formed on the bonding wires. This is because, when the specific orientation in the range of 0 ° to less than 20 °, such as <100>, exceeds 40%, the tearing of the bonding wire differs depending on the presence or absence of the specific orientation. The specific orientation is preferably 38% or less. More preferably, it is 37% or less. The reason why the angle is set to 20 ° instead of 15 ° is to collect as much information as possible from fine bonding wires.

In the copper alloy of the present invention, gold (Au) is 100 mass ppm to 3,000 mass ppm, silver (Ag) is 10 mass ppm to 1,000 mass ppm or phosphorus (P) is 5 mass ppm to 500 mass. It is preferable that the total amount of other impurity elements is 100 mass ppm or less and the remaining copper (Cu). More preferable phosphorus (P) content is 200 mass ppm or less. The synergistic effect of gold (Au) and silver (Ag) fixes oxygen contained in the copper alloy ingot, and also prevents surface segregation of phosphorus (P), so that three kinds of elements coexist. Particularly preferred. Also, a predetermined amount of gold (Au) increases the Young's modulus of the copper alloy.

Further, the copper alloy in the present invention is nickel (Ni), palladium (Pd) or platinum (Pt) of 0.02 mass% to 1 mass%, phosphorus (P) is 5 mass ppm to 500 mass ppm, other It is preferable that the total amount of the impurity elements is 100 mass ppm or less and the remaining copper (Cu). More preferable phosphorus (P) content is 200 mass ppm or less. This is because nickel (Ni) fixes oxygen contained in the copper alloy metal and can also prevent surface segregation of phosphorus (P). A predetermined amount of nickel (Ni) in the copper alloy matrix is finely dispersed to fix oxygen. Also, a predetermined amount of nickel (Ni) increases the Young's modulus of the copper alloy.

Here, the total amount of other impurity elements is set to 100 ppm by mass or less in order to prevent formation of oxides of base metal elements in the copper alloy matrix. This is because, when an oxide of a base metal element is formed at the crystal grain boundary of copper, the springbacked bonding wire is easily deformed. Preferably, the total amount of other impurity elements is 50 ppm by mass or less, and more preferably 5 ppm by mass or less, if the price of metal is neglected. For example, when copper ingot having a purity of 6N (99.9999 mass%) or more is used, the total amount of other metal elements is less than 1 ppm by mass. “Other impurity elements” refers to sulfur (S), oxygen (O), and the like. This is because when 10 mass ppm of sulfur (S) is present, the FAB becomes hard and chip cracking may occur during the first bonding. However, the copper alloy for ordinary bonding wires does not contain sulfur (S) exceeding 10 mass ppm.

In addition, the base material of 6N to 4N high-purity copper alloy can be used for the copper alloy of the present invention. In this base material, oxygen is usually contained in an amount of 0.2 mass ppm to 50 mass ppm. These amounts of oxygen hardly change in the copper alloy composition of the present invention even if the copper alloy base material is remelted / cast, primary wire drawing, intermediate heat treatment, secondary wire drawing, final heat treatment, storage and the like. When oxygen is contained in the copper (Cu) matrix, the base metal element easily forms an oxide. Generally, gas components are removed from high-purity copper alloys (Shoji Aoki et al., Journal of Copper and Copper Alloys, January 2003, Vol. 42, No. 21, p. 21).

Moreover, in this invention, it is preferable that the palladium (Pd) extending | stretching layer is coat | covered with the core material of the copper alloy. Furthermore, it is more preferable that the core material of the copper alloy is covered with a palladium (Pd) stretched layer and a gold (Au) thin stretched layer. This is because the bonding wire is easily torn after the wedge bonding. Here, the expression of “stretched layer” or “thin stretched layer” is not necessarily an accurate representation of actual surface properties, but fine particles of palladium (Pd) and gold (Au) from the surface of the bonding wire. The range in the depth direction in which is detected is the theoretical film thickness, and is expressed as a “layer” for the sake of convenience. Since the bonding wire of the present invention is extremely thin, if it is detected from the surface of the bonding wire by high frequency inductively coupled plasma optical emission spectrometry (ICP-AES), it is assumed that there are “stretched layer” and “thin stretched layer”. .

In the copper alloy bonding wire of the present invention, even if a palladium (Pd) stretched layer, or a palladium (Pd) stretched layer and a gold (Au) thin stretched layer are coated, these stretched layers are extremely thin, so copper Has little effect on the Young's modulus of the alloy core. The stretched palladium (Pd) layer has the effect of delaying the oxidation of the copper alloy fine wire. Further, when the gold (Au) thin stretched layer is coated, the spark discharge of the palladium (Pd) stretched layer in which the element such as sulfur (S) deposited on the surface from the copper alloy is fixed and the current flow is poor. Has the effect of stabilizing.

In the present invention, there are 50 to 250 copper alloy crystal grains per cross-sectional area, the maximum grain size is 1/3 or less of the diameter of the thin wire, and a specific orientation such as <111> or <100> In any case, a well-known manufacturing technique can be used to obtain a fine line that is 20% or less non-directional. For example, “9.3 Secondary Processing” of Naoji Inazuna, “Metal Drawing”, Chapter 9 “Recrystallized Fiber Texture and Secondary Processing” published by Modern Editing Co., Ltd. on July 1, 1985 The relationship between primary and secondary drawing of high-purity copper and intermediate annealing is described in detail. The wire drawing of the bonding wire has a final area reduction rate of 99% or more in the same book, and is subjected to a tempering heat treatment. In the present invention, the copper alloy bonding wire of the present invention can be manufactured by performing an intermediate annealing with a primary drawing rate of 95 to 99.99% or less.

According to the copper alloy bonding wire of the present invention, it is cut from the portion of the bonding wire that has become the thinnest at the time of wedge bonding, so that the tip of the bonding wire is not bent into a J-shape, and the cut end is the bonding wire. There is an effect that it is possible to provide a copper alloy bonding wire that does not protrude from the cross-sectional area. Further, when the shape of the bonding wire is stabilized, there is an effect that the FAB at the first bonding does not become a deformed ball. Furthermore, since the bonding wire can be easily cut only by pulling the bonding wire upward, there is an effect that the time of the bonding process can be shortened. Moreover, the effect of this invention is exhibited, so that a wire diameter is made small from 20 micrometers to 15 micrometers.

Moreover, according to the copper alloy bonding wire of the embodiment of the present invention, since the base metal oxide is not dispersed in the copper matrix, the wire itself is soft. In addition, since the position of the spark discharge at the time of the first bonding is also stabilized, the palladium (Pd) stretched layer, or the palladium (Pd) stretched layer and the gold (Au) thin stretched layer can be coated thinner than before, There is an effect that the FAB at the time of the first bonding is stabilized.

Furthermore, in the copper alloy bonding wire according to the embodiment of the present invention, when a gold (Au) stretched layer is provided on the outermost surface of the wire, the wires can stick to each other even if the wires are wound in multiple turns and wound by 10,000 meters. Absent. As a result, the wire unwinding property is improved. Further, as a concomitant effect, the slip of the wire surface with respect to the capillary is improved. Further, according to the copper alloy bonding wire of the present invention, the gold (Au) fine particles on the outermost surface of the wire are not peeled off from the stretched layer of palladium (Pd). Therefore, even if bonding is repeated many times, the oxide of copper (Cu) does not adhere to the capillary, so that the capillary is not contaminated.

The core material is copper (Cu) having a purity of 99.99998% by mass (5N), and phosphorus (P) and nickel (Ni) as well as palladium (Pd), platinum (Pt) gold (Au) and silver. (Ag) was used as an additive element. As the base metal element, an element generally contained in high-purity copper was selected. That is, bismuth (Bi), selenium (Se), tellurium (Te), zinc (Zn), iron (Fe), nickel (Ni) and tin (Sn) were appropriately selected. What blended these in the predetermined range was made into Examples 1-5.

Next, this is melted and continuously cast. Thereafter, the thick wire (1.0 mm in diameter) before being coated with the stretched material is obtained by performing primary wire drawing in a range of 95 to 99.99% or less. It was. Next, intermediate heat treatment (300 ° C. to 600 ° C. × 0.5 to 3 hours) was performed (Example 4 and Example 5) or not (Example 1 to Example 3). Thereafter, a thin stretched layer of gold (Au) (Examples 4 and 5) and a stretched layer of palladium (Pd) (Examples 3 to 5) were provided as necessary. These semi-finished wires are continuously wet-processed with a diamond die and subjected to secondary wire drawing with a cross-section reduction rate of 99% or more, and subjected to a tempering heat treatment at 480 ° C. for 1 second, and finally a copper alloy bonding wire having a diameter of 15 μm. Got. The average diameter reduction rate is 6 to 20%, and the final drawing speed is 100 to 1000 m / min. The purity of gold (Au) is 99.9999% by mass or more, and the purity of palladium (Pd) is 99.999% by mass or more.

(Crystal grain measurement)
Measurement of crystal grains per cross-sectional area of the bonding wire was performed as follows. That is, the bonding wire of Example 1 was cut using an ion milling device (model: IM4000 manufactured by Hitachi High-Technologies Corporation). Subsequently, the cross section was observed using FE-SEM (JSM-7800F made by JEOL Ltd.). In addition, the number of crystal grains per cross-sectional area was counted using an EBSD apparatus (OIM Data Collection system manufactured by TSL). The measurement results are shown in the right column of Table 1.

(Direction measurement)
The measurement of the orientation of the bonding wire was performed using an FE-SEM (JSM-7800F manufactured by JEOL Ltd.) and an EBSD device (OIM Data Collection system manufactured by TSL). The measurement results are shown in the right column of Table 1.

(Bending test for bonding wire)
The bending test of the bonding wire was performed as follows. That is, using a wire bonder (UTC-3000 manufactured by Shinkawa Co., Ltd.), 100 wedges were bonded to a silver (Ag) plated copper (Cu) plate at an ambient temperature of 25 ° C. under the conditions of an ultrasonic output of 100 mA and a bond load of 90 gf. Then, after the wedge bonding is finished, as shown in FIG. 1, the capillary (2) is raised, the bonding wire (1) is fed out to the tip of the capillary (2), and then the wire clamper (4) is closed. Then, the capillary (2) and the wire clamper (4) were raised together to cut the wire with the bonding wire (1) having a predetermined length extended from the tip of the capillary (2). This was performed 1,000 times, and the number of bendings of the bonding wire was examined with an enlargement projector. The measurement results are shown in the right column of Table 1.

Comparative example

The bonding wires having the compositions shown in Table 1 were referred to as Comparative Examples 1 and 2. The wires of Comparative Example 1 and Comparative Example 2 have a different number of crystal grains, and each has a unique preferred orientation. That is, the wire of Comparative Example 1 had a higher intermediate heat treatment temperature than the wire of Example 5, so the number of crystal grains was as small as 13, and the preferred orientation of <100> was 57% of the total. In addition, the wire of Comparative Example 2 was displayed innumerable with no crystal grains because the cross-section reduction rate of the temporary wire drawing was higher than that of the wire of Example 3. Further, the preferred orientation of <111> was 45% of the whole, and the preferred orientation of <100> was 10% of the whole.

When the bonding wires of Comparative Examples 1 and 2 were subjected to crystal grain measurement, orientation measurement, bonding wire bending test and protrusion test in the same manner as in the Examples, the results in the right column of Table 1 were obtained.

As is clear from these test results, all of the examples of the present invention had appropriate crystal grains and no preferred orientation, so the tip of the bonding wire was not bent into a J shape. On the other hand, the wires of Comparative Examples 1 and 2 had 8 and 14 wires, respectively, in which the tips of the bonding wires were bent in a J shape. Therefore, it turns out that the wire of a comparative example also affects FAB.

The copper alloy bonding wire of the present invention replaces the conventional gold alloy wire, in addition to general-purpose ICs, discrete ICs, memory ICs, IC packages for LEDs and ICs for automobile semiconductors that require low cost while being used for high temperature and high humidity There are semiconductor applications such as packages.

It is sectional drawing of the bonding wire obtained by the wedge joining of the copper alloy fine wire of this invention. It is a perspective view which shows the wedge joining process of a copper alloy fine wire. It is sectional drawing which shows the joining state obtained by wedge joining of a copper alloy fine wire. It is sectional drawing of the bonding wire bent in J shape.

1 Bonding wire 2 Capillary 3 Lead 4 Wire clamper

Claims (6)

A copper alloy bonding wire having a wire diameter of 15 μm or more and 20 μm or less, wherein the copper alloy is composed of a total amount of impurity elements of 100 mass ppm or less and the balance copper (Cu), and the impurity elements include bismuth (Bi), selenium ( Se), tellurium (Te), zinc (Zn), iron (Fe), nickel (Ni) and tin (Sn) containing a total amount of plural elements of 7 ppm to 70 ppm by mass, and the bonding wire in the longitudinal direction There are 50 to 250 crystal grains of copper alloy per cross-sectional area cut perpendicularly with respect to the angle of inclination of 20 °, and the maximum grain size is 1/3 or less of the diameter of the bonding wire. A copper alloy bonding wire characterized by having a specific orientation of 40% or less. A copper alloy bonding wire having a wire diameter of 15 μm or more and 20 μm or less, wherein the copper alloy has gold (Au) of 100 mass ppm to 3,000 mass ppm and silver (Ag) of 10 mass ppm to 1,000 mass ppm. Or phosphorus (P) 5 mass ppm or more and 500 mass ppm or less, and the total amount of impurity elements is 100 mass ppm or less and the balance copper (Cu). The impurity elements include bismuth (Bi) and selenium (Se). , tellurium (Te), zinc (Zn), iron (Fe), total amount of unrealized below 70 ppm by weight or more and 7 wt ppm of a plurality elements of nickel (Ni) and tin (Sn), the bonding wire in the longitudinal direction There are 50 to 250 crystal grains of copper alloy per cross-sectional area cut perpendicularly with respect to a large tilt grain boundary of 20 °, and the maximum grain size is Bonn. Is 1/3 or less of the diameter of Inguwaiya and copper alloy bonding wire any particular orientation is equal to or less than 40%. The copper alloy bonding wire according to claim 1 or 2 , wherein the copper alloy core material is covered with a palladium (Pd) stretched layer. The copper alloy bonding wire according to claim 1 or 2 , wherein the copper alloy core material is coated with a palladium (Pd) stretched layer and a gold (Au) thin stretched layer. The copper alloy bonding wire according to claim 1 or 2 , wherein the number of crystal grains is 80 to 200. The copper alloy bonding wire according to claim 1 or 2 , wherein the maximum particle diameter is 1/5 or less of a diameter of the bonding wire.

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