JP2014049523A - Wire bonding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire bonding method capable of simply and efficiently bonding a wire at first and second connection portions extending at different angles.SOLUTION: First and second connection portions extend at different angles. A capillary 2 has a relief face 2y around a tip 2x. When an inclined angle of the capillary 2 to a connection portion 5 when a metal wire 44 is connected to the connection portion 5 is designated as A and an inclined angle of the relief face 2y of the capillary 2 is designated as B, A≤B is satisfied.

Description

  The present invention relates to a wire bonding method, and more particularly to a wire bonding method performed for first and second connection locations extending at different angles.

  Wire bonding is usually performed for the first and second connection points extending in parallel with each other. However, there is a case where it is desired to wire bond for the first and second connection points extending non-parallel to each other, that is, at different angles. is there.

  For example, the angular velocity sensor 105 shown in the partial cross-sectional schematic diagram of FIG. 9 includes an IC device 102 and an angular velocity sensor element 101 in the recess of the package 104. The IC device 102 is fixed to the mounting surface 104a which is the bottom surface of the recess of the package 104, and the terminal portion of the IC device 102 and the electrode portion on the mounting surface 104a are electrically connected via the wire 103. . The angular velocity sensor element 101 is fixed to an inclined surface 101a that is inclined with respect to the mounting surface 104a, and the terminal portion of the angular velocity sensor element 101 and the electrode portion on the mounting surface 104a are electrically connected via a wire 106. It is connected. The substrate on which the angular velocity sensor 105 is mounted is used in a state inclined from the horizontal. At that time, the axis of the angular velocity sensor element 101 indicated by the dashed arrow is in the vertical direction (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2009-41962

  Wire bonding is performed as follows, for example. First, an object to be connected is placed on the table, a capillary for leading the wire is pressed against the first connection location of the connection object, and the wire is connected to the first connection location. Next, in a state where the wire is connected to the first connection location, the capillary and the table are relatively moved, the capillary is pressed against the second connection location of the connected object, and the wire is connected to the second connection location. To do.

  When connecting the wires, the capillary is perpendicular to the connection location. When the first and second connection points connecting the wires extend at different angles, such as the wire 106 connected to the angular velocity sensor element 101 described above, the capillary is not connected when the wire is connected to the first connection point. It is necessary to change the relative positional relationship between the connected object and the capillary so that the capillary is perpendicular to the second connection location when the wire is connected to the first connection location and the wire is connected to the second connection location. .

  In order to change the relative positional relationship between the connected object and the capillary, it is conceivable to change the angle of the table on which the connected object is placed or the angle of the head holding the capillary. In this case, a wire bonding apparatus having a special structure that can change the angle of the table and the head is required.

  Alternatively, the object to be connected is placed on the table via the jig, the jig is operated, and the wire is connected to the first connection location, and the wire is connected to the second connection location. It is conceivable to change the angle of the connected object. In this case, the structure of the jig becomes complicated.

  In either case, after connecting the wire to the first connection location, it is necessary to change the angles of the table, head, and jig corresponding to the second connection location, which reduces the efficiency of work.

  In view of such a situation, the present invention intends to provide a wire bonding method capable of simply and efficiently performing wire bonding with respect to first and second connection portions extending at different angles.

  In order to solve the above-described problems, the present invention provides a wire bonding method configured as follows.

The wire bonding method includes: (i) a first step of bringing a tip of a capillary close to a first connection location of an object to be connected, and connecting a wire coming out from the tip of the capillary to the first connection location; (Ii) In a state where the wire is connected to the first connection location, the tip of the capillary is brought close to the second connection location of the connected object, and the wire exits from the tip of the capillary. And a second step of connecting a wire to the second connection location. The first and second connection points extend at different angles. The capillary has a flank around the tip. In the first and second steps, an inclination angle of the capillary with respect to the connection location when the wire is connected to the connection location (that is, an angle formed between a normal line of the connection location and a center line of the capillary) A, the inclination angle of the flank of the capillary (that is, the inclination angle of the flank with respect to a plane perpendicular to the center line of the capillary) B,
A ≦ B (1)
To satisfy. The tilt angles A and B are defined by values from 0 ° to 90 °.

  According to the above method, when the tip of the capillary is brought close to the connection location and the wire is connected to the connection location, the distance between the flank face of the capillary and the connection location is the same or farther away from the center line of the capillary. Since it becomes large, a wire can be favorably connected to a connection location. If the expression (1) is satisfied, it is not necessary to make the capillary perpendicular to the connection location in the first and second steps, and therefore wire bonding can be performed easily and efficiently.

  Moreover, in order to solve the said subject, this invention provides the wire bonding method comprised as follows.

The wire bonding method includes: (i) a first step of bringing a tip of a capillary close to a first connection location of an object to be connected, and connecting a wire coming out from the tip of the capillary to the first connection location; In a state where the wire is connected to the first connection location, the tip of the capillary is brought close to the second connection location of the connected object, and the wire coming out from the tip of the capillary is And a second step of connecting to the second connection location. The first and second connection points extend at different angles. Bumps are formed in advance in at least one of the first and second connection locations, and the wires are connected to the first and second via the bumps in at least one of the first and second steps. Connect to at least one of the connection points. The height of the bump with respect to the connection location where the bump is formed in advance is H, the width of the clearance surface in the direction along the clearance surface is W, and the wire is connected to the connection location where the bump is formed in advance. Sometimes the inclination angle of the capillary with respect to the connection location (that is, the angle between the normal of the connection location and the center line of the capillary) is A, and the inclination angle of the flank of the capillary (that is, the capillary When the inclination angle of the flank relative to a plane perpendicular to the center line is B,
H ≧ W × sin (AB) (2)
To satisfy. The tilt angles A and B are defined by values from 0 ° to 90 °.

  According to the above method, by forming the bump, the wire can be favorably connected to the connection portion. If the expression (2) is satisfied, it is not necessary to make the capillary perpendicular to the connection location in the first and second steps, and therefore wire bonding can be performed easily and efficiently.

  According to the present invention, the first and second connecting portions extending at different angles by satisfying the predetermined inclination of the inclination angle B of the flank face of the capillary and the inclination angle A of the capillary with respect to the connection portion. Can be easily and efficiently wire-bonded.

It is a partial cross section schematic diagram of a to-be-connected thing. Example 1 It is an expanded sectional view of a connection part. (Explanation example 1) It is a graph which shows the result of a pull strength test. Example 1 It is explanatory drawing of a bump. (Example 2) It is explanatory drawing of a bump. (Example 2) It is an expanded sectional view of a connection part. (Example 2) It is explanatory drawing of the minimum bump height. (Example 2) It is a principal part expanded sectional view of a capillary. (Explanation example 2) It is a partial cross section schematic diagram of a to-be-connected thing. (Conventional example)

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  <Example 1> The wire bonding method of Example 1 will be described with reference to FIGS.

  FIG. 1 is a partial cross-sectional view of the connected object 10. As shown in FIG. 1, in the connected object 10, the first chip 20 and the second chip 30 are fixed in the recess 13 formed in the package 12. The first chip 20 is fixed to a horizontal support surface 14 that extends parallel to the bottom surface 18 of the package 12. The first chip 20 is an IC chip such as an ASIC. The second chip 30 is fixed to the inclined support surface 16 that is inclined with respect to the bottom surface 18 of the package 12. The second chip 30 is a physical quantity sensor chip such as an angular velocity sensor or an acceleration sensor.

  The first terminal portion 22 of the first chip 20 and the electrode portion 15 provided in the package 12 extend in parallel to each other and are electrically connected via a wire 40. For example, the package 12 is made of resin, and the electrode portion 15 is formed by a lead frame embedded in the resin of the package 12.

  The second terminal portion 24 of the first chip 20 and the terminal portion 32 of the second chip 30 are electrically connected via a wire 42. Since the second terminal portion 24 of the first chip 20 extends along the horizontal support surface 14, and the terminal portion 32 of the second chip 30 extends along the inclined support surface 16, the first chip The 20 second terminal portions 24 and the terminal portions 32 of the second chip 30 extend at different angles.

  Next, a wire bonding method for connecting the second terminal portion 24 of the first chip 20 extending at different angles and the terminal portion 32 of the second chip 30 with a wire 42 will be described.

  As schematically shown in FIG. 1, the second terminal portion 24 of the first chip 20 and the terminal portion 32 of the second chip 30 with the connected object 10 placed on the table 3 of the wire bonding apparatus. And wire 42 is connected.

  Specifically, with the tip of the capillary 2 held by a head (not shown) of the wire bonding apparatus facing the second terminal portion 24 of the first chip 20, the capillary 2 is shown as indicated by an arrow 8a. The tip of the capillary 2 is moved close to the second terminal portion 24 of the first chip 20 by moving in a direction perpendicular to the table 3. A metal wire to be a wire 42 is inserted into the capillary 2, and the end of the metal wire is drawn from the tip of the capillary 2. The end portion of the metal wire is pressed against the second terminal portion 24 of the first chip 20, and the end portion of the metal wire is ultrasonically bonded to the second terminal portion 24 of the first chip 20.

  Next, with the end of the metal wire connected to the second terminal portion 24 of the first chip 20, the capillary 2 is moved to the position indicated by the broken line as indicated by the arrow 6, and the second It is made to oppose the terminal part 32 of the chip | tip 30. FIG. Then, as indicated by the arrow 8b, the capillary 2 is moved in the direction perpendicular to the table 3, the tip of the capillary 2 is brought close to the terminal portion 32 of the second chip 30, and the metal wire drawn from the capillary 2 is drawn. The intermediate portion is pressed against the terminal portion 32 of the second chip 30, and the intermediate portion of the metal wire is ultrasonically bonded to the terminal portion 32 of the second chip 30.

  Next, the capillary 2 is retracted from the terminal portion 32 of the second chip 30 so that a portion 42 for connecting the second terminal portion 24 of the first chip 20 and the terminal portion 32 of the second chip 30 remains. Cut the metal wire.

  When connecting the wire 42 to the terminal portion 32 of the second chip 30, the capillary 2 is inclined with respect to the terminal portion 32 of the second chip 30 and is not vertical.

  Wire bonding is generally performed in a state where the capillary is perpendicular to the connection location. However, even if the capillary is not perpendicular to the connection location, that is, the capillary is tilted with respect to the connection location, as long as the inclination is within a predetermined range, the capillary is perpendicular to the connection location. It is possible to connect the wires with a certain degree of bonding strength. The allowable range of inclination of the capillary that can connect the wire with the same bonding strength as when the capillary is perpendicular to the connection point is the wire size / material, capillary size / shape / material, and capillary. It depends on processing conditions such as applied pressure, ultrasonic vibration magnitude and time.

  Further description will be given with reference to FIG. FIG. 2 is an enlarged cross-sectional view of the connection portion. As shown in FIG. 2, a wire hole 2 z is formed at the center of the capillary 2. The metal wire 44 is fed out from the tip 2x of the capillary 2 through the wire hole 2z. A flank 2 y is formed around the tip 2 x of the capillary 2. The flank 2y is formed rotationally symmetrical around the center line 2r of the capillary 2.

  The capillary 2 moves in a direction perpendicular to the table 3 as indicated by an arrow 6x. That is, the capillary 2 moves in the same direction as the center line 2 r of the capillary 2, and the center line 2 r of the capillary 2 is perpendicular to the table 3.

  Here, the inclination angle of the flank 2y of the capillary 2 is B. The inclination angle B is an inclination angle of the flank 2y with respect to a plane perpendicular to the center line 2r of the capillary 2 (that is, a plane parallel to the table 3). In addition, an inclination angle of the connection portion 5 with respect to the table 3 is A. This inclination angle A is equal to the angle of inclination of the capillary 2 with respect to the connection location 5 when the metal wire 44 is connected to the connection location 5, that is, the angle formed between the normal direction of the connection location 5 and the center line 2 r of the capillary 2. .

  As shown in FIG. 2, when B <A, the distance between the flank 2y and the connection portion 5 is further away from the center line 2r of the capillary 2 in the portion on the right side of the center line 2r of the capillary 2 in the drawing. Becomes smaller. In this portion, a space 9 is formed between the inner peripheral edge 2s side (side closer to the tip 2x of the capillary 2) of the flank 2y of the capillary 2 and the connection portion 5, and the outer peripheral edge 2t side of the flank 2y of the capillary 2 is formed. (The side far from the tip 2x of the capillary 2) contacts the metal wire 44. Therefore, it becomes difficult to connect the metal wire 44 well. For example, the transmission of pressure load or ultrasonic vibration power from the capillary 2 to the metal wire 44 becomes insufficient, or the metal wire 44 is crushed by the flank 2y of the capillary 2 so that the metal wire 44 becomes thin or cut. This is because the transmission position of the pressure load or ultrasonic vibration from the capillary 2 is shifted, the bonding position of the metal wire 44 is shifted, or the capillary 2 is damaged.

On the other hand, when B ≧ A, the distance between the flank 2y and the connection location 5 is the same or increases as the distance from the center line 2r of the capillary 2 increases, so that the metal wire 44 is well connected to the connection location 5. be able to. That is, with respect to the inclination angle B of the flank 2y of the capillary 2 and the inclination angle A of the capillary 2 with respect to the connection location 5 when the metal wire 44 is connected to the connection location 5,
A ≦ B (3)
If it satisfy | fills, the metal wire 44 can be favorably connected to the connection location 5. FIG.

  More specifically, the inclination angle B of the flank 2y of the capillary 2 is defined as an angle A at which the connection portion is inclined with respect to a plane perpendicular to the center line 2r of the capillary 2, that is, an inclination angle A of the capillary 2 with respect to the connection portion 5. By making it equal or more, the space 9 is eliminated between the inner peripheral edge 2s side of the flank 2y of the capillary 2 and the connection portion 5, and as a result, the power necessary for joining can be transmitted. Further, the bonding area of the metal wire 44 is increased, and the bonding quality is stabilized. Further, since the metal wire 44 is not thin at a portion other than the cutting position of the metal wire 44, that is, at a portion facing the outer peripheral edge 2t side of the flank 2y of the capillary 2, there is no fear of wire breakage. Since the metal wire 44 can be pressed against the connection portion 5 through the center portion of the capillary 2, damage to the capillary 2 can be alleviated.

  FIG. 3 is a graph showing the results of the pull strength test. A vertical axis | shaft shows the result of having measured the tensile load (pull strength) when the wire connected to the connection location is pulled in the direction perpendicular to the connection location and the wire peels from the connection location. The horizontal axis represents an angle A at which the connection portion is inclined with respect to a plane perpendicular to the center line of the capillary, that is, an inclination angle A of the capillary with respect to the connection portion. The inclination angle A was 0 °, 10 °, and 20 °. Using a capillary with a flank inclination angle B of 10 °, an Au wire was connected to the connection point of the sample, and the pull strength was measured. The symbols ◆, □, ▲, and * differ in wire joining conditions. That is, the combination (joining conditions) of the static load (gf) that presses the wire against the connection location and the number of vibrations (bit) of ultrasonic waves applied to the wire are different. The results of measuring the pull strength for each of the three samples are plotted with a slight shift in the horizontal axis direction for each joining condition. A broken line with a symbol P indicates an average value obtained by measuring the pull strength of another product sample in which the wire is connected in a state where the capillary is perpendicular to the connection portion. A broken line with a symbol Q is a criterion (lower limit value) for pull strength for other product samples in which the wire is connected in a state where the capillary is perpendicular to the connection location.

  From FIG. 3, it can be seen that when the inclination angle A is 10 ° or less, the pull strength is comparable to that of other product samples, so that the wire can be connected with sufficient bonding strength. Since the inclination angle B of the flank face of the capillary is 10 °, it can be understood that the wire can be satisfactorily connected when the above-described equation (3) is satisfied.

  As described above, if the expression (3) is satisfied, the second terminal portion 24 and the second chip 30 of the first chip 20 remain in a state where the connected object 10 is placed on the table 3 of the wire bonding apparatus. The wire 42 can be satisfactorily connected to both the terminal portion 32 and the terminal portion 32. After connecting the wire to the second terminal portion 24 of the first chip 20 and connecting the wire to the terminal portion 32 of the second chip 30, the capillary need not be perpendicular to the connection location. Therefore, wire bonding can be performed easily and efficiently.

  <Example 2> The wire bonding method of Example 2 will be described with reference to FIGS. Example 2 is substantially the same as Example 1. In the following, the same reference numerals are used for the same components as in the first embodiment, and differences from the first embodiment will be mainly described.

  In the second embodiment, a wire bonding method in which the second terminal portion 24 of the first chip 20 extending at different angles and the terminal portion 32 of the second chip 30 are connected by the wire 42 is different from the first embodiment. Different.

  In the second embodiment, bumps are formed in advance on the terminal portions 32 of the second chip 30 arranged obliquely. Note that bumps may be formed on the second terminal portions 24 of the first chip 20 arranged horizontally.

  For example, before fixing the second chip 30 to the package 12, bumps 34 having a height H1 are formed on the terminal portion 32 as shown in the explanatory view of FIG. The height H1 of the bump 34 is defined for the main portion 34a of the bump 34 as shown in FIG. When bumps are formed with capillaries, even if portions other than the main portion 34a such as the portion 34b remaining in the wire hole of the capillary and the end portion 34c of the cut metal wire are formed, the height due to them is ignored. .

  Alternatively, with the second chip 30 fixed to the package 12, bumps 36 having a height H2 are formed on the terminal portion 32 of the second chip 30 as shown in the explanatory view of FIG. The bump 36 is formed in a shape inclined with respect to the terminal portion 32. In this case, the height H2 of the bump 36 is defined as the height in the direction perpendicular to the terminal portion 32 with respect to the main portion 36a of the bump 36, as shown in FIG. When bumps are formed with a capillary, even if a portion other than the main portion 36a is formed, such as a portion 36b remaining in the capillary wire hole or an end portion 36c of a cut metal wire, the height due to them is ignored. .

  Next, as in the first embodiment, the wire 42 is connected to the second terminal portion 24 of the first chip 20 and the terminal portion 32 of the second chip 30.

  When the wire 42 is connected to the terminal portion 32 of the second chip 30, as shown in the enlarged cross-sectional view of the connecting portion in FIG. Connect to the unit 32.

  As described in the first embodiment, when A> B, the outer peripheral edge side of the flank face of the capillary crushes the wire, and a space is formed between the inner peripheral edge side of the flank face of the capillary and the connection portion. Therefore, when bumps are formed in advance at the connection locations and wires are connected on the bumps, the bumps 35 are sandwiched between the wires 42 and the connection locations (terminal portions 32) as shown in FIG. Since the wire 42 can be prevented from being crushed, the wire 42 can be connected well.

  That is, by previously forming bumps at the connection locations, there is no space between the flank face of the capillary and the connection locations, and the power of ultrasonic vibration necessary for joining is transmitted well. Further, since the bonding area of the wire is increased by the bump, the bonding quality is stabilized. In addition, due to the buffering effect of the bumps 35, the wire is not easily thinned, and damage to the capillaries can be reduced.

In order to connect the wires satisfactorily, the height H of the bump formed in advance may be set to the minimum bump height H ₀ or more shown in the explanatory diagram of FIG.

  FIG. 7 is an explanatory diagram of the minimum bump height. In FIG. 7, straight lines S <b> 1 and S <b> 2 are parallel to the table and are perpendicular to the center line 2 r of the capillary 2. The straight line S3 passes through the outer peripheral edge 2t of the flank 2y and is parallel to the connection location. The straight line S4 passes through the inner peripheral edge 2s of the flank 2y and is parallel to the connection location.

As indicated by a straight line S3, when a wire is sandwiched between the outer peripheral edge 2t of the flank 2y of the capillary 2 and the connection location, the height between the inner rim 2s of the flank 2y and the connection location is high. A space of H ₀ is formed. If a bump 38 as shown by a chain line is formed in advance at the connection location, the space of this height H ₀ can be filled, and the wire coming out of the capillary 2 is crushed on the outer peripheral edge 2t side of the flank 2y. Can be prevented. Thereby, a wire can be favorably connected to a connection location via a bump.

As shown in FIG. 7, the width of the flank 2y in the direction along the flank 2y is W, the inclination angle of the connection portion (ie, the inclination angle of the capillary 2 with respect to the connection portion) is A, and the inclination angle of the flank 2y (ie , B is an angle formed by a plane perpendicular to the center line 2r of the capillary 2 and the flank 2y)
H ₀ = W × sin (AB) (4)
It becomes.

Assuming that the height H of the bump to be formed in advance is
H ≧ H ₀ (5)
If it becomes.

Therefore, from equations (4) and (5)
H ≧ W × sin (AB) (6)
If it is made to satisfy | fill, a wire can be connected favorably.

  That is, if Expression (6) is satisfied, the second terminal portion 24 of the first chip 20 and the terminal portion of the second chip 30 remain in a state where the connected object 10 is placed on the table 3 of the wire bonding apparatus. The wire 42 can be connected to both of them. After connecting the wire to the second terminal portion 24 of the first chip 20, the terminal portion of the inclined second chip 30 is connected to connect the wire to the terminal portion 32 of the inclined second chip 30. The capillary need not be perpendicular to 32. Therefore, wire bonding can be performed easily and efficiently.

When formula (6) is transformed,
A ≦ B + sin ⁻¹ (H / W) (7)
Therefore, if the expression (7) is satisfied, the wires can be connected well. As can be seen from a comparison between the formula (3) and the formula (7), in the second embodiment in which the bumps are formed in advance, the inclination angle A of the connection portion can be made larger than that in the first embodiment.

  Note that bumps may be formed when A ≦ B. In this case, the expressions (6) and (7) are satisfied.

FIG. 8 is an enlarged cross-sectional view of the main part of the capillary 2. As shown in FIG. 8, the inclination angle of the flank 2y with respect to the plane perpendicular to the center line 2r of the capillary 2 is B, the outer diameter dimension of the flank 2y in the direction perpendicular to the center line 2r of the capillary 2 is T, and the capillary 2 The inner diameter dimension of the flank 2y in the direction perpendicular to the center line 2r is C, the width of the flank 2y in the direction perpendicular to the center line 2r of the capillary 2 is D, and the width of the flank 2y in the direction along the flank 2y is If W,
D = (TC) / 2 (8)
W = D / cos (B) (9)
It is.

The following Table 1 shows equations (4), (8), and (9) from the inclination angle A of the connection location, the inclination angle B of the flank face of the capillary, and the inner diameter dimension C and the outer dimension T of the capillary flank face. ) is an example of calculating the minimum bump height H ₀ using.

  Dimensions / shapes other than the height H of the bumps may be appropriately selected according to the dimension / shape of the flank face of the capillary, the inclination of the connection location, and the like.

  <Summary> As described above, the first and second extending at different angles by satisfying a predetermined conditional expression so that the inclination angle B of the flank face of the capillary and the inclination angle A of the capillary with respect to the connection portion satisfy the predetermined conditional expression. Wire bonding can be performed easily and efficiently at the two connection locations.

  The present invention is not limited to the above embodiment, and can be implemented with various modifications.

  For example, one or both of the first and second connection locations for wire bonding may be formed on a substrate or the like. In addition, one or both of the first and second connection portions to be wire bonded may be an electrode portion or the like provided on a package or a substrate. What is necessary is just to select the material of a wire or bump suitably.

  Moreover, this invention is applicable not only when connecting two places with a wire but when connecting three or more places with a continuous wire.

2 Capillary 2r Center line 2s Inner edge 2t Outer edge 2x Tip 2y Flank 2z Wire hole 3 Table 5 Connection place 9 Space 10 Connected object 12 Package 13 Recess 14 Horizontal support surface 15 Electrode 16 Inclined support surface 18 Bottom surface 20 First Chip 22 First terminal portion 24 Second terminal portion (first connection location)
30 Second chip 32 Terminal portion (second connection location)
34, 35, 36, 38 Bump 40, 42 Wire 44 Metal wire A, B Inclination angle H, H1, H2 Height H ₀ Minimum bump height

Claims (2)

A first step of bringing a tip of a capillary close to a first connection location of an object to be connected, and connecting a wire coming out of the tip of the capillary to the first connection location;
With the wire connected to the first connection location, the tip of the capillary approaches the second connection location of the object to be connected, and the wire coming out of the tip of the capillary is connected to the first connection location. A second step of connecting to the two connection points;
In a wire bonding method including:
The first and second connection points extend at different angles;
The capillary has a flank around the tip;
In the first and second steps,
A tilt angle of the capillary with respect to the connection location when the wire is connected to the connection location is A,
The inclination angle of the flank of the capillary is B,
Then,
A ≦ B
The wire bonding method characterized by satisfy | filling. A first step of bringing a tip of a capillary close to a first connection location of an object to be connected, and connecting a wire coming out of the tip of the capillary to the first connection location;
With the wire connected to the first connection location, the tip of the capillary approaches the second connection location of the object to be connected, and the wire coming out of the tip of the capillary is connected to the first connection location. A second step of connecting to the two connection points;
In a wire bonding method including:
The first and second connection points extend at different angles;
A bump is previously formed on at least one of the first and second connection locations,
In at least one of the first and second steps, the wire is connected to at least one of the first and second connection locations via the bump,
The height of the bump with respect to the connection location where the bump is previously formed is H,
The width of the flank in the direction along the flank is W,
When connecting the wire to the connection place where the bump is formed in advance, the inclination angle of the capillary with respect to the connection place is A,
The inclination angle of the flank of the capillary is B,
Then,
H ≧ W × sin (AB)
The wire bonding method characterized by satisfy | filling.

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