JPH054814B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bonding wedge (industrial application field) which is provided with a guide hole through which a wire is inserted and is inclined with respect to the distal end surface, and in which the wire is paid out at an angle downward from the distal end surface. The present invention relates to a wire bonding method in which wire bonding is performed using ultrasonic waves using a wedge (hereinafter abbreviated as wedge).

[Conventional technology]

As shown in FIG. 4a, the wedge 11 that has been widely used in the past has a guide hole 31 that is located approximately at a distance from the tip surface 41.
The wedge 11 is formed at an angle of 30 to 45 degrees, and when performing bonding, the wedge 11 is positioned directly above the bonding portion and moved downward as shown by the arrow 12 to apply ultrasonic vibrations.

Therefore, since the wire 2 is fed out at an angle of approximately 30 to 45 degrees, the wire 2 may hit electronic components on the board 6, which is inconvenient.

This inconvenience is caused by the distal end surface 4 as shown in FIG. 4b.
For example, by using a wedge 1 having a guide hole 3 at an angle of about 60°, the number of holes can be reduced.

[Problem that the invention seeks to solve]

However, with such a large inclination, the guide hole 3
If wire bonding is to be performed using wedge 1 equipped with In the case of bonding No. 7, the inclination of the wire 2 with respect to the first bonding portion 7 also becomes a large inclination of the same angle as the guide hole 3.

Therefore, even when the wedge 1 is lowered straight down as shown by the arrow 12, the wire 2 is difficult to bend at the base 9 having a length l, and as the wedge 1 is lowered, the wire 2 is
The wire 2 relatively escapes into the guide hole 3 while being bent and returns, making it impossible to compress the wire 2 of length l required for bonding between the tip surface 4 of the wedge 1 and the first bonding part 7. It becomes a state. If you want to avoid this, you can let out the wire 2 by a length that protrudes outward from the first bonding part 7, but if you do so, the tip of the protruding wire may be shot, and the wire 2 is also wasted. be.

The present invention is an attempt to solve the above-mentioned conventional problems, and it is possible to perform the first bonding reliably even when using a wedge having a steeply inclined guide hole with an angle of 45° or more with the tip surface. The purpose of this invention is to provide a wire bonding method that can be used.

[Means for solving problems]

The present invention provides a wire bonding method in which wire bonding is performed on a substrate using a bonding wedge, in which after bonding of a second bonding section is completed, the bonding wedge is moved relative to the next first bonding section. Before moving the bonding wedge, the bonding wedge is temporarily stopped and the wire is cut, and then a length of wire required for the next first bonding is fed out from the tip of the bonding wedge, and then the bonding wedge is moved relative to the Then, the wedge is lowered obliquely in the front and downward direction, and the wire fed out from the tip is pressed against the substrate or a member fixed to the substrate, and the wire is pulled in the vicinity of the front by the length required for the first bonding from the tip of the wire. Bend it in advance and place it along the tip of the bonding wedge, then
This wire bonding method is characterized by moving a bonding wedge to the next first bonding section.

In this specification, the front side of the wedge is the side facing in the direction of movement when the wedge is bonded and moved from the first bonding part to the second bonding part, and therefore, the front of the wedge refers to the direction in which this front face faces. Okay, the opposite direction is called backward.

[Effect]

In the present invention, after finishing the bonding of the second bonding part, the bonding wedge is moved to the next first part.
The bonding wedge is raised once until it moves relative to the upper part of the bonding part,
Cut the wire, then let out the wire of the length required for the next first bonding from the tip of the bonding wedge, then lower the bonding wedge diagonally downward relative to the front of the wedge and let it out from the tip. The wire is pressed against the substrate or a member fixed to the substrate, and the wire is bent in advance in the vicinity of the front side by the length required for the first bonding from the wire line so as to be placed along the tip end surface of the bonding wedge, After that, the bonding wedge is moved to the next first bonding section, so when bonding is performed using a wedge with a steeply sloped guide hole, it is possible to move the wedge straight down when bonding the first bonding section. The tip of the wire can be reliably pinched by a predetermined length l between the first bonding part and the tip end surface of the wedge. Therefore, bonding can be performed reliably.

〔Example〕

Embodiments of the present invention will be described using the drawings.

In Figures 1 to 3, the wedge 1 has a guide hole 3 through which the wire 2 is inserted at an angle of 45° to the distal end surface 4.
Provided at an angle of 90°, for example 60° in this example,
It is attached to an ultrasonic bonding device having a conventionally known configuration. That is, the wedge 1 is attached to the tip of the horn, and is integrated with the clamp 5.
Relative to the base 6, movement in the X direction on the horizontal plane, movement in the Y direction in the direction perpendicular to the X direction on the horizontal plane, movement in the Z direction (vertical movement) in the direction perpendicular to each of the X and Y directions. , it is possible to perform θ rotation so that the line connecting the first bonding portion 7 on the IC fixed to the substrate 6 and the second bonding portion 8 on the substrate 6 coincide with each other in the Y direction. The clamp 5 is attached to a clamp slider that moves together with the wedge 1 and can also reciprocate independently of the wedge 1 at an inclination of 60°, which is the same inclination as the guide hole 3. When the wire 2 between the guide hole 3 outlet and the clamp part is at the same angle as the guide hole 3 at 60°
It is provided so that it can be clamped while exhibiting the following characteristics.

In this embodiment, the X, Y, and Z direction moving devices are directed toward the wedge 1, and the θ rotation device is directed toward the substrate 6.
It is assumed that the wedge 1 is provided so that its front-rear direction coincides with the Y direction.

Next, the bonding operation will be explained based on FIGS. 1 and 2.

FIG. 1a shows the state where bonding of the second bonding section 8 has been completed, and corresponds to point A in FIG. 2. Clamp 5 is open.

While keeping the clamp 5 open, the wedge 1 is moved by Δz ₁ and Δy ₁ . At this time, a predetermined wire length l required for bonding the next first bonding part ₇₁ is drawn out from the tip surface 4 of the wedge 1, and the angle α is 60°, which is the same inclination as the guide hole 3. ₁ and Δy ₁ are selected. After moving the wedge 1 by Δz ₁ and Δy ₁ to feed the wire 2, the clamp 5 is closed. ... Point B is shown in Figure 1b and Figure 2.

The clamp slider is moved by Δl ₁ away from the wedge 1 as much as necessary to cut the wire.
Then, the wire 2 is cut at the end of the portion that is fixed to the second bonding part 8. ...Point c in Figure 1, point C in Figure 2.

Return the clamp slider by Δl ₁ . Then, the wire 2 is let out by a predetermined length l from the distal end surface 4 of the wedge 1, and the jagged cut surfaces of the distal end surface of the wire 2 and the cut end surface of the wire bonded to the second bonding part 8 are mutually aligned. They become engaged. ...Point d in Figure 1, point D in Figure 2.

Next, move wedge 1 forward and downward, for example Δz ₁ , Δy ₁
is lowered obliquely as shown by the arrow 10 so that the tip of the wire having a predetermined length l is sandwiched between the substrate 6 and the tip surface 4 and comes into contact with each other.

At this time, the tip end surface of the wire 2 is
Since it is engaged with the cut end surface of the wire of the bonding part 8, it is prevented from sliding in the lateral direction.
Therefore, the wire 2 is reliably bent at the base 9 a predetermined length l from the tip, and the tip surface 4 of the wedge 1 is bent.
A wire 2 having a predetermined length l can be placed along the line. ...Point e in Figure 1 and point E in Figure 2.

In this state, the wedge 1 is moved in x, y, and z until it is positioned directly above the first bonding section ₇₁ that will be bonded next. The substrate 6 is the first
The line connecting the bonding part 7 ₁ and the second bonding part 8 ₁ is rotated by θ so that it coincides with the Y direction, that is, the front-rear direction of the wedge 1 . ...Point f in Figure 1, point F in Figure 2.

Next, the wedge 1 is lowered straight down, a wire 2 of a predetermined length l is pressed between the tip end surface 4 of the wedge 1 and the first bonding part ₇₁ , and ultrasonic waves are applied by the wedge 1 to perform wire bonding. conduct.

Note that, after bending the wire 2, when moving the wedge 1 to the next first bonding part ₇₁ , if the wedge 1 is lowered diagonally backward and downward,
The required time can be shortened compared to direct lowering as described above.

The movement of the wedge 1 from FIGS. 1d to 1e, that is, from FIGS. 2D to E, is shown in an enlarged manner in FIG. In order to move from the state shown by the two-dot chain line to the state shown by the solid line, the wedge 1 may be lowered forward and downward in an arc shape, for example, as shown by the broken line arrow.
The wedge 1 may be lowered forward and downward in a straight line as shown by the solid arrow. In any case,
The wedge 1 can be lowered obliquely forward and downward so that the wire 2 is bent at the base 9 having a predetermined length l at the tip. In the case where the substrate 6 is provided in the same place, the substrate 6 can also be moved.

In addition, in the above-mentioned embodiment, the second bonding part 8
Immediately after completing the bonding, the wire tip was bent near the second bonding part 8, but the wire tip was bent near the second bonding part 8.
It is sufficient to bend it at any position on the substrate 6 or at any position on the member fixed to the substrate 6 at any time before moving to the bonding part 7 ₁ . Further, in the case of the first wire bonding on the substrate 6, the wire may be bent in advance at an appropriate position before performing the first bonding.

Furthermore, in the above embodiment, the wedge 1 is moved to feed the wire 2 before cutting the wire, so that the clamp slider only needs to reciprocate by an equal distance Δl ₁ , but the feed of the wire 2 is Alternatively, the wire may be cut first, and then the clamp slider may be moved relative to the wedge 1 to feed the wire.

〔Effect of the invention〕

In the present invention, after finishing the bonding of the second bonding part, the bonding wedge is moved to the next first part.
The bonding wedge is raised once until it moves relative to the upper part of the bonding part,
Cut the wire, then let out the wire of the length required for the next first bonding from the tip of the bonding wedge, then lower the bonding wedge diagonally downward relative to the front of the wedge and let it out from the tip. Press the wire that is attached to the substrate or a member fixed to the substrate, and bend the wire in advance near the front side by the length required for the first bonding from the tip of the wire so as to fit it along the tip end surface of the bonding wedge, After that, the bonding wedge is moved to the next first bonding part, so even if the wedge has a guide hole with a steep slope of 45 degrees or more with the tip surface, the first bonding can be performed reliably. can.

[Brief explanation of the drawing]

Figures 1 a to f are explanatory diagrams of the operation, Figure 2 is a time chart, and Figure 3 is an enlarged explanatory diagram of the main parts of the operation.
FIGS. 4a and 4b are explanatory diagrams of conventionally used wedges, respectively. 1, 11... Wedge, 2... Wire, 3, 3
DESCRIPTION OF SYMBOLS 1... Guide hole, 4, 41... Tip surface, 5... Clamp, 6... Substrate, 7, 7 ₁ ... First bonding part, 8, 8 ₁ ... Second bonding part, 9...
...base, 10, 12...arrow.

Claims (1)

[Claims] 1 In a wire bonding method in which wire bonding is performed on a substrate using a bonding wedge, the bonding wedge is moved relative to the next first bonding section after bonding of the second bonding section is completed. In the meantime, the bonding wedge is raised once, the wire is cut, and a length of wire required for the next first bonding is fed out from the tip of the bonding wedge. The wire is lowered diagonally downward in front of the wedge, and the wire fed out from the tip is pressed against the substrate or a member fixed to the substrate, and the wire is pre-folded near the front by the length required for the first bonding from the tip of the wire. A wire bonding method characterized in that the wire bonding wedge is bent and placed along the tip surface of the bonding wedge, and then the bonding wedge is moved to the next first bonding part.