JPH0244743A - Wire bonding - Google Patents

Abstract

PURPOSE:To substantially simultaneously cut and bend a wire, and to prevent the irregular feed amount of the wire and the deviation of a bent point by relatively raising a wedge while the wire remains continued from a second bonding part, and then relatively lowering the wedge in a state that the rearward movement of the wedge to the wire is stopped. CONSTITUTION:A wedge 1 is relatively raised while a wire 2 remains continued from a second bonding part 8 to set the length of the wire 2 between the part 8 and the wedge 1 to l. Then, the wedge 1 is relatively lowered directly thereunder or obliquely downward in the forward direction in a state that the rearward movement of the wedge 1 to the wire 2 is stopped. Thus, the cutting and the bending of the wire 2 can be substantially simultaneously continued only by this operation. In this manner, the irregular feed amount of the wire 2, the deviation of the bending point, and the lateral bending of the first bonding margin do not possibly occur.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a bonding wedge (hereinafter referred to as a The present invention relates to a wire bonding method in which wire bonding is performed using ultrasonic waves using a wedge (abbreviated as wedge).

(Prior Art) As shown in FIG. 4 (al), the wedge 11 that has been widely used in the past has a guide hole 31 with a diameter of approximately 30 to 45 mm with respect to the tip surface 41.
When bonding is performed, the wedge 11 is positioned directly above the bonding part.
The ultrasonic vibration was applied by moving it downward as shown by arrow 12.

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

This inconvenience can be reduced by using the wedge 1 having the guide hole 3 at an inclination of, for example, about 60@ with respect to the distal end surface 4, as shown in Part 4).

[Problem that the invention seeks to solve]

However, if wire bonding is to be performed using the wedge 1 having the guide hole 3 with such a large inclination, the wire 2 will extend over the tip end surface of the wedge 1 by the length l (first bonding distance) required for bonding. The first step is to perform bonding from the state where it is extended diagonally from 4.
In the bonding of the bonding part 7, the wire 2
The first bonding portion 7 of the first bonding margin at the tip of
The inclination relative to the guide hole 3 is also large and has the same angle as the guide hole 3.

Therefore, even if the wedge 1 is lowered straight down as shown by the arrow 12, the wire 2 is difficult to bend at a distance i from the tip, and as the wedge 1 is lowered, the wire 2 is bent and relatively guided. The wire 2 escapes into the hole 3 and returns, making it impossible to clamp the wire 2 of length β required for bonding between the tip end surface 4 of the wedge 1 and the first bonding portion 7 . 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 short-circuit, and the wire 2 is also wasted. be.

In order to solve the above-mentioned conventional problems, the present inventor proposed in Japanese Patent Application No. 62-199039 that the tip of the wire was previously aligned along the tip surface of the wedge 1 by the length required for the first bonding.
A method of forming the first bonding margin by bending it in advance is a.
However, the present invention aims to further improve this.

(Means for Solving the Problems) The present invention provides a wire bonding method in which wire bonding is performed on a substrate using a wedge. The wire 7 is raised forward and upward diagonally or directly upward by a distance equal to the length l of the wire, and the sea urchin 7 is moved backward relative to the wire, and the distance from the rising base of the wire that is continuous from the second bonding part to the wedge is The length of the wire is l, and then, with the wedge prevented from retreating relative to the wire, the wedge is lowered relatively straight down or diagonally forward and downward, and the wire is cut at the base rising from the second bonding part. A wire having a length l of the tip is pressed against the substrate or a member fixed to the substrate and placed along the wedge tip surface, and then the wedge is attached to the next first wire.
This is a wire bonding method characterized by moving the wire to a bonding section.

Note that in this specification, the front side of the wedge is the side facing the advancing direction 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 faces. ,
The opposite direction is called backward.

[For production]

In the present invention, after the application of ultrasonic waves to the second bonding part is completed, the wedge is connected to the length l of the wire required for the next first bonding.
The length of the wire from the rising base of the wire that is continuous from the second bonding part to the wedge is set as l by raising the wedge forward and upward diagonally or directly upward by the same distance as . Then, with the wedge prevented from retreating relative to the wire, the wedge is lowered diagonally downwardly or forwardly to cut the wire at the base rising from the second bonding part, and the length of the tip is l. Since the wire is pressure-contacted to the substrate or a member fixed to the substrate and made to run along the wedge tip surface, and then the wedge is moved to the next first bonding part, bonding is performed using a wedge having a steeply sloped guide hole. Even when bonding the first bonding part, if the wedge is lowered straight down, the tip of the wire is reliably pinched by a predetermined length l between the first bonding part and the tip surface of the wedge, Bonding is ensured.

In this case, the invention of Japanese Patent Application No. 62-199039 cuts the wire with a wire feeding mechanism and then feeds out the wire with the wire feeding mechanism, so there is play between the wire and the guide hole and variations in the wire feeding mechanism. However, in the present invention, it is possible to cause variations in the amount of the wire to be fed out, misalignment of the bending point, and bending of the bent first bonding mark in the lateral direction. The length of the wire between the second bonding part and the wedge is set to l by first relatively raising the wedge while keeping it continuous (the wire protrudes from the sea urchin 7 by a predetermined length l which is the first bonding margin). After that, the wedge is lowered diagonally directly downward or forwardly downward while preventing the wedge from retreating relative to the wire. This action alone causes the wire to be cut and bent almost simultaneously. Therefore, variations in the amount of wire payout and deviations in the bending point.

There is no possibility that the bent first bonding margin will be bent in the lateral direction, fewer operations are required, and there is no need for a wire feeding mechanism.

〔Example〕

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

In FIGS. 1 to 3, a wedge 1 has a guide hole 3 through which a wire 2 is inserted, inclined at an angle of 45' to 90 degrees, for example, 6 degrees in this embodiment, with respect to the distal end surface 4, which is superior to the conventional structure. Attached to sonic bonding equipment. That is, the wedge 1 is attached to the tip of the horn, and together with the clamp 5, it can be moved in the X direction on the horizontal plane, and in the Y direction in the direction perpendicular to the X direction on the horizontal plane. direction movement, Z direction movement (up and down) perpendicular to each of the X and Y directions, and a line connecting the first bonding part 7 on the IC fixed to the board 6 and the second bonding part 8 on the board 6 in the Y direction. It is possible to rotate θ to match the angle. As long as the wedge 1 and the clamp 5 are configured to move together as described above, they may have a common drive unit or may be provided separately. Further, the clamp 5 is provided on an extension line of the guide hole 3.

In this embodiment, a bonding head is placed on an X, Y table, and a wedge 1 and a clamp 5 equipped with a vertical movement device (rotation device) are provided on the bonding head so as to be vertically movable. It is assumed that the θ rotation device is provided on the side.

It is assumed that the wedge l 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. 1 (al indicates the point at which the application of ultrasonic waves to the second bonding portion 8 is completed, and corresponds to point A in FIG. 2. The clamp 5 is open.

With clamp 5 open, wedge l and clamp 5
directly above with a vertical movement device or with a vertical movement device and X, Y
The table raises it diagonally upward and forward. At this time, the predetermined wire length required for bonding the next first bonding portion 7°! The (first bonding margin) protrudes from the tip surface 4 of the wedge 1 while remaining continuous with the bonded wire of the second bonding portion 8. Note that in this embodiment, Δzl+Δyl is selected so that the wire 2 is raised obliquely with an inclination 606.

...in Figure 1), point B in Figure 2.

Clamp 5 is closed. ...Tel in Figure 1, 0 point in Figure 2, wedge IC1 wire 2C in Figure 3.

Next, when the wedge 1 is lowered with the clamp 5 straight down or forward downward (as shown in Fig. 1), if the lever 7 is raised diagonally, it can be either straight downward or forward downward, but the wedge 1 is raised straight upward. (If you do so, it will be limited to the front and downwards). In the embodiment, the absolute amount is Δ2fi, which is the same as Δ2°, and the horizontal distance between the wire rising base 13 from the second bonding part 8 and the guide hole exit part 14 of the wedge 1 is the length l.
so that the tip surface 4 is larger than the second bonding portion 8.
Only Δy2 selected to be outside of the arrow! It is lowered diagonally like an O. Then, wedge 1 is connected to wire 2
is lowered while bending the first bonding base 9 at the guide hole outlet 14 at a predetermined length l from the tip of the wire 2, and the linear distance between the wire rising base 13 and the guide hole outlet 14 exceeds the length e. The wire 2 is cut at the wire rising base 13. ...Figure 1 fd+, 2nd
Point D in the figure, wedge ID and wire 2D in Figure 3.

Furthermore, when the wedge 1 and the clamp 5 continue to be lowered together and the tip of the wire is pressed against the substrate 6 with the tip surface 4, the wire 2
is reliably bent at the first bonding margin base 9, and a first bonding margin of a predetermined length l is formed by bending along the distal end surface 4 of the wedge l. ...tel in Figure 1, point E in Figure 2, wedge IE and wire 2E in Figure 3.

In this state, the wedge 1 is moved in x, y, and z, and then the first bonding section 7 performs bonding.
Align it directly above 1. The substrate 6 has a first bonding portion 7. The Y-direction portion is rotated by θ so that the line connecting the second bonding portion 81 and the second bonding portion 81 coincides with the front-rear direction of the edge l. ...Figure 1 (fl, point F in Figure 2).

Next, the wedge 1 is lowered straight down to squeeze a first bonding margin of a predetermined length e 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. I do.

FIG. 1 (C1 to FIG. 1(e), that is, FIG. For example, the wedge 1 may be lowered forward and downward in an arc shape as shown by the broken line arrow, or the wedge 1 may be lowered forward and downward in a straight line as shown by the solid line arrow. .

In the embodiments described above, the wedge 1 and the clamp 5 are moved integrally, but in a device in which the wedge 1 and the clamp 5 are movable relative to each other, it is possible that the wedge 1 and the clamp 5 are not moved integrally. For example, when the clamp 5 is closed [first
It is also possible to keep the clamp 5 stationary relative to the substrate 6 as shown in FIG. 1(C) and move the wedge 1 as shown in FIG.

In any case, the wedge 1 is lowered relatively straight down or diagonally forward and downward, and the wire 2 is canted at the wire rising base 13 and bent at the first bonding margin base 9 to form the first bonding margin. For example, if a YZ direction moving device is provided on the substrate 6, the substrate 6 can be moved.

〔Effect of the invention〕

In the present invention, by first relatively raising the wedge while keeping the wire continuous from the second bonding part, the second
The length of the wire between the bonding part and the wedge is set to 1, and the wire is then cut and bent by lowering the wedge relatively directly downward or diagonally downward while preventing the wedge from retreating relative to the wire. Since these are carried out almost simultaneously, there is no risk of variations in the amount of wire being fed out, deviations in the bending point, or lateral bending of the formed first bonding seal, etc. Also, there is little movement and there is no need for a wire feeding mechanism. It is.

[Brief explanation of the drawing]

Figure 1 (al to ffl are explanatory diagrams of operation, Figure 2 is a time chart, Figure 3 is an enlarged explanatory diagram of the main parts of operation, Figure 4 (
al (bl is an explanatory diagram of conventionally used wedges. 1.11... Wedge, 2... Wire, 3.31...
...Guide hole, 4, 41...Tip surface, 5...Clamp, 6...Substrate, 7,71...First bonding part, 8.81...Second bonding part, 9... ...First bonding clearance base, 10.12...Arrow, 13...
- Wire rising base, 14... guide hole exit part. ``Patent Departure Asairi Umi'' Nidenki Co., Ltd. Representative Patent Attorney
Pharmacist Minoru Patent Attorney Yori
1) Takatsugu Patent Attorney Masayuki Takagi (a) (b) - Kazuno Kano

Claims (1)

[Claims] (1) In a wire bonding method in which wire bonding is performed on a substrate using a bonding wedge, the length l of the wire required for the next first bonding after the application of ultrasonic waves to the second bonding part is completed
The length of the wire from the rising base of the wire that is continuous from the second bonding part to the bonding wedge is determined by raising the bonding wedge forward and upward diagonally or directly upward by the same distance as . 1, and then, with the bonding wedge prevented from retreating relative to the wire, the bonding wedge is lowered relatively straight down or diagonally forward and downward to cut the wire at the base rising from the second bonding part, and cutting the wire at the base rising from the second bonding part. A wire bonding method characterized in that a wire having a length l is pressure-contacted to the substrate or a member fixed to the substrate so as to run along the tip end surface of the bonding wedge, and then the bonding wedge is moved to the next first bonding part.