TWI387171B - Electrode pattern and wire bonding method - Google Patents

Description

Electrode pattern and wire bonding method

The present invention relates to an electrode pattern and a wire bonding method for performing wire bonding on an electrode of a semiconductor device or a substrate.

When welding the wire connecting the electrode to the wire, the welding position must be taught to the welding device. In general, when wire bonding is performed with gold beads or the like, the gold beads are designed to be sufficiently housed in the electrode to be wire-bonded. In the wire bonding process at the time of manufacturing a semiconductor device, the technique for grasping the point where the wire bonding device is required to be connected is described in Japanese Laid-Open Patent Publication No. 2001-326241.

When wire bonding is performed on the laser diode, the electrode pattern for wire bonding is formed into an elongated shape. The recording type laser diode is increased in speed as the recording speed increases, and the output of the laser diode is required to be larger and larger, and the cost is also extremely required. In order to cope with these requirements, in order to increase the output, the longitudinal length of the laser diode is increased, and the lateral length of the laser diode is reduced in order to reduce the cost, so that the number of wafers taken out from a single wafer is increased. Therefore, in the case of, for example, a recording type high output laser diode of the order of 350 mW, the longitudinal length is more than 2000 μm and the lateral length is 150 μm or less, resulting in a very elongated shape.

The assembly form of the recording type high output laser diode is followed by AuSn soldering or the like on the eyelet to follow the auxiliary leg tube and the laser diode. Moreover, although the wire is soldered to the diode electrode with a wire or eyelet, but for the electrode The gold beads are formed at a predetermined position, and the characteristic pattern of the end of the electrode is clamped, and then the gold beads are wire-bonded in the longitudinal direction of the laser. When the auxiliary leg tube and the laser diode are attached to the hole, it can be seen that the center line of the hole and the center line of the laser diode are inclined by about 2 degrees at the maximum due to the influence of the accuracy of the assembly device.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-326241

When not tilted toward the center of the laser diode and the center of the hole, the gold beads can be welded to the center of the electrode. However, when there is a tilt, there is a problem that the gold beads will be squeezed out of the electrode. When the longitudinal length of the electrode is long and the length in the short side direction (electrode width) is short, the shift to the short side direction is large, and the amount of gold beads is also increased. When gold beads are formed in the vicinity of the end of the electrode, although the amount of gold beads extruded by the tilt error can be reduced, in this case, the laser diode can be supplied to the vicinity of the gold bead. The current density of the body changes, and the action of the laser diode becomes difficult. Therefore, gold beads must be formed near the center of the laser diode. When a gold bead is formed at an elongated electrode pattern such as a recording type high output laser diode, the effect is more remarkable.

The present invention is an object developed in order to eliminate the above problems, and provides an electrode pattern and a wire bonding method capable of performing wire bonding with high precision.

The electrode pattern of the present invention is used for wire bonding and has a short side and a long side, and is characterized by having a reference position for determining a wire bonding position. a wire bonding reference pattern and a wire bonding cognitive pattern, wherein a distance L between a line parallel to the short side and a line parallel to the short side and the reference position is formed at a metal portion of the wire pattern of the electrode pattern And a distance Lb between the line of the longitudinal direction of the cognitive pattern and the line of the short side passing through the wire and the maximum width position parallel to the short side of the metal portion and parallel to the line of the short side, L ≧14.3×(W-3d/4) Lb≦14.3×(W-3b/4) Wherein d is the maximum value of the short side width parallel to the metal portion of the electrode pattern of the electrode pattern; and W is the width of the short side of the parallel electrode pattern.

According to the present invention, it is possible to obtain an electrode pattern capable of forming a wire bonding wire for welding at an arbitrary position of the elongated electrode pattern.

Embodiment 1

Fig. 1 is a schematic view showing an electrode pattern for wire bonding according to an embodiment of the present invention. Further, Fig. 2 is a schematic view showing a semiconductor element using an electrode pattern for wire bonding according to an embodiment of the present invention. Hereinafter, description will be made using Figs. 1 and 2 . In the embodiment of the present invention, a semiconductor element in which wire bonding is performed on an elongated laser diode wafer is exemplified. At the laser diode wafer, an electrode pattern 103 for wire bonding is formed. A gold bead 109 having a diameter d is formed in the wire bonding field 111 on the electrode pattern 103 to implement a line. welding. At this time, when the center of the eyelet 201 shown in FIG. 2 and the center of the laser diode 205 are not inclined and shifted (θ = 0), the center of the gold bead is made long in the center of the short side direction of the parallel electrode pattern 103. On the side direction line, gold beads 109 are formed and wire bonding is performed. A characteristic pattern that becomes the wire bonding cognitive pattern 107 is formed in the electrode pattern 103. In the present embodiment, a rectangular slit is formed on the longitudinal direction of the electrode pattern 103, and the line-welded cognitive pattern 107 is used. Let each size be determined as follows.

L: the shortest distance between the electrode pattern edge portion (electrode end portion 105) and the center of the gold bead 109 formed in the wire bonding field 111

Lb: the shortest distance between the line in the short side direction of the center in the longitudinal direction of the line pattern of the cognitive pattern 107 in parallel and the center of the gold ball 109 formed in the wire bonding field 111

d: diameter of gold beads 109

W: width in the direction parallel to the short side of the electrode pattern 103

The tilt offset θ between the center of the aperture 201 and the center of the laser diode 205 is at most 2 degrees higher than the accuracy of the assembly devices. When the gold bead 109 is formed in the wire bonding field 111, the amount extruded from the wire bonding field 111 is regarded as x, and x is expressed by the following formula.

x=d/2-W/2+Ltan θ

Here, when the extrusion amount x is allowed to be d/8, tan2 degrees = 0.0349, so L and Lb become the following formulas, respectively.

L=14.3×(W-3d/4)

Lb=14.3×(W-3d/4)

In the present embodiment, the electrode end portion 105 is regarded as a specific line. A wire bonding reference pattern for the reference of the welding position. The distance L between the wire bonding reference pattern and the center of the diameter d gold bead 109 in the wire bonding field 111 is wire bonding at a position of L ≧ 14.3 × (W - 3d / 4). At this time, the distance Lb parallel to the center of the gold bead 109 parallel to the center in the longitudinal direction of the line in the longitudinal direction of the wire bonding cognitive pattern 107 formed on the electrode pattern 103 is positioned at Lb ≦ 14.3 × (W-3d / 4) The position of (μm). When the recording type high output laser diode is taken as an example, the longitudinal length of the laser diode is regarded as 2000 μm, the width is regarded as 120 μm, the electrode width is regarded as 80 μm, and when the gold bead diameter is 80±10 μm, the L system is used. When the cognitive pattern is wirelessly soldered, the gold bead is formed only at the end of the elongated electrode, and the current density to be injected changes at the upper end portion and the lower end portion of the electrode, and the operation of the laser diode is unstable. By forming the wire bonding cognitive pattern of the present invention at a desired position, the problem of unevenness of the injected current density can be easily eliminated.

In the present embodiment, the electrode end portion 105 is used for the wire bonding reference pattern. However, the characteristic pattern in the electrode may be used as the wire bonding reference pattern in addition to the electrode end portion. For example, at one of the four corners of the electrode pattern 103, a notch for confirming the front and rear of the wafer or the like is formed, and the notch may be used as the wire bonding reference pattern. In the present embodiment, the notch is a combination of rectangular shapes, but may be other shapes such as a circle or a triangle. Further, in the present embodiment, although the gold beads are formed and the wire bonding is performed, in the case of the wedge welding, the ultrasonic welding wire tip may be connected without forming the gold beads.

Embodiment 2

In the third and fourth drawings, a schematic view of an electrode pattern for wire bonding according to the second embodiment of the present invention is shown. In the first embodiment, as shown in Fig. 1, the wire bonding recognition pattern 107 is formed into a rectangular notch pattern. However, in the present embodiment, the wire bonding recognition pattern is a circle shown in Fig. 3. The shape of the cognitive pattern, or the triangular shape shown in Fig. 4. In the circular line welding cognitive pattern 307, when the wire bonding cognitive pattern 307 is made small, or when an etching method with a low processing precision is used, even if a sag angle is generated, the shape is circular, and the cognition can be prevented. error. Further, when the cognitive pattern 407 is welded to the line of the triangle, the length of the straight portion can be lengthened as compared with the square of the same size, so that the influence of the pattern crack due to the etching collapse angle or the like can be reduced.

The wire bonding cognitive patterns 307, 407 are formed on the side portions of the longitudinal sides of the electrode patterns 303, 403, and can be easily formed by the lift-off method. Further, when a method such as etching is used, as shown in FIG. 5, the wire bonding cognitive pattern 507 may be formed inside the electrode pattern 503.

Embodiment 3

In the present embodiment, there is a method of performing wire bonding on a cognitive wire bonding cognitive pattern.

Referring to Figs. 1 and 2, the outline position of the wire bonding cognitive pattern 107 can be known by recognizing the outer shape of the eyelet 201. Next, the wire bonding cognitive pattern 107 formed on the electrode pattern 103 is recognized. At this time, when necessary, the camera magnification is changed to recognize the wire bonding cognitive pattern 107. Finally, wire bonding is performed by the bonding wires 211, 213, and the connection of the wires 207 and CND is performed. When using this method, the laser diode 205 on the aperture 201 is a cause In order to set the loss, the pre-pairing of the heart, or the positioning of the fixture, etc., and the positional offset, it can be found immediately. That is, after recognizing the shape of the aperture, there is no line-welding cognitive pattern at the intended position, so the device will stop here. This makes it possible to suppress the positional deviation defective product in the laser diode subsequent step to a minimum, and therefore, it is possible to suppress the loss caused by the continuous production of the defective product.

Embodiment 4

In this embodiment, another method of performing wire bonding on the cognitive wire bonding cognitive pattern is used.

As in the third embodiment, the outline position of the wire bonding cognitive pattern can be known by recognizing the outer shape of the eyelet. Next, it is recognized that the wire bonding reference pattern is the wire bonding reference. In the present embodiment, the electrode end portion 105 is regarded as a wire bonding reference pattern. Next, the wire bonding cognitive pattern 107 formed on the electrode pattern 103 is recognized. At this time, when necessary, the camera magnification is changed to recognize the wire bonding cognitive pattern 107. Finally, wire welding is carried out. When this method is used, since the position of the wafer is recognized, the position of the wire bonding cognitive pattern 107 can be more accurately recognized than in the third embodiment. Further, the notch formed in one of the four corners of the electrode pattern 103 may be used as a wire bonding reference pattern for position confirmation. In the present embodiment, the notch is a combination of rectangular shapes, but may be other shapes such as a circle or a triangle.

Embodiment 5

In this embodiment, another method of performing wire bonding on the cognitive wire bonding cognitive pattern is used.

Referring first to Fig. 1, the outline position of the wire bonding cognitive pattern 107 can be known by recognizing the shape of the eyelet. Next, the wire bonding cognitive pattern 107 formed on the electrode pattern 103 is recognized. At this time, when necessary, the camera magnification is changed to recognize the wire bonding cognitive pattern 107. Next, the pattern of the electrode end portion 105 at the intended position is recognized, and the wire bonding is finally performed. When this method is used, in the third embodiment, it is possible to detect the positional shift in the subsequent step, and it is possible to immediately detect the defect in the case of the laser diode of the different types. The laser diode chip has different longitudinal lengths of the laser diodes due to the output optical power. Therefore, when the wafers of different types are used, the pattern of the electrode ends cannot be recognized and the device stops. It is possible to suppress the loss caused by the poor carrying of the wafers of different models. Further, a notch formed in one of the four corners of the electrode pattern 103 may be used for confirmation of the electrode end. In the present embodiment, the notch is a combination of rectangular shapes, but may be other shapes such as a circle or a triangle.

Further, although the present invention relates to an electrode pattern having a short side and a long side, the width of the short side direction of the electrode pattern is affected by the inclination shift of the center line of the laser diode with respect to the center line of the aperture. The smaller W is, the bigger it is. When W is large, the edge with respect to the offset is large, but when W is less than 100 μm, this edge hardly becomes. Therefore, the present invention is particularly effective when W is less than 100 μm.

Further, although the present invention has been described with respect to a recording type high output laser diode, it can also be applied to other red laser diodes or blue-violet laser diodes, and communication laser diodes. Wire bonding of body, LED, other semiconductor devices, or wiring patterns on packages or substrates, etc. The electrode pattern.

103‧‧‧electrode pattern

105‧‧‧electrode end

107‧‧‧Wire welding cognitive pattern

109‧‧‧Gold beads

303‧‧‧electrode pattern

307‧‧‧Wire welding cognitive pattern

403‧‧‧electrode pattern

407‧‧‧Wire welding cognitive pattern

503‧‧‧electrode pattern

507‧‧‧Wire welding cognitive pattern

Fig. 1 is a schematic view showing an electrode pattern of an embodiment of the present invention.

2(a) and 2(b) are schematic views showing a semiconductor element using an electrode pattern according to an embodiment of the present invention.

Fig. 3 is a schematic view showing an electrode pattern of an embodiment of the present invention.

Fig. 4 is a schematic view showing an electrode pattern of an embodiment of the present invention.

5(a) to 5(c) are schematic views showing an electrode pattern according to an embodiment of the present invention.

101‧‧‧Semiconductor substrate

103‧‧‧electrode pattern

105‧‧‧electrode end

107‧‧‧Wire welding cognitive pattern

109‧‧‧Gold beads

111‧‧‧Wire welding field

Claims (8)

An electrode pattern for wire bonding and having a short side and a long side, characterized by having a wire bonding reference pattern and a wire bonding cognitive pattern indicating a reference position for determining a wire bonding position, and then bonding to the electrode pattern At the metal portion, the distance L from the position of the maximum width in the direction parallel to the short side and the line parallel to the short side, and the distance from the reference position, and the center of the longitudinal direction of the line-fed cognitive pattern are parallel and The line of the short side and the distance Lb passing through the line of the maximum width parallel to the short side and the line of the short side of the aforementioned metal portion are L≧14.3×(W-3d/4) Lb≦14.3×(W-3d) /4) wherein d is the maximum value of the short side width parallel to the metal portion of the electrode pattern of the electrode pattern; and W is the width of the short side of the parallel electrode pattern. The electrode pattern according to claim 1, wherein the wire bonding reference pattern is an electrode pattern end portion. The electrode pattern according to claim 1 or 2, wherein the metal portion of the wire for bonding to the electrode pattern is a gold bead. The electrode pattern according to claim 1 or 2, wherein the metal portion for bonding the electrode pattern is a wire end portion which is flattened for wedge welding. An electrode pattern as described in claim 1 or 2, wherein The aforementioned W system is 100 μm or less. A wire bonding method for performing wire bonding on an electrode pattern according to claim 1 or 2, wherein after the shape of the package is recognized, the wire bonding cognitive pattern is recognized to determine a wire bonding position, and wire bonding is performed. A wire bonding method for performing wire bonding on an electrode pattern described in claim 1 or 2, characterized in that after the shape of the package is recognized, the wire bonding reference pattern is recognized, and after recognizing the wire bonding cognitive pattern , implementation of wire welding. A wire bonding method for wire bonding according to the first or second aspect of the wire welding application, characterized in that after recognizing the shape of the package, the wire bonding cognitive pattern is recognized, and at the cognitive electrode end After the pattern, wire bonding is performed.