TW202036694A - Substrate for inspection and inspection method capable of quantitatively evaluating an area where the leaking light reaches - Google Patents

Abstract

A substrate for inspection is provided to inspect the light leakage of a laser beam in order to quantitatively evaluate an area where the leaking light can reach. A substrate for inspection is provided to inspect the light leakage of a laser beam. The substrate for inspection comprises a side surface irradiated with the laser beam having a wavelength penetrating through the substrate for inspection; the other side surface opposite to the side surface; a cutting passage set at the other side surface; a plurality of first inspection wires, each of which is arranged on the other side surface along the cutting passage and at different distances from the cutting passage; and a plurality of first electrode pads disposed on the other side surface, wherein two or more of the plurality of first electrode pads are provided on each of the plurality of first inspection wires and arranged apart from each other in each of the plurality of first inspection wires in a direction along the cutting passage .

Description

Inspection board and inspection method

The present invention relates to an inspection substrate for inspecting the light leakage of the laser beam when processing a workpiece with the laser beam, and an inspection method using the inspection substrate to inspect the light leakage of the laser beam.

There is known a disk-shaped wafer in which semiconductor elements are formed in each area divided by a plurality of predetermined dividing lines (ie, dicing lanes) arranged in a grid. In order to divide wafers along dicing lanes and manufacture semiconductor wafers, for example, laser processing equipment is used.

For example, a laser processing device is used to position the condensing point of a pulsed laser beam with a wavelength penetrating through the wafer inside the wafer, and move from the wafer along the dicing lane on the front side of the wafer. The back side is illuminated with a laser beam. In this way, multiphoton absorption is generated near the condensing point, and a modified layer with reduced mechanical strength is formed along the scribe line. Thereafter, by applying an external force to the wafer, the wafer is divided along the dicing lane with the modified layer as a starting point.

When forming the modified layer, multiple modified layers are usually formed at different depth positions of the wafer. For example, the depth position of the focusing point is positioned at a predetermined depth position on the front side of the wafer, and the laser beam is irradiated along a dicing line. The first layer of modified layer is formed by irradiating the laser beam once along the cutting path (that is, the irradiation of the laser beam in the first stroke).

After that, after moving the depth position of the condensing point a predetermined distance to the back side, the laser beam is irradiated again along the same cutting path (that is, the laser beam of the second stroke is irradiated) to form the second layer Modified layer. Similarly, repeatedly moving the depth position of the condensing point to the back side by a predetermined distance and the irradiation of the laser beam to form multiple (for example, 2 to 5) modified layers inside the wafer.

When forming the modified layer, although the laser beam is mainly absorbed by the wafer at the condensing point located at a predetermined depth, a part of the laser beam may be transferred from the modified layer located on the front side of the position more than the predetermined depth or from Refraction or reflection due to cracks and other extensions of the modified layer.

Suppose that a part of the laser beam becomes light leakage through refraction or reflection (that is, light that reaches the semiconductor device beyond the target irradiation area (ie, dicing channel)), then the leaked light will reach the crystal divided by multiple dicing channels. A semiconductor element formed in each area on the front side of the circle. In this case, there is a concern that the semiconductor element will be damaged due to light leakage. Therefore, it is necessary to select the irradiation conditions of the laser beam (ie, laser processing conditions) so that the leaked light does not reach the semiconductor element.

Therefore, a known method is to form a coating layer of tin (Sn) or oil-based ink on the front side of the wafer, and then irradiate a laser beam from the back side of the wafer to confirm that it reaches the front side of the wafer. Light leakage (for example, refer to Patent Document 1) [Literature Technical Literature] [Patent Literature]

[Patent Document 1] JP 2017-216413 A

[The problem to be solved by the invention] However, the method described in Patent Document 1 only observes the deteriorated area by the laser beam reaching the coating layer, and there is no method for quantitatively evaluating the area reached by the leaked light.

The present invention is an invention made in view of this problem, and its purpose is to provide an inspection substrate for quantitatively evaluating the area where the light leakage will reach, for inspecting the light leakage of the laser beam.

[Technical means to solve the problem] According to an aspect of the present invention, there is provided an inspection substrate for inspecting light leakage of a laser beam, the inspection substrate having: one side surface irradiated with the laser beam having a wavelength penetrating the inspection substrate ; The other side surface is the opposite side to the one side surface; the cutting lane is set on the other side surface; multiple first inspection wires, each along the other side surface The cutting lane is arranged at different distances from the cutting lane; and a plurality of first electrode pads are provided on each of the plurality of first inspection wires on the other side surface, and In each of the plurality of first inspection wires, they are arranged separately in the direction along the scribe lane. Preferably, the inspection substrate further includes a plurality of second inspection wirings which are separated from the plurality of first inspection wirings along the dicing path on the other side surface, and each of which is along The cutting lane is arranged at different distances from the cutting lane.

According to another aspect of the present invention, there is provided an inspection method for inspecting light leakage of a laser beam using an inspection substrate, the inspection substrate having: one side surface irradiated with the laser having a wavelength penetrating the inspection substrate Beam; the surface on the other side is the opposite side of the surface on the other side; the cutting lane is set on the surface on the other side; multiple first inspection wires, each on the other side Along the scribe lane and are arranged at different distances from the scribe lane; and a plurality of first electrode pads are provided on each of the plurality of first inspection wires on the other side surface , And arranged separately in the direction along the cutting lane in each of the plurality of first inspection wires. The inspection method includes: a holding step of holding the other surface side of the inspection substrate with a chuck table; and a laser processing step of irradiating from the one surface side of the inspection substrate along the scribe path The laser beam is used to form a modified layer along the scribe line inside the inspection substrate; and a light leakage confirmation step, after the laser processing step, the detector is brought into contact with each of the plurality of first inspection wirings For the plurality of first electrode pads provided on the strip, the presence or absence of the light leakage is confirmed by confirming the disconnection of the plurality of first inspection wires.

[Invention Effect] According to the inspection substrate of one aspect of the present invention, the surface on one side of the laser beam irradiated with the laser beam and the surface on the other side of the opposite side have a plurality of first inspection wires and a plurality of first electrode pads. Each of the plurality of first inspection wires is arranged along the dicing lane at a different distance from the dicing lane. In addition, the plurality of first electrode pads are provided with two or more for each of the plurality of first inspection wires, and are arranged separately in the direction along the dicing lane in each of the plurality of first inspection wires.

After the laser beam is irradiated along the dicing path, for example, the inspection of the first inspection wiring is performed by contacting each of the two first electrode pads with a probe (ie, probe) and energizing it. With this, it is possible to determine at which position the first inspection wiring receives light leakage and breaks, among the plurality of first inspection wirings arranged at different distances from the cutting lane, so it can be quantitatively determined Assess the impact of light leakage.

The embodiments of one aspect of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of the frame unit 1. The frame unit 1 has an inspection substrate 11 for inspecting light leakage. The inspection substrate 11 has a disk shape. The inspection substrate 11 has a circular front surface (the other side surface) 11 a and a back surface (one side surface) 11 b, and has a thickness of about 500 μm to 1000 μm.

The inspection substrate 11 is a wafer formed of a silicon (Si) substrate. However, the inspection substrate 11 is not limited to silicon, and may be formed of semiconductor materials such as gallium arsenide (GaAs), silicon carbide (SiC), and gallium nitride (GaN), sapphire, various glasses, or the like.

A plurality of dicing lanes 13 are set on the front surface 11a side of the inspection substrate 11 so as to cross each other. Each cutting lane 13 is set to be parallel to the first direction A or to the second direction B orthogonal to the first direction A.

In each of the plurality of areas divided by the plurality of dicing lanes 13, an element 15a and an inspection area 15b are provided. In addition, in this specification, the area where the element 15a and the inspection area 15b are provided is referred to as an element area 15A.

For example, the plurality of elements 15a are arranged in a row along the first direction A, and the plurality of inspection areas 15b are arranged along the first direction A so as to be adjacent to the row of the elements 15a in the second direction B Into a row. In this way, the plurality of elements 15a and the plurality of inspection regions 15b each arranged in a row are alternately arranged from one end of the element region 15A in the second direction B to the other end.

However, the arrangement of the element 15a and the inspection area 15b is not limited to the above example. The plurality of elements 15a and the plurality of inspection regions 15b may be arranged in a row along the second direction B, and alternately arranged from one end of the element region 15A in the first direction A to the other end.

In addition, the plurality of elements 15a and the plurality of inspection regions 15b may be alternately arranged in the first direction A and the second direction B (that is, in a checkerboard shape). In addition, the element 15a may not be provided in the element region 15A. When the element 15a is not provided, the inspection area 15b is provided in each area divided by the plurality of dicing lanes 13.

Next, the inspection area 15b will be described in detail. Fig. 2 is a plan view showing an element region 15A of the first embodiment partially enlarged. In addition, in FIG. 2, for convenience, the cutting lane 13 along the first direction A is designated as the cutting lane 13-1, and the cutting lane 13 along the second direction B is designated as the cutting lane 13-2.

2 shows two elements 15a arranged along the first direction A, two inspection areas 15b arranged along the first direction A and adjacent to the two elements 15a in the second direction B, and in the second The direction B is adjacent to the two inspection areas 15b and is arranged along the first direction A and two further elements 15a.

The inspection area 15b has a plurality of first inspection wires 23a arranged on the front side (the other side surface) 11a side. Each 1st inspection wiring 23a is arrange|positioned along the dicing lane 13-2. Each of the first inspection wiring 23a is a thin-film wiring layer formed of a conductive material (for example, tin (Sn)).

Each of the first inspection wiring 23a has a line width and thickness that are broken by a laser beam of a predetermined energy. Therefore, each of the first inspection wires 23a can be broken by the light leakage of the laser beam of predetermined energy.

For example, each first inspection wiring 23a has a line width of 10 nm or more and 5 μm or less, and has a thickness equivalent to one layer of the multilayer wiring provided on the element 15a (for example, a thickness of 10 nm or more and 1 μm or less).

Each of the plurality of first inspection wiring 23a (23a-1, 23a-2, 23a-3, 23a-4, 23a-5) is arranged at a position at a different distance from the dicing lane 13-2. The first inspection wiring 23a-1 is adjacent to the dicing lane 13-2.

The first inspection wiring 23a-2, 23a-3, 23a-4, and 23a-5 are arranged in this order so as to gradually move away from the first inspection wiring 23a-1. That is, the first inspection wiring 23a-2 is closest to the first inspection wiring 23a-1, and the first inspection wiring 23a-5 is the farthest from the first inspection wiring 23a-1.

The plurality of first inspection wires 23a are arranged such that each adjacent wire is separated from each other by a predetermined distance. For example, each of the first inspection wires 23a is separated from each other by the same distance as one side of the substantially square first electrode pad 25a described later.

As the first inspection wiring 23a is farther from the dicing lane 13-2, the length in the second direction B becomes shorter. That is, the length of the plurality of first inspection wires 23a in the second direction B is the longest in the first inspection wire 23a-1 and the shortest in the first inspection wire 23a-5.

Each of the first inspection wires 23a is arranged such that the center position of the length in the second direction B is arranged in a row along the first direction A. Therefore, both ends of the first inspection wiring 23a-1 are located outside the both ends of the first inspection wiring 23a-2, and both ends of the first inspection wiring 23a-2 are located more than the first inspection wiring 23a. The ends of -3 are also on the outside.

In addition, the both ends of the first inspection wiring 23a-3 are located outside the both ends of the first inspection wiring 23a-4, and the both ends of the first inspection wiring 23a-4 are located more than the first inspection wiring 23a. The two ends of -5 are also outside.

In each of the first inspection wires 23a, the first electrode pads 25a are arranged at two positions (more specifically, both ends in the longitudinal direction) separated in the direction of the scribe lane 13-2. The first electrode pad 25a has, for example, a substantially square shape of several tens of μm, and one side thereof is located at the end of the first inspection wiring 23a in the longitudinal direction.

The first electrode pad 25a is, for example, a layer formed of tin, and has the same thickness as the first inspection wiring. However, one side of the first electrode pad 25a is wider than the line width of the first inspection wiring 23a.

A plurality of second inspection wires (23b-1, 23b-2, 23b-3, 23b-4, and 23b-5) are arranged at positions separated from the plurality of first inspection wires 23a along the cutting lane 13-2 . Each of the plurality of second inspection wires 23b is arranged at a different distance from the dicing lane 13-2. The second inspection wiring 23b-1 is adjacent to the dicing lane 13-2.

The second inspection wirings 23b-2, 23b-3, 23b-4, and 23b-5 are arranged in this order so as to gradually move away from the second inspection wiring 23b-1. That is, the second inspection wiring 23b-2 is closest to the second inspection wiring 23b-1, and the second inspection wiring 23b-5 is the farthest from the second inspection wiring 23b-1. The plurality of second inspection wires 23b are also the same as the plurality of first inspection wires 23a, and are arranged in such a manner that each adjacent wire is separated from each other by a predetermined distance

The second inspection wiring 23b is also farther away from the dicing lane 13-2, the shorter the length in the second direction B becomes. In addition, each second inspection wire 23b is arranged such that the center position of the length in the second direction B is arranged in a row along the first direction A.

A second electrode pad 25b is also arranged at both ends of each of the second inspection wires 23b. The second electrode pad 25b has the same shape as the first electrode pad 25a and is formed of tin. The second electrode pad 25b is also arranged so that one side thereof is located at the end of the second inspection wiring 23b in the longitudinal direction.

The plurality of first inspection wires 23a and the plurality of second inspection wires 23b are alternately arranged along the dicing lane 13-2 while being separated from each other in the second direction B. In addition, in order to densely arrange as many first inspection wires 23a and multiple second inspection wires 23b as possible, the first electrode pads 25a and second electrode pads 25b adjacent to each other in the second direction B are only separated, for example, more than The length of one side of one first electrode pad 25a is still small.

To give a more specific example, the first electrode pad 25a and the second electrode pad 25b adjacent in the second direction B are separated by the same length as the spot diameter of the laser beam. In this way, in the vicinity of the cutting lane 13-2 of the inspection area 15b, a plurality of first inspection wiring 23a and a plurality of second inspection wires are densely arranged from one side of the second direction B (for example, the positive direction side) The wiring 23b is to the other side (for example, the negative direction side).

Similarly, in one inspection area 15b, in the vicinity of the dicing lane 13-2 located on the opposite side to the dicing lane 13-2 in the first direction A, a plurality of second direction B is also densely arranged from one side 1 inspection wiring 23a and a plurality of second inspection wirings 23b to the other side.

In addition, in the same inspection area 15b, a plurality of first inspection wires 23a are arranged alternately and densely from one side of the first direction A in the vicinity of the dicing lane 13-1 located on one side of the second direction B And a plurality of second inspection wires 23b to the other side.

Furthermore, in the same inspection area 15b, a plurality of first inspection wiring lines are arranged alternately and densely from one side of the first direction A in the vicinity of the cutting lane 13-1 located on the other side of the second direction B 23a and a plurality of second inspection wires 23b to the other side.

In addition, in FIG. 2, the first inspection wiring 23a and the second inspection wiring 23b are shown only as the inspection wiring 23. Similarly, the first electrode pads 25a and the second electrode pads 25b are shown only by The electrode pad 25 is indicated.

Here, returning to FIG. 1, the frame unit 1 will be explained. On the front side 11a side of the inspection substrate 11, there is an outer peripheral surplus area 15B that surrounds the outer circumference of the element area 15A without installing the element 15a and the inspection area 15b.

A notch 11c indicating the crystal direction of the wafer is provided in a part of the outer peripheral end of the inspection substrate 11. In addition, other marks may be provided instead of the orientation plane of the notch 11c.

The inspection substrate 11 is fixed to the opening of the metal ring frame 19 through the cutting adhesive film 17, for example. The dicing film 17 is a film made of a resin having ductility. The dicing adhesive film 17 has a laminated structure, and the laminated structure is an adhesive layer (not shown) made of an adhesive resin and a base layer (not shown) made of a resin without adhesiveness.

The adhesive layer is, for example, an ultraviolet-curing resin layer, and is provided on the entire surface of one surface of the base layer. If ultraviolet rays are irradiated to the adhesive layer, the adhesive force of the adhesive layer decreases, and it becomes easy to peel the dicing film 17 from the inspection substrate 11.

The ring frame 19 has an opening having a diameter larger than that of the inspection substrate 11. In the state where the inspection substrate 11 has been arranged in this opening, the frame unit 1 is formed by attaching the adhesive layer side of the dicing film 17 to the front surface 11a of the inspection substrate 11 and one surface of the ring frame 19.

Next, an inspection method for inspecting light leakage will be described using FIGS. 3, 4, 5(A), 5(B), and FIG. 6. In addition, FIG. 6 is a flowchart showing the inspection of light leakage. In the inspection method of the first embodiment, first, the frame unit 1 is held by the laser processing apparatus 10 by the chuck table 12 (holding step (S10)). 3 is a partial cross-sectional side view of the frame unit 1 and the laser processing device 10.

The laser processing device 10 has a chuck table 12. On the surface side of the chuck table 12, a disc-shaped porous plate formed of porous ceramics or the like is provided. The perforated plate communicates with a flow path (not shown) provided inside the chuck table 12 and is connected to a suction source (not shown) such as an ejector. The negative pressure generated by the suction source generates suction on the surface of the perforated plate (ie, the holding surface 12a).

A plurality of clamping units 14 are fixed to the outer peripheral side surface of the chuck table 12. For example, when the chuck table 12 is viewed from a plan view, one clamping unit 14 is arranged at each position of the hour hand at 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock.

An X-axis moving unit (not shown) and a Y-axis moving unit (not shown) are provided below the chuck table 12. The X-axis moving unit and the Y-axis moving unit each have a ball screw mechanism and can move the chuck table 12 in the X-axis direction and the Y-axis direction. In addition, the chuck table 12 is connected to a rotation drive source (not shown) such as a motor, and can rotate about a straight line substantially parallel to the Z-axis direction (vertical direction) as a rotation axis.

A processing head 16 constituting a laser beam irradiation unit is provided above the chuck table 12. The pulsed laser beam L having a wavelength penetrating the inspection substrate 11 is irradiated from the processing head 16 toward the holding surface 12a substantially perpendicularly.

In the holding step (S10), first, the frame unit 1 is placed on the holding surface 12a with the back surface 11b of the inspection substrate 11 facing upward. In this state, the suction source is operated and negative pressure is applied to the holding surface 12a.

Furthermore, the position of the ring frame 19 is fixed by the clamping unit 14. Thereby, the front side (the other side surface) 11 a side which is located on the opposite side to the back side (one side surface) 11 b is held by the chuck table 12 through the cut film 17.

Next, using the laser processing apparatus 10, the laser beam L is irradiated to the back surface (one side surface) 11b side along the scribe line 13 of the inspection substrate 11 (laser processing step (S20)). First, the rotation drive source is operated, and the direction of the chuck table 12 is adjusted so that the dicing path 13 of the inspection substrate 11 becomes parallel to the X-axis direction.

Then, the position of the chuck table 12 is adjusted by the X-axis moving unit so that the lower end of the processing head 16 is located on the extension line of one side of the X-axis direction (for example, the -X direction) side of one cutting path 13. Thereafter, the laser beam L is irradiated from the processing head 16 to the back surface 11b side of the inspection substrate 11 so that the condensing point of the laser beam L is positioned inside the inspection substrate 11.

After that, in a state where the focal point of the laser beam L irradiated from the back surface 11b of the inspection substrate 11 is positioned inside the inspection substrate 11, the X-axis moving unit is operated to move the chuck table 12 to the X-axis The other side of the direction (for example, the +X direction) side.

While the processing head 16 is relatively moved to the chuck table 12, the laser beam L is irradiated along the dicing path 13 (first stroke), thereby forming the first layer along the dicing path 13 inside the inspection substrate 11 The modified layer 11d.

After the first stroke, after moving the depth position of the condensing point a predetermined distance to the back side 11b, the chuck table 12 is moved along the same cutting path 13 to one of the X-axis directions (for example, the -X direction) (the first 2 itinerary). Thereby, the second modified layer 11d is formed.

After the second stroke, after moving the depth position of the focusing point by a predetermined distance to the back side 11b, move the chuck table 12 to the other side of the X axis direction (for example, the +X direction) along the same cutting path 13 (The third trip). Thereby, the third modified layer 11d is formed.

In the same manner, the laser beam L of the fourth and fifth passes is irradiated on the same dicing lane 13 to form the fourth and fifth modified layers 11d. After that, the irradiation of the laser beam L is temporarily stopped. The laser processing conditions are set as follows, for example.

The wavelength of the laser beam L: 1342nm Pulse repetition frequency: 90kHz Average output: 1.9W Point diameter: 10μm to 20μm Processing feed speed: 700mm/s

Next, the chuck table 12 is indexed and fed to the Y-axis direction by a predetermined indexing amount, and the lower end of the processing head 16 is positioned on another cutting lane adjacent to the newly processed cutting lane 13 in the Y-axis direction 13 on.

Then, the laser beam L is irradiated from the first pass to the fifth pass along the other cutting lane 13 in the same manner. In this way, five modified layers 11d are formed along all the cutting lanes 13 parallel in one direction.

After that, the chuck table 12 is rotated by 90 degrees, and the laser beam L is irradiated from the first stroke to the fifth stroke along all the cutting lanes 13 parallel to the other direction orthogonal to one direction. Thereby, 5 modified layers 11d are formed along each of all the cutting channels 13. In addition, the number of modified layers 11d is not limited to five layers. The number of modified layers 11d may be a predetermined number of layers greater than two.

However, when the laser beam L is irradiated, a part of the laser beam L is refracted or reflected, causing light leakage D (refer to Figure 4) (that is, light that exceeds the target irradiation area (cut lane 13) and reaches the element 15a) Case.

For example, when the modified layer 11d of the second layer is formed, a part of the laser beam L is refracted or reflected due to the cracks 11e formed from the modified layer 11d of the first layer toward the modified layer 11d of the second layer. And light leakage D occurs.

FIG. 4 is an enlarged view of area C in FIG. 3. FIG. 4 shows light leakage D that occurs when the second modified layer 11d is formed. If the leaked light D having a predetermined energy exceeds the dicing lane 13-2 and reaches the first inspection wiring 23a and the like in the inspection area 15b, the first inspection wiring 23a and the like may be damaged, for example, disconnected.

Then, after the laser processing step (S20), the disconnection of the inspection wiring 23 is confirmed (light leakage confirmation step (S30)). To this end, first, after attaching a replacement adhesive film (not shown) to the back surface (one side) 11b of the inspection substrate 11, the dicing adhesive film 17 is irradiated with ultraviolet rays to reduce the adhesive force of the adhesive layer . After that, the dicing adhesive film 17 is peeled from the inspection substrate 11 using a peeling device not shown.

In the light leakage confirmation step (S30), the disconnection of the inspection wiring 23 is confirmed using an inspection jig (not shown) such as a wafer prober. The inspection jig has a plurality of probes (ie, probes) that can contact the electrode pad 25.

In the light leakage confirmation step (S30), for example, the first probe of the inspection jig is brought into contact with the first electrode pad 25a at one end of the first inspection wiring 23a-1, and the second probe is brought into contact with the first electrode pad 25a at one end of the first inspection wiring 23a-1. The first electrode pad 25a at the other end of the inspection wiring 23a-1. In this state, let current flow between the first detector and the second detector.

For example, when a part of the inspection wiring 23 receives light leakage D and deteriorates, so that the conductivity of the inspection wiring 23 is significantly reduced, the current measurable within the predetermined measurement range will not be measured between the first detector and the second detector. 2 Circulate between the detectors. Therefore, it can be determined that the inspection wiring 23 is disconnected.

On the other hand, when a current greater than a predetermined value that can be measured within a predetermined measurement range passes through the first inspection wiring 23a-1 and flows between the first probe and the second probe, it can be determined that the first The inspection wiring 23a is not disconnected.

In this way, the presence or absence of the disconnection of the first inspection wiring 23a-1 can be confirmed using the inspection jig. In the same manner, it is also possible to confirm the presence or absence of disconnection from the first inspection wiring 23a-2 to 23a-5 and the plurality of second inspection wiring 23b.

Since it is possible to check the presence or absence of a disconnection by performing the conduction inspection of each inspection wiring 23, it is possible to determine at which position the inspection wiring 23 receives the light leakage D and is disconnected. Therefore, it is possible to quantitatively evaluate the influence of the light leakage D from how long the scribe lane 13 has covered.

FIG. 5(A) is a plan view showing a part of the element region 15A in an enlarged manner. An example of the result in the light leakage confirmation step (S30) is shown in FIG. 5(A). In addition, the arrow in FIG. 5(A) is the relative movement direction E of the laser beam L and the chuck table 12, and is, for example, parallel to the X-axis direction of the laser processing device 10.

In the example shown in FIG. 5(A), only the inspection area 15 b on the side (for example, the positive direction side) in the first direction A of the scribe lane 13-2 is formed with a deteriorated area 27. The inspection wiring 23 in which the altered region 27 is formed is in a disconnected state. In addition, the inspection area 15 b on the other side (for example, the negative direction side) of the scribe lane 13-2 in the first direction A is not formed with a deteriorated area 27.

However, due to the misalignment between the center of the laser beam L and the optical axis of the lens of the optical system used to irradiate the laser beam L or the center of the slit of the optical system, there may be a gap in the laser beam L When the energy distribution is shifted. In this case, the leaked light D will reach an area different from the example shown in FIG. 5(A). FIG. 5(B) is a plan view showing a part of the element region 15A in an enlarged manner. Another example of the result in the light leakage confirmation step (S30) is shown in FIG. 5(B).

In the example shown in FIG. 5(B), the modified area 27 is formed in the inspection area 15b sandwiching both sides of the dicing lane 13-2. The inspection wiring 23 in which the deterioration area 27 is formed is in a disconnected state, and the inspection wiring in which the deterioration area 27 is not formed is in a non-disconnected state.

In this way, by performing the continuity inspection using the inspection wiring 23 provided in the inspection area 15b, it is possible to determine at which position the inspection wiring 23 receives the light leakage D and breaks. Therefore, it is possible to quantitatively evaluate the influence of the light leakage D from how long the dicing lane 13 is over, and at how often the light leakage D will occur. In addition, based on quantitative evaluation, the irradiation conditions of the laser beam L can be corrected.

Next, the inspection substrate 11 of the second embodiment will be described. FIG. 7 is a partial enlarged view of the element region 15A of the second embodiment. The inspection substrate 11 of the second embodiment has a plurality of inspection wirings 23 on the scribe lane 13-2 in addition to the inspection area 15b.

More specifically, between two inspection areas 15b arranged to face each other with the dicing lane 13-2 sandwiched therebetween, a plurality of third inspection wirings 23c (23c- 1, 23c-2, 23c-3 and 23c-4). The plurality of third inspection wires 23c are arranged in a direction orthogonal to the dicing lane 13-2 so that each adjacent one is separated from each other by a predetermined distance.

Each of the third inspection wires 23c has the same length in the second direction B as the first inspection wires 23a-1. In addition, a third electrode pad 25c is provided at both ends of each of the third inspection wiring 23c. The third electrode pad 25c is formed of the same material as the first electrode pad 25a and has the same shape and size.

Along the second direction B, a plurality of fourth inspection wires 23d (23d-1, 23d-2, 23d) are provided along the dicing lane 13-2 in a state separated by a predetermined distance from the plurality of third inspection wires 23c -3 and 23d-4). The plurality of fourth inspection wires 23d are arranged in a direction orthogonal to the dicing lane 13-2 so that each adjacent one is separated from each other by a predetermined distance.

Each piece of the fourth inspection wiring 23d has the same length in the second direction B as the second inspection wiring 23b-1. In addition, a fourth electrode pad 25d is provided at both ends of each of the fourth inspection wiring 23d. The fourth electrode pad 25d is formed of the same material as the second electrode pad 25b and has the same shape and size.

In order to densely arrange the third inspection wiring 23c and the fourth inspection wiring 23d, the third electrode pad 25c and the fourth electrode pad 25d adjacent in the second direction B are the second electrode pads adjacent in the second direction B. The first electrode pad 25a and the second electrode pad 25b are separated by the same distance. In addition, the plurality of third inspection wires 23c and the plurality of fourth inspection wires 23d are alternately arranged along the dicing lane 13-2.

In the second embodiment, since a plurality of inspection wires 23 are provided in the scribe lane 13-2 of the inspection substrate 11, it is possible to quantitatively evaluate which range of the scribe lane 13-2 affects the light leakage D. Furthermore, based on the number of disconnected third inspection wiring 23c and fourth inspection wiring 23d, the frequency of the leakage light D reaching the third inspection wiring 23c and fourth inspection wiring 23d can be calculated.

In addition, the arrangement of the third inspection wiring 23c and the fourth inspection wiring 23d is not limited to the above example. The third inspection wiring 23c and the fourth inspection wiring 23d may be provided so as to be connected in a line along the second direction B through the third electrode pad 25c and the fourth electrode pad 25d. In addition, the third electrode pad 25c and the fourth electrode pad 25d may be provided in the dicing lane 13-2 instead of being provided in the dicing lane 13-1.

Next, the inspection substrate 11 of the third embodiment will be described. FIG. 8 is a partial enlarged view of the element region 15A of the third embodiment. In the inspection area 15b of the third embodiment, a plurality of fifth inspection wirings 23e (corresponding to a modified example of the plurality of first inspection wirings 23a) are provided on the side of the scribe lane 13-2.

Each of the plurality of fifth inspection wires 23e (23e-1, 23e-2, 23e-3, 23e-4, and 23e-5) has a side substantially equal to one side of the inspection area 15b along the second direction B length. The positions of both ends of each fifth inspection wire 23e in the second direction B are the same.

A fifth electrode pad 25e is provided at each end of both ends in the longitudinal direction of the fifth inspection wiring 23e. In addition, each of the fifth inspection wiring 23e is further provided with one or more fifth electrode pads 25e at a predetermined interval at a position between the two ends thereof.

In addition, in each fifth inspection wiring 23e, a plurality of fifth electrode pads 25e adjacent in the first direction A are aligned in the first direction A. That is, the plurality of fifth electrode pads 25e adjacent to each other in the first direction A are arranged at the same position in the second direction B.

In the inspection substrate 11 of the third embodiment, the first probe is brought into contact with one of the pair of fifth electrode pads 25e adjacent in the second direction B in the fifth inspection wiring 23e, and the second 2 The detector contacts the other to conduct a continuity check.

Thereby, it can be confirmed whether a part of the fifth inspection wiring 23e located between any pair of the fifth electrode pads 25e adjacent in the second direction B is disconnected. In addition, based on the number of disconnected regions, the frequency of the leakage light D reaching the fifth inspection wiring 23e can be calculated.

The inspection wiring 23 of the third embodiment has the same length in the second direction B regardless of the distance from the dicing lane 13-2. Therefore, for example, in the first embodiment, the light leakage D that reaches between the first inspection wiring 23a-5 and the second inspection wiring 23b-5 that are adjacent in the second direction B will also reach the third embodiment. The fifth inspection wiring 53e-5. Therefore, the frequency of the leakage light D can be calculated more accurately than in the first embodiment.

In addition, in the third embodiment, a plurality of fifth inspection wires 23e are similarly provided across the four sides of one inspection area 15b. That is, in the first direction A, the vicinity of the dicing lane 13-2, which is located on the opposite side to the dicing lane 13-2, and the vicinity of the dicing lane 13-2 located in the second direction B (for example, the positive direction side) and the other in the second direction B The fifth inspection wiring 23e is installed in the vicinity of the dicing lane 13-1 on the side (for example, the negative direction side).

Therefore, in each of the four sides of one inspection area 15b, the frequency at which the leakage light D reaches can be calculated based on the number of areas of the disconnected fifth inspection wiring 23e. In addition, in the third embodiment, in each of the four sides of one inspection area 15b, the influence of the light leakage D may be quantitatively evaluated up to how long the dicing lane 13 covers.

In addition, the structure, method, etc. of the above-mentioned embodiment may be appropriately modified and implemented without departing from the scope of the object of the present invention. For example, the arrangement of the inspection wiring 23 and the shape and arrangement of the electrode pad 25 are not limited to the above-mentioned examples. The third inspection wiring 23c and the fourth inspection wiring 23d of the second embodiment can also be applied to the scribe lane 13 of the inspection substrate 11 of the third embodiment.

In addition, in the above-described embodiment, the disconnection of the inspection wiring 23 is determined by whether or not the current that can be measured within the predetermined measurement range flows between the first probe and the second probe. However, it is also possible to determine whether the inspection wiring 23 is partially damaged or whether the inspection wire 23 is disconnected by measuring the change in the impedance value of the inspection wiring 23.

1: frame unit 10: Laser processing device 11: Substrate for inspection 11a: Front side (face on the other side) 11b: Back (face on one side) 11c: gap 11d: modified layer 11e: crack 12: Chuck table 12a: Keep the face 13,13-1,13-2: cutting lane 14: Fixture unit 15a: component 15b: Inspection area 15A: component area 15: Remaining area of outer periphery 16: Processing head 17: Cutting the film 19: Ring frame 23: Wiring for inspection 23a: Wiring for the first inspection 23b: Wiring for second inspection 23c: Wiring for third inspection 23d: Wiring for the 4th inspection 23e: 5th inspection wiring 25: Electrode pad 25a: The first electrode pad 25b: 2nd electrode pad 25c: 3rd electrode pad 25d: 4th electrode pad 25e: 5th electrode pad 27: Metamorphic area A: 1st direction B: 2nd direction C: area D: Light leakage E: Moving direction L: Laser beam

Figure 1 is a perspective view of the frame unit. Fig. 2 is a plan view showing a part of an element region of the first embodiment in an enlarged manner. Fig. 3 is a partial cross-sectional side view of the frame unit and the laser processing device. FIG. 4 is an enlarged view of area C in FIG. 3. FIG. 5(A) is a plan view showing a part of the element area enlarged; FIG. 5(B) is a plan view showing a part of the element area enlarged. Fig. 6 is a flowchart showing the inspection method. Fig. 7 is a partial enlarged view of the element area of the second embodiment. Fig. 8 is a partial enlarged view of the element area of the third embodiment.

13-1, 13-2: cutting lane

15A: component area

15a: component

15b: Inspection area

23: Wiring for inspection

23a-1, 23a-2, 23a-3, 23a-4, 23a-5: Wiring for the first inspection

23b-1, 23b-2, 23b-3, 23b-4, 23b-5: Wiring for second inspection

25: Electrode pad

25a: The first electrode pad

25b: 2nd electrode pad

A: 1st direction

B: 2nd direction

Claims (3)

An inspection substrate for inspecting light leakage of a laser beam, characterized in that the inspection substrate includes: One side surface is irradiated with the laser beam having a wavelength penetrating the inspection substrate; The surface on the other side is the opposite side to the surface on the one side; The cutting path is set on the other side surface; A plurality of first inspection wires, each of which is along the cutting lane and arranged at a different distance from the cutting lane on the other side surface; and A plurality of first electrode pads are provided on each of the plurality of first inspection wirings on the other side surface, and in each of the plurality of first inspection wirings along the Separately arranged in the direction of the cutting lane. The inspection board according to claim 1, further comprising a plurality of second inspection wirings separated from the plurality of first inspection wirings along the dicing lane on the other side surface, and Each of them is arranged along the cutting lane at a different distance from the cutting lane. An inspection method that uses an inspection substrate to inspect the light leakage of a laser beam, which is characterized in that: The inspection substrate has: One side surface is irradiated with the laser beam having a wavelength penetrating the inspection substrate; The surface on the other side is the opposite side to the surface on the one side; The cutting path is set on the other side surface; A plurality of first inspection wires, each of which is along the cutting lane and arranged at a different distance from the cutting lane on the other side surface; and A plurality of first electrode pads are provided on each of the plurality of first inspection wirings on the other side surface, and in each of the plurality of first inspection wirings along the Separately arranged in the direction of the cutting path; The inspection method has: A holding step, holding the other side of the inspection substrate with a chuck table; A laser processing step, irradiating the laser beam from the side of the inspection substrate along the scribe path, and forming a modified layer along the scribe path inside the inspection substrate; and In the light leakage confirmation step, after the laser processing step, the detector is brought into contact with the plurality of first electrode pads provided on each of the plurality of first inspection wires, by confirming the plurality of first inspection wires To confirm the light leakage.

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