Semiconductor device manufacturing method

Abstract

A wedge tool according to an embodiment of the present disclosure is used for wedge bonding in which a metal wire 2 is pressed and ultrasonic vibrations are applied to bond the metal wire 2 to a body 6 to be bonded to. The wedge tool comprises: a wire holding groove 3 extending along the longitudinal direction of the metal wire 2 in a tip-end portion 1 of the wedge tool to hold the metal wire 2, and at least two protrusions 8 formed in a groove bottom portion 5 of the wire holding groove 3, the protrusions 8 having side surfaces spaced apart from side walls 4 of the wire holding groove 3 and arranged in the longitudinal direction of the metal wire 2. In this way, by inspecting a contact mark 9 formed on the metal wire 2 instead of the exterior shape of the metal wire 2 deformed by the pressing, it is possible to confirm whether excessive force has been applied to the body 6 to be bonded to. Thus, a decrease in inspection accuracy can be reduced.

Description

[Technical field]

[0001] The present disclosure relates to a wedge tool and a method for manufacturing a semiconductor device. [Background technology]

[0002] Wedge bonding, which is used in the manufacture of semiconductor devices, is a bonding method in which a metal wire is pressed against a bonded object with a wedge tool and ultrasonic vibration is applied to bond the metal wire and the bonded object. For this reason, a structure in which staggered protrusions are provided on the groove wall of the wedge tool in order to suppress slippage between the wedge tool and the metal wire and improve bonding performance has been disclosed as a prior art. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-116334 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional technology, if the force with which the wedge tool presses the metal wire against the bonded object is excessive, the bonded object may be damaged. Therefore, in order to non-destructively check whether excessive force is being applied to the bonded object, a visual inspection of the shape of the metal wire that is deformed by being pressed by the wedge tool is performed.

[0005] On the other hand, the end of the metal wire that is pressed and deformed by the wedge tool does not necessarily have the same thickness or shape every time, and the appearance may vary depending on the amount of light used during the inspection. This causes variations in pass / fail judgments even in visual appearance inspections using an optical microscope or appearance inspections using image recognition. In other words, there is a problem that the inspection accuracy may decrease when the appearance shape of the deformed metal wire is used as an indicator for appearance inspection.

[0006] The present disclosure has been made to solve the problems described above, and aims to provide a wedge tool and a method for manufacturing a semiconductor device using this wedge tool, which suppresses a decrease in inspection accuracy compared to conventional methods, in wedge bonding, which joins a metal wire to a bonded object, by forming a contact mark on the metal wire when pressing down the metal wire with the wedge tool, and performing a visual inspection using the contact mark as an indicator of the force with which the metal wire was pressed. [Means for solving the problem]

[0007] A manufacturing method of a semiconductor device disclosed in the present application is a manufacturing method of a semiconductor device in which a metal wire is bonded to a bonded body, the manufacturing method comprising the steps of: pressing the metal wire against the bonded body using a wedge tool used in wedge bonding in which the metal wire is bonded to the bonded body by pressing the metal wire and applying ultrasonic vibrations to the metal wire, the wedge tool having a wire holding groove extending along the length of the metal wire at the tip of the wedge tool and holding the metal wire, and at least two convex portions formed at the bottom of the wire holding groove, the side surfaces of which are spaced apart from the side walls of the wire holding groove and aligned in the length direction of the metal wire, the convex portions being aligned in the length direction of the metal wire, and ... Effect of the Invention

[0013] According to the present disclosure, a wedge tool is used to press a metal wire and apply ultrasonic vibrations to the metal wire to join the workpieces, and if the pressing force on the workpieces exceeds a predetermined force, a contact mark is formed on the metal wire by a convex portion formed on the bottom of the wire holding groove. As a result, by inspecting the contact mark formed on the metal wire, rather than the external shape of the metal wire deformed by pressing, it is possible to check whether an excessive force is being applied to the workpieces, and therefore deterioration of inspection accuracy can be suppressed. [Brief description of the drawings]

[0014] [Figure 1] 1 is a front view of a tip portion 1 of a wedge tool according to a first embodiment. [Diagram 2] 2 is a cross-sectional view taken along line AA of the tip 1 of the wedge tool according to the first embodiment. FIG. [Diagram 3] 1 is a schematic view showing the appearance of a metal wire 2 according to a first embodiment that is appropriately pressed. FIG. [Figure 4] 1 is a schematic BB cross-sectional view of the metal wire 2 according to the first embodiment that is appropriately pressed. FIG. [Diagram 5] 1 is a schematic view showing the appearance of the metal wire 2 according to the first embodiment that is excessively pressed. FIG. [Figure 6]4 is a schematic cross-sectional view taken along line CC of the metal wire 2 according to the first embodiment that is excessively pressed. FIG. [Figure 7] FIG. 1 is a front view of the tip of a prior art wedge tool. [Figure 8] FIG. 1 is a side view of the tip of a prior art wedge tool. [Figure 9] FIG. 1 is a schematic view of the appearance of a metal wire that has been properly pressed in the prior art; [Figure 10] FIG. 1 is a schematic diagram showing the appearance of a metal wire that has been excessively pressed in the prior art. [Figure 11] FIG. 1 is a schematic DD cross-sectional view of a metal wire normally pressed in the prior art. [Figure 12] FIG. 1 is a schematic view of an E-E cross section of a metal wire that has been overly pressed in the prior art. [Figure 13] FIG. 11 is a front view of a tip portion 1 of a wedge tool according to a second embodiment. [Figure 14] 11 is an FF sectional view of a tip portion 1 of a wedge tool according to a second embodiment. FIG. [Figure 15] 11 is a schematic view showing the appearance of a metal wire 2 according to a second embodiment that is appropriately pressed. FIG. [Figure 16] FIG. 11 is a schematic view showing the appearance of the metal wire 2 according to the second embodiment that is excessively pressed. [Figure 17] FIG. 11 is a front view of a tip portion 1 of a wedge tool according to embodiment 3. [Figure 18] 11 is a cross-sectional view taken along line GG of a tip portion 1 of a wedge tool according to embodiment 3. FIG. [Figure 19] FIG. 11 is a schematic view showing the appearance of a metal wire 2 that is appropriately pressed according to a third embodiment. [Figure 20] FIG. 11 is a schematic view showing the appearance of the metal wire 2 according to the third embodiment that is excessively pressed. [Figure 21] FIG. 11 is a front view of a tip portion 1 of a wedge tool according to a fourth embodiment. [Figure 22] 11 is a HH sectional view of a tip portion 1 of a wedge tool according to embodiment 4. FIG. [Figure 23]FIG. 11 is a schematic view showing the appearance of a metal wire 2 that is appropriately pressed according to a fourth embodiment. [Figure 24] FIG. 13 is a schematic view showing the appearance of the metal wire 2 according to the fourth embodiment that is excessively pressed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a wedge tool and a method for manufacturing a semiconductor device according to an embodiment of the present disclosure will be described with reference to the drawings. Components having the same or corresponding functions are denoted by the same reference numerals, and repeated description may be omitted.

[0016] Embodiment 1 FIG. 1 shows a front view of a tip portion 1 of a wedge tool according to the first embodiment, and FIG. 2 shows a cross-sectional view of the tip portion 1 of the wedge tool according to the first embodiment along the line AA in FIG. 1. As shown in FIG. 1, the tip portion 1 of the wedge tool has a recessed wire holding groove 3 for holding a metal wire 2, and the wire holding groove 3 extends along the length of the metal wire 2 and has a side wall 4 and a groove bottom 5. A columnar protrusion 8 is provided on the groove bottom 5, and the side surface of the columnar protrusion 8 is formed to be spaced apart from the side wall 4. Also, as shown in FIG. 2, in the first embodiment, three columnar protrusions 8 are provided side by side along the wire holding groove 3 extending in the length direction of the metal wire 2. In order to prevent the columnar protrusions 8 from applying excessive force to the metal wire 2 and the bonded object, the height of the columnar protrusions 8 is preferably in the range of 10±5% of the diameter of the metal wire 2 used. For example, when the diameter of the metal wire is 200 μm, the height of the columnar protrusions 8 is preferably in the range of 20±10 μm. However, the diameter of the metal wire used in wedge bonding is generally about 50 μm to 600 μm, and is a design item that should be selected according to the product specifications and manufacturing conditions, so the columnar protrusions 8 are not limited to the above height. In addition, the number of columnar protrusions 8 provided at the groove bottom 5 is set to three in order to reliably prevent recognition errors from the viewpoint of use in visual inspection, and it is preferable to provide at least two columnar protrusions 8.

[0017] A case where the tip 1 of the wedge tool is pressed appropriately against the metal wire 2 and a case where the tip 1 of the wedge tool is pressed excessively by performing wedge bonding using the wedge tool configured as above will be described. FIG. 3 is an external view of the metal wire 2 that is appropriately pressed according to the first embodiment, and FIG. 4 is a cross-sectional view of the metal wire 2 that is appropriately pressed according to the first embodiment, taken along the line BB in FIG. 3. When the tip 1 of the wedge tool is pressed appropriately against the metal wire 2 in the configuration shown in the first embodiment, the columnar convex portion 8 comes into slight contact with the surface of the metal wire 2, and a contact mark is formed by deforming the arc-shaped surface of the metal wire 2 into a substantially flat surface, as shown in FIG. 4. On the other hand, FIG. 5 is an external view of the metal wire 2 that is excessively pressed according to the first embodiment, and FIG. 6 is a cross-sectional view of the metal wire 2 that is excessively pressed according to the first embodiment, taken along the line CC in FIG. 5. When the tip 1 of the wedge tool shown in the first embodiment presses the metal wire 2 excessively, the columnar protrusion 8 bites into the metal wire 2, and a contact mark 9 having a clear depth is formed on the metal wire 2 as shown in Fig. 6. In addition, since the side surface of the columnar protrusion 8 is formed away from the side wall 4 of the wire holding groove 3, the region where the metal wire 2 is deformed due to contact with the side wall 4 does not overlap with the contact mark 9 formed due to contact with the columnar protrusion 8. In other words, the contact mark 9 is formed reflecting only the shape of the columnar protrusion 8.

[0018] Here, the difference between the wedge tool of the prior art and the wedge tool of the present disclosure will be described. FIG. 7 is a front view of the tip of the wedge tool of the prior art, and FIG. 8 is a side view of the tip of the wedge tool of the prior art. The tip 1 of the wedge tool has a wire holding groove 3 for holding the metal wire 2, and the wire holding groove 3 extends along the length direction of the metal wire 2 and has a side wall 4 and a groove bottom 5, and the groove bottom 5 does not have a columnar protrusion 8 like the wedge tool shown in the first embodiment. When the metal wire 2 is joined to the bonded body 6, as shown in FIG. 7, the side wall 4 contacts the metal wire 2 so as to sandwich it, thereby holding the metal wire 2, and the tip 1 of the wedge tool is pressed toward the bonded body 6. Furthermore, as shown in FIG. 8, ultrasonic vibration is applied to the metal wire 2 via the tip 1 of the wedge tool, thereby bonding the metal wire 2 to the bonded body 6. The vibration direction 7 of the applied ultrasonic vibration is in the length direction of the metal wire 2 as shown in FIG. 8.

[0019] Next, the appearance of the metal wire 2 wedge-bonded by the wedge tool of the prior art will be described. Fig. 9 is a schematic view of the appearance of the metal wire 2 normally pressed in the prior art, and Fig. 10 is a schematic view of the appearance of the metal wire 2 excessively pressed in the prior art. When the metal wire 2 is excessively pressed by the tip 1 of the wedge tool, the metal wire 2 is largely deformed in the diameter direction of the metal wire 2, which is perpendicular to the pressing direction, compared to when the metal wire 2 is normally pressed. Therefore, the excessively pressed metal wire 2 shown in Fig. 10 has a wider appearance than the normally pressed metal wire 2 shown in Fig. 9.

[0020] 11 is a schematic cross-sectional view of the DD section in FIG. 9 of the metal wire 2 normally pressed in the conventional technology, and FIG. 12 is a schematic cross-sectional view of the EE section in FIG. 10 of the metal wire 2 excessively pressed in the conventional technology. As described above, FIG. 11 and FIG. 12 show that when the metal wire 2 is excessively pressed compared to when it is normally pressed, the metal wire 2 is greatly deformed in the diameter direction of the metal wire 2, which is a direction perpendicular to the pressing direction, and therefore the cross-sectional shape and thickness of the end of the pressed and deformed metal wire 2 are different. If the cross-sectional shape and thickness of the end of the metal wire 2 are different, this causes the appearance of the metal wire 2 to vary, and therefore using the appearance of the metal wire 2 as an indicator of appearance inspection means that the inspection accuracy may be reduced.

[0021] Therefore, when the wedge tool of the prior art is used, the indicator for the visual inspection is only the external shape of the deformed metal wire 2, so that there is variation. However, when the wedge tool of the first embodiment is used, at least two columnar convex parts 8 whose sides are separated from the sidewall 4 are provided at the groove bottom 5 of the wire holding groove 3, so that when the tip 1 of the wedge tool presses the metal wire 2 excessively, a deep and independent contact mark 9 is formed. As a result, when the wedge tool of the first embodiment is used, it is possible to judge whether the pressing force applied to the bonded body 6 was excessive by using as an indicator whether the contact mark 9 is formed on the metal wire 2. Also, it is possible to perform visual inspection using as an indicator the presence or absence of the contact mark 9 or the depth of the contact mark 9. In particular, when image recognition is used, the wedge tool of the first embodiment improves the recognition accuracy, so that it is possible to obtain an effect of suppressing the decrease in inspection accuracy compared to conventional visual inspection.

[0022] Next, a method for manufacturing a semiconductor device using the wedge tool according to the embodiment 1 will be described. The method for manufacturing a semiconductor device using the wedge tool according to the embodiment 1 includes the steps of pressing the metal wire 2 against the bonded objects 6 with the tip 1 of the wedge tool using the wedge tool described above as the embodiment 1, applying ultrasonic vibrations while pressing the metal wire 2, and determining that the pressing force applied to the bonded objects 6 exceeded a predetermined force if a contact mark 9 was formed on the metal wire 2 by the columnar protrusion 8 in the step of pressing the metal wire 2, and determining that the pressing force applied to the bonded objects 6 was equal to or less than the predetermined force if the contact mark 9 was not formed on the metal wire 2.

[0023] By applying the manufacturing method for a semiconductor device configured in this manner, it is possible to use the presence or absence of contact mark 9 on metal wire 2 as an indicator to determine whether the pressing force applied to bonded object 6 was excessive, thereby providing a manufacturing method for a semiconductor device that suppresses deterioration in inspection accuracy compared to conventional visual inspection.

[0024] Another method is shown as a method for manufacturing a semiconductor device using the wedge tool according to the first embodiment. The method for manufacturing a semiconductor device using the wedge tool according to the first embodiment includes the steps of pressing the metal wire 2 against the bonded object 6 with the tip 1 of the wedge tool using the wedge tool described above as the first embodiment, applying ultrasonic vibrations while pressing the metal wire 2, and judging whether the pressing force applied to the bonded object 6 is appropriate or not according to the depth of the contact mark 9 formed on the metal wire 2 by the columnar protrusion 8 in the step of pressing the metal wire 2. For example, the range of the depth of the contact mark 9 formed when an appropriate pressing force is applied is preset, and if the depth of the contact mark 9 formed on the metal wire 2 is shallower than the predetermined depth range, it is judged that the pressing force is small. Also, if the depth of the contact mark 9 formed on the metal wire 2 is within the predetermined depth range, it is judged that the pressing force is appropriate. Furthermore, if the depth of the contact mark 9 formed on the metal wire 2 is deeper than the predetermined depth range, it is judged that the pressing force is large.

[0025] As described above, by applying a manufacturing method for a semiconductor device in which the appropriateness of the pressing force applied to the bonded object 6 is determined depending on the depth of the contact mark 9 formed on the metal wire 2, the depth of the contact mark 9 formed on the metal wire 2 can be used as an indicator to determine whether the pressing force applied to the bonded object 6 is appropriate or not, thereby providing a manufacturing method for a semiconductor device in which the decrease in inspection accuracy is suppressed compared to conventional visual inspection.

[0026] Embodiment 2 FIG. 13 is a front view of the tip 1 of the wedge tool according to the second embodiment, and FIG. 14 is a cross-sectional view of the tip 1 of the wedge tool according to the second embodiment taken along the line F-F in FIG. 13. As shown in FIG. 13, the tip 1 of the wedge tool has a wire holding groove 3 for holding the metal wire 2, and the wire holding groove 3 extends along the length of the metal wire 2 and has a side wall 4 and a groove bottom 5. A columnar protrusion 8 is provided on the groove bottom 5, and the side surface of the columnar protrusion 8 is formed spaced apart from the side wall 4. In the wedge tool shown in the second embodiment, as shown in FIG. 14, three columnar protrusions 8 are arranged side by side and spaced apart from each other along the wire holding groove 3 extending in the length direction of the metal wire 2, and are configured in a combination of different heights. In order to prevent the columnar protrusions 8 from applying excessive force to the metal wire 2 and the bonded object, the height of the columnar protrusions 8 is preferably in the range of 10±5% of the diameter of the metal wire 2 used. For example, when the diameter of the metal wire 2 is 200 μm, the height of the columnar protrusions 8 is preferably in the range of 20±10 μm. In the second embodiment, as an example, two columnar protrusions 8 with a height of 10 μm and one columnar protrusion 8 with a height of 30 μm are combined. However, the diameter of the metal wire 2 used in wedge bonding is generally about 50 μm to 600 μm, and is a design item that should be selected according to the product specifications and manufacturing conditions, so the columnar protrusions 8 are not limited to the above height. In addition, the number of columnar protrusions 8 provided at the groove bottom 5 is set to three in order to reliably prevent recognition errors from the viewpoint of use in visual inspection, and it is preferable to provide at least two columnar protrusions 8.

[0027] A case where the tip 1 of the wedge tool is appropriately pressed against the metal wire 2 and a case where the tip 1 of the wedge tool is excessively pressed against the metal wire 2 by performing wedge bonding using the wedge tool configured in this manner will be described below. Fig. 15 is a schematic view of the appearance of the appropriately pressed metal wire 2 according to the second embodiment, and Fig. 16 is a schematic view of the appearance of the excessively pressed metal wire 2 according to the second embodiment. When the tip 1 of the wedge tool shown in the second embodiment presses the metal wire 2 appropriately, the higher columnar protrusion 8 bites into the metal wire 2, and the lower columnar protrusion 8 does not bite into the metal wire 2, so that only one deep contact mark 9 is formed on the metal wire 2 as shown in FIG. 15. On the other hand, when the tip 1 of the wedge tool presses the metal wire 2 excessively, in addition to one of the higher columnar protrusions 8, two of the lower columnar protrusions 8 bite into the metal wire 2, so that three deep contact marks 9 are formed on the metal wire 2 as shown in FIG. 16. In addition, since the columnar protrusions 8 are formed away from the side wall 4, the region where the metal wire 2 is deformed due to contact with the side wall 4 does not overlap with the contact mark 9 formed due to contact with the columnar protrusions 8. In other words, the contact mark 9 is formed reflecting only the shape of the columnar protrusions 8.

[0028] Therefore, when the wedge tool shown in the second embodiment is used, at least two columnar protrusions 8 of different heights are provided at a distance from the side wall 4 on the groove bottom 5 of the wire holding groove 3, so that when the tip 1 of the wedge tool presses the metal wire 2 excessively compared to when it is pressed within a predetermined range, the contact marks 9 are deep and a large number of independent contact marks 9 are formed. As a result, it is possible to perform an appearance inspection using the number of contact marks 9 as an index, and since the recognition accuracy is improved particularly when image recognition is used, it is possible to obtain an effect of suppressing a decrease in inspection accuracy compared to conventional appearance inspections.

[0029] In the second embodiment, the wire holding groove 3 has the columnar protrusions 8 of two different heights, but may have three or more different heights. When the wire holding groove 3 has the columnar protrusions 8 of three or more different heights, the force applied to the workpiece 6 can be estimated more accurately in a visual inspection than when the wire holding groove 3 has the columnar protrusions 8 of two different heights.

[0030] Next, a method for manufacturing a semiconductor device using a wedge tool according to the second embodiment will be described. The method for manufacturing a semiconductor device using a wedge tool according to the second embodiment includes the steps of pressing the metal wire 2 against the bonded object 6 with the tip 1 of the wedge tool using the wedge tool described above as the second embodiment, applying ultrasonic vibrations while pressing the metal wire 2, and judging whether the pressing force applied to the bonded object 6 is appropriate or not, depending on the number of contact marks 9 formed on the metal wire 2 by the columnar protrusion 8 in the step of pressing the metal wire 2. For example, a range of the number of contact marks 9 formed when an appropriate pressing force is applied is preset, and if the number of contact marks 9 formed on the metal wire 2 is less than the predetermined number range, it is judged that the pressing force is small. Also, if the number of contact marks 9 formed on the metal wire 2 is within the predetermined number range, it is judged that the pressing force is appropriate. Furthermore, if the number of contact marks 9 formed on the metal wire 2 is more than the predetermined number range, it is judged that the pressing force is large.

[0031] As described above, by applying a manufacturing method for a semiconductor device in which the appropriateness of the pressing force applied to the bonded object 6 is determined depending on the number of contact marks 9 formed on the metal wire 2, the number of contact marks 9 formed on the metal wire 2 can be used as an indicator to determine whether the pressing force applied to the bonded object 6 is appropriate or not, thereby providing a manufacturing method for a semiconductor device in which the decrease in inspection accuracy is suppressed compared to conventional visual inspection.

[0032] Embodiment 3 Fig. 17 is a front view of the tip portion 1 of the wedge tool according to the third embodiment, and Fig. 18 is a cross-sectional view taken along line G-G of the tip portion 1 of the wedge tool according to the third embodiment. The third embodiment has a configuration in which the columnar protrusion 8 provided at the groove bottom 5 in the second embodiment is replaced with a conical protrusion 10, and the other configuration is the same as that of the second embodiment. Note that, although the shape of the protrusion is conical in the third embodiment, it may be polygonal pyramid-shaped.

[0033] By performing wedge bonding using the wedge tool configured in this manner, the same effect as in the second embodiment can be obtained. In addition, by using the conical protrusion 10 instead of the columnar protrusion 8, the conical protrusion 10 can easily bite into the metal wire 2 compared to the columnar protrusion 8, and the contact mark 9 can be formed more clearly. In order to form the contact mark 9 more clearly, it is sufficient that the shape of the conical protrusion 10 is such that it can easily bite into the metal wire 2 compared to the columnar protrusion 8, so the shape of the conical protrusion 10 may be a polygonal pyramid. FIG. 19 is a schematic view of the appearance of the metal wire 2 that is appropriately pressed according to the third embodiment, and FIG. 20 is a schematic view of the appearance of the metal wire 2 that is excessively pressed according to the third embodiment.

[0034] Therefore, in addition to the same effects as those of the second embodiment, when the wedge tool shown in the third embodiment is used, the conical protrusion 10 can form a clearer contact mark 9 on the metal wire 2. As a result, when the wedge tool shown in the third embodiment is used, the visibility of the contact mark 9 is further improved, and in particular, when image recognition is used, the recognition accuracy is also improved, so that an effect of further suppressing the decrease in inspection accuracy is obtained compared to the appearance inspection of the second embodiment.

[0035] Next, a method for manufacturing a semiconductor device using a wedge tool according to embodiment 3 will be described. The method for manufacturing a semiconductor device using a wedge tool according to embodiment 3 includes the steps of pressing the metal wire 2 against the workpiece 6 with the tip 1 of the wedge tool using the wedge tool described above as embodiment 3, applying ultrasonic vibrations while pressing the metal wire 2, and judging whether the pressing force applied to the workpiece 6 is appropriate or not depending on the number of contact marks 9 formed on the metal wire 2 by the conical protrusion 10 in the step of pressing the metal wire 2.

[0036] By applying the manufacturing method for a semiconductor device configured as described above, in addition to the same effects as those of the second embodiment, in the third embodiment, the conical protrusion 10 can form a clearer contact mark 9 on the metal wire 2. As a result, the visibility of the contact mark 9 is further improved, and in particular, when image recognition is used, the recognition accuracy is also improved, so that a manufacturing method for a semiconductor device can be provided in which the decrease in the inspection accuracy of the visual inspection is further suppressed compared to the manufacturing method for a semiconductor device shown in the second embodiment.

[0037] Embodiment 4 FIG. 21 is a front view of the tip 1 of the wedge tool according to the fourth embodiment, and FIG. 22 is a cross-sectional view of the tip 1 of the wedge tool according to the fourth embodiment, taken along the HH cross section in FIG. 21. In the fourth embodiment, the columnar convex portion 8 provided at the groove bottom 5 in the second embodiment is replaced with a convex portion 11, and the convex portion 11 has a first convex portion, a second convex portion, a third convex portion, and a fourth convex portion integrally formed in the longitudinal direction of the metal wire, and the heights of the first convex portion, the second convex portion, the third convex portion, and the fourth convex portion from the groove bottom 5 are different from each other. The other configurations are the same as those of the second embodiment. In the fourth embodiment, the heights of the first convex portion, the second convex portion, the third convex portion, and the fourth convex portion are configured so that they decrease in the order of the first convex portion, the second convex portion, the third convex portion, and the fourth convex portion. In addition, since the convex portion 11 is integrally formed with a plurality of convex portions, it is sufficient that at least one or more convex portions are provided.

[0038] A case where the tip 1 of the wedge tool is appropriately pressed against the metal wire 2 and a case where the tip 1 of the wedge tool is excessively pressed against the metal wire 2 by performing wedge bonding using the wedge tool configured in this manner will be described below. Fig. 23 is a schematic view of the appearance of the appropriately pressed metal wire 2 according to the fourth embodiment, and Fig. 24 is a schematic view of the appearance of the excessively pressed metal wire 2 according to the fourth embodiment. In the configuration shown in the fourth embodiment, when the tip 1 of the wedge tool presses the metal wire 2 appropriately, the first convex portion that is higher from the groove bottom 5 bites into the metal wire 2, and the second, third, and fourth convex portions that are lower from the groove bottom 5 than the first convex portion do not bite into the metal wire 2, so that a contact mark 9 is formed on the metal wire 2 whose length in the longitudinal direction of the metal wire 2 corresponds to the first convex portion, as shown in Fig. 23. On the other hand, when the tip 1 of the wedge tool presses the metal wire 2 excessively, the first, second, third, and fourth convex portions bite into the metal wire 2, so that a contact mark 9 is formed on the metal wire 2 whose length in the longitudinal direction of the metal wire 2 includes the first, second, third, and fourth convex portions, as shown in Fig. 24. In addition, since the side surface of the protrusion 11 is formed away from the side wall 4, the region where the metal wire 2 is deformed due to contact with the side wall 4 does not overlap with the contact mark 9 formed due to contact with the protrusion 11. In other words, the contact mark 9 is formed reflecting only the shape of the protrusion 11.

[0039] Therefore, when the wedge tool shown in the fourth embodiment is used, the groove bottom 5 of the wire holding groove 3 has at least two convex parts whose side faces are separated from the sidewall 4 and integrally formed in the longitudinal direction of the metal wire, and the convex parts are provided with convex parts 11 whose heights from the groove bottom 5 are different from each other, so that when the tip 1 of the wedge tool presses the metal wire 2 excessively as compared with the case where the tip 1 presses the metal wire 2 within a predetermined range, the contact mark 9 is formed long in the longitudinal direction of the metal wire 2. As a result, it is possible to perform an appearance inspection using the length of the contact mark 9 in the longitudinal direction of the metal wire 2 as an index, and since the recognition accuracy is improved particularly when image recognition is used, it is possible to obtain an effect of suppressing a decrease in the inspection accuracy compared to the conventional appearance inspection.

[0040] In the fourth embodiment, the protrusion 11 has the first, second, third and fourth convex portions, but may have at least two convex portions. The more convex portions constituting the protrusion 11, the more accurately the force applied to the bonded body 6 can be estimated in the visual inspection.

[0041] Next, a method for manufacturing a semiconductor device using a wedge tool according to the fourth embodiment will be described. The method for manufacturing a semiconductor device using a wedge tool according to the fourth embodiment includes the steps of pressing the metal wire 2 against the bonded object 6 using the wedge tool described above as the fourth embodiment, applying ultrasonic vibrations while pressing the metal wire 2, and judging whether the pressing force applied to the bonded object 6 is appropriate or not, depending on the length of the contact mark 9 formed on the metal wire 2 by the convex portion 11 in the step of pressing the metal wire 2. For example, when an appropriate pressing force is applied, the range of the length of the contact mark 9 in the length direction of the metal wire 2 is set in advance, and when the length of the contact mark 9 formed on the metal wire 2 in the length direction of the metal wire 2 is shorter than the predetermined length range, it is judged that the pressing force is small. Furthermore, when the length of the contact mark 9 formed on the metal wire 2 in the length direction of the metal wire 2 is within the predetermined length range, it is judged that the pressing force is appropriate. Furthermore, when the length of the contact mark 9 formed on the metal wire 2 in the length direction of the metal wire 2 is longer than the predetermined length range, it is judged that the pressing force is large.

[0042] As described above, by applying a manufacturing method for a semiconductor device in which the appropriateness of the pressing force applied to the bonded object 6 is determined depending on the length of the contact mark 9 formed on the metal wire 2 in the longitudinal direction of the metal wire 2, the appropriateness of the pressing force applied to the bonded object 6 can be determined using the length of the contact mark 9 formed on the metal wire 2 in the longitudinal direction of the metal wire 2 as an indicator, so that a manufacturing method for a semiconductor device can be provided in which the decrease in inspection accuracy is suppressed compared to conventional visual inspection.

[0043] Furthermore, the embodiments disclosed in this specification can be freely combined within the scope of the specification, and each embodiment can be modified or omitted as appropriate. [Explanation of symbols]

[0044] 1 Tip of wedge tool 2 Metal Wire 3 Wire retention groove 4 side wall 5 Groove bottom 6 Object to be joined 7. Direction of ultrasonic vibration 8 Columnar protrusion 9 Contact marks 10 Cone-shaped protrusion 11 Convex

Claims

1. A method for manufacturing a semiconductor device in which a metal wire is bonded to a bonded object, comprising: A wedge tool used in wedge bonding in which a metal wire is pressed and ultrasonic vibration is applied to bond the metal wire to a workpiece, the wedge tool comprising: a wire holding groove that extends along the length of the metal wire at the tip of the wedge tool and holds the metal wire; pressing the metal wire against the workpiece using a wedge tool having at least two protrusions formed on a groove bottom of the wire holding groove, the protrusions having side surfaces spaced apart from the side walls of the wire holding groove and aligned in the longitudinal direction of the metal wire; applying ultrasonic vibration to the metal wire while pressing the metal wire; determining whether or not a pressing force applied to the workpiece exceeds a predetermined force based on whether or not a contact mark is formed on the metal wire by the protrusion in the step of pressing the metal wire; A method for manufacturing a semiconductor device comprising the steps of:

2. A method for manufacturing a semiconductor device in which a metal wire is bonded to a workpiece, comprising: A wedge tool used in wedge bonding in which a metal wire is pressed and ultrasonic vibration is applied to bond the metal wire to a workpiece, the wedge tool comprising: a wire holding groove that extends along the length of the metal wire at the tip of the wedge tool and holds the metal wire; a protrusion formed at a groove bottom of the wire holding groove and having a different height from the groove bottom; pressing the metal wire against the workpiece using a wedge tool; applying ultrasonic vibration to the metal wire while pressing the metal wire; determining whether or not a pressing force applied to the workpiece exceeds a predetermined force based on whether or not a contact mark is formed on the metal wire by the protrusion in the step of pressing the metal wire; A method for manufacturing a semiconductor device comprising the steps of:

3. A method for manufacturing a semiconductor device in which a metal wire and a workpiece are joined, comprising: A wedge tool used in wedge bonding in which a metal wire is pressed and ultrasonic vibration is applied to bond the metal wire to a workpiece, the wedge tool comprising: a wire holding groove that extends along the length of the metal wire at the tip of the wedge tool and holds the metal wire; pressing the metal wire against the workpiece using a wedge tool having at least two protrusions formed on a groove bottom of the wire holding groove, the protrusions having side surfaces spaced apart from the side walls of the wire holding groove and aligned in the longitudinal direction of the metal wire; applying ultrasonic vibration to the metal wire while pressing the metal wire; a step of determining whether or not the pressing force applied to the workpiece is appropriate depending on the depth of a contact mark formed on the metal wire by the protrusion in the step of pressing the metal wire; A method for manufacturing a semiconductor device comprising the steps of:

4. A method for manufacturing a semiconductor device in which a metal wire and a workpiece are joined, comprising: A wedge tool used in wedge bonding in which a metal wire is pressed and ultrasonic vibration is applied to bond the metal wire to a workpiece, the wedge tool comprising: a wire holding groove that extends along the length of the metal wire at the tip of the wedge tool and holds the metal wire; a protrusion formed at a groove bottom of the wire holding groove and having a different height from the groove bottom; pressing the metal wire against the workpiece using a wedge tool; applying ultrasonic vibration to the metal wire while pressing the metal wire; a step of determining whether or not the pressing force applied to the workpiece is appropriate depending on the depth of a contact mark formed on the metal wire by the protrusion in the step of pressing the metal wire; A method for manufacturing a semiconductor device comprising the steps of:

5. A method for manufacturing a semiconductor device in which a metal wire and a workpiece are joined, comprising: A wedge tool used in wedge bonding in which a metal wire is pressed and ultrasonic vibration is applied to bond the metal wire to a workpiece, the wedge tool comprising: a wire holding groove that extends along the length of the metal wire at the tip of the wedge tool and holds the metal wire; pressing the metal wire against the workpiece using a wedge tool having at least two protrusions formed on a groove bottom of the wire holding groove, the protrusions having side surfaces spaced apart from the side walls of the wire holding groove and aligned in the longitudinal direction of the metal wire; applying ultrasonic vibration to the metal wire while pressing the metal wire; a step of determining whether or not the pressing force applied to the workpiece is appropriate depending on the number of contact marks formed on the metal wire by the protrusion in the step of pressing the metal wire; A method for manufacturing a semiconductor device comprising the steps of:

6. A method for manufacturing a semiconductor device in which a metal wire and a workpiece are joined, comprising: A wedge tool used in wedge bonding in which a metal wire is joined to a workpiece by pressing the metal wire and applying ultrasonic vibrations thereto, a wire holding groove that extends along the length of the metal wire at the tip of the wedge tool and holds the metal wire; a protrusion formed at a groove bottom of the wire holding groove and having a different height from the groove bottom; a step of pressing the metal wire against the workpiece using a wedge tool, the wedge having a first convex portion and a second convex portion integrally formed in a longitudinal direction of the metal wire, the first convex portion and the second convex portion being at different heights from the bottom of the groove; applying ultrasonic vibration to the metal wire while pressing the metal wire; a step of determining whether or not the pressing force applied to the workpiece is appropriate depending on a length of a contact mark formed on the metal wire by the protrusion in the step of pressing the metal wire in the longitudinal direction of the metal wire; A method for manufacturing a semiconductor device comprising the steps of:

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