JP6790269B2 - Winding spool, winding structure and spool case of bonding wire - Google Patents

Description

The present invention relates to a winding spool of a bonding wire and a method for manufacturing the same, a winding structure of the bonding wire, a winding method and a joining method for these, and a spool case for a winding spool and a method for manufacturing the same.

Various spools for winding the bonding wire have been developed so far, but the bonding wire wound on the spool may become loose or biased due to vibration or shaking transmitted to the spool during long-distance transportation. .. When the wire is loosened, the wound wire hangs down, the wire enters the hanging space, and it becomes like a string tied, and when the wire is unwound for wire bonding, the wire is often entangled and cannot be unwound well. Was there.

In addition, the impact of installing the spool on which the bonding wire is wound on the wire bonding device is transmitted to the spool, which creates a gap between the wound wire and the wire and between the wire and the flange, and the wire falls into the gap. There was also a problem that the wire bite into the gap when the wire was unwound and could not be unwound smoothly.

In view of the above, the subject of the present invention is that the synthetic resin spool is loosened or wound around due to vibration or rolling during transportation, and between wires due to vibration or impact generated during attachment to a bonding apparatus. Winding spool of bonding wire and its manufacturing method, winding structure of bonding wire to improve unwinding when unwinding the wire from the bonding device with respect to wire falling into the gap between the wire and the flange and biting. And a winding method and a joining method for these, a spool case for a winding spool, and a method for manufacturing the same.

In order to solve this problem, the present inventor started by analyzing the cause of why the unwinding property deteriorates. The winding spool of the bonding wire is roughly classified into a metal spool that has been anodized and the like and a synthetic resin spool such as polycarbonate. The bonding wire for a semiconductor device is made of gold and has an ultrafine wire having a diameter of 30 μm or less, and is wound on a metal spool at 3000 to 5000 m. On the other hand, as the bonding wire for a power device, a thick wire such as an aluminum wire having a diameter of 75 μm to 800 μm is used. In order to wind a thick wire, a spool larger than the ultrafine wire is required, and a resin winding spool is used due to the manufacturing cost of the spool and the like.

Since the aluminum bonding wire for the power device uses a thick wire as compared with the gold ultrafine bonding wire, it was found that the filling rate of the wound wire is lower than that of the ultrafine wire when wound on the spool. That is, the wires are wound in a large and faint state. It was also discovered that aluminum has a specific gravity seven times smaller than that of gold, so it is vulnerable to left-right shaking and vibration, and is prone to loosening. Loose winding may cause wire breakage if the wire is entangled or passes through the wire. Therefore, the wire cannot be smoothly unwound by the bonding device, and the device may stop, which significantly reduces the productivity of the wire bonding process. become.

Further, a wire having a large wire diameter can be wound on a spool in a smaller amount than an ultrafine wire. If the amount of winding is small, the frequency of replacement work of spool attachment in the bonding device increases, which significantly impairs productivity. Therefore, in order to wind more wire, the resin spool is fully wound from the flange to the flange. The wire can be wound up to the vicinity of the flange, but since the wire has a round shape, it was found that even if the wire is fully wound, a gap is inevitably created between the place where the wire is wound and the flange. .. To explain in a little more detail, even if the first layer of wire that has begun to be wound around the spool body is wound tightly from flange to flange, the layer above the first layer that is wound next is directly above the first layer of wire. It was clarified that the wire in the layer above the first layer inevitably has a gap between the flange and the wire because it is wound between the wires in the first layer or in a place slightly deviated.

On the other hand, the resin spool has a drawback that the strength is weaker than that of the metal spool. When setting the spool on the bonding device, it must be firmly fixed with force so that there is no idling or play, so the flange should be pushed in firmly before installation. We carefully observed and examined what kind of process and phenomenon occurred in the flange and the wound wire at this time. When the spool is attached to the bonding device, the flange and the wire wound near the flange are once pushed inside the body. It was then found that the flange returned to its original position, but the wire was left behind inside, widening the gap between the wire and the flange. Then, it was clarified that since the wire falls into this gap, the wire bites into the gap, and a problem occurs in which the wire cannot be unwound when the wire is unwound.

We also examined transportation problems regarding wire unwinding. Naturally, there is a problem of vibration in transportation. The vibration causes the wires to unwind or creates gaps between the wires. Furthermore, it was found that the reason why the wire falls due to the gap between the wire and the flange is not only the vibration and impact during transportation but also the shrinkage of the resin due to the temperature difference. Especially in the case of air transportation, the temperature difference between the ground and the sky is large, so when the flange shrinks and a gap is created in the cold sky, the wire falls there and the temperature is higher than the sky on the ground, so the flange becomes It was clarified that when the wire expands and returns to its original position, the wire bites into the wire and cannot be fed out.

As described above, the dimensions of the resin spool also change slightly due to repeated repetition of attachment to the bonding device, vibration during transportation, shrinkage of the spool resin due to temperature changes during air transportation, and the like. Since the resin spool is washed and reused after unwinding the wire, the reused spool has more unwinding problems than the new spool. That is, the more frequently the spool is reused, the larger the dimensional error becomes. Therefore, if the flange is widened when winding the wire, a gap is created between the wire and the flange, and the wire falls into the gap and is unwound. It turns out that more defects occur. As an example, a specific solution will be described in detail below with a drawing number.

The take-up spool of the present invention is a take-up spool for a bonding wire made of synthetic resin composed of a perforated guide portion 14, a body portion 12 and a flange portion 13, and an elevation angle 19 of the inner surface of the flange portion is 76 degrees or more and 86 degrees or less. The inclined portion is characterized in that the vertical height (h) is 50% or more of the total vertical height (H) of the inner surface of the flange portion.

Further, the winding structure of the bonding wire of the present invention is the inner surface of the flange portion in the winding structure of the bonding wire wound on the synthetic resin take-up spool including the perforated guide portion 14, the body portion 12 and the flange portion 13. The elevation angle 19 has an inclined portion of 76 degrees or more and 86 degrees or less, and the vertical height (h) of the inclined portion is 50% or more of the total vertical height (H) of the inner surface of the flange portion. It is characterized in that the height of the end portion is higher than the height of the central portion of the body portion around which the bonding wire 42 is wound.

Further, the spool case for a take-up spool of the present invention is a spool case for a take-up spool composed of a lid 21 and a main body 31 made of synthetic resin, and the main body has a substantially square weight base with the lid side open. It is characterized in that each of the paired side surfaces of the main body has a single or a plurality of expansion portions 34.

Here, the "synthetic resin" in the take-up spool and the winding structure described above generally means a plastic resin injection-molded with the synthetic resin. The synthetic resin can be molded by injection molding, embossing, embossing, vacuum forming, or the like. Examples of the synthetic resin described above include ABS resin, polycarbonate resin, impact-resistant polystyrene, and the like.

Further, here, the "inclined portion" in the flange portion 13 of the take-up spool has a vertical height (h) of 50% or more of the total vertical height (H) of the inner surface of the flange portion. Moreover, it refers to an inclined portion whose elevation angle 19 is 76 degrees or more and 86 degrees or less.

Further, here, the "elevation angle" means the angle between the inner surface of the body portion 12 and the flange portion 13. FIG. 4 shows an elevation angle 19 of a typical flange portion 13. Further, here, the "elevation angle" also includes the angle of the point where the extension line of the inclined portion and the body portion intersect.

Further, it is the flange portion 13 that "the vertical height (h) of the inclined portion is 50% or more of the total vertical height (H) of the inner surface of the flange portion" in the flange portion 13 of the take-up spool. If the vertical height (h) of the inner surface of the flange portion 13 is less than 50% of the total vertical height (H) of the inner surface of the flange portion 13, the force in the vertical direction of the wound bonding wire becomes large and the gap is formed. This is because it becomes easy to drop and the winding amount of the bonding wire is reduced. The height of the inclined portion of the take-up spool can be measured using a caliper, a ruler, a laser microscope, or the like.

Further, in the above-mentioned take-up spool, "the elevation angle 19 of the inner surface of the flange portion is 76 degrees or more and 86 degrees or less" is defined as the vertical direction as described above when the elevation angle 19 of the flange portion 13 exceeds 86 degrees. This is because a large force acts on the wire, so that the wire easily falls into the gap between the wound wires or the gap between the wire and the flange portion 13. Further, when the elevation angle 19 of the flange portion 13 is less than 76 degrees, since the angle is gentle, the wire on the surface layer to be wound is shaken to the left and right by the impact in the horizontal direction, and the winding is disturbed. Further, since there is a standard for the dimensions of the spool to which the bonding device is attached, the length of the body portion and the flange diameter is also limited. Therefore, if the elevation angle of the flange portion is small, the winding amount of the bonding wire is reduced. When the winding amount is small, the spool replacement work in the bonding process becomes frequent, and the productivity is significantly reduced. Further, it is more preferable that the elevation angle 19 of the inclined portion of the flange portion 13 is 79 degrees or more and 83 degrees or less.

The inclination of the flange portion 13 of the take-up spool 10 is as shown in FIG. 1 (a), (b), (c), (d), and (e) when there are two inclinations. The problem of the present invention can be solved even when there are three inclinations as in f) and (g). Further, as shown in FIG. 1 (h), the protrusions on the upper part of the flange are not included in the vertical height (H), and the problem of the present invention is overcome even when the elevation angles of the left and right flanges are different as shown in FIG. 1 (i). it can. FIGS. 1 (a) and 1 (f) show the overall vertical height (H) of the inner surface of the flange portion, the vertical height (h) of the inclined portion of the inner surface of the flange portion, and the elevation angles “θ” and “θ ′”.

Here, the "height of the end portion" in the winding structure of the bonding wire of the take-up spool 10 is the point where the inner surface of the flange portion and the body portion intersect in the winding structure, that is, the starting point at which the flange portion rises. It is defined as the height of the bonding wire wound in the space between the flange and the wire that is assumed to be drawn perpendicular to the body from this point. Further, "the height of the central portion of the body portion around which the bonding wire 42 is wound" is defined as the height of the outermost layer portion of the bonding wire wound around the body portion other than the end portion.

Further, in the above-mentioned winding structure of the bonding wire, "the height of the end portion is higher than the height of the central portion of the body around which the bonding wire 42 is wound" is defined as the wound bonding. This is because the gap between the wires 42 and the gap between the bonding wire 42 and the flange portion 13 can be filled, and it is possible to prevent a problem of being caught when the wires are operated due to the bonding wire 42 falling into the gap.

In most cases, it can be visually confirmed that "the height of the end portion is higher than the height of the central portion of the body around which the bonding wire 42 is wound", but screen projection, a laser microscope, and the like. It can also be confirmed with a length measuring microscope and a roughness meter. The winding structure of the present invention is preferably wound as long as the height of the end portion is higher than the height of the central portion of the body portion around which the bonding wire 42 is wound, which is equal to or larger than the radius of the wound bonding wire. It is more preferable that the height is one bonding wire, that is, the diameter or more.

Here, the "substantially quadrangular pyramid" in the spool case for the take-up spool means a pyramid stand having a quadrangular opening, but the take-up spool opening has a polygonal shape, or It may be even if the corners are rounded.

Further, here, the "expansion portion" is a structure provided inside the main body 31 which is a substantially square weight base, and is raised inward and makes point contact or line contact with the flange portion of the stored take-up spool. Say what to do. As shown in FIG. 2, a plurality of wavy grooves are typical examples, but other shapes may be used as long as they are in point contact or line contact. From the viewpoint of point contact or line contact, the expansion portion is preferably a ridge or a protrusion.

In the take-up spool spool case of the present invention shown above, the main body 31 has a substantially square weight base with the take-up spool insertion side open, as shown in FIG. The opening on the lid side of the main body 31 may be polygonal or curved. The thickness of the spool case body 31 made of synthetic resin is preferably 0.1 mm or more and 0.9 mm or less, and particularly preferably 0.2 mm or more and 0.5 mm or less.

Next, the mode of the spool case main body 31 is shown in FIGS. 2 (a) to 2 (e). 2 (a) and 2 (b) are openings of the spool case main body 31, FIG. 2 (a) shows a case where the corners are rounded, and FIG. 2 (b) shows a case where the spool case is polygonal. 2 (c) to 2 (e) are vertical cross-sectional views of the spool case main body 31, FIG. 2 (c) shows the tip portion when the angle of the tip portion is round, and FIGS. 2 (d) and 2 (e) show the tip portion. The case where the inclination angle is 2 or more is shown. These shapes can also solve the problems of the present invention.

Further, the reason why the spool case for the take-up spool described above "has a single or a plurality of expansion portions 34" is that the spool and the spool case are in point contact or line contact, so that a space is created between the spool and the spool case. This is because the direct impact on the spool can be alleviated by providing it and dispersing the impact from the outside.

The embodiment of the winding spool for the bonding wire of the present invention is as follows. It is preferable that two or more and six or less reinforcing ribs 16 are connected to the outer peripheral surface of the perforated guide portion on one side or both sides and the inner peripheral surface of the body portion. The strength of the take-up spool is increased as compared with the case where the reinforcing rib 16 is not provided, and the flange portion 13 is deformed due to pressure or impact when it is attached to the bonding device, and the winding collapse due to the deformation, and bonding with the flange portion 13 caused by the deformation. It is possible to prevent the bonding wire 42 from biting into the gap between the wire 42 and getting caught in the gap, and the reinforcing ribs are reinforced to withstand horizontal impact and vibration, and withstand long-term transportation. You will be able to do it. Further, even if it is set in the repetitive bonding device, the impact is dispersed if there is a reinforcing rib, so that deformation and deterioration of the flange can be suppressed. Since the spool is reused repeatedly, it is very beneficial that the spool does not deform and deteriorate.

Hereinafter, aspects of the reinforcing ribs of the present invention will be illustrated. FIG. 5A shows a reinforcing rib that fills a part of the flange. FIG. 5B shows a flange on one side completely filled with no cavities and four reinforcing ribs on the other side. FIG. 5C shows 6 reinforcing ribs. 5 (d) shows the case where the reinforcing ribs have a curved shape, FIG. 5 (e) shows the case where the reinforcing ribs have a rectangular rod shape, and FIG. 5 (f) shows the case where two reinforcing ribs form one shape. , FIG. 5 (g) shows a case where three reinforcing ribs form one shape. 5 (a) to 5 (g) are schematic views of the inner surface of the body. Further, FIG. 5B shows only the reinforcing ribs of the flanges on both sides and on the other side.

Further, it is preferable that the winding spool 10 for the bonding wire and the spool case 20 are transparent. This is because the internal structure of the bottom portion or the like around which the bonding wire is wound can be visually observed from the outside of the spool case 20, so that defects on the wire surface such as winding disorder and foreign matter adhesion can be easily found. The degree of transparency may be such that the collapse of the wire can be visually recognized. In addition, since the colorant added to the colored resin has a large shrinkage rate due to heat, the dimensions of the spool itself change slightly when expansion and contraction are repeated, resulting in a gap between the wire and the flange, causing the wire to drop. It is also a cause of biting and biting. For this reason as well, the spool resin is preferably transparent.

Further, it is preferable that the bonding wire 42 is an aluminum metal or an aluminum alloy. Further, the bonding wire may be a bonding wire in which an aluminum metal or an aluminum alloy is used as the core material of the wire and the core material is coated with a metal other than the core material. Other materials of the bonding wire 42 of the present invention include sterling silver or silver alloy, pure copper or palladium-coated copper alloy, but there are problems such as unwinding of the winding spool 10 for the thick wire bonding wire 42 of aluminum alloy having a light specific gravity. Can be solved more effectively. In winding a thick wire bonding wire of aluminum metal or aluminum alloy having a light specific gravity around the winding spool, a higher effect of suppressing unwinding can be obtained when the wire diameter is 75 μm or more and 800 μm or less.

In the take-up spool spool case 20 of the present invention, it is preferable that the lid body is a film that does not allow oxygen and water to permeate and is peelable. Specific examples of the material for the film include polyvinylidene chloride (PVDC), polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE) and the like. This is because the effect of preventing oxidation and corrosion due to the intrusion of oxygen and water during transportation and storage of the bonding wire 42 wound around the take-up spool 10 can be expected. The impermeability of oxygen and water can be measured using a commercially available oxygen permeability measuring device (for example, OX-TRAN 2/22 manufactured by MOCON). Oxygen permeability (JIS standard: conforms to JIS K 7126) is 3000 cm ³/ (M²· 24h · atm) or less, more preferably 1000cm³/ (M²・ 24h ・ atm) or less, more preferably 300cm³/ (M²・ 24h ・ atm) or less, optimally 100cm³/ (M²・ 24h ・ atm) or less. If the oxygen permeability is appropriate, water molecules larger than oxygen molecules do not permeate, so oxygen and water molecules do not permeate.

Further, the lid body 21 is made of synthetic resin and has a fitting ridge 23 having a substantially square pyramid shape inside the outer peripheral edge 22, and the fitting ridge 23 is formed in an arc groove 24 and its side wall in the central portion thereof. It is preferable that the arc groove 24 has the engaging piece 25 and has a shape along the outer peripheral end of the left and right flange portions 13 of the take-up spool 10 for the bonding wire. This is because, like the film, it absorbs a large impact and changes it into a small impact. The lid 21 and the main body 31 may be used upside down as shown in FIG. 2, that is, the lid 21 may be used as the base of the spool case 20 and the main body 31 may be used as the covering body thereof.

By the way, as for the early winding spools for bonding wires made of synthetic resin, those related to winding spools used for winding metal wires such as tungsten and molybdenum are published in Japanese Patent Application Laid-Open No. 58-151154 (Patent Document 1 described later). )It is described in. At the time of 1982, a take-up spool in which flange portions 3, 3'was provided at both ends of a cylindrical body portion 2 as shown in FIG. 1 was common. However, in such a take-up spool, as shown in FIGS. 2A and 2B, the winding thickness is often disturbed near the inner side surface of the flange portions 3 and 3'(the end portion of the body portion 2). It is described in the specification that wire entanglement is likely to occur due to winding deviation near the inner side surface of the flange portion and wire biting into the lower layer portion.

Therefore, in the above-mentioned Utility Model No. 58-151154 (Patent Document 1 described later), as shown in FIG. 3 of the same publication, "the inclination angle of the inner surface of the flange portion with respect to the axial direction is 20 to 45 degrees. (Refer to Claims for Utility Model Registration (2)) ”A wound plate spool for thin metal wires is shown. That is, it can be seen that the wound plate spool for thin metal wires having an elevation angle of 20 to 45 degrees in the cross section is shown. This Patent Document 1 is different from the present invention because it is an invention in which a thin wire such as tungsten or molybdenum is wound, but by the way, when the elevation angle of the flange portion is 20 to 45 degrees, it looks like a thick and light aluminum wire. In the bonding wire, the winding surface layer portion is disturbed and the wire winding amount is reduced.

The same inclination angle is also found in the winding spool of the semiconductor bonding wire made of gold wire. For example, claim 1 of Japanese Patent Application Laid-Open No. 2001-85462 (Patent Document 2 described later) states that "in a spool for winding a semiconductor bonding wire composed of a body and flanges provided at both ends thereof, the outer peripheral surface of the body is covered. , A spool for winding a semiconductor bonding wire, characterized in that an inclined side surface inclined from both ends toward a central portion is provided, is disclosed. FIG. 1 of the same publication illustrates a flange (2) having a plane inclined side surface (5) having an elevation angle of about 60 degrees in the cross section. This Patent Document 2 is also different from the present invention because it is a spool for winding a semiconductor bonding wire made of a gold wire, but as described above, when the flange angle is about 60 degrees, an aluminum wire having a light specific gravity or the like There is a problem that the winding collapse occurs and the winding amount becomes small.

According to claim 1 of JP-A-2004-87536 (Patent Document 3 described later), "a spool for a bonding wire used for winding and unwinding a wire, and a winding body for winding the wire. The winding body is a concentric cylinder with different diameters between the winding body adjacent to the flange and the winding body at the center, and the winding body and the center adjacent to the flange. The winding body of the part is integrated with a smooth slope, and the diameter of the winding body adjacent to the flange is larger than the diameter of the winding body in the center, smaller than the diameter of the flange, and the winding body in the center. A "spool for a bonding wire" is disclosed, wherein the angle formed by the portion and the smooth slope is 10 to 60 degrees. FIG. 2 of the same publication shows a smooth slope (4) having a depression angle of about 30 degrees (6). Paragraph 0019 of the same publication describes "Au wire having a diameter of 25 μm and a length of 2,000 m", and it can be seen that this spool is a spool for bonding wires for Au ultrafine wires. This Patent Document 3 is also an invention of a spool for a bonding wire for Au ultrafine wire, which is completely different from the present invention. However, as described above, when the flange angle is about 10 to 60 degrees, the specific gravity is also completely different. If it is a light aluminum wire, it will be shaken to the left and right due to a lateral impact, causing turbulence, and the problem of winding amount cannot be overcome.

Claim 1 of Japanese Patent No. 2679697 (Patent Document 4 described later) states that "a container body made of synthetic resin integrally provided with an upwardly bulging fitting ridge for fitting a tubular spool, and the container. It is a spool case made of a lid that fits on the outer peripheral wall ridge of the main body, and the plane shape of the part of the container body that contacts and supports the spool of the fitting ridge is polygonal, and the corners are rounded. A featured spool case for a bonding wire ”is disclosed and illustrated in FIG. In paragraph 0021 of the same gazette, "Since the spool case of the present invention supports the corners on each side of the polygonal pillar, the repulsive force of the corners increases, and the corners are firmly pressed against the spool to ensure firmness. Hold the spool in. " Patent Document 4 relating to this spool case is also an invention of a spool case for a spool in which fine wires used for a semiconductor or a superconducting element are wound, which is different from the present invention. However, in this spool case, a spool flange is provided inside the container body. Because they are in direct surface contact with each other, the impact during transportation and the vibration in the manufacturing process are directly transmitted to the spool, and the bonding wire is unwound. Further, since the spool is stored in the spool case in the same direction as the wire is wound, the wire is more likely to be unwound.

An invention that exhibits a similar spool adhesion effect is also disclosed in Japanese Patent No. 3533658 (Patent Document 5 described later). That is, claim 1 of the same publication states that "a container body integrally provided with an upwardly bulging fitting ridge that fits with the inner peripheral surface of the tubular spool and an outer edge peripheral wall ridge that fits with the lid body. In the take-up spool spool case including the lid that fits the outer peripheral wall ridge of the container body, there is a groove around the fitting ridge of the container body that fits the flange of the tubular spool from the outer circumference. A "spool case for a take-up spool, which is characterized by being formed in a circumferential shape" has been disclosed and is illustrated in FIG. 2 and the like. This spool case "can be firmly fixed to the spool because it is supported at two points, the inner peripheral surface of the spool and the outer peripheral surface of the flange ... (Omitted) ... Therefore, it is forced to pull out with a strong force when taking out the spool. It has the effect of preventing accidents such as accidental contact with the wire or accidental dropping of the spool when the spool case lid is opened due to insufficient fixing between the spool and the container body, and it can withstand repeated use. (Paragraph 0024 of the same publication) ”. Patent Document 5 relating to the invention of this spool case is also a spool case for a spool around which a thin bonding wire used for a semiconductor or a superconducting element is wound, so that it is different from the spool case of the present invention, but in the same direction as the spool is wound. It is a fitting method, and is susceptible to shocks and vibrations directly, similar to the above-mentioned problems, and it is still impossible to overcome the unwinding and turbulence of the bonding wire in the vertical direction.

Reference patent documents

Jikkai Sho 58-151154 Japanese Unexamined Patent Publication No. 2001-85462 Japanese Unexamined Patent Publication No. 2004-87536 Japanese Patent No. 2679697 Japanese Patent No. 3533658

The invention's effect

According to the take-up spool of the present invention, the force in the vertical direction of the bonding wire wound on the spool is distributed, so that unwinding failure due to wire dropping into the gap between the wire winding portion and the flange is reduced. A sufficient amount of wire can be wound, and a synergistic effect is produced by winding the winding spool of the present invention with the winding structure of the present invention, and good unwinding property is obtained even with a larger impact. Be done. Further, by storing it in the spool case of the present invention, it is possible to maintain good unwinding property against vibrations and shocks during transportation. As a result, a good bonding method to the electrode can be maintained.

FIG. 1 is a perspective view showing an embodiment of a winding spool for a bonding wire of the present invention, and (a) to (i) of the figure show each embodiment. FIG. 2 is a perspective view showing an embodiment of the main body and the lid of the spool case of the present invention, and FIGS. 2A to 2E in the figure show the respective embodiments. FIG. 3 is a schematic view showing a mounted state of a take-up spool attached to the motor rotating shaft of the wire bonding device. FIG. 4 is a schematic view showing the winding structure of the bonding wire of the present invention and the elevation angle 19. 5 (a) to 5 (g) show each embodiment of the left and right reinforcing ribs of the winding spool of the present invention. FIG. 6 is a schematic view showing an unwinding test of the bonding wire. FIG. 7 is a plan view showing a state in which the winding structure of the bonding wire is unwound.

Hereinafter, as an example of the embodiment of the present invention, the embodiment of the present invention will be described with reference to the drawings. 1 and 2 show embodiments of the present invention. The take-up spool 10 shown in FIG. 1 is an integral product made of injection-molded transparent impact-resistant polystyrene resin. The basic configuration of the take-up spool 10 includes a body portion 12, left and right flange portions 13, and a perforated guide portion 14, and the perforated guide portion 14 has a guide hole 17 formed on the center line. The guide hole 17 can be fixed to the motor rotation shaft (not shown) of the wire bonding device. Four left and right reinforcing ribs 16 are provided in a cross shape on the front and back surfaces of the hollow disk-shaped support portion 15 from the body portion 12 to the left and right flange portions 13, and the left reinforcing rib 16 is shown on FIG. .. Both ends of the left reinforcing rib 16 are integrally connected to the perforated guide portion 14 and the body portion 12. Further, the height of the left reinforcing rib 16 is the same as the height of the outer peripheral surface of the left flange portion 13. Although it is difficult to read on the drawing, the left and right flange portions 13 have an elevation angle of 81 degrees, and the width of the outer peripheral surface of the left and right flange portions 13 is wider than the width of the inner peripheral surface. The left and right flanges 13 of the take-up spool 10 are provided with cut grooves 18 for stopping the start and end of the bonding wire.

The spool case 20 shown in FIG. 2 shows the embodiment of claim 10. The spool case 20 shown in FIG. 2 is composed of a lid 21 made of polyethylene terephthalate (PET) and a main body 31. The lid 21 and the main body 31 are each molded by a vacuum forming method or the like. The lid 21 has a substantially square pyramid-shaped fitting ridge 23 bulging inside the outer peripheral edge 22, and an arc groove 24 for accommodating the take-up spool 10 is formed in the central portion of the fitting ridge 23. Further, the side wall of the fitting ridge 23 has two engaging pieces 25 each, for a total of four engaging pieces 25. The bottom of the arc groove 24 has a protruding leg groove 26. The shape of the arc groove 24 is along the outer peripheral edge of the left and right flanges 13 of the take-up spool 10, and an arc having a length to height ratio of approximately 7: 2 (length: height ≈ 7: 2) is cut out. Shape. The depth of the arc groove 24 is substantially the same as the height of the protruding leg groove 26. Although not shown, in the case of the lid according to claim 11, there is an effect that the lid comes into line contact with the spool case 20 to absorb a large impact.

The main body 31 has a substantially square pyramid-shaped peripheral wall ridge 33 bulging inside the upper peripheral edge 32, and three swelling portions 34 are provided on two side walls facing each other of the peripheral wall ridge 33. Further, there are a total of four locking pieces 35, two on each side wall of the main body 31, corresponding to the engaging piece 25 of the lid body 21. The three expansion portions 34 on both sides of the peripheral wall ridge 33 abut and fix the spool case 20 at their tips.

If the expansion portions 34 abut at least one point on each side surface, the left and right flange portions 13 of the take-up spool 10 can be supported. In the spool case 20 of the present invention, a play of the take-up spool 10 is provided between the take-up spool 10 and the spool case 20 in order to cope with a large external impact. Specifically, it is preferable to provide a gap of 1 mm or less, preferably 0.5 mm or less in the front-rear and left-right directions between the take-up spool 10 and the spool case 20.

The fitting ridge 23 of the lid body 21 is fitted with the peripheral wall ridge 33 of the main body 31, and the engaging piece 25 of the lid body 21 and the locking piece 35 of the main body 31 are fitted to form the spool case 20. In the take-up spool 10 housed in the spool case 20, the bottom surface of the peripheral wall ridge 33 of the main body 31 and the take-up spool 10 are in point contact, and the arc groove 24 of the lid 21 and the take-up spool 10 are in line contact. Is held by. The width and length of the lid 21 and the main body 31 of the spool case 20 are larger than the width and length of the take-up spool 10, and the expansion portion 34 of the main body 31 prevents the take-up spool 10 from rolling significantly. Further, the arc groove 24 has substantially the same height as the protruding leg groove 26. Therefore, the take-up spool 10 can swing between the narrow gaps of the peripheral wall ridge 33 of the main body 31.

After being transferred to the customer, the bonding wire take-up spool 10 is attached to the motor rotating shaft 41 of the bonding device 40 of the bonding wire 42, as shown in FIG. The bonding device 40 is generally designed so that it can be applied to an object having a width between the outermost surfaces of the left and right flange portions 13 of the take-up spool of 31 to 40 mm. Further, the diameter of the take-up spool is generally 88 mm, but a maximum diameter of 150 mm can be attached. After mounting, the take-up spool 10 is rotated to feed the bonding wire 42 by a predetermined length.

The unwound bonding wire 42 is air-tensioned, held by the wire clamp 43, and unwound from the capillary 44. Aluminum (Al), nickel (Ni), copper (Cu), silicon (Si), silver ( An electrode member whose main component is one or more elements selected from Ag), palladium (Pd), platinum (Pt), tin (Sn), iron (Fe), magnesium (Mg) and the like. Ultrasonic bonding, spot bonding, ball bonding, etc. are performed on the electrode connection unit or circuit board.

(Example 1)
A take-up spool 10 in which 500 m of an Al-0.5 mass% Ni alloy bonding wire (diameter 400 μm) is wound will be described. The take-up spool 10 was made of a transparent polycarbonate resin. The wall thickness of the perforated guide portion 14 having the 11 mm guide hole 17 is about 1.5 to 2.5 mm, the diameter of the body portion 12 is 50 mm, the width is 40 mm, and the diameter of the left and right flange portions 13 is 88 mm. The number of reinforcing ribs 16 is four on each side of the body portion 12 (the elevation angle 19 of the flange portion 13 is 78 degrees). Further, the length of one cut groove 18 is 5 mm and the depth is 2 mm. Further, the ratio of the vertical height (h) of the inclined portion of the inner surface of the flange portion to the vertical height (H) of the entire inner surface of the flange portion 13 is 100%. Here, the winding is performed by the conventional winding method that does not form the end portion of the present invention. For convenience, the conventional winding method is hereinafter referred to as "flat winding".

(Examples 2 to 7)
For Examples 2 to 7, the wire diameter, the winding length, the angle of elevation angle 19, and the ratio of the vertical height (h) of the inclined portion of the inner surface of the flange portion to the total vertical height (H) of the inner surface of the flange portion 13. The winding was performed under the same conditions as in Example 1 except that the take-up spool 10 as shown in Table 1 was used.

(Examples 8 to 10)
In Examples 8 to 10, the diameter of the left and right flange portions 13 is 150 mm, and the wire diameter, winding length, elevation angle 19, and inclination of the inner surface of the flange portion with respect to the overall vertical height (H) of the inner surface of the flange portion 13. The winding was performed under the same conditions as in Example 1 except that the take-up spool 10 having the vertical height (h) ratio of the portions as shown in Table 1 was used.

(Comparative Examples 1 to 4)
For Comparative Examples 1 to 4, the wire diameter, the winding length, the angle of the elevation angle 19, and the ratio of the vertical height (h) of the inclined portion of the inner surface of the flange portion to the total vertical height (H) of the inner surface of the flange portion 13. The winding was performed under the same conditions as in Example 1 except that the take-up spool 10 as shown in Table 1 was used.

(Comparative Examples 5 and 6)
In Comparative Examples 5 and 6, the diameter of the left and right flange portions 13 is 150 mm, and the wire diameter, winding length, elevation angle 19, and inclination of the inner surface of the flange portion with respect to the overall vertical height (H) of the inner surface of the flange portion 13. The winding was performed under the same conditions as in Example 1 except that the take-up spool 10 having the vertical height (h) ratio of the portions as shown in Table 1 was used.

(Examples 11 to 17)
For Examples 11 to 17, the ratio of the wire diameter, the winding length, the angle of the elevation angle 19, and the vertical height (h) of the inclined portion of the inner surface of the flange portion to the total vertical height (H) of the inner surface of the flange portion 13. The Al-0.5 mass% Ni alloy bonding wire was wound around the take-up spool 10 under the same conditions as in Example 1 except that as shown in Table 2 so as to have the winding structure of the present invention.

(Examples 18 to 20)
In Examples 18 to 20, the diameter of the left and right flange portions 13 is 150 mm, and the wire diameter, winding length, elevation angle 19, and inclination of the inner surface of the flange portion with respect to the overall vertical height (H) of the inner surface of the flange portion 13. The winding was performed under the same conditions as in Examples 11 to 17 except that the take-up spool 10 having the ratio of the vertical height (h) of the portions as shown in Table 2 was used.

(Comparative Examples 7 to 10)
For Comparative Examples 7 to 10, the wire diameter, the winding length, the angle of the elevation angle 19, and the ratio of the vertical height (h) of the inclined portion of the inner surface of the flange portion to the total vertical height (H) of the inner surface of the flange portion 13. The winding was performed under the same conditions as in Example 1 except that the take-up spool 10 as shown in Table 2 was used.

(Comparative Examples 11 and 12)
In Comparative Examples 11 and 12, the diameter of the left and right flange portions 13 is 150 mm, and the wire diameter, winding length, elevation angle 19, and inclination of the inner surface of the flange portion with respect to the overall vertical height (H) of the inner surface of the flange portion 13. The winding was performed under the same conditions as in Example 1 except that the take-up spool 10 having the ratio of the vertical height (h) of the portions as shown in Table 2 was used.

(Examples 21 to 27)
For Examples 21 to 27, the wire diameter, the winding length, the angle of elevation angle 19, and the ratio of the vertical height (h) of the inclined portion of the inner surface of the flange portion to the total vertical height (H) of the inner surface of the flange portion 13. Two take-up spools 10 wound under the same conditions as in Examples 11 to 17 were inserted into the spool case of the present invention except that the take-up spool 10 as shown in Table 3 was used, and each was covered. The lid was closed with a lid similar to that of the body 21 or a lid made of a film.

The main body 31 of the case of the present invention has a substantially square pyramid shape with a depth of 84 mm, a bottom surface of 90 mm × 46 mm, and a space of the upper surface of 92 mm × 48 mm, and has an upper peripheral edge 32 of 3 mm on the entire circumference of the upper surface. Further, the three expansion portions 34 have a semi-cylindrical shape with a length of 70 mm on both side surfaces of the take-up spool 10 facing the left and right flange portions 13. The tip of the central expansion portion 34 is in contact with the bottom surface of the main body 31, and is equal to the width of the left and right flange portions 13 of the take-up spool 10 and is in contact with the take-up spool 10 at the left and right flange portions 13.

(Examples 28 to 30)
In Examples 28 to 30, the diameter of the left and right flange portions 13 is 150 mm, and the wire diameter, winding length, elevation angle 19, and inclination of the inner surface of the flange portion with respect to the overall vertical height (H) of the inner surface of the flange portion 13. FIG. 2 shows two take-up spools 10 wound under the same conditions as in Examples 11 to 17 except that the take-up spool 10 having a vertical height (h) ratio as shown in Table 3 was used. It was inserted into a spool case of the present invention similar to the main body 31 of the above, and each was covered with a lid similar to the lid 21 or a lid made of a film.

(Comparative Examples 13 to 16)
For Comparative Examples 13 to 16, the ratio of the wire diameter, the winding length, the angle of elevation angle 19, and the vertical height (h) of the inclined portion of the inner surface of the flange portion to the total vertical height (H) of the inner surface of the flange portion 13. Two take-up spools 10 wound under the same conditions as in Examples 21 to 27 were inserted into the spool case of the conventional product except that the take-up spool 10 as shown in Table 3 was used, and each was covered. The lid was closed with the same lid as the body 21.

(Comparative Examples 17 and 18)
In Comparative Examples 17 and 18, the diameter of the left and right flange portions 13 is 150 mm, and the flange portion has a wire diameter, a winding length, an elevation angle of 19, and a vertical height (H) of the entire inner surface of the flange portion 13 in the vertical direction. Two take-up spools 10 wound under the same conditions as in Examples 21 to 27 except that the take-up spool 10 having the ratio of the vertical height (h) of the inclined portion on the inner surface as shown in Table 3 was used. They were inserted into the spool cases of the conventional products one by one, and each was covered with a lid body similar to the lid body 21.

The case of the conventional product has a winding spool 10 placed horizontally and a lid is placed on the side surface of the flange portion 13. There is no structure like the expansion portion of the present invention between the bottom surface of the spool case and the lid body, and the inner surface of the case and the flange portion 13 are in surface contact with each other. Further, in the case of the conventional product, the lid body made of a seal is not covered.

(Impact test)
Each of the 20 winding structures of the bonding wires wound flat on the winding spools 10 of Examples 1 to 10 and Comparative Examples 1 to 6 was dropped four times from a height of 100 mm without a case. I let you.

The guide holes 17 of the 20 wound structures after each of the above impact tests were inserted into guide pins (not shown) at a height of 1,600 mm. Then, the bonding wire fixed in the cut groove 18 of the take-up spool 10 was cut, and the bonding wire 42 was unwound from the winding structure. A schematic diagram is shown in FIG. At this time, the presence or absence of defects in the bonding wire 42 unwound from the take-up spool 10 was observed at a position away from the flange portion 13.

(Detachment to / from bonding equipment and drop test)
For each of the 20 winding structures of the take-up spools 10 of Examples 11 to 20 and Comparative Examples 7 to 12, a motor of Orthodyne 3600 Plus manufactured by Orthodyne, which is a bonding device 40 used for wire bonding of Al bonding wires. The attachment / detachment to / from the rotating shaft 41 was repeated 10 times for each spool, and the winding structure of the take-up spool 10 after attachment / detachment was dropped from a height of 200 mm four times without inserting a case. Further, the winding structure of the take-up spool 10 after dropping is unwound by the same method as the above-mentioned impact test, and the presence or absence of a defect of the bonding wire 42 unwound from the take-up spool 10 is separated from the flange portion 13. Observed by position.

(Vibration and drop test)
The winding structure of the bonding wire wound on the winding spool 10 of Examples 21 to 30 is used in the case of the present invention, and the winding structure of the bonding wire wound on the winding spool 10 of Comparative Examples 13 to 18 is used in the case of the present invention. 20 pieces each were put in the case of the conventional product.

Regarding the winding structure of the take-up spool 10 put in the case of the present invention or the case of the conventional product, assuming long-distance land transportation, the vibration tester is used under the conditions of acceleration ± 1 G and frequency 10 Hz 24. Time Vibrated in the left and right flange width directions of the above case. Then, the winding structure of the vibrated take-up spool 10 put in the case was dropped four times from a height of 500 mm. Further, the winding structure of the take-up spool 10 after dropping is unwound by the same method as the above-mentioned impact test, and the presence or absence of a defect of the bonding wire 42 unwound from the take-up spool 10 is separated from the flange portion 13. Observed by position.

(Test results)
The results of the rotary solving test after the above test are shown in Tables 1, 2 and 3. Regarding the "winding method of the present invention" in Tables 2 and 3, the winding method of the present invention is defined as "concave", and the winding method of flat winding is defined as "flat". .. Regarding the "case type" in Table 3, the case using the main body 31 of the present invention was set to "new", and the case using the conventional case was set to "conventional".

Regarding the "rotary solving test results" in Tables 1, 2 and 3, when the bonding wire 42 unwound from the right side of the flange portion 13 in FIG. 6 is unwound beyond “b” in the figure (in the figure). The range from "b" to "c" or the range on the left side of "c") was defined as "feeding failure", and the range from "a" to "b" in the figure was defined as "good". Of the 20 spools after the impact test in the rotary solving test results, only the spools for which no abnormality of the above "feeding failure" was found were marked with "○", and if any abnormality was found, It was set as "x".

Table 1

Table 2

Table 3

In the present invention, additional evaluation was performed to see if there was a significant difference in the wire diameter of the bonding wire. Five types of bonding wires having a wire diameter of 200 μm to 800 μm were wound around a spool having the same flange diameter of 150 mm as in Examples 8 to 10. For each spool, the elevation angle of the flange was 82 degrees, and the height ratio of the inclined portion was 100%. The impact test conditions were all flat winding, and 20 pieces of each were dropped from a height of 100 mm four times without a case. The results are shown in Table 4. The unwinding test was good in all five types, but in the case where the wire diameter of Example 31 was 200 μm and the wire diameter of Example 35 was 800 μm, winding disorder occurred. From this, it was found that the optimum wire diameter of the bonding wire in the present invention is from 300 μm to 600 μm.

Table 4

From the results of the unwinding test in Table 1 above, it can be seen that the unwinding property is good at the angle of the flange portion of the spool and the ratio occupied by the inclined portion with respect to most vibrations and impacts. From the unwinding test results in Table 2, the wire winding structure of the present invention should be added to the impact due to attachment / detachment to / from the bonding device and dropping, in addition to the angle of the spool flange and the proportion occupied by the inclined portion. It was found that it exerts a synergistic effect and can withstand a larger impact than the test conducted in Table 1. Table 3 shows the results of the unwinding test in which the vibration of the transport of the wound spool was simulated, and the test was performed by dropping the spool from a higher position than in Table 2. It was found that by putting it in the spool case of the present invention, the unwinding property can be kept good even with a considerably large impact.

Although not shown in Table 1 above, in Examples 1 to 10, although it was not determined that the feeding was defective, a slight unwinding was observed. However, for spools with an elevation angle of 79 degrees or more and 83 degrees or less, there was no such unwinding. FIG. 7 shows an example of a state in which the winding structure of the bonding wire is unwound. In the figure, "X" indicates a loosened bonding wire, and "Y" indicates a gap.

Further, when the take-up spool 10 of the above embodiment was installed in the bonding device 40 of the bonding wire 42 by the method described in paragraph 0051 and fed out and ultrasonically bonded, no particular problem was observed.

The take-up spool and spool case for a bonding wire of the present invention particularly relates to a bonding wire of an aluminum metal and an aluminum alloy, but other than that, such as pure silver or a silver alloy, pure copper or a copper alloy, and a palladium-coated copper alloy. It can be widely used for various bonding wires and bonding ribbons.

10 ... Winding spool 12 ... Body 13 ... Flange 14 ... Perforated guide 15 ... Hollow disc-shaped support 16 ... Reinforcing rib 17 ... Guide hole 18 ... Cutting groove 19 ... Elevation angle 20 ... Spool case 21 ... Lid body 22 ... Outer peripheral edge 23 ... Fitting ridge 24 ... Arc groove 25 ... Engagement piece 26 ... Protruding leg groove 31 ... Main body 32 ... Upper peripheral edge 33 ... ... Peripheral wall ridge 34 ... Expansion part 35 ... Locking piece 40 ... Bonding device 41 ... Motor rotating shaft 42 ... Bonding wire 43 ... Wire clamp 44 ... Capillary

Claims (13)

A winding for a synthetic resin bonding wire consisting of a cylindrical body portion, left and right flange portions provided at both ends of the body portion, and a perforated guide portion having the same center line as the body portion and the left and right flange portions. In the take spool , the inner surface of the flange portion has an inclined portion having an elevation angle of 76 degrees or more and 86 degrees or less, and the vertical height (h) of the inclined portion is the total vertical height (H) of the inner surface of the flange portion. A take-up spool characterized by being 50% or more of. The take-up spool according to claim 1, wherein the elevation angle has an inclined portion of 79 degrees or more and 83 degrees or less. The winding according to claim 1 or 2, wherein the outer peripheral surface of the perforated guide portion and the inner peripheral surface of the body portion are connected by reinforcing ribs on one side or both sides of the take-up spool. Tori spool. The take-up spool according to claim 3, wherein the reinforcing ribs have at least two or more and six or less on one side. A winding for a synthetic resin bonding wire consisting of a cylindrical body portion, left and right flange portions provided at both ends of the body portion, and a perforated guide portion having the same center line as the body portion and the left and right flange portions. In the method of manufacturing the take spool, the inner surface of the flange portion has an inclined portion having an elevation angle of 76 degrees or more and 86 degrees or less, and the vertical height (h) of the inclined portion is the total vertical height of the inner surface of the flange portion. A method for manufacturing a take-up spool, which comprises 50% or more of (H). A winding for a bonding wire made of synthetic resin consisting of a cylindrical body portion, left and right flange portions provided at both ends of the body portion, and a perforated guide portion having the same center line as the body portion and the left and right flange portions. In the winding structure of the bonding wire wound on the take spool , the inner surface of the flange portion has an inclined portion having an elevation angle of 76 degrees or more and 86 degrees or less, and the inclined portion has a vertical height (h) of the flange portion. The bonding wire is 50% or more of the total vertical height (H) of the inner surface, and the height of the end portion is higher than the height of the central portion of the body around which the bonding wire is wound. Winding structure. The winding structure of the bonding wire according to claim 6, wherein the bonding wire is an aluminum metal or an aluminum alloy. A winding for a bonding wire made of synthetic resin, which consists of a cylindrical body portion, left and right flange portions provided at both ends of the body portion, and a perforated guide portion having the same center line as the body portion and the left and right flange portions. In the winding method of the winding structure of the bonding wire wound on the take spool , the inner surface of the flange portion has an inclined portion having an elevation angle of 76 degrees or more and 86 degrees or less, and the inclined portion has a vertical height (h). Is 50% or more of the total vertical height (H) of the inner surface of the flange portion, and the winding structure of the bonding wire whose end height is higher than the height of the central portion of the body around which the bonding wire is wound. Winding method. A winding for a bonding wire made of synthetic resin consisting of a cylindrical body portion, left and right flange portions provided at both ends of the body portion, and a perforated guide portion having the same center line as the body portion and the left and right flange portions. In the bonding method in which the bonding wire is unwound from the winding structure of the bonding wire wound on the take spool and joined, the inner surface of the flange portion has an inclined portion having an elevation angle of 76 degrees or more and 86 degrees or less, and the inclined portion has an inclined portion. The vertical height (h) is 50% or more of the total vertical height (H) of the inner surface of the flange portion, and the winding structure of the bonding wire is higher than the height of the central portion of the body around which the bonding wire is wound. A bonding method in which the bonding wire has a wound structure in which the height of the end portion is high, and the bonding wire is bonded to an electrode member, an electrode connection unit, or a circuit board. In the spool case for the take-up spool according to claim 1, which comprises a lid body and a main body made of synthetic resin, the main body has a substantially square weight stand shape with the lid body side open, and is a pair of the main bodies. A spool case for a take-up spool, characterized by having one or more expansion portions on each side surface. The spool case for a take-up spool according to claim 10, wherein the lid is a film that does not allow oxygen and water to permeate and is peelable. The lid is made of synthetic resin and has a substantially square pyramid-shaped fitting ridge inside the outer peripheral edge, and the fitting ridge has an arc groove in the center thereof and an engaging piece on its side wall. The spool case for a take-up spool according to claim 10, wherein the shape of the arc groove is a shape along the outer peripheral end of the left and right flange portions of the take-up spool for the bonding wire. In the method for manufacturing a spool case for a take-up spool according to claim 1, which comprises a lid and a main body made of synthetic resin, the main body has a shape of a substantially square weight base with the lid side open, and the main body has a shape of a substantially square weight base. A method for manufacturing a spool case for a take-up spool, which comprises having one or more expansion portions on each of the paired side surfaces.

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