TWI414369B - Sieve, sieve apparatus, solder ball and sieving method for spherical particle - Google Patents

Abstract

The present invention provides a sieve apparatus having a sieve 1 produced from nickel alloy, in which the shape of a hole for sieving solder balls 2 is adapted to be a long hole 3, a plurality of the long hole 3 are provided such that an extension line of a longitudinal direction of any one of the long holes 3 is orthogonal to an intermediate point a of a longitudinal direction of another long hole 3, and the width of the long hole 3 is adapted to be equal to a diameter x of the solder balls 2 to be classified. Thereby, the present invention provides a sieve apparatus having improved sieving efficiency so that productivity of sieving operation can be greatly improved.

Description

Sieve, sieve device, solder ball and sieving method of spherical particles

The present invention relates to a sieve device having a sieve made of metal with high classification efficiency, and particularly relates to a solution for a configuration of a plurality of holes provided in the sieve, which can improve the efficiency of the sieve and greatly improve the productivity of the screening operation. Screen device.

The operating speed of the screen of the sieve device for efficiently sifting spherical particles is known as an important elemental technology that directly affects the productivity of all industries. In particular, from the viewpoints of cost, quality, and the like, a method of efficiently sifting spherical particles (for example, solder balls) close to a true circle is an extremely important subject.

Conventionally, the shape of the holes constituting the sieve of the sieve device is mostly circular or square. Further, the arrangement of the holes is often arranged at the position of the square eye, or occasionally arranged at the apex of the triangle, and any one of them is equally arranged, and is called a so-called "mesh".

When a mesh mesh is used, in the screening operation, the mesh is driven in the vertical direction, the horizontal direction, the radial direction, and the like, and vibration is constantly applied. The purpose of this vibrating operation is to allow the particles to fall through the holes as quickly as possible after the particles are in contact with the holes of the screen.

However, there is a problem that the particles cannot jump through the holes due to the vibration of the upper and lower sides vibrating around the holes of the sieve. Further, in the so-called two-dimensional plane vibrations of the front, rear, left and right, there is a problem that the particles pass through the upper portion of the hole due to their speed and acceleration, and the sieve cannot be efficiently sifted. In addition, when the shape of the hole of the sieve is close to a conventional square or true circle, that is, surrounded by the arc of the shortest hole, there is also a problem that the particles are fixed in a manner of embedding the recess to cause the hole to be blocked.

The mechanism by which the particles pass through the pores is that the vibrating particles approach and contact the pore walls and fall after being caught at the ends of the pore walls. That is, the longer the length of the pore wall through which the particles are to pass, the more chances of contact with the particles to be passed, and thus the passage can be more easily passed. Therefore, in the conventional mesh screen, it is difficult to pass through the hole for the particles moving on the mesh plane while relying on the force in the lateral direction, and the screening operation efficiency is poor. problem.

In addition, when particles having a particle size of 20 μm or less are generated by sieving, a negative pressure is applied to the side of the sieve while a positive pressure is applied to the particle side, thereby making it possible to smooth the sieving operation. When the particles are trapped in the pores, the particles are also difficult to separate from the pores due to the force caused by the negative pressure, and the pores of the conventional mesh screens are prone to blockage of the pores and the efficiency is not good.

In view of the above-mentioned problem, for example, Patent Document 1 listed below proposes a fine powder separation and removal device which improves the separation efficiency when the shape of the hole of the sieve is a long hole and the fine powder is sieved.

Further, in Patent Document 2, in order to sift out the microspheres of the target diameter a, a rectangular sieve having a shape in which the shape of the hole is a short side b having a length of 0.9 a or less and a long side c having a length exceeding a is proposed.

Similarly, Patent Documents 3 and 4 also propose a sieve in which the shape of the hole is a long hole.

(previous technical literature) (Patent Literature)

(Patent Document 1) Japanese Patent Publication No. 06-170160

(Patent Document 2) Japanese Patent Laid-Open Publication No. 2006-122826

(Patent Document 3) Japanese Patent Publication No. 11-347491

(Patent Document 4) Japanese Patent Laid-Open No. Hei 11-47693

However, in Patent Documents 1 to 4, since a plurality of long holes formed in the screen are parallel to each other, when the sieve particles are vibrated in at least a two-dimensional plane, the classification speed is slow in either of the vibration directions.

As described above, in the conventional sieve, although various studies have been carried out such that the particles fall as quickly as possible through the holes and the pores of the mesh are prevented from being blocked, there is still no such thing as making the screening work efficient. The subject of decisive means.

The present invention has been made in view of the above circumstances, and its main object is to provide a sieve which can improve the efficiency of the screen and greatly improve the productivity of the screening operation.

The invention of the first aspect is a sieve having a metal plate having a long hole, characterized in that a plurality of the long holes are provided so that the long holes cross each other on an extension line in the longitudinal direction.

The screen of the second aspect of the invention is characterized in that a plurality of the long holes are provided so that the long holes are orthogonal to each other in the longitudinal direction extension line.

The sieve of the third aspect of the invention is characterized in that the width of the long hole is set to be equal to the diameter of the classified spherical particles.

The sieve according to the fourth aspect of the invention is characterized in that the cross section of the long hole is set to be meandering so that the width of the long hole on the surface side of the sieve is wider than the width of the long hole on the back side of the sieve. The width of the long hole on the back side of the sieve is set to be equal to the diameter of the particles.

The sieve according to the fifth aspect of the invention is characterized in that the long hole is orthogonal to the midpoint in the longitudinal direction of the other long holes in an extension line in the longitudinal direction.

The sieve of the sixth aspect of the invention is characterized in that the corner portion of the long hole is formed into a shape having a circular arc.

The sieve of the invention of the seventh aspect is characterized in that the metal plate is made of nickel or a nickel alloy.

The sieve of the eighth aspect of the invention is characterized in that a fluorocarbon particle of 0.1 μm to 2 μm is electrodeposited on the surface of the aforementioned metal plate by nickel plating.

The sieve of the invention of the ninth aspect is characterized in that the fluorocarbon particles are electrodeposited by nickel plating in the two-hole walls in the longitudinal direction of the long holes until the thickness reaches 1 μm to 30 μm.

A sieve device according to a tenth aspect of the invention is characterized in that the sieve described in any one of the first aspect to the ninth aspect is vibrated by a vibration means for vibrating at least in a plane of two planes.

The invention of the eleventh aspect is a plurality of solder balls classified by the sieve device described in the tenth aspect, wherein the existence of the solder balls having damage on the surface of the plurality of solder balls is less than 0.1. %.

The solder ball of the invention of the twelfth aspect is characterized in that the existence probability of the solder ball having a discoloration on the surface among the plurality of solder balls is less than 0.1%.

The invention of the thirteenth aspect is a method for sieving spherical particles, which comprises the steps of: sieving spherical spherical particles by a sieve device described in the tenth aspect; and obtaining the passage through the aforementioned screening step The step of the aforementioned spherical particles after the long holes.

That is, the present invention forms a mesh-like sieve with metal, designs the shape of the hole, and improves the arrangement thereof, and is configured according to the arrangement of the holes and the action of the vibration, thereby improving the efficiency of the sieve and greatly improving the screening operation. Productive.

Specifically, the shape of the hole of the sieve is made into an oblong or rectangular shape, and is arranged to include a long hole having a curved shape. Further, the long holes are arranged such that the extension lines of the respective longitudinal directions intersect each other.

In the present invention, a plate-shaped sieve made of a metal mesh device is used, and the shape of the hole for sifting the spherical particles is formed into a long hole shape, and is disposed so as to intersect the length direction of the other long holes in the extension line in the longitudinal direction. Since a plurality of long holes are formed, even when the particles are classified, even if the sieve vibrates in each vibration direction, the particles easily pass through the long holes, and the classification speed becomes faster. Therefore, the working efficiency of the screen can be improved. In particular, when a plurality of long holes are provided so as to be orthogonal to the longitudinal direction of the other long holes in the extension line in the longitudinal direction, the classification speed becomes faster.

Further, by setting the width of the long hole to be equal to or larger than the diameter of the classified particles, and making the long hole in the longitudinal direction and the midpoint of the other long holes And the corner portion of the long hole of the sieve is formed into a shape having a circular arc, so that the working efficiency of the sieve is more efficient. In particular, by making the corner portion of the long hole of the sieve into a shape having a circular arc, it is possible to obtain an additional effect of preventing the sieve from being mechanically vibrated by the sieve device and causing damage due to mechanical fatigue. .

Further, the sieve is electroformed, specifically, a nickel or a nickel alloy is used, and a fluorocarbon particle of 0.1 μm to 2 μm is electrodeposited on the surface of the sieve by nickel plating, and additionally added by nickel plating. The electrodeposited fluorocarbon particles are laminated to have a thickness of from 1 μm to 30 μm in thickness from the length of the long holes, so that fluorocarbon particles of 0.1 μm to 2 μm are electrodeposited by nickel plating to form, for example, 10 μm thick from the electroformed substrate. The sieve is then peeled off, and the electrodeposited fluorocarbon particles are additionally composited by nickel plating until the thickness of the two-hole wall in the longitudinal direction of the long hole of the sieve is from 1 μm to 30 μm, and the above-mentioned control is performed while controlling. Through a series of operations, the size of the long holes can be controlled, and the thickness of the screen can be ensured, and the thickness of the mesh can be sufficiently ensured compared with the area ratio of the long holes. Further, the electrodeposited fluorocarbon particles are additionally composited by nickel plating until the thickness of the two-hole wall in the longitudinal direction of the long hole is 1 μm to 30 μm, whereby the cross-sectional shape of the long hole is in the center in the depth direction of the hole. Since the portion is narrowed, the contact time of the classified particles with the inner side of the hole wall when passing through the long hole is minimized, the passage time is minimized, and the work efficiency of the sieve is made more efficient. In addition, the method of composite electrodepositing fluorocarbon particles by nickel plating can improve the smoothness of the surface of the sieve, and also has the effect of improving wear resistance and greatly extending the life of the sieve.

Further, since the sieve is vibrated by the vibration means, after the particles are in contact with the pores of the sieve, the particles can be quickly dropped through the holes as much as possible, and the operation efficiency of the sieve can be made more efficient.

Hereinafter, several embodiments of the sieve device of the present invention will be described in detail based on the drawings.

Fig. 1 is an explanatory view showing the arrangement of the long holes of the sieve of the sieve device of the first embodiment of the present invention. Fig. 2 is an explanatory view showing the arrangement of the long holes of the sieve of the sieve device of the second embodiment of the present invention. Fig. 3 is an explanatory view showing the arrangement of the long holes of the sieve of the sieve device of Comparative Example 1. Fig. 4 is an explanatory view showing the arrangement of the long holes of the sieve of the sieve device of Comparative Example 2. Fig. 5 is an explanatory view for arranging holes of a conventional sieve into a square and square-shaped mesh. Fig. 6 is a cross-sectional view showing the long hole of the sieve of the sieve device of the embodiment 1 or the embodiment 2 of the present invention in the depth direction, and Fig. 7 is a view showing the sieve of the embodiment 1 or the embodiment 2 of the present invention. An illustration of the dimensional relationship of long holes.

(Example 1)

As shown in Fig. 1, the plate-like sieve 1 of the sieve device of the present invention (this embodiment 1) is made of a metal (for example, nickel or a nickel alloy) and is used to sift spherical particles (for example, the sixth The shape of the hole of the solder ball 2) shown in the figure is made into the long hole 3. In the sieve 1, a plurality of long holes 3 are provided so as to be orthogonal to the midpoint a in the longitudinal direction of the other long holes 3 on the extension line in the longitudinal direction, and the interval B is set to the diameter x of the graded solder ball 2 3 to 5 times (for example, 3 times), and the length L of the long hole 3 in the longitudinal direction is set to be 3 times the diameter x of the graded solder ball 2. Further, the width W of the long hole 3 is set to be equal to the diameter x of the graded solder ball 2.

Further, the diameter x of the solder ball 2 classified in the first embodiment was 67 μm. Further, the thickness T1 of the sieve 1 was 35 μm.

The sieve 1 is produced by electroforming, and a fluorocarbon particle of 0.1 μm to 2 μm is electrodeposited on the surface by a nickel plating method to a thickness of, for example, 10 μm. Further, as shown in Fig. 6, the electrodeposited fluorocarbon particles are additionally composited by nickel plating from the hole wall 31 in the longitudinal direction of the long hole 3 of the sieve 1 toward the center portion until the thickness reaches 1 μm to 30 μm (more) The thickness is preferably from 1 μm to 20 μm so as to gradually increase in thickness in the depth direction of the long hole 3, and has a substantially semicircular shape when viewed in cross section.

Further, when the sieve device having the sieve 1 of the present invention is operated, the sieve 1 is vibrated by a vibration means having a predetermined frequency and amplitude, and the solder balls 2 are classified to perform the screening operation.

Thereby, the sieve 1 of the present invention can ensure a high aperture ratio by making the provided hole into the above-mentioned long hole 3, and the work efficiency of the screening can be greatly improved. Further, since the interval b in which the long holes 3 are arranged is set to three times the diameter of the graded solder balls 2, an appropriate aperture ratio is set, so that the long holes 3 can be prevented from being excessively close to each other and the screen 1 can be weakened. In order to optimize the efficiency of the operation of the sieve. Further, a plurality of long holes 3 of the plurality of screens 1 are provided so as to be orthogonal to the midpoint a in the longitudinal direction of the other long holes 3 on the extension line in the longitudinal direction, and the falling speed is set by the arrangement of the long holes 3 described above. Very good. Since the aperture of the long hole 3 is controlled by electroforming, the hole wall 31 in the longitudinal direction of the long hole 3 is formed into a cross-sectional shape which is bulged in the depth direction of the long hole 3, and the long hole 3 is formed. The aperture is the minimum resistance required to pass the solder ball 2 on one side.

(Example 2)

As shown in Fig. 2, the sieve 1 of the sieve apparatus of the second embodiment is different from the first embodiment in that a plurality of long holes 3 provided in the sieve 1 are extended on the longitudinal direction and the other long holes 3 The arbitrary positions in the longitudinal direction are arranged orthogonally.

Here, a method of manufacturing the electroforming using the sieve 1 of the above-described Embodiment 1 or Example 2 will be described in detail based on Fig. 6.

The electroforming system described below is a method for solving the following situation, that is, a method of increasing the opening ratio. Generally, as long as the hole is close to the hole, the strength of the screen 1 becomes low as a result of the fact that the elongated hole 3 is dense and the partition wall is thinned, so that the adjacent wall is desired. (the hole wall 31 of the long hole 3) is thickened in the depth direction to greatly increase the aspect ratio (ratio of the depth to the width). At this time, if the aspect ratio is increased, the thickness T1 (long) of the sieve 1 is relatively long. The depth direction of the hole 3 becomes large, causing the function of the screen to be affected, resulting in a problem that the falling speed of the solder ball 2 is slowed down or the chance of blocking in the middle of the long hole 3 is increased.

When the screen 1 is produced by electroforming, generally, it expands laterally in excess of the thickness of the resist. Therefore, when the screen 1 is grown in the depth direction, the long hole 3 shown in Fig. 6 is filled. Therefore, in the step of electroforming, after plating on the surface of the sieve 1 to form a nickel mesh having a thickness of about 2 to 10 μm (for example, 10 μm), the nickel mesh is peeled off from the surface of the substrate 4 of the sieve 1. Next, as shown in FIG. 7, the fluorocarbon particles are additionally electrodeposited on both surfaces of the sieve 1 by nickel plating, whereby the hole walls 31 in the longitudinal direction of the long holes 3 are made to face the long holes 3. The section bulging in the depth direction is in the shape of a crucible. In this case, the hole diameter of the long hole 3 is such that the thickness t of the additional plating 5 by the nickel plating method is 2 μm or more, and the hole diameter control of the long hole 3 can be achieved by the hole through which the solder ball 2 falls. The least resistance. The thickness T1 of the sieve 1, the thickness T2 of the additional plating 1 and the thickness t of the additional plating 5 are T2=T1+2t, and the plating thickness t of the hole wall 31 in the longitudinal direction of the long hole 3 is performed by plating. The diameter D of the long hole 3 is contracted by an amount equal to -2t.

The nickel plating which performs the composite electrodeposition of the fluorocarbon particles is such that the smoothness of the surface of the sieve 1 is good, and the friction when the solder balls 2 are dropped as much as possible is suppressed to a low level. Therefore, gloss nickel is preferable.

At this time, the thickness of the composite electrodeposition from the hole wall toward the center portion in the longitudinal direction of the long hole 3 is only required to be 1 to 60 μm in total, and preferably 1 to 40 μm. Thereby, the wear resistance is also improved, and the life of the sieve 1 is greatly extended.

Hereinafter, the results of the performance test of the sieve device of the present invention will be described.

<About work efficiency>

In the first embodiment shown in Fig. 1, the second embodiment shown in Fig. 2, the comparative example 1 shown in Fig. 3, the comparative example 2 shown in Fig. 4, and the comparative example 3 shown in Fig. 5 The performance was compared between the time required for the particles (solder balls 2) to pass through the sieve 1, the recovered weight of the solder balls 2, and the opening ratio of the sieve 1.

Here, as shown in FIGS. 1 to 5, the difference between Comparative Example 1 or Comparative Example 2 and Example 1 and Example 2 lies in the arrangement of the long holes 3, and Comparative Example 1 and Comparative Example 2 The difference is in the size of the long hole 3 (aspect ratio). In Comparative Example 3, a sieve 1 configured in a square shape and a square eye shape represented by a conventional example was used.

Further, in any of the examples or the comparative examples, the thickness T1 of the sieve 1 is 35 μm, and is made of a nickel alloy by electroforming, and the wall of the longitudinal direction of the long hole 3 is formed toward the depth of the long hole 3. The shape of the bulge.

In the experiment, the solder ball 2 having the same particle diameter distribution of the solder particles is used (specifically, 50 g of particles having a diameter of 62 μm or more and 67 μm or less and a diameter of 67.1 μm or more and 72 μm or less) are mixed. 50g of 100g solder balls 2), for the purpose of classifying solder balls 2 of 67μm or less, each sieve 1 is laid on a 75mm stainless steel frame and hung on a general vibrating screen device to compare the screening operations. speed. The results are shown in Table 1.

In addition, the opening ratio refers to each area when the long hole 3 and the interval b are repeated in the vertical direction and the lateral direction, and is set as a unit (one side) (area shown by the hatched area in the first to fifth figures) The area ratio of the long hole 3.

As is apparent from the results of Table 1, the sieve 1 of Example 1 of Fig. 1 has the shortest passage time, and therefore the passage speed is the fastest. The recovered weight was 50.1 g or 50.2 g, which was approximately the same. Further, the sieving speed shows that the effect of setting the long hole 3 is more effective than the dependence on the aperture ratio. Further, from the comparison between Example 1 and Example 2, the arrangement of the long holes 3 has a subtle influence on the sieving speed. From the comparison between Comparative Example 1 and Comparative Example 2, the aspect ratio of the long holes 3 has a subtle influence on the screening speed. Further, it was found that by performing the arrangement of the long holes 3 of the first embodiment or the second embodiment, the working efficiency of the screen can be improved with respect to any of the comparative examples 1 to 3.

Therefore, in the present invention, the plate-like sieve 1 is electroformed by using a nickel alloy of a sieve device, and the shape of the hole for sieving the solder ball 2 is made into the shape of the long hole 3, and is elongated in the length direction. A plurality of long holes 3 are provided on the line orthogonal to the midpoint a of the lengthwise direction of the other long holes 3, and the width W of the long holes 3 is set to be equal to the diameter of the graded solder balls 2, and the long holes 3 are formed. Since the length L in the longitudinal direction is set to three times the diameter of the graded solder ball 2, when the long hole 3 is disposed, a high aperture ratio can be ensured, and the operation efficiency of the screen can be made more efficient. In particular, since the interval b is set to three times the diameter of the classified particles and is set to an appropriate aperture ratio, it is possible to prevent the long holes 3 from being excessively close to each other and causing the mesh of the sieve 1 to be weakened. The efficiency of the screening work becomes the most efficient.

Further, in the electroforming step, the sieve 1 is formed on the upper surface of the substrate 4 by electroplating to a thickness of 10 μm, and then peeled off, and then additionally electrodeposited from the both surfaces of the sieve 1 by nickel plating. The fluorocarbon particles can be controlled until the length of the two-hole wall 31 in the longitudinal direction of the long hole 3 of the sieve 1 is 1 μm to 30 μm, and the length of the long hole 3 can be controlled while controlling the sieve 1 The thickness T1 is sufficient to ensure the thickness of the mesh eye as compared with the area ratio of the long holes. Further, the electrodeposited fluorocarbon particles are additionally composited by nickel plating until the thickness of the two-hole wall 31 in the longitudinal direction of the long hole 3 reaches 1 μm to 30 μm, whereby the cross-sectional shape of the long hole 3 is at the depth of the hole. Since the direction is gradually narrowed, the contact time of the classified particles through the long holes 3 and the length of the hole walls 31 of the long holes 3 is minimized, and the passage time is minimized, so that the work efficiency of the screen 1 is more efficient. . In addition, the method of composite electrodepositing fluorocarbon particles by nickel plating can improve the smoothness of the surface of the sieve, and also has the effect of improving wear resistance and greatly extending the life of the sieve.

Thus, the present invention can provide a sieve device having a sieve 1 which can improve the efficiency of the sieve and greatly improve the productivity of the screening operation.

<Relationship between length L and screening speed>

Next, in the arrangement of the long holes 3 of the second embodiment, the length L of the long holes 3 in the longitudinal direction was changed, and the influence of the length L on the screening speed was evaluated.

In this evaluation, the size of the entire sieve 1 of Example 2 was set to a disk shape having a diameter of 50 mm, and the width W of the long hole 3 was set to 300 μm. Further, it is prepared to change the length L of the long hole 3 in the longitudinal direction to the width W of the long hole 3 (the same size as the sieved solder ball 2) to 1 time (300 μm) and 2 times (600 μm). 3 times (900 μm), 5 times (1500 μm), 10 times (3000 μm) of sieve 1. Further, in the case of the solder balls 2 sieved by the sieves 1, 2 million pieces of 300 μm in diameter and 200 g in mass were prepared, and the pressure applied to the surface of the screen 1 was set to 10 g/cm ² .

Further, the opening ratio system of each of the sieves 1 was 40%, and the sieve 1 having the length L of 1 was regarded as the same as that of Comparative Example 3.

In the evaluation method, the solder balls 2 are mounted on the respective sieves 1 prepared in the above manner, and the solder balls 2 are shaken on the surface of the sieve 1 by applying ultrasonic vibration. Next, the sieving time of all the solder balls 2 passing through the long holes 3 of the sieve 1 was measured, and the sieving speed was calculated.

Fig. 8 is a graph showing the results of evaluating the relationship between the length L of the longitudinal direction (long side) and the sieving speed. Further, the sieving speed in Fig. 8 is based on the length L of the long side of the long hole 3 and the sieving speed of the sieve 1 having the width W of the long hole 3 of 300 μm (for convenience). For example, although the hole of the sieve 1 appears as the long hole 3, it is a square at this time.

As is apparent from the evaluation results shown in Fig. 8, the longer the long side of the long hole 3, the higher the sieving speed. Further, by setting the length L of the long side to three times the width W, the sieving speed is greatly increased as compared with the case where the length L of the long side is 1 or 2 times, and when it exceeds 3 times, the sieving is performed. The rate of increase in speed will decrease. From the above results, it can be said that since the strength of the sieve 1 is to be considered, the length L of the long side is preferably 2 times or more and less than 5 times, more preferably about 3 times.

<About the influence on the solder ball 2>

Next, the influence of the hole arrangement of the sieve 1 and the shape of the hole on the solder ball 2 after the application of the sieve was evaluated.

In this evaluation, the comparison was carried out using the sieve 1 of Example 2 and the sieve 1 of Comparative Example 4 shown in Fig. 9. Further, in the case of the solder balls 2 sieved by the sieves 1, 2 million pieces of 300 μm in diameter and 200 g in mass were prepared, and the pressure applied to the surface of the screen 1 was set to 10 g/cm ² .

Further, the sieve 1 of the second embodiment has a whole disk size of 50 mm in diameter, and the length L of the long hole 3 is set to 3 times the diameter of the solder ball 2 (that is, 900 μm), and the width W is set to The same diameter as the solder ball 2 is 300 μm. On the other hand, in the sieve 1 of Comparative Example 4, similarly to Comparative Example 3, the shape of the pores was not a long hole 3 but a circular shape having the same size as the diameter of the solder ball 2.

In the evaluation method, the solder balls 2 are mounted on the respective sieves 1 prepared in the above manner, and the solder balls 2 are shaken on the surface of the sieve 1 by applying ultrasonic vibration. Next, after all the solder balls 2 have passed through the long holes 3 of the screen 1, the existence probability of the solder balls 2 having damage to the entire solder balls 2 that have been screened is confirmed.

The above-mentioned existence probability was evaluated by observing the surface state of the solder ball 2 using an electron microscope (manufacturer: TOPCON model: ABT-60).

Fig. 10 to Fig. 12 show electron micrographs showing the surface state of the solder balls 2. Fig. 10(A) is an electron micrograph (magnification: 250 times) of the solder ball 2 before being sieved by a sieve, and Fig. 10(B) is a partial view of the solder ball 2 shown in Fig. 10(A) Magnified electron micrograph (magnification: 500 times). Fig. 11(A) is an electron micrograph (magnification: 250 times) of the solder ball 2 sieved by the sieve of Example 2, and Fig. 11(B) shows the solder shown in Fig. 11(A) Electron micrograph of a partial enlargement of the sphere 2 (magnification: 500 times). Fig. 12(A) is an electron micrograph (magnification: 250 times) of the solder ball 2 sieved by the sieve of Comparative Example 4, and Fig. 12(B) shows the solder shown in Fig. 12(A) Electron micrograph of a partial enlargement of the sphere 2 (magnification: 500 times).

As shown in Fig. 11, it is understood that the surface of each of the solder balls 2 screened by the sieve 1 of the embodiment 2 is inferior to the surface of the solder ball 2 before the screening shown in Fig. 10, and Damage and discoloration are completely absent. Therefore, the existence probability of the solder ball 2 having damage or discoloration is 0%. In addition, in this evaluation, "injury" means a damage which can be discerned in an electron microscope photograph at a magnification of 500 times, and does not include a slight damage which cannot be discerned in the electron micrograph. "Discoloration" means that the discoloration in an electron microscope photograph can be discerned by a human eye at a magnification of 500 times, and does not include discoloration which is indistinguishable to the human eye.

On the other hand, as shown in Fig. 12, in the solder ball 2 sieved by the sieve 1 of Comparative Example 4, the solder balls 2 having damage on the surface were scattered. Therefore, when the number of damaged solder balls 2 is counted and the probability of existence is investigated, the probability is 7%. Further, in the solder ball 2 sieved by the sieve 1 of Comparative Example 4, the solder balls 2 having discoloration on the surface were dispersed. Therefore, when the number of the solder balls 2 having the color change is calculated and the probability of existence is investigated, the probability is 3%.

The summary of the above evaluation results is shown in Table 2.

<About surface analysis>

Next, surface analysis (EDS analysis) was performed on each of the solder balls 2 sieved by the sieve 1 of Example 2 and the sieve 1 of Comparative Example 4. In this analysis, an energy dispersive X-ray analysis apparatus (manufacturer: Japan Philips Model: EDAX DX-4) was used.

Fig. 13 is a view showing the results of EDS analysis of the solder balls 2 sieved by the sieve 1 of Example 2. Fig. 14 is a view showing the results of EDS analysis of the solder ball 2 having discoloration sieved by the sieve 1 of Comparative Example 4.

As shown in Figs. 13 and 14, in comparison with the surface of the solder ball 2 sieved by the sieve 1 of Example 2, in the solder ball 2 sieved by the sieve 1 of Comparative Example 4, in the energy The weaker light element side shows the peak of carbon or oxygen. From this, it was confirmed that the solder balls 2 sieved by the sieve 1 of Comparative Example 4 were discolored by oxidation.

(Modification)

Hereinabove, several embodiments of the present invention have been described in detail, but the present invention is not limited to the above embodiments. Further, the present invention can be variously modified as long as it does not deviate from the matters described in the scope of the patent application.

For example, since the shape of the long hole of the sieve device of the present invention is formed by the operation of the sieve while vibrating, it is preferable that the corner portion shown in Fig. 15(a) has an arc, and the crucible does not pass. Damage to particles during the operation of the sieve. In addition, it is also effective to have the entire short side of the long hole having an arc. Since the screen receives mechanical vibrations from the top and bottom, and finally cracks due to mechanical fatigue, it is possible to prevent the corner portion from being damaged by applying an arc to the long hole. Further, as shown in Fig. 15(b), it is not necessary to form a straight line in the longitudinal direction of the long hole, and if it has a circular arc shape (a file shape), it is preferable in terms of area depending on the case.

The width of the long hole may have the effect of the present invention even if it is equal to or larger than the diameter of the classified particles.

Further, the long hole shape of the sieve of the sieve device of the present invention is a cross shape (Fig. 15 (c)) and a parallelogram shape as shown in Figs. 15(c) to (f) (Fig. 15 (d) )), the flyback shape (Fig. 15(e)), and the trapezoidal shape (Fig. 15(f)), the effect of the present invention obtained by the above embodiment can also be obtained, and the efficiency of the sieve can be improved and A sieve which can greatly improve the productivity of the sieving operation, and it is expected to obtain a good result of high efficiency of the screening operation in consideration of the area.

Further, in the first to second embodiments, the length L of the long hole 3 of the sieve 1 is three times the diameter of the classified particles, but if it is larger than the diameter of the solder ball 2 by 2 times, 4 times, 5 The present invention can also be applied to times, 6 times, and the like.

Further, the plurality of long holes 3 of the sieve 1 are described as being arranged such that the extension lines in the longitudinal direction are orthogonal to each other. However, in the present invention, they may be provided so as to intersect each other at least on the extension line in the longitudinal direction.

Further, in the vibration means of the sieve 1, the sieve 1 may be vibrated in the vertical direction, the horizontal direction, the radial direction, or the like. However, if it is vibrated in at least the two axial directions, it may be carried out by, for example, manual operation. Any means of vibration.

Furthermore, it has been explained that the existence probability of the solder balls 2 having damage or discoloration on the surface of the solder balls 2 screened by the sieve 1 of the embodiment 2 is 0%, but the probability of existence is at least less than 0.1. The probability of existence of % can be regarded as the solder ball 2 classified by the present invention.

In addition, all of the plurality of long holes 3 of the sieve 1 do not have to cross each other in the extension line in the longitudinal direction. For example, a plurality of blocks (regions) may be disposed in the sieve 1, and a plurality of long holes parallel to each other are arranged in each block. 3. The long holes 3 in the block of one side and the long holes 3 in the block of the other side are arranged to be orthogonal to each other on the extension line in the longitudinal direction.

For example, it will be specifically described using FIG. 16 and FIG. Fig. 16(A) is a view showing an example of the arrangement of the long holes provided in the block, and Fig. 16(B) is a view showing another example of the arrangement of the long holes provided in the block, Fig. 16 (C) is a view showing still another example of the arrangement of the long holes provided in the block. Fig. 17 (A) to (C) are diagrams showing an example of arrangement of blocks.

First, as shown in Fig. 16 (A) to (C), a plurality of long holes 3 which are parallel to each other are arranged in the block BL. The length L of the long holes 3 in the block BL in the longitudinal direction is different from each other, and the ratio of the length L of the long holes 3 in the longitudinal direction to the width W of the long holes 3 can be arbitrarily set. Further, the arrangement of the long holes 3 can also be applied to the regularity of Figs. 16(A) and (C), or the irregularity of Fig. 16(B).

Furthermore, a plurality of the blocks BL are arranged in the screen 1, for example, as shown in Fig. 17(A), the long holes 3 in one block and the long holes 3 in the other block are in the length direction. Each of the blocks BL is arranged such that the extension lines are orthogonal to each other. Further, for example, as shown in FIG. 17(B), the long holes 3 in one of the blocks BL and the long holes 3 in the other block BL may be arranged so as to intersect each other on the extension line in the longitudinal direction. The block BL can also be arbitrarily set to the intersection angle. Further, as shown in Fig. 17(C), in the sieve 1, each of the blocks BL may be arranged in a radial shape, or the block BL may be disposed in the center of the radial shape. Further, the size and shape of the block BL itself are also not particularly limited.

(industrial availability)

The present invention is not limited to the classification of the solder ball as in the above embodiment, and can be applied to the classification of various particles and objects such as a ball for a bearing ball, a dummy ball and a spacer, a glass bead, and a spacer for liquid crystal. Screening improves work efficiency by increasing the speed of the grading. Therefore, the cost of the particles or objects to be classified is lowered, and the effect is extremely large. In particular, this effect is most effective for the classification of spherical particles including solder balls.

1. . . Sieve (metal plate)

2. . . Solder ball (particle)

3. . . Long hole

4. . . Substrate

5. . . Additional plating

31. . . hole wall

a. . . midpoint

BL. . . Block

b. . . interval

Dψ. . . Diameter of long hole

L. . . Length of the long hole in the length direction

T1. . . Sieve thickness

T2. . . Additional plating thickness

t. . . Additional plating thickness

W. . . Length of long hole

x. . . The diameter of the solder ball (the diameter of the particle)

Fig. 1 is an explanatory view showing the arrangement of the long holes of the sieve of the first embodiment of the present invention.

Fig. 2 is an explanatory view showing the arrangement of the long holes of the sieve of the second embodiment of the present invention.

Fig. 3 is an explanatory view showing the arrangement of the long holes of the sieve of the sieve device of Comparative Example 1.

Fig. 4 is an explanatory view showing the arrangement of the long holes of the sieve of the sieve device of Comparative Example 2.

Fig. 5 is an explanatory view for arranging holes of a conventional sieve into a square and square-shaped mesh.

Fig. 6 is a cross-sectional view showing the long hole of the sieve of Example 1 or Example 2 of the present invention taken along the depth direction.

Fig. 7 is an explanatory view showing the dimensional relationship between the sieve and the long hole of Example 1 or Example 2 of the present invention.

Fig. 8 is a graph showing the results of evaluating the relationship between the length L of the longitudinal direction (long side) and the sieving speed.

Fig. 9 is an explanatory view showing the arrangement of the long holes of the sieve of the sieve device of Comparative Example 4.

Fig. 10(A) is an electron micrograph (magnification: 250 times) of the solder ball before being sieved by a sieve, and Fig. 10(B) is a partial enlargement of the solder ball shown in Fig. 10(A). Electron micrograph (magnification: 500 times).

Fig. 11(A) is an electron micrograph (magnification: 250 times) of a solder ball sieved by the sieve of Example 2, and Fig. 11(B) is a solder ball shown in Fig. 11(A). Partially magnified electron micrograph (magnification: 500 times).

Fig. 12(A) is an electron micrograph (magnification: 250 times) of a solder ball sieved by the sieve of Comparative Example 4, and Fig. 12(B) is a solder ball shown in Fig. 12(A). Partially magnified electron micrograph (magnification: 500 times).

Fig. 13 is a view showing the results of EDS analysis on the solder balls sieved by the sieve of Example 2.

Fig. 14 is a view showing the results of EDS analysis of the solder balls having discoloration which were sieved by the sieve of Comparative Example 4.

Fig. 15 is an explanatory view showing a deformation of the shape of the long hole of the sieve of the sieve device of the present invention, wherein (a) is a long hole shape having a circular arc at the corner portion, (b) is a sickle shape, and (c) is a cross. The shape of the shape, (d) is a parallelogram shape, (e) is a flyback type, and (f) is an explanatory view of a long hole having a trapezoidal shape.

Fig. 16(A) is a view showing an example of the arrangement of the long holes provided in the block, and Fig. 16(B) is a view showing another example of the arrangement of the long holes provided in the block, Fig. 16 (C) is a view showing still another example of the arrangement of the long holes provided in the block.

Fig. 17 (A) to (C) are diagrams showing an example of arrangement of blocks.

1. . . Sieve (metal plate)

3. . . Long hole

31. . . hole wall

a. . . midpoint

b. . . interval

L. . . Length of the long hole in the length direction

W. . . Length of long hole

Claims (13)

A sieve comprising a metal plate having a long hole, wherein the sieve has a plurality of first long holes in a first longitudinal direction and a plurality of second long holes in a second longitudinal direction, the first The longitudinal direction and the second longitudinal direction intersect each other on the extension line, and the first elongated hole and the second elongated hole are alternately arranged on the upper, lower, left and right sides. A sieve according to the first aspect of the invention, wherein the plurality of long holes are provided such that the long holes are orthogonal to each other in an extension line in the longitudinal direction. A sieve according to the first aspect of the invention, wherein the width of the long hole is set to be equal to the diameter of the classified spherical particles. a sieve according to the third aspect of the invention, wherein the cross section of the long hole is formed in a meandering manner such that the width of the long hole on the surface side of the sieve is wider than the width of the long hole on the back side of the sieve. The width of the long hole on the back side of the sieve is set to be equal to the diameter of the aforementioned particles. The sieve according to any one of claims 1 to 4, wherein the long hole is orthogonal to a midpoint in a longitudinal direction of the other long hole in an extension line in the longitudinal direction. A sieve according to any one of claims 1 to 4, wherein the corner portion of the long hole is formed into a circular arc shape. A sieve according to any one of claims 1 to 4, wherein the metal plate is made of nickel or a nickel alloy. A sieve according to any one of claims 1 to 4, wherein the fluorocarbon particles of 0.1 μm to 2 μm are electrodeposited by nickel plating. On the surface of the aforementioned metal plate. A sieve according to claim 8 wherein the fluorocarbon particles are electrodeposited by nickel plating to the walls of the two holes in the longitudinal direction of the long holes until the thickness reaches 1 μm to 30 μm. A sieve device characterized in that the sieve of any one of the first to ninth aspects of the patent application is vibrated by a vibration means for vibrating at least in a plane of two planes. A solder ball, which is a plurality of solder balls classified by a sieve device of claim 10, wherein the solder ball is characterized in that the existence of the solder ball having damage on the surface of the plurality of solder balls is not up to 0.1%. The solder ball of claim 11, wherein the existence of the solder ball having a discoloration on the surface of the plurality of solder balls is less than 0.1%. A sieving method for a spherical particle, comprising: a step of sieving spherical spherical particles by using a sieve device of claim 10; and obtaining the spherical shape after passing through the long hole by the sieving step The step of the particle.