Squeegee for solder ball mounting device and solder ball mounting device

Abstract

An object of the present invention is to provide a squeegee for a solder ball mounting device and a solder ball mounting device which can prevent damage to the end connecting portions of the squeegee for a long period of time and can withstand long-term use. [Solution] The squeegee of the solder ball mounting device of the present invention is a squeegee of a solder ball mounting device that mounts solder balls onto the electrodes through a mask having openings at positions corresponding to the electrodes on the surface of a substrate on which a plurality of electrodes are formed, and is characterized in that it is formed in a thin plate shape and has a plurality of slits at a predetermined angle to the direction of travel when the solder balls are mounted, and has connecting portions at both side ends in the direction of travel that connect the thin plates separated by the slits, and the connecting portions are formed to be freely expandable at least in the direction of travel.

Description

[Technical field]

[0001] The present invention relates to a squeegee for a solder ball mounting device and a solder ball mounting device. [Background technology]

[0002] The solder ball mounting device places a mask with openings at positions corresponding to the electrodes on a substrate surface on which multiple electrodes are formed and flux is applied, and is equipped with a squeegee with multiple slits in a thin plate, and deposits solder balls into the openings in the mask.

[0003] Patent Documents 1 to 3 disclose techniques for solder ball mounting devices. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-105889 A [Patent Document 2] JP 2010-135457 A [Patent Document 3] JP 2016-154193 A Summary of the Invention [Problem to be solved by the invention]

[0005] When multiple slits are formed in a thin plate, the squeegee of a solder ball mounting device requires connecting parts at both ends in the direction of travel to connect the thin strips formed by adjacent slits together so that they do not come apart. This squeegee (which may be referred to as a slit squeegee hereinafter because it has slits) is formed in a semi-cylindrical shape, and the cylindrical part is pressed against the mask to make contact and move over the mask. Solder ball mounting devices using a squeegee configured in this way have a high solder ball mounting rate and are useful, so they have been widely used in this field for a long time. This has led to a demand for longer-term use.

[0006] That is, in conventional squeegees, even if a pressing force is applied to the center, the slits open slightly to absorb the pressing force. However, there are connecting parts on both ends of the squeegee in the moving direction that connect the narrow strip members together. As a result, these connecting parts cannot absorb the pressing force and are subjected to stress, which causes a problem that the connecting parts are damaged by this stress during long-term use. For this reason, in the conventional techniques (the techniques of Patent Documents 1 to 3), it was necessary to periodically replace the squeegee after continuous use, for example, hundreds to thousands of times.

[0007] An object of the present invention is to provide a squeegee for a solder ball mounting device and a solder ball mounting device which can prevent damage to the connecting portions at both ends of the squeegee for a long period of time and which can withstand long-term use. [Means for solving the problem]

[0008] The squeegee of the solder ball mounting device of the present invention is a squeegee for a solder ball mounting device that mounts solder balls on the electrodes through a mask having openings at positions corresponding to the electrodes on the surface of a substrate on which a plurality of electrodes are formed, the squeegee being formed in a thin plate shape and having a plurality of slits at a predetermined angle with respect to the direction of movement of the solder balls when mounted, and having connecting parts at both end portions on the direction of movement that connect the thin plates separated by the slits, the connecting parts beingThe connecting portions are alternately arranged with the auxiliary slits so that the connecting portions are not continuous in the traveling direction, so that the connecting portions are formed to be freely stretchable at least in the traveling direction. This is characterized by the fact that Alternatively, the squeegee of the solder ball mounting device of the present invention is a squeegee of a solder ball mounting device that mounts solder balls on the surface of a substrate on which a plurality of electrodes are formed through a mask having openings at positions corresponding to the electrodes, and mounts the solder balls on the electrodes through the openings, the squeegee being formed in a thin plate shape and having a plurality of slits at a predetermined angle to the direction of travel when the solder balls are mounted, and is characterized in that it is provided with connecting portions at both side ends in the direction of travel that connect the thin plates separated by the slits, and the connecting portions are formed from an elastic material and are therefore freely stretchable in the direction of travel.

[0009] The solder ball mounting device of the present invention uses a mask having openings at positions corresponding to the electrodes on a substrate surface having a plurality of electrodes formed thereon and a surface coated with flux, and uses a squeegee formed in a semi-cylindrical shape with a plurality of slits in a thin plate to mount solder balls supplied onto the mask onto the electrodes through the openings. The squeegee is formed in a thin plate shape, and has a plurality of slits at a central portion corresponding to the substrate surface, which are angled relative to the direction of travel, and has connecting portions at both side ends in the direction of travel that connect the thin plates separated by the slits, and the connecting portions are The squeegee is formed to be expandable and contractible at least in the traveling direction by alternately arranging the sub-slits in the connecting portion so that the connecting portion is not continuous in the traveling direction. This is characterized by the fact that Alternatively, the solder ball mounting device of the present invention is a solder ball mounting device that mounts solder balls supplied onto a substrate surface on which a plurality of electrodes have been formed and a surface on which flux has been applied, through a mask having openings at positions corresponding to the electrodes, using a squeegee formed into a semi-cylindrical shape with a thin plate having a plurality of slits, through the openings, onto the electrodes, the squeegee being formed in a thin plate shape and having a plurality of slits in a central portion corresponding to the substrate surface, and having connecting portions at both side ends in the traveling direction that connect the thin plates separated by the slits, and the connecting portions of the squeegee are formed from an elastic material and are therefore formed to be freely stretchable at least in the traveling direction. Effect of the Invention

[0010] According to the present invention, it is possible to provide a squeegee for a solder ball mounting device and a solder ball mounting device that can prevent damage to the connecting portions on both side ends of the squeegee for a long period of time and can withstand long-term use. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic overall configuration diagram of a solder ball mounting device; [Diagram 2] 1 shows a schematic configuration of the fill head and sweeper head while the fill head is moving to the left. [Diagram 3] 1 shows a schematic configuration of the fill head and sweeper head while the fill head is moving to the right. [Figure 4] FIG. 13 is a diagram showing a state in which the sweeper head is moving. [Diagram 5] FIG. [Figure 6] 6 shows a cross-sectional view taken along line AA in FIG. 5. [Figure 7] 1A and 1B show an overall view and an enlarged view of an excerpt of a slit squeegee according to an embodiment of the present invention. [Figure 8]8 is an explanatory diagram showing the expansion and contraction state of a connecting portion caused by the stress of a slit squeegee shown in FIG. 7. FIG. [Figure 9] 8 is an enlarged perspective view showing a corner portion of the slit squeegee shown in FIG. 7, and a perspective view showing the state in which this slit squeegee is attached to a squeegee holder. FIG. [Figure 10] FIG. 4 is a perspective view showing a state in which the slit squeegee is attached to a squeegee holder. [Figure 11] FIG. 4 is a diagram illustrating the operation of the filling head and the sweeper head. [Figure 12] 4 is a continuation of the diagram illustrating the operation of the filling head and sweeper head. [Figure 13] FIG. 11 is a plan view of another embodiment of the slit squeegee of the present invention. [Figure 14] FIG. 11 is a plan view of still another embodiment of the slit squeegee of the present invention. [Figure 15] 1A and 1B are a plan view and a partially enlarged plan view showing a conventional slit squeegee; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiment is an example for explaining the present invention, and is omitted and simplified as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise limited, each component may be singular or plural. The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings. EXAMPLES

[0013] There are various methods for printing solder balls on electrode parts. In particular, the pitch of the printing object tends to become smaller, from 40 μm to 150 μm, and the size of the solder balls is also becoming smaller, from φ20 to φ100 μm. Therefore, a technology that can print small solder balls reliably and with high precision is desired.

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a solder ball printing apparatus (solder ball mounting apparatus) of the present invention will be described with reference to the drawings.

[0015] The overall configuration of a solder ball mounting device for printing solder balls is shown in Figure 1. Figure 1(a) shows the state in which the mask and the substrate are aligned, and Figure 1(b) shows the state in which the solder balls are printed on the substrate.

[0016] The solder ball mounting device 1 is provided with a printing table 21 equipped with a drive unit 22 so that it can move up and down. The printing table 21 is configured as an XYθ table so that it can move in the XYθ directions. A magnet 33 is placed on the printing table 21, and the board 20 is placed on it. Also, the alignment marks on the surface of the mask 8 attached to the solder ball mounting device 1 via a mask frame 9 and the surface of the substrate 20 are captured using a camera 18 (two-view camera), and a control unit (not shown) processes the images to determine the positional deviation of the marks. Using the determined deviation amount, the control unit drives and controls the printing table 21 on which the substrate 20 is placed in the horizontal direction (XYθ direction) to align the marks, thereby performing alignment. A camera moving frame 24 for moving the camera 18 is provided between the printing table 21 and the back side of the mask 8. This camera moving frame 24 is provided so as to be movable in the front-to-rear direction in FIG. 1.

[0017] After alignment is performed using camera 18, alignment camera 18 is retracted, and as shown in Fig. 1(b), drive unit 22 is operated to raise print table 21 on which substrate 20 is placed, and mask 8 provided on the upper part is brought into contact with the surface of substrate 20. Thereafter, head up-down drive mechanism 5 is driven to lower filling head 2 (sometimes referred to as transfer head) to the mask surface side, and a filling member (hereinafter sometimes referred to as squeegee or slit squeegee) (see Fig. 2), consisting of a plurality of thin strip-shaped members constituting the filling member of filling unit 3, is brought into contact with the mask surface with a predetermined pressing pressure.

[0018] The filling member is made equal to or larger than the width of the substrate to be printed, and the mask openings can be filled with solder balls by moving the filling head 2 once in the horizontal direction (longitudinal direction of the substrate). In practice, the filling head is moved back and forth once in the longitudinal direction of the substrate to reliably fill the mask openings. When moving the filling head horizontally, the driving mechanism 13 (see FIG. 5) provided in the filling unit 3 is operated to rotate the filling unit 3. The filling unit 3 is rotated at a relatively slow speed of 1 to 5 revolutions per second. If it is rotated too fast, the thin strip members constituting the slit squeegee 12 may cut the solder balls to be filled, causing volume defects, and may also cause unnecessary vibrations in the mask, causing double balls.

[0019] Next, the head drive unit (motor 2g) is driven to rotate the ball screw 2b and move the filling head 2 in the horizontal direction. As shown in Fig. 1, while the filling head 2 is moving, the filling unit 3 rotates at a predetermined number of revolutions in the same direction as the moving direction of the filling head 2 at the contact portion with the mask surface when the solder balls are mounted (so as to sweep out the solder balls 11). This allows the solder balls to be filled into the mask openings, and also scrapes up the surrounding solder balls 11 so that they do not remain on the mask surface.

[0020] By rotating the filling member in this manner with its rotation axis positioned parallel to the mask surface, the pressing force of the slit squeegee 12 against the mask surface can be reduced and balls can be filled uniformly over a wide area along the rotation axis.

[0021] Also, the rotation speed of the filling section 3 can be low, and scattering of the solder balls 11 due to rotation can be reduced. It is preferable to use a variable speed motor so that the rotation speed of the filling section 3 can be changed according to the size and amount of the solder balls 11. Furthermore, in this device, a cleaning mechanism 25 for cleaning the back surface of the mask is provided on the camera moving frame 24, and is configured to be able to move in the horizontal direction like the camera 18. Also, a sweeper head 26 is provided next to the filling head 2. This sweeper head 26 is for cleaning the small amount of solder balls remaining on the mask surface outside the printing area after the filling head 2 operates to finish filling the solder balls 11. Details of the sweeper head 26 will be described later.

[0022] A schematic diagram of the overall configuration of the fill head and sweeper head is shown in Figures 2 and 3. Figure 2 shows the fill head moving to the left, and Figure 3 shows the fill head moving to the right.

[0023] As shown in Fig. 2, the filling head 2 is configured such that the filling section 3 is housed within the cover 4, and a piston rod 6a attached to a cylinder 5a is connected to a cover support member 10, so that the filling head 2 can move up and down together with the cover 4 by driving the cylinder 5a. A receiver for a piston rod 6b that is shorter than the piston rod 6a attached to the cylinder 5b is provided on the end side of the cover support member 10, and by driving the cylinder 5b to determine the stopping position of the piston rod 6b, the lift height of the filling head 2 is determined when the solder ball filling section 3 is lifted upward. The cover 4 is provided to prevent the unfilled solder balls 11 from scattering outside the cover 4 due to the rotation of the filling section 3.

[0024] Furthermore, when in a printing state (when the filling section 3 is in contact with the mask surface), a gap is formed between this cover 4 and the mask 8 surface. Also, air supply sections 4a are provided at the front and rear of the cover 4, each equipped with an air supply port that blows air into the cover from the bottom of the cover and onto the lower end of the cover so that no solder balls remain on the mask surface outside the cover. The air blown into the cover 4 from the air supply section is exhausted from an exhaust port 4n provided in the cover support member 10. A mesh-shaped filter 4f is provided in this exhaust port 4n, so that the solder balls 11 do not scatter from inside the cover 4 to the outside.

[0025] As shown in FIG. 2, when the filling head 2 moves to the left side of the figure, the filling unit 3 rotates in a clockwise direction as shown in the figure. Also, as shown in FIG. 3, when the filling head 2 moves to the right side of the figure, the filling unit 3 is configured to rotate in a counterclockwise direction. In this way, by rotating the filling unit 3 in such a way that the solder balls 11 are swept out to the moving side of the filling head 2 according to the moving direction, and by blowing air from the cover, it is possible to prevent the scattering of the solder balls 11, ensure the filling amount into the mask opening, and minimize the remaining of the excess solder balls on the mask surface. Also, instead of air, a gas such as nitrogen that retards the oxidation of the solder balls 11 may be blown into the cover 4.

[0026] The filling section 3 is supported at both longitudinal ends of the cover 4. The cover 4 is supported by a piston rod 6a constituting a cylinder 5a provided on the upper part of the head mounting frame 7 via a cover support member 10. The head mounting frame 7 is configured to move back and forth in the horizontal direction on a linear rail (not shown) by rotating a ball screw 2b provided on the printer body using a motor 2g as shown in FIG. 1. The main body of the solder ball mounting device 1 is provided with a mask holding section that holds a mask frame 9 to which a mask 8 having a plurality of openings is attached. The substrate 20, which is the object to be printed, is held on the surface of a magnet 33 placed on a printing table 21 that is movable in the XYθ and Z directions and is provided on the main body of the solder ball mounting device.

[0027] The magnets 33 provided on the printing table are for bringing the substrate 20 and the mask 8 into close contact with each other. The mask 8 is made of a magnetic material such as nickel, and when the printing table is raised and brought into contact with the mask surface, the magnetic force further improves the adhesion between the substrate 20 and the mask 8.

[0028] Furthermore, a sweeper head 26, which is provided in parallel with the filling head 2, is attached to a ball screw or timing belt (not shown). This sweeper head 26 is attached to a sweeper mounting frame 29, like the filling head. A cylinder 5c, which is a drive source for moving a sweeper portion 27 of the sweeper head 26 up and down, is provided on the upper part of the sweeper mounting frame 29. The sweeper portion 27 has a sweeper holder 4s attached to a sweeper support member, and a sweeper member attached to the tip of the sweeper holder 4s.

[0029] This sweeper member is basically of approximately the same configuration as the filling member used in the filling head for solder balls described above, and will be described in detail later. The drive section of the sweeper head 26 is equipped with a cylinder 5d and a piston shaft 6d that determine the lift height of the sweeper head 26, just like the filling head 2.

[0030] Figure 4 shows the sweeper head in operation. When the filling head 2 has finished filling the openings on the mask surface with solder balls 11, the sweeper head 26 moves the filling head 2 to the end of the mask 8. Next, the sweeper head 26, which is waiting above the mask surface in the waiting position, moves in the direction of the arrow (to the right in Figure 4) to collect the solder balls 11 remaining on the mask surface on the side of the mask surface where the filling head 2 is waiting. After that, with the sweeper head lowered, the printing table is lowered to separate the mask from the board surface. The printing operation will be described in detail later.

[0031] Next, a schematic structure of the filling unit 3 will be described. Fig. 5 shows a front view of the filling unit, and Fig. 6 shows a cross-sectional view taken along line AA in Fig. 5. Fig. 7 shows a plan view of the slit squeegee, which is a filling member, before it is attached, and Fig. 10 shows the state in which the slit squeegee is fixed to the squeegee holder.

[0032] As shown in FIG. 5 and FIG. 6, the filling section 3 has a filling section mounting member (hereinafter, sometimes referred to as a squeegee holder 14) fixed to each side of an octagonal fixing member 15 provided on a rotating shaft 16 by bolts 17. The fixing member 15 is not limited to an octagonal shape, and may be a polygonal shape from a hexagon to a dodecagon. Both ends of the rotating shaft 16 are supported by the cover 4 via bearings. A driving mechanism 13 is provided on one end of the rotating shaft 16, and the rotating shaft 16 can be rotated at a predetermined number of revolutions by driving a motor constituting the driving mechanism 13. As shown in FIG. 5, the filling section 3 is formed long in the direction perpendicular to the moving direction of the filling head 2 (the width direction of the board). This length is formed to be longer than the width of the board 20 on which the solder balls are printed.

[0033] As a result, essentially, by moving the solder ball filling head 2 horizontally once over the mask surface, it is possible to fill almost all of the electrode portions of the substrate 20 with solder balls 11. The length of the filling member is Lj as shown in the figure, the mask width Lm is made larger than this Lj, and the substrate width Lt is made smaller than the mask width Lm and the filling member width Lj. In other words, there is a relationship of Lm ≧ Lj ≧ Lt.

[0034] As shown in FIG. 6, the squeegee holder 14 is fitted with a slit squeegee 12 made up of a number of thin strip-shaped members as shown in FIG. 7. The cross section of the squeegee holder 14 is trapezoidal as shown in the figure, with the long sides being rectangular. The squeegee holder 14 is fitted with the short sides of the trapezoid facing the central axis. The trapezoidal cross section allows the slit squeegee 12 to be fitted efficiently in a semi-cylindrical shape. As shown in FIG. 10, magnets 31 are embedded in the rectangular portion of the squeegee holder 14 at a predetermined interval in the longitudinal direction. The magnets 31 are used to fix the slit squeegee 12 to the squeegee holder. Positioning pins 32 are provided between the magnets, and these pins are adapted to fit into insertion holes 12H provided in fixing parts 12P provided at both ends of the slit squeegee 12 in the width direction.

[0035] As shown in Fig. 7, the slit squeegee 12 is made of a steel plate having a thickness of 0.05 to 0.1 mm, with main slits 12S spaced at intervals of 0.1 mm to 0.3 mm, and is etched at a line width of 0.1 mm with an inclination of θ = 5 degrees to 35 degrees, except for fixed portions 12P, to form a plurality of wires at once. The fixed portions 12P provided at both ends in the width direction are fixed to both sides of the squeegee holder 14. The slit squeegee 12 may be formed by electroforming instead of etching.

[0036] FIG. 15(a) is a plan view showing a conventional squeegee P12 in an expanded state, and FIG. 15(b) is an enlarged view showing the portion B surrounded by the dashed line in FIG. 15(a). For example, this squeegee P12 uses a steel plate having a thickness of 0.05 to 0.1 mm, and slits P12S having a width of 0.1 mm to 0.3 mm are provided at intervals of 0.1 mm to 0.3 mm with an inclination of θ=5 degrees to 35 degrees. In this way, a narrow strip-shaped member P12L having a width of 0.1 mm to 0.3 mm is formed by adjacent slits P12S. The slits P12S are formed, for example, by etching a steel plate having a thickness of 0.05 to 0.1 mm. The squeegee P12 is attached in a semi-cylindrical shape with fixing parts P12P provided at both ends in the width direction fixed to both sides of the squeegee holder 14, and advances in the advance direction F indicated by the arrow.

[0037] By forming the slits P12S in the steel plate, fixed portions P12P are provided at the front and rear of the steel plate in the traveling direction F, so that the narrow strip members P12L formed by adjacent slits P12S do not come apart, but both side ends in the traveling direction F do come apart. Therefore, connecting portions P12C are formed at both side ends by the narrow strip members P12L that are continuously formed by the ends of the slits P12S, connecting the narrow strip members P12L.

[0038] As described above, the conventional squeegee P12 presses its semi-cylindrical portion against the mask 8 to come into contact with it and travels over the mask 8, but in the center of the squeegee P122, even when this pressure is applied, the slits P12S open slightly to absorb the pressure. However, since both side ends in the traveling direction F of the squeegee P12 have connecting portions P12C that simply connect the narrow strip members P12L together, the connecting portions cannot absorb the pressure and are subjected to stress. This has resulted in a problem that the connecting portions may be damaged by this stress during long-term use.

[0039] Therefore, in one embodiment of the present invention, the slit squeegee 12 is configured as shown in Fig. 7. In this figure, Fig. 7(a) is a plan view showing one embodiment of the present invention, Fig. 7(b) is a partially enlarged view of the portion indicated by the dashed line portion B in Fig. 7(a), and Fig. 7(c) is an enlarged view of a connecting portion 41 configured at a side end portion of the slit squeegee 12 in the traveling direction F. Note that Fig. 9(a) is an enlarged perspective view of the end portion of the slit squeegee 12, and Fig. 9(b) is an enlarged perspective view of the end portion where the slit squeegee 12 is attached to the squeegee holder 14.

[0040] In the central portion 40 of the slit squeegee 12 in the traveling direction F, as in the conventional case, a thin steel plate having a thickness of 0.05 to 0.1 mm is used, for example, and main slits 12S having a width of 0.1 mm to 0.3 mm are provided at intervals of 0.1 mm to 0.3 mm with an inclination of θ = 5 degrees to 35 degrees. In this way, adjacent main slits 12S form a narrow strip-shaped member 12L having a width of 0.1 mm to 0.3 mm. The main slits 12S are formed, for example, by etching a steel plate having a thickness of 0.05 to 0.1 mm. The main difference from the conventional case is the configuration of the connecting portion 41. Conventionally, the thin strip-shaped members P12L were simply connected continuously by the connecting portion P12C, but according to this embodiment, a large number of auxiliary slits 42 are arranged alternately in the connecting portion 41, and these auxiliary slits 42 cut off the continuity of the connecting portions 41 arranged on both side ends of the slit squeegee 12 in the traveling direction F of the slit squeegee 12.

[0041] 7(c), the embodiment has sub-slit 42a arranged over almost the entire area of ​​connecting portion 41 and closed at both ends, sub-slit 42b having one end open at the end of slit squeegee 12 and the other end extending to the central portion of connecting portion 41, and sub-slit 42c forming connecting portion 43a between the end of the central portion of sub-slit 42b. Sub-slits 42c located on both sides of sub-slit 42a communicate with each other on the main slit 12S side.

[0042] The thin strip-shaped members 12L formed by adjacent main slits 12S arranged in the central portion 40 of the slit squeegee 12 are connected at the ends of three adjacent strips, and this connection portion 43b is further connected to the connection portion 43a by the thin strip-shaped members 43L formed by the adjacent sub-slits 42c described above.

[0043] Due to the arrangement of these sub-slits 42a, 42b, 42c, the continuity of the connecting portion 41 (such as the continuity of the conventional slit squeegee connecting portion P12C) is cut off in the moving direction F of the slit squeegee 12, as shown by the connecting portion 43a, and the side ends of the slit squeegee 12 are connected by the connecting portion 43a and the substantially diamond-shaped sub-strip member 43m formed by the sub-slits 42a. With this configuration, the connecting portion 41 has a substantially mesh-like or pantograph-like shape. As a result, even if stress is applied to both side ends of the slit squeegee 12 when the semi-cylindrical portion of the slit squeegee 12 is pressed against and comes into contact with the mask 8 and moves over the mask 8, the sub-slits 42a open slightly to absorb this stress. In particular, by making the connecting portion 41 symmetrical like a pantograph or approximately diamond shaped, the sub-slit 42a expands and contracts approximately uniformly in the left-right or up-down directions (arrow f) and the amount of displacement when expanding and contracting is approximately uniform, so that the applied load is distributed and reduced and stress concentration is alleviated, thereby contributing to an extension of the lifespan.

[0044] The connecting portions 43c appropriately connect adjacent main slits 12S so that the strip-shaped members 12L formed by the adjacent main slits 12S do not come apart. In the embodiment, the connecting portions 43c are generally arranged in a staggered pattern, but this is not limiting and they may be appropriately arranged so that the main slits 12S do not come apart.

[0045] Fig. 8 is a simplified diagram for easy understanding of the slit squeegee 12 of this embodiment, and Fig. 8(a) is similar to Fig. 7(c). Fig. 8(b) is a diagram showing the part indicated by X in Fig. 8(a) and is a schematic diagram in which the thin strip-shaped member formed as a result of the various slits described above is emphasized by thick lines. Figs. 8(c) and 8(d) are diagrams for explaining the state in which the connecting portion 41 is deformed by stress applied thereto. In these figures, the same reference numerals as those in Fig. 7 indicate the same parts.

[0046] That is, under normal circumstances, the shape of the slit squeegee 12 is stable as shown in Figures 8(a), 8(b), and 8(c), but when the slit squeegee 12 is pressed onto the mask 8 during the solder ball mounting operation and stress is applied to both side ends of the slit squeegee 12, the connecting parts 41 at the side ends are pulled up and down as shown in Figure 8(d). As a result, a force is applied to the roughly diamond-shaped sub-strip members 43m formed by the sub-slits 42a in the direction shown by the arrow f, causing the sub-slits 42a to open, thereby absorbing the stress.

[0047] Furthermore, the connecting portion 41 of the slit squeegee 12 is flexible in response to the applied stress, and as a result, absorbs this stress.

[0048] Next, a method for attaching the slit squeegee 12 to the squeegee holder 14 will be described with reference to Figure 10. Figure 10(a) shows a perspective view, and Figure 10(b) shows a cross-sectional view.

[0049] The squeegee holder 14 is provided with a plurality of positioning pins 32 spaced at predetermined intervals, and magnets 31 are embedded between the positioning pins 32. When attaching the slit squeegee 12 to each squeegee holder 14, the positioning pins 32 provided on both sides of the squeegee holder 14 are inserted into the insertion holes 12H of the slit squeegee 12, respectively. Thereafter, the positioning pins 32 are inserted into the insertion holes 30H provided in the squeegee pressing plate 30 made of a magnetic material, whereby a magnetic force acts on the pressing plate 30 to fix it in place. In this manner, positioning can be easily performed, and the slit squeegee 12 can be easily attached and removed.

[0050] In addition, such a structure can reduce the fixing space, so that the interval between the squeegee holders 14 can be reduced. The narrow strip members 12L constituting the slit squeegee 12 are attached so as to have a predetermined inclination with respect to the longitudinal direction and to form a space with respect to the squeegee holder 14. That is, the slit squeegee 12 is composed of the narrow strip members 12L that are semi-spiral in the longitudinal direction. Furthermore, as shown in FIG. 5, the narrow strip members 12L constituting the slit squeegee 12 are attached so that the inclination direction of the narrow strip members 12L is opposite to that of the adjacent squeegee holders 14. By alternately changing the inclination direction of the slit squeegee 12 in this way, the excess solder balls that are not filled in the mask openings and remain on the mask surface can be efficiently collected to the filling section side.

[0051] Next, a series of operations for printing solder balls will be described with reference to FIGS.

[0052] First, the substrate 20 with flux printed on the electrode portion is carried into the solder ball mounting device and placed on the magnet 33 on the printing table 21. The printing table 21 and the magnet 33 are provided with a plurality of suction ports for supplying negative pressure, and by supplying negative pressure to these ports, the substrate 20 is held on the magnet 33 so that it does not move.

[0053] Next, the alignment marks provided on the surface of the substrate 20 and the alignment marks provided on the mask 8 are imaged using an alignment camera 18. The imaged data is sent to a control unit (not shown), which processes the image to determine the amount of misalignment, and based on the result, the printing table 21 is moved in a direction to correct the misalignment by a horizontal movement mechanism (not shown).

[0054] When the alignment is complete, the drive unit 22, which is a mechanism for lifting the printing table 21, is driven to lift the printing table 21 and bring it into contact with the rear surface of the mask 8. At this time, the mask 8 can be brought into close contact with the substrate 20 by the magnets 33 on the printing table 21.

[0055] Next, a solder ball supplying device (not shown) supplies solder balls 11 to the front portion of the initial position (printing start position) of the filling head 2 on the surface of the mask 8 in the moving direction. After that, the filling head 2 is moved horizontally to the printing start position and lowered to the mask surface. At this time, the filling unit 3 is lowered to a position where a predetermined pressing force acts on the mask surface.

[0056] Next, as shown in FIG. 11 (1) (or FIG. 6), the filling unit 3 is rotated clockwise. After that, the solder ball filling head 2 is moved horizontally on the mask surface in the left direction of the arrow in the figure. At this time, the air supply unit 4a blows air toward the inside of the cover 4 with the slit squeegee while moving. Also, by rotating the filling unit 3 in this way, the solder balls 11 are pushed into the openings at the mask openings and attached to the flux on the board 20, and in the areas other than the openings, the filling unit 3 moves the solder balls 11 in the traveling direction on the mask surface. When the filling unit 3 reaches the end of the board, the rotation of the filling unit 3 is stopped, the supply of air from the air supply unit 4a is stopped, and the filling unit 3 is raised. After that, the filling head 2 is moved leftward as shown in FIG. 11 (2). In this way, by moving the filling head, the filling head 2 is positioned behind the position of the solder ball 11 to be filled next. When the movement is completed, the filling unit 3 is lowered again to a position where it contacts the mask surface with a predetermined pressing pressure. Then, as shown in FIG. 11 (3), the air supply unit resumes supplying air into the cover, and the filling unit 3 is rotated counterclockwise to move the filling head 2 to the right side of the figure. Then, when it reaches a position close to the end of the board, the air supply unit stops supplying air, and as shown in FIG. 11 (4), the filling unit 3 of the filling head 2 is raised, the filling head 2 is moved further to the right, and the filling unit 3 is lowered as shown in FIG. 11 (5), so that the remaining solder ball 11 is positioned to the left of the filling unit 3. After that, the filling unit is lowered onto the mask surface and placed in a standby state. In this way, in this embodiment, the filling head 2 is made to reciprocate once to fill the mask opening with the solder balls, thereby ensuring reliable filling.

[0057] In steps (1) to (4) of FIG. 11, the sweeper head 26 waits with the sweeper part 27 lowered on the surface of the mask 8. Next, as shown in FIG. 11(6), the sweeper head 26 is moved to the right side of the figure (the side where the filling head 2 is waiting). It is moved to the vicinity of the waiting position of the filling head 2. As shown in FIG. 12(7), when the sweeper head 26 reaches the vicinity of the filling head 2, the sweeper part 27 is raised and separated from the mask surface. Then, the sweeper head 26 is returned to the initial waiting position. When it returns to the waiting position as shown in FIG. 12(8), the sweeper part 27 is lowered again to the mask surface and contacted with a predetermined contact pressure. As shown in FIG. 12(9), it is moved again over the mask surface to the vicinity of the waiting position of the filling head 2. This movement allows the solder balls 11 remaining on the mask surface to be collected at a position completely off the substrate surface. When this cleaning is completed, with the filling head 2 and the sweeper head 26 still in contact with the mask surface, the printing table 21 is lowered to separate the substrate 20 from the mask surface.

[0058] In this explanation, the sweeper head 26 is operated twice, but by operating it multiple times, it is possible to reliably move the remaining solder balls on the mask surface to a position away from the substrate position.

[0059] Furthermore, in this embodiment, it has been explained that after filling the mask openings with solder balls 11 using the filling head 2, the sweeper head 26 is operated to clean the remaining solder balls on the mask surface to the mask surface away from the substrate, but if the filling head of the embodiment is used, it is considered that there will be almost no solder balls remaining on the mask surface, making cleaning unnecessary, and there may be cases where a sweeper head is not required. Alternatively, it is possible to use the filling head 2 and the sweeper head 26 as an integrated head.

[0060] 11(6) to 12(9), when the filling head 2 is on standby, air or nitrogen may be blown from the air supply unit 4a toward the inside of the cover 4. In this way, it is possible to prevent the solder balls 11 from leaking out of the cover, and the oxidation of the solder balls 11 can be delayed.

[0061] Next, the printed state of the printed substrate 20 is photographed by a camera to check for defects. After checking for defects, the cleaning mechanism 25 is driven to clean the back surface of the mask. If defects are found, the substrate 20 is transported to a repair section where the defects are repaired. After the defects are repaired, the substrate is transported to a reflow section where the solder balls are melted and fixed.

[0062] The above describes the general process of printing solder balls, but as the repair and reflow sections use separate equipment from the above-mentioned devices, they will not be described in detail.

[0063] In this process, by using the solder ball supply head of the present invention, it is possible to reliably supply solder balls having a minute diameter onto the flux through the mask openings. EXAMPLES

[0064] 13 is a plan view showing another embodiment of the slit squeegee of the present invention. In the first embodiment, the connecting parts 41 formed on both end parts in the traveling direction F of the slit squeegee 12 are configured to be expandable and contractable in the traveling direction F by rationally arranging the auxiliary slits, but in this embodiment, the connecting parts 412 are configured from an elastic body, and are configured to be expandable and contractable in the traveling direction F.

[0065] Here, the slit squeegee 122 is a conventional slit squeegee P12. Elastic resin 50 is pressed onto both side ends of the slit squeegee 122 in the traveling direction F. Subsequently, this elastic resin 50 is polished until it is as thin as possible, until it becomes the same thickness as the thin steel plate constituting the slit squeegee P12, and then the connecting portion P12C is cut along line YY to configure the connecting portion 412 to be freely expandable and contractible in the traveling direction F by the elastic force of the elastic body. As another example of joining elastic bodies, for example, the example shown in JP 2006-294527 A can also be applied.

[0066] In this way, the slit squeegee 122 presses the semi-cylindrical portion against the mask 8 to come into contact with it and travels over the mask 8, as described above, but even when this pressure is applied to the central portion 402, the main slit 12S opens slightly to absorb the pressure. And, because the narrow strip members 12L are connected to both side ends of the slit squeegee 122 in the travel direction F by an elastic body, the elastic body expands and contracts under the pressure, absorbing stress. Therefore, damage to the connecting portions 412 present at both side ends of the slit squeegee 122 can be prevented for a longer period of time, and a squeegee for a solder ball mounting device and a solder ball mounting device that can withstand long-term use can be obtained.

[0067] The attachment of the slit squeegee 122 to the squeegee holder 14 is similar to that of the slit squeegee 12 . EXAMPLES

[0068] 14 is a plan view showing still another embodiment of the slit squeegee. In the first embodiment, the connecting parts 41 formed on both end parts in the traveling direction F of the slit squeegee 12 are configured to be expandable and contractable in the traveling direction F by rationally arranging the auxiliary slits, but in this embodiment, the connecting parts 413 are configured from metal plates 60 having elasticity, and the connecting parts 413 are configured to be expandable and contractable in the traveling direction F.

[0069] Here, the slit squeegee 123 uses a conventional slit squeegee 12, as in the second embodiment. Elastic metal plates 60 are joined to both end portions of the slit squeegee 123 in the traveling direction F. The elastic metal plate 60 is then rolled and polished until it is as thin as possible, and is the same as the thin steel plate constituting the slit squeegee 12. Thereafter, the connecting portion P12C is cut along the line YY, and the connecting portion 413 is configured to be expandable and contractible in the traveling direction F by the elasticity of the elastic metal plate 60. Other examples of elastic metal plates and their joining can also be applied, for example, to the cases shown in Japanese Patent Application No. 2007-546902 and Japanese Patent Laid-Open No. 02-107884.

[0070] In this manner, the slit squeegee 123, like the above, presses the semi-cylindrical portion onto the mask 8 to come into contact with it and moves over the mask 8, but even when this pressing force is applied to the connecting portion 413, the main slit 12S opens slightly to absorb this pressing force. And, because the narrow strip members 12L are connected to both side ends of the slit squeegee 123 in the moving direction F by the elastic metal plate 60, this pressing force causes the elastic metal plate 60 to expand and contract, absorbing stress.

[0071] Therefore, damage to the connecting portions 413 present at both ends of the slit squeegee 123 can be prevented for a longer period of time, and a squeegee for a solder ball mounting device and a solder ball mounting device that can withstand long-term use can be obtained.

[0072] The attachment of the slit squeegee 123 to the squeegee holder 14 is similar to that of the slit squeegee 12 .

[0073] As is clear from the above description of the embodiment, according to the present invention, the squeegee is formed in a thin plate shape, has a plurality of slits at a predetermined angle with respect to the direction of movement when the solder balls are mounted, and has a connecting portion at both ends in the direction of movement that connects the thin plates separated by the slits, and this connecting portion is formed to be flexible at least in the direction of movement, so that even if stress is applied to both ends of the squeegee when the squeegee is pressed against the mask to make contact and move over the mask, this stress is absorbed by its flexibility. Therefore, it is possible to provide a squeegee for a solder ball mounting device and a solder ball mounting device that can withstand long-term use by preventing damage to the connecting portions at both ends of the squeegee for a long period of time. In other words, it is possible to reduce the frequency of replacement due to damage to the ends of the squeegee.

[0074] As explained in the embodiment, it is preferable to form the squeegee in a semi-cylindrical shape and use it when mounting the solder balls. By pressing the semi-cylindrical cylindrical part against the mask, the cylindrical part is deformed and adheres closely to the surface of the mask. This configuration extends the life of the squeegee and improves its functionality.

[0075] Furthermore, as shown in the examples, it is preferable to form the connecting parts from an elastic body or a metal plate having elasticity in order to allow the connecting parts to expand and contract freely. This configuration further extends the life of the product.

[0076] In the examples, in explaining the alternating arrangement of sub-slits, sub-slits that are open at their ends and sub-slits that are closed at their ends are arranged alternately. However, alternating arrangement here means alternating one by one, as well as alternating multiple, or one and then two, etc., and the combination can be selected as needed.

[0077] In the squeegee of this embodiment, it is preferable that the narrow strip members formed by adjacent main slits are appropriately connected to the adjacent narrow strip members at the central portion corresponding to the substrate surface by the main slit connecting portion.

[0078] Furthermore, by providing mounting portions at both ends of the squeegee in the direction of travel and forming a semi-cylindrical shape by attaching the mounting portions to the squeegee holder, the life of the squeegee can be extended and its functionality can be improved. [Explanation of symbols]

[0079] 1...solder ball mounting device, 2...filling head, 3...filling section, 4...cover, 5...head up / down drive mechanism, 7...head mounting frame, 8...mask, 10...cover support member, 10a...sweeper support member, 11...solder ball, 12...slit squeegee, 14...squeegee holder, 16...rotating shaft, 18...camera, 20...substrate, 21...printing table, 31...magnet, 32...positioning pin, 33...magnet, 40, 402, 403...center of squeegee, 41, 412, 413...squeegee connection section, 42a...secondary slit closing at end, 42b...secondary slit opening at end, 50...elastic resin, 60...metal plate with elasticity

Claims

1. A squeegee of a solder ball mounting device is provided on a surface of a substrate on which a plurality of electrodes are formed, the mask having openings at positions corresponding to the electrodes, and solder balls are supplied onto the mask through the openings to mount the solder balls on the electrodes, The solder ball is formed in a thin plate shape and has a plurality of slits at a predetermined angle with respect to the direction of movement of the solder ball when the solder ball is mounted. a connecting portion for connecting the thin plates separated by the slit at both end portions in the traveling direction; A squeegee for a solder ball mounting device, characterized in that the connecting portions are formed to be freely expandable and contractible at least in the traveling direction by alternately arranging secondary slits in the connecting portions so that the connecting portions are not continuous in the traveling direction.

2. 2. The squeegee of claim 1, The squeegee of the solder ball mounting device is characterized in that the squeegee is used in a state formed into a semi-cylindrical shape.

3. 2. The squeegee of claim 1, The squeegee of a solder ball mounting device is characterized in that the connecting portion is formed to be freely expandable and contractible at least in the direction of travel by alternating sub-slits that open at the end and sub-slits that close at the end.

4. 2. The squeegee of claim 1, A squeegee for a solder ball mounting device, characterized in that adjacent narrow strip members formed by the slits are connected to adjacent narrow strip members by a slit connecting portion at a central portion corresponding to the board.

5. 2. The squeegee of claim 1, A squeegee for a solder ball mounting device, comprising attachment portions at both ends in the moving direction, the attachment portions being attached to a squeegee holder to form a semi-cylindrical shape.

6. A squeegee for a solder ball mounting device which applies a solder ball to a surface of a substrate on which a plurality of electrodes are formed through a mask having openings at positions corresponding to the electrodes, and mounts the solder ball on the electrodes through the openings, The solder ball is formed in a thin plate shape and has a plurality of slits at a predetermined angle with respect to the direction of movement of the solder ball when the solder ball is mounted. a connecting portion for connecting the thin plates separated by the slit at both end portions in the traveling direction; 4 is a squeegee for a solder ball mounting device according to the first embodiment of the present invention;

7. 7. The squeegee of claim 6, The squeegee of the solder ball mounting device is characterized in that the elastic body is formed of a metal plate having elasticity, and is thus formed to be freely stretchable at least in the traveling direction.

8. A solder ball mounting device is provided for mounting solder balls on a substrate surface having a plurality of electrodes and a surface coated with flux, the device being provided with a mask having openings at positions corresponding to the electrodes, the mask being provided with a semi-cylindrical squeegee having a plurality of slits in a thin plate, through which the mask is used to mount solder balls on the electrodes through the openings, the device comprising: The squeegee is formed in a thin plate shape, a plurality of slits at a central portion corresponding to the substrate surface and having a predetermined angle with respect to the traveling direction; a connecting portion for connecting the thin plates separated by the slit at both end portions in the traveling direction; A solder ball mounting device characterized in that the connecting portion is formed to be freely expandable and contractible at least in the traveling direction by alternately arranging secondary slits in the connecting portion so that the connecting portion of the squeegee is not continuous in the traveling direction.

9. 9. The solder ball mounting device according to claim 8, A solder ball mounting device characterized in that the connecting portion of the squeegee is formed to be freely expandable and contractible at least in the direction of travel by alternating sub-slits that open at the end and sub-slits that close at the end.

10. 9. The solder ball mounting device according to claim 8, a squeegee that is connected to the substrate surface by a slit connecting portion, the squeegee being connected to the substrate surface by a slit connecting portion, and the squeegee is connected to the substrate surface by a slit connecting portion.

11. 9. The solder ball mounting device according to claim 8, The solder ball mounting device is characterized in that the squeegee has mounting portions at both ends in the moving direction thereof, and the mounting portions are attached to a squeegee holder to form the semi-cylindrical shape.

12. 9. The solder ball mounting device according to claim 8, a semi-cylindrical cylindrical portion that is pressed against the mask, whereby the cylindrical portion is deformed and comes into close contact with the surface of the mask;

13. A solder ball mounting device which mounts solder balls supplied onto a mask having openings at positions corresponding to the electrodes on a substrate surface having a plurality of electrodes formed thereon and a flux applied thereon, using a squeegee formed in a semi-cylindrical shape having a plurality of slits in a thin plate through the mask and mounting the solder balls onto the electrodes through the openings, The squeegee is formed in a thin plate shape, a plurality of slits at a central portion corresponding to the substrate surface and having a predetermined angle with respect to the traveling direction; a connecting portion for connecting the thin plates separated by the slit at both end portions in the traveling direction; The solder ball mounting device is characterized in that the connecting portion of the squeegee is formed of an elastic body, and is thereby formed to be freely expandable at least in the traveling direction.

14. 14. The solder ball mounting device according to claim 13, The solder ball mounting device is characterized in that the connecting portion of the squeegee is formed of a metal plate having elasticity, and is thereby formed to be freely expandable at least in the traveling direction.

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