JP4995664B2 - Apparatus and mask for filling conductive balls - Google Patents

Description

  The present invention relates to an apparatus for filling a plurality of openings of a mask with conductive balls, and a mask that can be suitably used for the apparatus.

In order to obtain an electrical connection such as mounting a semiconductor device, a conductive ball such as a solder ball may be used. Patent Document 1 discloses an apparatus for placing conductive balls on a substrate and filling a plurality of openings in the mask with conductive balls in a state where a mask for placing the conductive balls on the substrate is set on the substrate. It is disclosed. Patent Document 1 discloses, as an example of this apparatus, one having a head including a squeegee protruding toward a mask. The head holds the population of conductive balls in a partial area of the surface of the mask by rotating about an axis perpendicular to the mask. The apparatus having the head moves the vertical axis along the surface of the mask while rotating the head, thereby causing the conductive balls held in the area to pass through the plurality of parts of the mask through which the area passes. The openings are sequentially filled, and conductive balls are disposed on the substrate through the plurality of openings of the mask.
International Publication No. 2006/004000 Pamphlet

  According to the apparatus described in Patent Document 1, the head moves on the mask while holding a group of conductive balls in a limited area on the surface of the mask. Thus, the conductive balls held in the area are sequentially filled into the plurality of openings of the mask. Therefore, according to the apparatus described in Patent Document 1, the density of the conductive balls in the area can be increased even with a relatively small number of conductive balls. For this reason, the conductive ball can be efficiently filled into the opening of the mask in the portion through which the area passes. Further, the number of conductive balls to be held in a limited area on the surface of the mask may be very small as compared with the case where the conductive balls are held uniformly over the entire mask. Therefore, the amount of conductive balls that can be damaged by moving on the mask can be reduced. For this reason, the loss of the conductive ball by filling can be reduced.

  However, in order to arrange (arrange) the conductive balls on the substrate using the apparatus as described above, it is necessary to pass the head over the entire area of the mask surface where the conductive balls are to be arranged. There is. Therefore, a certain amount of time is required to arrange the conductive balls on one substrate. As an apparatus for filling the conductive balls, an apparatus capable of further shortening the time required to dispose the conductive balls on one substrate (hereinafter referred to as tact time) is required.

  According to one embodiment of the present invention, a mask including a plurality of openings for disposing conductive balls on a plurality of electrodes of a substrate including a plurality of electrodes and a substrate are set, and the plurality of openings are conductive. It is an apparatus for filling the sex balls. The substrate includes a plurality of electrode patterns that are an array of a plurality of electrodes, and the mask includes a plurality of mask patterns that are an array of a plurality of openings. The plurality of mask patterns of the mask correspond to the plurality of electrode patterns on the substrate. The mask further includes a plurality of groove-shaped first recesses extending in the first direction parallel to the upper surface of the mask. Several mask patterns are arranged in each recess of the plurality of first recesses, and each recess has a depth corresponding at least to the radius of the conductive ball.

  The apparatus includes a holding unit for holding the mask on the substrate, a plurality of heads provided along a second direction intersecting the first direction when the mask is held by the holding unit, and a plurality of heads. Moving means for moving the head in the first direction. In this apparatus, the mask is held by the holding means, and the heads of the plurality of heads are moved in the first direction by the moving means in a state where the heads enter the respective recesses of the plurality of first recesses. The conductive ball in each recess is moved in the first direction along each recess, and the conductive ball is filled in a plurality of openings included in several mask patterns provided in each recess.

  The mask held by the holding means of this apparatus is such that each recess of the plurality of first recesses extending along the first direction has a depth corresponding to at least the radius of the conductive ball (more than the radius of the conductive ball). Depth) and several mask patterns are arranged in each recess. Since the position of the upper end of each recess is higher than the position of the center of gravity of the conductive ball supplied into each recess, the conductive ball supplied into each recess is once moved by each head. However, basically, it does not get over each recess, or it is difficult to get over.

  Therefore, by moving the heads of the plurality of heads in the first direction by the moving means in a state of entering the concave portions of the mask, the plurality of heads are respectively in the plurality of first concave portions. , Forming a group of a plurality of isolated (independent, distinct) conductive balls. Each head has a group of conductive balls in a first direction (a direction in which the groove-shaped first recess extends, a longitudinal direction of the groove-shaped first recess) along each recess. Move while pushing away. Therefore, the distribution of the conductive ball group on the mask (including the spread of the conductive balls and the overlapping state) can be controlled in units of each recess. Since the distribution of the conductive balls does not fluctuate in units of the width of the entire mask, for example, the density of the conductive balls comparable to the size of each mask pattern does not occur, and the conductive ball mask opening is not generated. It is possible to prevent the occurrence of a situation where the filling of the container becomes irregular.

  Furthermore, according to this apparatus, since the group of conductive balls is formed by each recess, the density of the conductive balls in each recess can be increased even with a relatively small number of conductive balls. Therefore, the conductive balls can be efficiently filled into the plurality of openings of several mask patterns arranged (included) in each recess. Further, the number of balls included in the group of conductive balls formed for each recess may be very small as compared to the case where the conductive balls are uniformly held with respect to the entire mask. Accordingly, since the amount of conductive balls that can be damaged by moving on the mask can be reduced, loss of the conductive balls due to filling can be reduced.

  On the other hand, according to this apparatus, the plurality of heads are moved in parallel, and the conductive balls in the plurality of recesses are filled in the plurality of openings of the plurality of mask patterns included in these recesses. For this reason, it is possible to suppress an increase in time (tact time) for arranging the conductive balls on one substrate.

  This apparatus is used when conductive balls are arranged (arranged) on a substrate having a plurality of electrode patterns, and the substrate may be a silicon wafer (silicon wafer, semiconductor wafer). This device is particularly suitable for placing conductive balls on a substrate having a slightly wide space between electrode patterns, such as a printed wiring board (printed wiring board, printed circuit board, printed circuit board, circuit board, printed board). Is suitable.

  Since a substrate such as a printed wiring board mounts a plurality of semiconductor chips (semiconductor devices) in a matrix or array, a plurality of electrode patterns are provided in a matrix or array with a certain distance. A mask for disposing conductive balls on such a substrate is also provided with a plurality of mask patterns in a matrix or array with a certain distance. For this reason, the mask has a region where an opening is provided and a region where no opening is provided.

  By forming the plurality of first concave portions of the mask so as not to include the region where the opening is not provided as much as possible, the conductive ball fills the region where the opening is not provided (fills the conductive ball) It is possible to prevent passing through a region that is not necessary. For this reason, with a small number of conductive balls, the density of the conductive balls in the region where the openings are provided (the region where the conductive balls need to be filled) can be increased. Furthermore, loss when the conductive ball passes through a region where no opening is provided, for example, damage to the conductive ball can be reduced.

  In this apparatus, it is preferable that the plurality of heads are supported by a common base, and the moving means moves the base in the first direction. A plurality of heads can be moved in the first direction by a moving means having a relatively simple configuration. The plurality of heads may be moved individually by the moving means.

  Further, in this apparatus, for example, a head provided with a pair of sweep members opposed in the first direction can be used as each head. In this case, by moving each head into each recess, a pair of sweep members of each head and both sides of each recess form a moving area in which a group of conductive balls is held on a part of the surface of the mask. Then, by moving the plurality of heads in the first direction by the moving means, the plurality of moving areas formed in parallel in the second direction are moved in the first direction along each of the plurality of first recesses. It is preferable to move it to the position. By forming a moving area in which a group of conductive balls is held on a part of the surface of the mask by the pair of sweep members of each head and both sides of each recess, the conductive balls exist in each recess. The region can be further limited. Therefore, even with a relatively small number of conductive balls, the density of the conductive balls in a limited area (moving area) can be increased. On the other hand, the conductive balls can be efficiently filled, and the loss of the conductive balls due to the filling can be further reduced.

  In this apparatus, the mask can be removed from the holding means, and the mask to be used can be easily changed depending on the substrate. Therefore, this apparatus may not hold a mask. For example, it is preferable to use a mask having different intervals between the first concave portions for substrates having different electrode patterns.

  Furthermore, the mask applied to this apparatus preferably further includes a plurality of second concave portions provided on the lower surface of the mask so as to correspond to the plurality of mask patterns, respectively. When the mask is set on the substrate, it is difficult for the flux applied on the electrodes to adhere to the lower surface of the mask, thereby preventing the occurrence of a stray ball or the like.

Since the substrate includes a plurality of electrode patterns that are an array of a plurality of electrodes, the mask includes a plurality of mask patterns that are an array of a plurality of openings, and the plurality of mask patterns correspond to the plurality of electrode patterns on the substrate. is doing. The mask further includes a plurality of groove-shaped first recesses extending in the first direction parallel to the upper surface of the mask. Several mask patterns are arranged in each recess of the plurality of first recesses, and each recess has a depth corresponding at least to the radius of the conductive ball.

  The conductive balls supplied into the recesses of the mask basically do not get over the recesses or are difficult to get over. Therefore, by adopting this mask, a group of conductive balls separated by the convex portions between the concave portions can be formed in each concave portion, and the group of these conductive balls is first formed along the concave portions. It can be moved in the direction.

  The mask preferably further includes a plurality of second concave portions provided on the lower surface thereof so as to correspond to the plurality of mask patterns, respectively. It can suppress that the flux etc. which were apply | coated on the electrode adhere to the lower surface of a mask.

  As a board | substrate which arrange | positions a conductive ball, a silicon wafer and a printed wiring board are mentioned, for example. When a printed wiring board or the like is used as the substrate, it is preferable that the mask further has a frame-shaped third recess provided on the lower surface so as to surround all of the plurality of mask patterns. The frame-shaped third recess is preferably formed so that the edge of the substrate includes a corresponding position when the mask pattern of the mask and the electrode pattern of the substrate are made to correspond to each other.

  When the printed wiring board is formed by cutting a multi-piece substrate, burrs generated at the time of cutting may remain on the edge of the printed wiring board. In addition, the printed wiring board may be plated on the surface. In such a case, plating may be abnormally deposited on the edge of the printed wiring board. When the mask is set on the substrate by providing a frame-shaped third recess that surrounds all of the plurality of mask patterns on the lower surface of the mask (the mask pattern of the mask is associated with the electrode pattern of the printed wiring board). The edge of the substrate and the third recess can be made to face each other. For this reason, even if protrusions such as burrs or abnormal deposits of plating exist on the edge of the substrate, it is difficult to contact (interfere) with the lower surface of the mask.

According to still another aspect of the present invention, a mask having a plurality of openings for disposing conductive balls on a plurality of electrodes of a substrate having a plurality of electrodes is used, and the plurality of openings are filled with the conductive balls. For this purpose, a conductive ball is disposed on a plurality of electrodes of a substrate. The substrate includes a plurality of electrode patterns that are an array of a plurality of electrodes. The mask includes a plurality of mask patterns that are an array of a plurality of openings, and the plurality of mask patterns correspond to a plurality of electrode patterns on the substrate. The mask further includes a plurality of groove-shaped first recesses extending in the first direction parallel to the upper surface of the mask. Several mask patterns are arranged in each recess of the plurality of first recesses, and each recess has a depth corresponding at least to the radius of the conductive ball. The apparatus includes a holding unit for holding the mask on the substrate, a plurality of heads provided along a second direction intersecting the first direction when the mask is held by the holding unit, and a plurality of heads. And a moving means for moving the base in the first direction. Each head of the plurality of heads includes a pair of sweep members that face each other in the first direction. The method includes the following steps.
(A) By causing the heads of the plurality of heads to enter the recesses of the plurality of first recesses of the mask held by the holding means, the pair of sweep members of each head and the both sides of each recess Forming a moving area in which a group of conductive balls is held on a part of the surface of the mask (forming step).
(B) By moving the base in the first direction by the moving means, the plurality of moving areas formed in parallel in the second direction are moved in the first direction along each of the plurality of first recesses. And the conductive balls are filled into a plurality of openings included in several mask patterns provided in each recess (filling step).

  According to this method, the conductive balls can be arranged on one substrate in a relatively short time. In addition, since a group of conductive balls is held in the moving area, the density of the conductive balls in the moving area can be increased even with a relatively small number of conductive balls. Therefore, the conductive balls can be efficiently filled into the mask openings where the plurality of moving areas pass, and the loss of the conductive balls due to the filling is small.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an example of a ball mounting device (a mounting device, a ball mounting system, and a ball mounter). FIG. 2 is a plan view showing an example of the substrate. FIG. 3 is an enlarged view of a region surrounded by a circle III in FIG.

  The ball mounting device 1 is a device for mounting a conductive ball (conductive fine particles, see FIGS. 8 and 9) B at a predetermined position on the substrate 100. The ball mounting apparatus 1 of this example is suitable for mounting the conductive balls B on the plurality of electrodes 101 of the planar rectangular printed wiring board 100. The printed wiring board 100 is also called a printed wiring board, a printed circuit board, a printed circuit board, a circuit board, or a printed board, and includes a semiconductor mounting board on which a semiconductor is mounted, a build-up board, a multilayer board, and the like. In the printed wiring board 100 in which a plurality of semiconductor chips (semiconductor devices) are mounted in a matrix or array, the plurality of electrodes 101 are a plurality of electrode patterns (electrodes) provided in a matrix (array). Group) N are arranged. In the printed wiring board 100 of this example, a plurality of electrode patterns N each including a plurality of electrodes 101 are arranged on the printed wiring board 100, for example, in 8 rows and 6 columns, for a total of 48 pieces. Yes. Each of the plurality of electrode patterns N often includes several hundreds (several tens to thousands) of electrodes 101.

  The electrode 101 provided on the printed wiring board 100 is, for example, a land-like (convex) electrode (land) (see FIGS. 8 and 9). In the case where the printed wiring board 100 is a multilayer board or the like, a resist layer is formed, and a portion of the resist layer corresponding to the electrode 101 is removed by etching or the like. Therefore, in such a printed wiring board 100, the electrode portion may be concave.

  The conductive balls B mounted on the plurality of electrodes 101 of the substrate 100 are for obtaining an electrical connection. The diameter of the conductive balls B handled by the apparatus 1 is, for example, 1 mm or less. Is about 10 to 500 μm. Such a ball B is sometimes called a micro ball (micro ball, micro particle). The conductive ball B includes solder balls (balls containing silver (Ag), copper (Cu), etc., the main component of which is tin (Sn)), metal balls such as gold or silver, and ceramics. This includes balls or plastic balls that have been subjected to a treatment such as conductive plating. In this example, a solder ball having a diameter of about 60 μm is used as the conductive ball B.

  The ball mounting apparatus 1 includes an XYZθ stage 2 for holding the substrate 100, a robot 8 for transporting the substrate 100, and loading (supplying) and unloading the substrate 100 to the stage 2 by the transport robot 8. Loader / unloader device 3 for storing), a pre-alignment device (aligner) 4 for finely adjusting the position of the substrate 100, a correction device 5 for correcting warpage of the substrate 100, and the conductivity of the substrate 100. Conductive balls B are arranged (arranged) on a substrate 100 through a mask 110 and a flux coating device (flux printing device, screen printing device) 6 for applying a material (flux) for bonding the ball B. And a ball filling device 10 for the purpose, an X axis table, a Y axis table, a Z axis table, and a θ table, A stage transfer device 7 for transferring (conveying) and a control unit (not shown) for controlling them. The correction device 5, the flux application device 6, and the ball filling device 10 are arranged side by side in the X direction.

  The loader / unloader device 3 includes a first package 3 a for loading (supplying) the substrate 100 and a second package 3 b for unloading (accommodating) the substrate 100. The substrate 100 is carried in from the first package 3 a of the loader / unloader device 3 and is carried out to the second package 3 b of the loader / unloader device 3. Note that the loader / unloader device 3 may include one package. The transfer robot 8 carries the substrate 100 from the first package 3 a of the loader / unloader device 3 above the pre-alignment device 4, transfers the substrate 100 from the pre-alignment device 4 to the moving stage 2, and moves from the moving stage 2. The substrate 100 is carried out to the second package 3 b of the loader / unloader device 3.

  The moving stage 2 corrects the warpage of the substrate 100 by pressing the outer peripheral portion of the substrate 100 at, for example, eight points with the correction device 5, and corrects the warpage of the substrate 100 by a method such as vacuum suction. It is held on the upper surface (in this example, the XY plane). The moving stage 2 moves the substrate 100 to an arbitrary position among the correction device 5, the flux coating device 6, and the ball filling device 10 by the stage transfer device 7. In addition, the moving stage 2 can adjust the position of the substrate 100 in the X-axis direction, the Y-axis direction, the Z-axis direction, and the θ direction. An example of a method of holding the substrate 100 on the moving stage 2 is vacuum suction, but the method of holding the substrate 100 on the moving stage 2 is not limited to vacuum suction, but is an electrostatic chuck. They may be present, or they may be used in combination.

  The ball filling apparatus 10 is a state in which a mask 110 having a plurality of openings (holes, apertures, apertures) for disposing conductive balls on a plurality of electrodes 101 of the substrate 100 and the substrate 100 are set. It is an apparatus for filling a plurality of openings of the mask 110 with conductive balls in a (superposed state).

  In this ball mounting apparatus 1, the conductive ball B is mounted on the substrate 100 as follows. First, the transfer robot 8 carries the substrate 100 from the first package 3a of the loader / unloader device 3 to the upper side of the pre-alignment device 4, and performs rough alignment (pre-alignment). Next, the substrate 100 is transferred from the pre-alignment apparatus 4 to the moving stage 2 by the transfer robot 8. The moving stage 2 transports the substrate 100 to the correction device 5 to correct the warp. Thereafter, the warped substrate 100 is transferred to the flux application device 6 by the moving stage 2. In the flux application device 6, the substrate 100 is aligned and flux is applied onto the plurality of electrodes 101. Further, the substrate 100 is transferred to the ball filling apparatus 10 by the moving stage 2. By aligning (setting) the substrate 100 with the mask 110 and filling the openings (holes) 111 of the mask 110 with the conductive balls B, the conductive balls B are placed on the plurality of electrodes 101 via the mask 110. Arrange (arrange). The conductive ball B filled in the opening 111 is in close contact with the flux and temporarily fixed on the electrode 101 of the substrate 100. The stage 2 is returned to the initial position, and the substrate 100 is carried out to the second package 3 b of the loader / unloader device 3 by the transfer robot 8. As described above, the conductive ball B can be mounted on the electrode 101 of the substrate 100. Thereafter, the conductive ball B is fixed to the substrate 100 through a known reflow process.

  FIG. 4 shows an example of the mask 110 by a plan view (viewed from above). In FIG. 4, a two-dot chain line indicates a position of an edge 102 of the substrate 100 when the mask 110 and the substrate 100 are set (alignment). FIG. 5 is a cross-sectional view of the mask 110 taken along the line VV (X direction, second direction) in FIG. FIG. 6 is a cross-sectional view of the mask 110 taken along the line VI-VI (Y direction, first direction) in FIG.

  The mask 110 is made of metal (metal mask), for example. In this example, the thickness of the mask 110 (mask thickness, the thickness of the portion where none of the recesses 121 to 123 described below is formed, the maximum thickness) Tmax is about 110 μm. A plurality of openings 111 (see FIGS. 7 to 9) formed in the mask 110 are for disposing the conductive balls B at predetermined positions on the substrate 100, and the diameter of each opening 111 is made conductive. It corresponds to the size of the ball B. In this example, since the diameter of the conductive ball B is about 60 μm, the diameter of the opening 111 is about 70 μm. Note that the end (opening end) of each opening 111 may be chamfered.

  As described above, in this example, the substrate 100 is a printed wiring board, and the plurality of electrodes 101 includes a plurality of electrode patterns N provided in a two-dimensionally distributed matrix form (array form). Each of the plurality of electrode patterns N is an array of a plurality of electrodes 101. In the mask 110, a plurality of openings 111 for arranging the conductive balls B on the plurality of electrodes 101 formed on the substrate 100 are opened at positions corresponding to the plurality of electrodes 101 formed on the substrate 100. ing. Therefore, the mask 110 is two-dimensionally distributed in a matrix (array) so that the plurality of openings 111 correspond to the plurality of electrode patterns N included in the plurality of electrodes 101 of the substrate 100. It includes a plurality of (arranged) mask patterns (opening patterns, opening groups) M. Each of the plurality of mask patterns M is an array of a plurality of openings 111. In this example, the substrate 100 has a total of 48 electrode patterns N arranged (arranged) in 8 rows and 6 columns. Therefore, the mask 110 also has a total of 48 mask patterns M arranged (arranged) in 8 rows and 6 columns so as to correspond to these electrode patterns N. Each mask pattern M often includes several hundred (several tens to several thousand) openings 111 corresponding to the electrode pattern N.

  The mask 110 has a plurality of groove-shaped first recesses 121 on its upper surface 110a. Each recess 121 extends along the Y direction (first direction), and each recess 121 is formed with one row of mask patterns M (eight mask patterns M) arranged in the Y direction. That is, the mask 110 is formed on the upper surface 110a between six groove-shaped first recesses (grooves) 121 extending in the Y direction in parallel to each other, and the first recesses 121. In parallel, there are convex portions (lands) 129 extending in the Y direction. Each recess 121 has a depth corresponding to at least the radius of the conductive ball B (a depth approximately equal to the radius of the conductive ball B or a depth exceeding the radius of the conductive ball B). In this example, each recess 121 has a depth D1 of about 40 μm. Since the diameter of the conductive ball B is about 60 μm in diameter (about 30 μm in radius), the position of the upper end of each recess 121 is the center of gravity of the conductive ball B when the conductive ball B is supplied into each recess 121. Higher than position.

  The mask 110 has a plurality of second recesses 122 on the lower surface 110b so as to correspond to the plurality of mask patterns M, respectively. As described above, the mask 110 includes a total of 48 mask patterns M in 8 rows and 6 columns. Therefore, a total of 48 second recesses 122 arranged in 8 rows and 6 columns are formed on the lower surface 110 b of the mask 110. Each of the recesses 122 is formed to a depth (height) that allows the flux on the electrode 101 to escape without causing the conductive ball B to be a stray ball (less than the diameter of the conductive ball B). ing. In this example, the depth D2 of each recess 122 is about 30 μm.

  In the mask 110, the plurality of electrode patterns N face the plurality of second recesses 122 in a state where the mask 110 is set on the substrate 100. Therefore, the flux applied on the electrode 101 is difficult to adhere to the lower surface 110b of the mask 110.

  That is, on the electrode 101 of the substrate 100, a material (flux or the like) for bonding the substrate 100 and the conductive ball B is generally applied. When the mask 110 and the substrate 100 are set, that is, when the mask 110 and the substrate 100 are overlapped, the region where the mask pattern M is provided corresponds to the region where the electrode pattern N is provided. When the lower surface of the region where the mask pattern M is provided contacts the substrate 100, the flux applied on the electrode 101 may adhere to the lower surface 110b of the mask 110. If flux or the like adheres to the mask 110, the conductive ball B may adhere to the mask 110 via the flux or the like, resulting in a lost ball. By providing the second recess 122 on the lower surface (back surface) 110b of the mask 110, such a situation can be prevented.

  Further, the printed wiring board 100 may be formed by cutting a multi-piece substrate. In such a case, a burr generated at the time of cutting may remain on the edge 102 of the printed wiring board 100. . Further, the printed wiring board 100 may be plated on its surface. In such a case, plating may be abnormally deposited on the edge 102 of the printed wiring board 100. That is, since the silicon wafer is hard and brittle, it is easily cracked or chipped during processing. In order to prevent this, the cut silicon disk is subjected to a chamfering process, so-called beveling. For this reason, it is not considered that the edge of the wafer interferes with the mask when the mask is superimposed on the wafer. In contrast, the printed wiring board 100 does not normally require beveling. For this reason, a portion that interferes with the mask 110 may be formed on the edge 102 of the printed wiring board 100.

  The mask 110 has a frame-shaped third concave portion 123 surrounding all the mask patterns M on the lower surface 110b. The third concave portion 123 is a position facing the edge 102 of the substrate 100 when the mask pattern M of the mask 110 and the electrode pattern N of the substrate 100 are made to correspond (when the opening 111 and the electrode 101 are made to correspond). It is formed to include. The third recess 123 is formed at a depth to the extent that the protrusions due to burrs, abnormal deposits of plating, etc. can escape from the edge 102 of the printed wiring board 100. In this example, the depth D3 of the third recess 123 is about 30 μm (the same depth as the second recess 122).

  In the mask 110, the edge 102 of the substrate 100 faces the frame-shaped third recess 123 in a state where the mask 110 is aligned with the substrate 100. Therefore, even if protrusions such as burrs or abnormal plating deposits exist on the edge 102 of the printed wiring board 100, the protrusions are unlikely to interfere with the lower surface 110b of the mask 110.

  As described above, the mask 110 has a maximum thickness Tmax of approximately 110 μm, a depth D1 of the first recess 121 is approximately 40 μm, and a depth D2 of the second recess 122 is approximately 30 μm. Since the region (portion) where the second recess 122 is formed is included in the region (portion) where the first recess 121 is formed, in the region where the second recess 122 is formed, on both sides There will be a recess. Accordingly, the region where the second recess 122 is formed is the region where the mask thickness is the thinnest in the whole, and the mask thickness (minimum thickness) Tmin is about 40 μm.

  However, since no recess is formed between the first recesses 121 adjacent to each other (projection) 129, the maximum thickness Tmax (about 110 μm) is held in the projection 129. Moreover, on the lower surface 110 b of the mask 110, the second recess 122 is intermittently formed along the first recess 121. For this reason, in the lower surface 110b of the mask 110, the area | region (part) in which the 2nd recessed part 122 is not formed is extended in the grid | lattice form in the X direction and the Y direction. Even if the region where the second recess 122 is not formed is a region where the first recess 121 is formed on the upper surface 110a, the mask thickness is about 70 μm. Therefore, in the region where the second recess 122 is not formed, the mask thickness is at least about 70 μm (70 μm or 110 μm). Therefore, in this mask 110, ribs extending in the Y direction are formed on the upper surface by the concave portions 121 and the convex portions 129 on the upper surface, and lattice-shaped ribs are formed on the lower surface by the concave portions 122 on the lower surface. Therefore, the thickness of the portion of the mask 110 where the opening 111 is formed is very thin, about 40 μm, but the strength of the entire mask is ensured. For this reason, it can suppress that the part in which the opening 111 of the mask 110 was formed is distorted, and a lost ball is generated.

  The region where the third recess 123 is formed basically does not overlap with the region where the first recess 121 is formed and the region where the second recess 122 is formed. In the region (part) where the third recess is formed, the mask thickness is about 80 μm. Therefore, the strength of the mask 110 can be maintained also in this respect.

  Such a mask 110 can be formed by etching both surfaces of a metal plate having a thickness of about 110 μm (corresponding to the maximum thickness Tmax). Alternatively, such a mask 110 can be formed by a method of depositing metal on both surfaces of a metal plate having a thickness of about 40 μm (corresponding to the minimum thickness Tmin) by additive processing. The mask 110 can also be manufactured by other methods such as machining.

  The mask 110 is fixed to the mask frame 119 in a state where a certain amount of tension is applied. The mask 110 is set on a mask holder 130 included in the ball filling apparatus 10 via a mask frame 119.

  Returning to FIG. 1, the ball filling device 10 includes a mask holder 130, a ball dispenser 140, and a moving device 150. The mask holder 130 detachably holds the mask 110 fixed to the mask frame 119 so that the substrate 100 can be aligned with the held mask 110. The ball dispenser 140 includes a plurality of heads 141 provided along a second direction that intersects the Y direction, which is the first direction, for example, the X direction orthogonal to each other, and a base 142 that supports the plurality of heads 141. ing. The plurality of heads 141 are attached to the base 142 so as to correspond to the plurality of first recesses 121 of the mask 110 held by the mask holder 130, respectively. As described above, in this example, the mask 110 has the six first recesses 121. For this reason, the dispenser 140 includes six heads 141 so as to correspond to the respective recesses 121.

  As shown in FIGS. 7, 8, and 9, each head 141 provided along the X direction (second direction) has a pair of sweep members (in the Y direction (first direction)). Squeegees 143a and 143b are provided. In this example, the sweep member 143a and the sweep member 143b have substantially the same shape. Each of the sweep members 143a and 143b is obtained by bundling both ends of a plurality of ultra-fine metal or non-metal wires, and is detachably attached to the base 142 so that the whole becomes a downward U-shape. It has been. These sweep members 143a and 143b are supported by the base 142 so that the pitch of the head 141 composed of the respective sweep members 143a and 143b is the same as the pitch of the recesses 121.

  Each of the sweep members 143a and 143b is capable of moving the conductive ball B on the mask 110 (in the first concave portion 121 of the mask 110) by pushing off the conductive ball B or the like. Good. It is preferable that the sweep members 143a and 143b are relatively soft in contact with the upper surface 110a of the mask 110 and can sweep up the conductive balls B on the upper surface 110a. More preferably, the sweep members 143a and 143b are provided with elasticity that does not scrape the conductive ball B once filled (inserted) into the opening 111.

  The above-described sweep members 143a and 143b made of a member including a wire (including metallic and non-metallic) bent so as to be in contact with the upper surface 110a of the mask 110 are suitable examples. Other examples of the sweep member include an elastic member such as a rubber plate or sponge shaped to contact the upper surface 110a of the mask 110, a metal plate such as stainless steel shaped to contact the upper surface 110a of the mask 110, and a mask. For example, a brush-like member (including metallic and non-metallic) including a plurality of wires extending so as to be in contact with the upper surface 110a of 110 can be used.

Mobile device 150 includes a X-axis table 151 x, the pair of the Y-axis table 152y ₁ and 152y _2. X-axis table 151x is provided with a motor 153x, a pair of Y-axis tables 152y ₁ and 152y _2, respectively, and a motor 154Y ₁ and 154Y _2. X-axis table 151x are disposed so as to straddle the pair of Y-axis tables 152y ₁ and 152y _2. The dispenser 140 is detachably attached to the X-axis table 151x. The moving device 150 further includes a Z-axis stem 155z and a motor 156z for moving the dispenser 140 in the Z direction. For this reason, the dispenser 140 can move up and down in the Z direction.

By driving the motors 154y ₁ and 154y ₂ and moving the position of the X-axis table 151x in the Y direction along the Y-axis tables 152y ₁ and 152y ₂ , the dispenser 140 moves the surface 110a of the mask 110 in the Y direction. To do. Further, the position of the dispenser 140 in the X direction can be finely adjusted by driving the motor 153x and moving the position of the dispenser 140 in the X direction along the X-axis table 151x. If fine adjustment of the dispenser 140 in the X direction is unnecessary, the motor 153x can be omitted.

  In this ball filling apparatus 10, for example, the mask 110 is held by the mask holder 130, and the heads 141 are in contact with the bottoms of the concave portions 121 at the tips of the pair of sweep members 143 a and 143 b (U-shaped belly portions). It moves in a state where it enters into each recess 121 to such an extent that it does. While moving each head 141 into each recess 121, the ball dispenser 140 (base 142) is moved in the Y direction, which is the first direction, by the moving device 150, so that each head 141 is moved to each recess 121. The conductive ball B is moved while being pushed away in the Y direction which is the first direction along each recess 121, and the conductive ball B is moved to a plurality of openings of the eight mask patterns M included in each recess 121. 111 is filled. The conductive balls B filled in the plurality of openings 111 are in close contact with the flux and are disposed on the electrodes 101 of the substrate 100.

  In the ball filling apparatus 10 of this example, a group Bg of conductive balls is formed in each recess 121, and a total of six groups Bg of conductive balls move inside each recess 121 by each head 141. Each head 141 includes a pair of sweep members 143a and 143b. For this reason, by causing the pair of sweep members 143a and 143b of each head 141 to enter the respective recesses 121, the region where the group of conductive balls Bg expands is defined as the pair of sweep members 143a and 143b of each head 141, It is limited between both side portions 121a and 121b of each recess 121. For this reason, the moving area A in which the group Bg of conductive balls is held can be formed in a part of the surface 110 a of the mask 110 and in a part of the recess 121.

  FIG. 7 shows a state in which the moving area A is formed by the pair of sweep members 143 a and 143 b of the head 141 and the both side portions 121 a and 121 b of the first recess 121 of the mask 110 from above the filling device 10. Is enlarged and schematically shown. FIG. 8 is a schematic view partially showing an example of the ball filling device 10, and shows a state in which the conductive ball B is mounted on the electrode 101 of the printed wiring board 100 in the X direction (second direction). ) Along the line. FIG. 9 is a schematic view partially showing an example of the ball filling device 10, and shows a state in which the conductive ball B is mounted on the electrode 101 of the printed wiring board 100 in the Y direction (first direction). ) Along the line. 8 and 9 are schematic views in which the number of openings 111 included in one mask pattern M is reduced for easy understanding.

  In this ball filling apparatus 10, a total of six moving areas A are formed by the pair of sweep members 143 a and 143 b of the six heads 141 and the both side parts 121 a and 121 b of the six recesses 121. In addition, a group Bg of six conductive balls is held. These six moving areas A move in parallel in the X direction by moving the plurality of heads 141 in the Y direction by the moving device 150. Accordingly, the group Bg of six conductive balls also moves in parallel in the Y direction.

  FIG. 10 is a flowchart showing an example of a method for arranging conductive balls using the ball filling apparatus 10.

  The mask 110 and the substrate 100 are aligned, and the respective heads 141 arranged in the Y direction so as to correspond to the respective recesses 121 of the mask 110 are held in the mask holder 130 in step 201, and the respective recesses 121 of the mask 110 are held. Get inside (insert). As a result, a moving area A in which the conductive ball group Bg is held in each recess 121 is formed.

  In step 202, the moving device 150 moves the base 142 in the Y direction, thereby moving the plurality of moving areas A formed in parallel in the X direction in the Y direction along each of the plurality of first recesses 121. The conductive ball B is moved and filled into the plurality of openings 111 of the six mask patterns M included in the recesses 121. In this example, the plurality of moving areas A are reciprocated once or several times in each of the plurality of first recesses 121 so that the group Bg of conductive balls passes through each opening 111 two or more times. The conductive balls B are sequentially filled (transferred) into the plurality of openings 111 of the mask 110 where the moving area A passes, and the conductive balls B are arranged on the substrate 100 through the plurality of openings 111 of the mask 110. The

  Since the head 141 includes a pair of sweep members 143a and 143b, the moving area A can be reciprocated along the first recess 121, and the conductive ball B remaining without being filled can be returned to the original state. You can return to the place (home position). Therefore, it is easy to collect the conductive balls B that remain without being filled. Further, at the home position, by replenishing the conductive ball B in the head 141 (in the moving area A), the amount of the conductive ball B that is filled and reduced (consumed) in the opening 111 is kept constant. It is also possible to move to the next work (work to place the ball on the next substrate 100).

  In this case, it is preferable that the filling device 10 includes a ball supply device. The filling device 10 includes a device provided with a device for replenishing the conductive balls B in the head 141, the moving area A, or the recess 121. An example of the ball filling apparatus 10 is supported by the X-axis table 151x, moves with the dispenser 140, and replenishes the ball B into the head 141, the moving area A, or the recess 121 via the base 142. is there. Further, by moving the ball replenishing device together with the head 141, the conductive ball can be replenished even while the head 141 is moving in the recess 121.

  As described above, according to the filling device 10, the plurality of heads 141 can move the conductive balls B in the plurality of recesses 121 in the Y direction without spreading over the recesses 121. Since the plurality of openings 111 of the plurality of mask patterns M included in the recesses 121 can be filled with the conductive balls B in parallel, the conductive balls B can be arranged on one substrate 100 in a relatively short time. Therefore, the tact time required for disposing the conductive balls B on the electrodes 101 of the substrate 100 can be shortened.

  In the mask 110, the opening 111 is formed only in the recess 121, and the opening 111 is not formed in the region (projection) 129 between the recesses 121. According to this apparatus 10, a group Bg of each conductive ball can be formed in a region that needs to be filled with the conductive ball B, that is, each recess 121, and the opening 111 can be filled therewith. Therefore, since the area through which the conductive ball group Bg passes (moves) can be limited, the tact time can be shortened without using a large amount of the conductive balls B. When the conductive ball B is miniaturized, the number required to cover a certain area with the conductive ball B increases dramatically, for example, at least in inverse proportion to the square of the radius of the conductive ball B. For this reason, it is important that the area through which the conductive ball B passes can be limited.

  Further, the conductive ball group Bg does not pass through a region where the conductive ball B does not need to be filled, that is, the convex portion 129 between the concave portions 121. For this reason, it is possible to reduce the possibility that the conductive ball B is damaged due to the movement of the region on the mask 110 where there is no opening 111 to be filled, and the loss of the conductive ball B can be reduced.

  Furthermore, according to the filling device 10 and the conductive ball arrangement method, the pair of sweep members 143a and 143b of each head 141 and the side portions 121a and 121b of each recess 121 are electrically conductive to a part of the surface 110a of the mask 110. A moving area A in which the sex ball group Bg is held can be formed. Therefore, the region where the conductive ball B exists in each recess 121 is further limited. For this reason, even with a smaller number of conductive balls B, the density of the conductive balls B in the limited region (moving area) A can be increased. Therefore, the conductive balls B can be efficiently filled into the plurality of openings 111 of the mask 110 where the plurality of moving areas A pass, and the loss of the conductive balls B due to the filling can be further reduced.

  In addition, when the conductive balls B are pushed away by a sweep member such as a squeegee, the distribution of the conductive balls B in front of the sweep member may not be constant and density may occur. If the distribution of the conductive balls B is uneven, there is a high possibility that a filling error will occur in the rough portion. It is assumed that it is more difficult to control the distribution of the conductive balls B as the sweep member becomes longer, and it becomes more difficult as the number of the conductive balls B becomes smaller and pushed away by the sweep member.

  According to this filling device 10, since the independent (separated) group of conductive balls Bg is formed in each recess 121, the sweep members 143a and 143b for pushing away the respective conductive ball groups Bg are short. In addition, the amount of the conductive ball B controlled by the respective sweep members 143a and 143b is reduced. Therefore, it becomes easy to control the distribution of the conductive balls B in the recess 121, and the occurrence of a filling mistake can be suppressed.

  Further, each head 141 is moved in the Y direction while accelerating the conductive ball B held inside each head 141 by vibrating each head 141 in the Y direction or changing the moving speed in the Y direction. It is also effective. Considering a state in which the conductive ball B is filled in the opening 111, the conductive ball B is easily filled in the opening 111 when the conductive ball B is stacked on the upper side of the opening 111 in a state of one layer or close to it. The occurrence of filling mistakes can be suppressed. By applying acceleration in the Y direction to the conductive ball B by each head 141, the conductive ball B is forcibly dispersed inside the moving area A, and the conductive ball B is one layer or more in the moving area A. The area existing in a close state can be widened.

  FIG. 11 shows another example of the mask 110 in plan view.

  This mask 110 has three first recesses 121 on its upper surface 110a. Each recess 121 is formed to include two rows of mask patterns M (8 × 2 = 16 mask patterns M) arranged in the Y direction (first direction). Each recess 121 has a depth corresponding at least to the radius of the conductive ball B. As described above, one recess 121 may include two rows of mask patterns M. One recess 121 may include three or more rows of mask patterns M. That is, one recess 121 may include at least one column of mask patterns M arranged in the first direction. One recess 121 may be formed so as to include several mask patterns M arranged in the first direction. For example, two recesses 121 may be included so as to include half of the mask patterns M arranged in one line in the first direction. The recesses 121 may be formed side by side in the first direction. In any case, by providing the head 141 so as to correspond to the recess 121, the tact time can be shortened compared to the case where the entire surface of the substrate is covered with one head.

  FIG. 12 is a schematic view partially showing a modification of the ball filling apparatus 10. FIG. 12 shows a state in which the conductive ball B is mounted on the electrode 101 of the printed wiring board 100, cut along the Y direction (first direction).

  The ball filling apparatus 10 is the same as the apparatus described above in that each head 141 includes a pair of sweep members 143a and 143b. However, one of the sweep members 143a includes a first base 142a, The other sweep member 143b is detachably attached to a second base 142b different from the first base 142a. The first and second bases 142a and 142b move up and down independently in the Z direction by Z-axis stems 155az and 155bz included in the moving device 150 and motors (not shown) corresponding thereto. .

  In this apparatus 10, for example, the conductive balls B are arranged as follows. First, the other sweep member 143 b is raised to the outside of the corresponding recess 121, and the one sweep member 143 a is lowered until it enters the corresponding recess 121. By moving the one sweep member 143a in the Y direction from the one end side (one sweep member 143a side) to the other end side (the other sweep member 143b side) by the moving device 150, the inside of each recess 121 The conductive ball group Bg is pushed away in the Y direction along the recesses 121 from one end to the other end, and the conductive balls B are filled into the openings 111 of the mask pattern M in the recesses 121. Let At this time, the other sweep member 143b is running in parallel with the one sweep member 143a while keeping the distance from the one sweep member 143a at a predetermined distance while being raised to the outside of the corresponding recess 121. To move from one end side to the other end side.

  When the conductive ball group Bg approaches the other end, the other sweep member 143b is lowered until it enters the corresponding recess 121. One of the sweep members 143a is raised to the outside of the corresponding recess 121. By moving the other sweep member 143b in the Y direction from the other end side to the one end side by the moving device 150, the conductive ball group Bg in each recess 121 is moved from the other end side to the one end side. It pushes in the Y direction along each recessed part 121 toward. When there is an unfilled opening 111 in each recess 121, the conductive ball B is filled when the group of conductive balls Bg moves from the other end side to the one end side. At this time, one sweep member 143a is running in parallel with the other sweep member 143b while keeping the distance from the other sweep member 143b at a predetermined distance while being raised to the outside of the corresponding recess 121. To move from the other end side to the one end side. Even in the above-described manner, the conductive balls B can be disposed on the substrate 100 in a short processing time.

  By the way, when the amount of the ball B pushed away by the sweep member along the recess (groove) 121 is relatively small, the balls B are often distributed in one layer in the recess 121. On the other hand, when the amount of the ball B pushed away by the sweep member along each recess 121 increases, the ball B near the sweep member may overlap with a plurality of layers as shown in FIG. The ball B is pushed away by repeating the generation and collapse of a plurality of layers by the movement of the sweep member.

  When the amount of balls is large, it becomes easy to control the quantity fluctuation of the balls B pushed away by the sweep member, but there arises a problem that the balls B are easily protruded from the sweep member. The problem is that the width of the sweep member (the length of the sweep member in the direction perpendicular to the ball conveying direction) is made longer than the width of the recess (groove) 121 so that the ball B is surrounded by the center of the sweep member. Can be solved.

  One of the objects of the present embodiment is to provide an apparatus (ball mounting apparatus, ball filling apparatus), a ball arrangement method, and a mask that can shorten the tact time. However, partial changes and variations obvious to those skilled in the art are considered to be within the scope of the present invention.

  For example, in the mask of this embodiment, the conductive balls once supplied into the recesses do not basically get over the recesses or are difficult to get over. Even if it is not completely held, the conductive ball does not spread over the recesses. The mask according to the present embodiment is opened to the head or downward to hold the group of conductive balls in a partial area (moving area) of the surface of the mask by rotating around an axis perpendicular to the mask. It may be made to cooperate with a cup-type head or the like, and by using the mask of this embodiment, even if conductive balls flow out from those heads, the conductive balls flow out from each recess. Can be prevented.

  Each head cooperating with the mask may be provided with one sweep member that pushes the conductive ball in the first direction along each recess. Since the conductive ball is pushed by one sweep member, the conductive ball spreads in the traveling direction, but the region to be moved is defined by the sweep member and both sides of each recess. Does not spread, and a group of conductive balls can be formed in each recess.

The top view which shows schematic structure of an example of a ball mounting apparatus. The top view which shows an example of a printed wiring board. The figure which expands and shows the area | region enclosed by the circle | round | yen III in FIG. The top view which shows an example of a mask. Sectional drawing cut | disconnected and shown along the VV line in FIG. Sectional drawing cut | disconnected and shown along the VI-VI line in FIG. The figure which shows typically the state which forms the movement area by a pair of sweep member of a head, and the both sides of the 1st recessed part of a mask. It is the schematic which shows partially an example of a ball | bowl filling apparatus, Comprising: The figure which cuts along the X direction and shows the state which has mounted the electroconductive ball on the electrode of a printed wiring board. It is the schematic which shows partially an example of a ball filling apparatus, Comprising: The figure which cuts along the Y direction and shows the state which has mounted the electroconductive ball on the electrode of a printed wiring board. The flowchart for demonstrating an example of the arrangement | positioning method of an electroconductive ball. The top view which shows the other example of a mask. It is the schematic which shows the modification of a ball filling apparatus partially, Comprising: The figure which cuts along the Y direction and shows the state which has mounted the electroconductive ball on the electrode of a printed wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ball mounting apparatus, 10 Ball filling apparatus 100 Printed wiring board (board | substrate), 101 Electrode 110 Mask, 110a Mask upper surface, 110b Mask lower surface 111 Opening, 121 1st recessed part 122 2nd recessed part, 123 3rd recessed part 130 Mask holder (holding means)
141 Head, 142 Base 143a, 143b Sweep member 150 Moving device (moving means)

Claims (5)

A plurality of openings are filled with conductive balls in a state where a mask having a plurality of openings for placing conductive balls on the plurality of electrodes of the substrate having a plurality of electrodes and the substrate are set. A device for
The substrate includes a plurality of electrode patterns that are an array of the plurality of electrodes,
The mask includes a plurality of mask patterns that are an array of the plurality of openings, the plurality of mask patterns correspond to the plurality of electrode patterns of the substrate, and the mask is parallel to an upper surface thereof. A plurality of groove-shaped first recesses extending in a first direction, and a plurality of mask patterns are disposed in each recess of the plurality of first recesses, and each recess is formed of a conductive ball. Has a depth corresponding at least to the radius,
The device is
Holding means for holding the mask on the substrate;
A plurality of heads provided along a second direction intersecting with the first direction when the mask is held by the holding means;
Moving means for moving the plurality of heads in the first direction;
The mask is held by the holding means, and the heads of the plurality of heads are moved in the first direction by the moving means in a state where the heads are inserted into the respective recesses of the plurality of first recesses. To move the conductive balls in the respective recesses in the first direction along the respective recesses, so that the conductive balls are included in the plurality of mask patterns provided in the respective recesses. A device that fills the opening.   2. The apparatus according to claim 1, wherein the plurality of heads are supported by a common base, and the moving unit moves the base in the first direction. 3. The head according to claim 1, wherein each of the heads includes a pair of sweep members opposed to the first direction.
By moving the heads into the recesses, a moving area in which a group of conductive balls is held on a part of the surface of the mask by the pair of sweep members of the heads and both sides of the recesses. Formed,
By moving the plurality of heads in the first direction by the moving means, the plurality of moving areas formed in parallel in the second direction are moved along the first recesses, respectively. A device that moves in a first direction. In any of claims 1 to 3 ,
The mask further includes a plurality of second recesses provided on a lower surface of the mask so as to correspond to the plurality of mask patterns, respectively. Using a mask having a plurality of openings for disposing conductive balls on the plurality of electrodes of the substrate having a plurality of electrodes, the apparatus for filling the plurality of openings with the conductive balls, the substrate A method of disposing a conductive ball on the plurality of electrodes, comprising:
The substrate includes a plurality of electrode patterns that are an array of the plurality of electrodes,
The mask includes a plurality of mask patterns that are an array of the plurality of openings, the plurality of mask patterns correspond to the plurality of electrode patterns of the substrate, and the mask is parallel to an upper surface thereof. A plurality of groove-shaped first recesses extending in a first direction, and a plurality of mask patterns are disposed in each recess of the plurality of first recesses, and each recess is formed of a conductive ball. Has a depth corresponding at least to the radius,
The device is
Holding means for holding the mask on the substrate;
A plurality of heads provided along a second direction intersecting with the first direction when the mask is held by the holding means;
A base for supporting the plurality of heads;
Moving means for moving the base in the first direction;
Each head of the plurality of heads includes a pair of sweep members opposed to the first direction,
The method is
The heads are caused to enter the recesses of the plurality of first recesses of the mask held by the holding means, whereby the pair of sweep members of the heads and the both sides of the recesses Forming a moving area in which a group of conductive balls is held on a part of the surface of the mask;
By moving the base in the first direction by the moving means, a plurality of the moving areas formed in parallel in the second direction are moved along the first recesses, respectively. Moving in a first direction and filling a plurality of openings included in the several mask patterns provided in the respective recesses with conductive balls.

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