JP3575317B2 - Apparatus and method for mounting conductive ball - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a conductive ball mounting apparatus and a conductive ball mounting method for mounting a conductive ball on a work.
[0002]
[Prior art]
In a process of forming a bump as a protruding electrode on an electronic component, a conductive ball such as a solder ball is mounted on an electrode of the electronic component. In recent years, as a mounting form of the conductive balls, a method of mounting the conductive balls in a state of a wafer before electronic components are cut into individual pieces, that is, in a state where a large number of semiconductor elements as electronic components are formed in a grid-like arrangement. Is used.
[0003]
[Problems to be solved by the invention]
However, when conductive balls are directly mounted on a wafer, there have been the following problems in the related art. Since the wafer has a circular shape, and a rectangular individual electronic component is cut out from the circular wafer, the cutout line does not coincide with the outer periphery of the wafer. For this reason, the cutting line has an irregular step shape near the outer periphery of the wafer. As a result, when the conductive balls are mounted on each electronic component of the wafer, a plurality of electronic components cannot be bundled as a well-formed rectangular block, and may be mounted individually or as a whole. I had no choice but to choose either. For this reason, when mounting in individual pieces, it is necessary to perform many times of mounting, which lowers productivity, and when mounting the whole as a batch, there is a problem in reliability to ensure normal mounting Conventionally, it has been difficult to efficiently and stably mount conductive balls directly on a wafer.
[0004]
Therefore, an object of the present invention is to provide a conductive ball mounting apparatus and a mounting method capable of efficiently and stably mounting a conductive ball on a work.
[0005]
[Means for Solving the Problems]
The conductive ball mounting apparatus according to claim 1, wherein the conductive ball is vacuum-adsorbed and picked up by a pickup head having a suction tool having a plurality of suction holes formed on a lower surface, and the conductive ball is mounted on a work. A mounting device, which is detachably mounted from a mounting port provided on a side surface of the pickup head, and abuts on an upper surface of the suction tool to form the plurality of suction holes according to a ball mounting range of a conductive ball. And a mask member which is closed.
[0006]
According to a second aspect of the present invention, there is provided the conductive ball mounting apparatus according to the first aspect, further comprising fixing means for fixing the mask member to a pickup head.
[0007]
According to a third aspect of the present invention, there is provided a method for mounting a conductive ball on a workpiece by vacuum-sucking and picking up the conductive ball by a pickup head having a suction tool having a plurality of suction holes formed on a lower surface. A mounting method, wherein a mask member that partially closes the plurality of suction holes from a mounting port provided on a side surface of the mounting head according to a mounting range of a conductive ball is brought into contact with an upper surface of the suction tool. The conductive balls are mounted on different mounting ranges by a single pickup head.
[0008]
According to the present invention, a single pickup head differs by mounting a mask member that partially closes a suction hole from a mounting port provided on a side surface of a pickup head according to a mounting range of a conductive ball. The conductive balls can be stably mounted in the mounting range.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a conductive ball mounting apparatus according to an embodiment of the present invention, FIG. 2A is a sectional view of a pickup head of the conductive ball mounting apparatus, and FIG. FIG. 3A is a plan view of the pickup head of the conductive ball mounting device, FIG. 4A is a plan view of the same wafer, and FIG. 4B is a plan view of the same wafer. 5 (a) and 5 (b) are plan views of the same wafer, FIG. 6 (a) is a perspective view of the same mask member, FIG. 6 (b) is a plan view of the same mask member, and FIG. FIGS. 7 (a), 7 (b), 7 (c), 7 (d), and 7 (e) are side views of the mask exchange section, and FIGS.
[0010]
First, the structure of the conductive ball mounting device will be described with reference to FIG. In FIG. 1, a transport path 2 is provided at the center of a base 1. The transfer path 2 transfers and positions the plate 3 holding the wafer 4. The wafer 4 is a substantially circular substrate, and a plurality of semiconductor elements are formed in a lattice shape as described later. Two Y-axis tables 5 are arranged at both ends of the upper surface of the base 1. An X-axis table 6 is installed on the two Y-axis tables 5, and a mounting head 7 is mounted on the X-axis table 6.
[0011]
The mounting head 7 has a pickup head 8 at the lower part. By driving the X-axis table 6 and the Y-axis table 5, the mounting head 7 moves horizontally. A ball supply unit 9 is provided in front of the transport path 2, and a large number of conductive balls 10 are stored in the ball supply unit 9. The pickup head 8 picks up the conductive ball 10 by moving the pickup head 8 up and down with the mounting head 7 positioned above the ball supply unit 9. Then, by positioning the mounting head 7 on the positioned wafer 4 and moving the pickup head 8 up and down again, the conductive balls 10 held by the pickup head 8 are mounted on the wafer 4.
[0012]
A mask exchanging unit 11 provided with a plurality of types of mask members 12 which are closing plates mounted on the pickup head 8 is provided beside the ball supply unit 9. By moving the pickup head 8 with respect to the mask replacement unit 11 and positioning it at a predetermined position, the mask member 12 can be attached to and detached from the pickup head 8.
[0013]
Here, the wafer 4 will be described with reference to FIG. As shown in FIG. 4A, the wafer 4 is a substantially circular substrate, and a large number of semiconductor elements 4a, which are rectangular electronic components, are formed in a lattice at an arrangement pitch PxPPy on the wafer 4. As shown in FIG. 4B, a large number of electrodes 4b on which the conductive balls 10 are mounted are formed in a predetermined electrode arrangement pattern on each semiconductor element 4a, and these electrodes 4b form an electrode group 4c. ing. That is, in the wafer 4, the range in which these electrode groups 4c are formed is the ball mounting range (the range surrounded by the thick line in FIG. 4A), and the outer shape of the ball mounting range is step-shaped.
[0014]
Next, the pickup head 8 provided on the mounting head 7 and the suction tool 8a on the lower surface of the pickup head 8 will be described with reference to FIGS. As shown in FIG. 2A, the lower surface of the pickup head 8 is a protrusion-shaped suction tool 8a, and a plurality of suction holes 8b are provided on the suction surface of the lower surface of the suction tool 8a. The conductive ball 10 is suction-held in the suction hole 8b by vacuum suction from the suction hole 8c.
[0015]
3, a mounting opening 8e for inserting the plate portion 12a of the mask member 12 is formed on a side surface of the pickup head 8. The plate portion 12a of the mask member 12 inserted into the mounting opening 8e abuts on the upper surface of the suction tool 8a to close a part of the suction hole 8b. The mounting hole 8e after the plate portion 12a is inserted is closed by the flange portion 12b of the mask member 12. Since the mounting opening 8e is provided on the side surface of the pickup head 8 and the mask member 12 is mounted on the mounting opening 8e, there is no need to remove the suction tool 8a from the pickup head 8 when the mask member 12 is attached or detached. Further, since the mounting opening 8e is closed by the mask member 12, the mask member 12 can be mounted with a relatively simple structure. The shape and function of the mask member 12 will be described later.
[0016]
Here, the arrangement of the suction holes 8b will be described. On the suction surface of the suction tool 8a, suction portions 14 which are a collection of suction holes 8b are arranged in a grid pattern over the entire suction surface. Here, the arrangement pitch of the suction portions 14 is equal to the arrangement pitch Px, Py of the semiconductor elements 4a on the wafer 4. In each of the suction portions 14, a plurality of suction holes 8b are formed at positions corresponding to the electrode arrangement patterns of the electrodes 4b constituting the electrode group 4c. That is, the arrangement of the conductive balls 10 sucked and held in the suction holes 8 b of the suction portions 14 corresponds to the array of the electrodes 4 b of the semiconductor elements 4 a of the wafer 4.
[0017]
Next, division of the above-mentioned ball mounting area when the conductive balls are mounted on the wafer 4 using the suction tool 8a will be described with reference to FIG. The size of the wafer 4 usually exceeds the size in which conductive balls can be collectively mounted in a single mounting operation by a single suction tool in many cases. It is divided into divided sections, and a conductive ball is mounted on each divided section.
[0018]
As shown in FIG. 5, the ball mounting area of the wafer 4 is divided into a plurality of sections. FIG. 5A shows an example in which the ball mounting area of the wafer 4 is divided into four sections. At this time, the suction surface (size WX, WY) of the suction tool 8a covers each of the divided sections [1], [2], [3], [4]. That is, when dividing the ball mounting area, the divided sections of the ball mounting area of the wafer 4 are set such that each divided section is equal to or smaller than the size of the suction surface of the suction tool 8a.
[0019]
FIG. 5A shows an example in which the ball mounting area of the wafer is divided into four divided sections [1], [2], [3], and [4] having substantially the same shape. The shape and the size are not limited to the same shape and the same size. For example, as shown in FIG. 5B, when the ball mounting area of the wafer 4 ′ having a size larger than the wafer 4 is divided, the suction tool 8 a Considering the size that the suction surface can cover, for example, it may be divided into nine sections [1] to [9]. That is, if the arrangement pitch of the semiconductor elements 4a and the electrode arrangement pattern in the semiconductor elements 4a are the same, the setting of the division section is changed even for wafers having different sizes, so that the same suction tool is used. The ball can be mounted.
[0020]
Next, a description will be given of the mask member 12 used when mounting the conductive balls on different divided sections using the same suction tool 8a. As shown in FIG. 2A, the mask member 12 is removably mounted through a mounting opening 8e provided on the side surface of the pickup head 8, and the plate portion 12a which comes into contact with the suction surface of the suction tool 8a is provided as shown in FIG. As shown in (b), the suction hole 8b of the suction portion 14 is partially closed. As shown in FIG. 2A, the conductive ball 10 is sucked only in the area B of the suction section 14 of the suction tool 8a, and the suction hole 8b of the suction section 14 is in the area A of the plate section 12a. The conductive ball 10 is not adsorbed because it is closed.
[0021]
That is, the mask member 12 is a suction hole closing means, and the suction hole 8b in the range A is closed so that the conductive ball 10 is suctioned only to the suction portion 14 in a predetermined range in the divided section. It is a limiting means. The mask member 12 is sucked and fixed to the pickup head 8 by vacuum suction from the suction hole 8d. That is, the suction holes 8d serve as fixing means for the mask member 12. By fixing the mask member 12, the mask member 12 can be stably held even when a positive pressure is applied to the inside of the pickup head 8 for vacuum release for the purpose of releasing suction of the conductive balls 10. In addition to the fixing means using vacuum suction, the mask member 12 may be mechanically pressed against the pickup head 8 and fixed by an actuator such as an air cylinder.
[0022]
As shown in FIG. 6A, the mask member 12 includes a plate portion 12a provided with a notch in a predetermined range, and the four divided sections [1] and [2] shown in FIG. , [3] and [4] are prepared. That is, the mask member 12A used when mounting the conductive ball in the divided section [1] has a plate portion 12a having a shape (a wavy hatched portion) as shown in FIG. The conductive ball 10 is sucked only in a predetermined range that targets only the suction portion 14 corresponding to the semiconductor element 4a in the divided section [1]. The same applies to the mask members 12B, 12C, and 12D used when the conductive balls 10 are mounted on the divided sections [2], [3], and [4].
[0023]
These four types of mask members 12A, 12B, 12C, and 12D are vertically stacked and stored in the mask replacement unit 11 as shown in FIG. 6C. The mask exchanging unit 11 can pull out or insert the mask member 12 from the pickup head 8 by a mask exchanging mechanism (not shown). The mask member 12 can be detached and another optional mask member 12 can be newly installed.
[0024]
The conductive ball mounting device is configured as described above, and the ball mounting method will be described below with reference to FIG. In FIG. 7A, a mask member 12A corresponding to the divided section [1] is mounted on the pickup head 8, and the pickup head 8 is lowered with respect to the conductive balls 10 in the ball supply section 9, The conductive ball 10 is vacuum-sucked by the suction tool 8a.
[0025]
At this time, the mask member 12A closes the suction holes 8b of the suction tool 8a except for the predetermined range C, and the conductive balls 10 are suctioned only to the suction portions 14 corresponding to the semiconductor elements 4a in the divided section [1]. You. Next, the pickup head 8 is raised and moved onto the wafer 4, and is positioned with respect to a predetermined portion of the wafer 4, and the pickup head 8 is lowered, as shown in FIGS. 7B and 7C. The conductive ball 10 is mounted on each electrode 4b (see FIG. 4) of each semiconductor element 4a belonging to the divided section [1].
[0026]
After that, the pickup head 8 is raised and moved to the mask changing unit 11. Then, the pickup head 8 is positioned at a predetermined position for mask replacement, and the fixing of the mask member 12A is released as shown in FIG. Next, the pickup head 8 is moved to the mounting position of the mask member 12B to be used next time for positioning, and the mask member 12B corresponding to the divided section [2] is mounted from the side surface of the pickup head 8.
[0027]
Next, the pickup head 8 on which the mask member 12B is mounted is moved again onto the ball supply unit 9 and is moved up and down so that the conductive balls 10 are sucked only in the predetermined range D on the lower surface of the suction tool 8a. I do. Then, similarly, the conductive balls 10 are mounted on the electrodes of the semiconductor elements 4a belonging to the divided section [2] of the wafer 4. By repeating the above operation four times while replacing the mask member 12, the conductive balls 10 can be mounted on each electrode of all the semiconductor elements 4a of the wafer 4.
[0028]
In the above mounting operation, the number of reciprocations of the mounting head 7 only needs to be four times, and the number of reciprocations is much smaller than that of the conventional method of mounting each individual piece, thus improving the mounting efficiency of the conductive balls. be able to. In this embodiment, the same expensive suction tool 8a is used, and only the mask member 12, which can be manufactured simply and inexpensively, is replaced, so that the equipment cost can be reduced. In addition, since the size of the divided section is set within a reasonable range that does not become excessive in view of the conventional results, a stable mounting of conductive balls with few mounting defects is ensured. That is, it is possible to achieve both good mounting efficiency and stable mounting quality, which have been difficult to achieve with the conventional method.
[0029]
In this embodiment, a wafer on which semiconductor elements are formed is shown as an example of a work on which conductive balls are mounted. However, the present invention is not limited to this. For example, a plurality of electronic components are formed in a grid. The embedded substrate may be used. In this case, conductive balls are mounted on electrodes of a plurality of electronic components.
[0030]
【The invention's effect】
According to the present invention, the mask member that partially closes the suction hole from the mounting port provided on the side surface of the pickup head having the suction tool according to the mounting range of the conductive ball is brought into contact with the upper surface of the suction tool. Since the ball is mounted, conductive balls can be attracted only to the suction holes corresponding to the ball mounting range, and a single pickup head stably mounts conductive balls in different ball mounting ranges can do.
[Brief description of the drawings]
FIG. 1 is a perspective view of a conductive ball mounting apparatus according to an embodiment of the present invention; FIG. 2A is a cross-sectional view of a pickup head of the conductive ball mounting apparatus according to an embodiment of the present invention; FIG. 3 is a plan view of the lower surface of the pickup head of the conductive ball mounting device according to one embodiment of the present invention. FIG. 3 is a perspective view of the pickup head of the conductive ball mounting device according to one embodiment of the present invention. (A) Plan view of a wafer according to an embodiment of the present invention (b) Partial plan view of a wafer according to an embodiment of the present invention FIG. 5 (a) Plan view of a wafer according to an embodiment of the present invention (B) A plan view of a wafer according to an embodiment of the present invention. FIG. 6 (a) A perspective view of a mask member according to an embodiment of the present invention. (B) A plane view of a mask member according to an embodiment of the present invention. FIG. 7 (c) is a side view of a mask changing section according to an embodiment of the present invention. FIG. (B) Process explanatory diagram of the conductive ball mounting method of the embodiment (b) Process explanatory diagram of the conductive ball mounting method of one embodiment of the present invention (c) of the conductive ball of one embodiment of the present invention Process description diagram of mounting method (d) Process description diagram of conductive ball mounting method of one embodiment of the present invention (e) Process description diagram of conductive ball mounting method of one embodiment of the present invention Description]
Reference Signs List 4 Wafer 4a Semiconductor element 4b Electrode 8 Pickup head 8a Suction tool 8b Suction hole 8d Suction hole 8e Mounting port 10 Conductive balls 12, 12A, 12B, 12C, 12D Mask member 12a Plate portion 14 Suction portion

Claims (3)

A pickup device having a suction tool having a plurality of suction holes formed on a lower surface thereof, a conductive ball is vacuum-sucked and picked up, and a conductive ball mounting device mounted on a work is provided on a side surface of the pickup head. A mask member that is removably mounted from a mounting port provided and abuts on an upper surface of the suction tool to partially close the plurality of suction holes according to a ball mounting range of the conductive ball. Conductive ball mounting device. 2. The conductive ball mounting apparatus according to claim 1, further comprising fixing means for fixing the mask member to a pickup head. A method for mounting a conductive ball on a work by vacuum-sucking and picking up a conductive ball by a pickup head having a suction tool having a plurality of suction holes formed on a lower surface, provided on a side surface of the mounting head. A mask member that partially closes the plurality of suction holes according to the mounting range of the conductive ball from the set mounting port is mounted in contact with the upper surface of the suction tool, and thereby a different pickup head is used. A method for mounting a conductive ball, wherein the conductive ball is mounted in a mounting range.

Images