JP3189693B2 - Device for holding conductive balls - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for holding conductive balls such as solder balls.

[0002]

2. Description of the Related Art In recent years, conductive balls have been used to form bumps (protruding electrodes) on electrodes such as semiconductor chips.

In a conventional conductive ball holding device, a large number of fine suction holes are formed in a head, a suction device is connected to the suction holes, and a negative pressure is applied to the inside of the suction holes. Was sucked into the suction hole by vacuum.

[0004]

However, such a structure not only increases the response time when turning on / off the suction, but also causes foreign matters other than the conductive balls (such as dust and flux) to be present in the suction hole. ) Is easily adsorbed and the suction hole is clogged.

Accordingly, an object of the present invention is to provide a conductive ball holding device capable of holding a conductive ball without vacuum suction.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a device for holding a conductive ball, comprising: a recess for holding the conductive ball; at least two terminals for contacting the conductive ball in the recess; The apparatus includes a supply unit, a magnetic field line generating unit that applies a magnetic line in a direction perpendicular to the direction of the current, and a head that holds at least a concave portion and a terminal.

[0007]

A conductive ball holding device according to a first aspect of the present invention includes a concave portion for holding the conductive ball, at least two terminals contacting the conductive ball in the concave portion, and a current flowing through the terminal. The apparatus includes a supply unit, a magnetic field line generating unit that applies a magnetic line in a direction perpendicular to the direction of the current, and a head that holds at least a concave portion and a terminal. Therefore, when the current supply means is operated, the conductive ball can be attracted to the concave portion or the conductive ball can be separated from the concave portion by the action of the current and the magnetic force lines. Here, this operation can be realized only by flowing or not flowing the current from the current supply means, so that the operation responsiveness can be improved. In addition, foreign substances that do not allow current to pass therethrough, such as conductive balls, are not affected by such an effect, so that trouble such as clogging can be prevented.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a conductive ball mounting apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a base, and 2 denotes a ball reservoir provided on the base 1 and accommodating a large number of conductive balls 3 therein. The upper part of the ball reservoir 2 is opened so that the conductive balls 3 can be supplied from the upper part.

Reference numeral 4 denotes a positioning portion provided on the base 1 adjacent to the ball reservoir 2 for positioning the substrate 5. A circuit pattern 6 is formed on the upper surface of the substrate 5, and the conductive balls 3 are mounted on the circuit pattern 6.

Reference numeral 7 denotes a drive shaft provided above the base 1 over the ball reservoir 2 and the positioning portion 4, and reference numeral 8 denotes a moving unit which is moved by the drive shaft 7 in the left-right direction of FIG. A head 9 that moves up and down with respect to the moving unit 8 is provided below the moving unit 8. Further, a permanent magnet 10 is attached to the upper portion of the head 9 as a magnetic force line generating means that moves integrally with the head 9. The permanent magnet 10 generates magnetic force lines in the direction of the arrow N1.

FIG. 2 shows the head 9 when viewed from the lower surface 9a side. That is, reference numeral 11 denotes a concave portion having a shape in which the lower surface 9a is dented into a quadrangular pyramid, and a plurality of concave portions 11 are formed on the lower surface 9a. In each recess 11, an anode 13 and a cathode 14 are arranged opposite to each other so as to be orthogonal to the direction N1 of the line of magnetic force, and a current supply unit 12 is connected to the anode 13 and the cathode 14. That is, in each recess 11,
When the conductive ball 3 approaches and the conductive ball 3 comes into contact with the anode 13 and the cathode 14 as shown in FIG. 3, a current I flows in a direction (arrow N2) orthogonal to the direction N1 of the line of magnetic force B.

As a result, the force F in the direction of arrow N3 acts on the conductive ball 3 by the Fleming's left-hand rule, and the conductive ball 3 is pressed (adsorbed) into the concave portion 11. When the current supply means 12 is turned off, this force F is not generated, and the conductive ball 3 is separated from the recess 11 by its own weight and falls. ON / OFF of current supply means 12
Since the off-switching is an electrical operation, the off-switching can be performed in a much shorter time than in the case of switching on / off of vacuum suction as in a conventional conductive ball holding device. In addition, even if there is a foreign matter that does not allow electric current to be present near the concave portion 11, the force F does not act on the foreign material, so that there is no trouble that the concave portion 11 is clogged by the foreign material.

Next, another embodiment of the present invention will be described with reference to FIGS. In this example, the lower surface 9a of the head 9 is not
Form two protrusions. A portion surrounded by these protrusions is a concave portion 19 (FIG. 5) into which the conductive ball 3 can enter.

Here, of the four protrusions, the protrusions at positions parallel to the direction N1 of the magnetic force lines B are simply the protrusions 17, 18 through which no current flows. Further, one of the protrusions at a position orthogonal to the direction N1 of the magnetic field line B has an anode 15 and the other has a cathode 16, and these anode 15 and cathode 16 are connected to the current supply means 12.

Therefore, as shown in FIG. 5, similarly to the above-described embodiment (FIG. 3), when the current supply means 12 is turned on, a force F directed toward the concave portion 19 can be applied to the conductive ball 3, and The conductive ball 3 is attracted to the recess 19. On the other hand, when the current supply means 12 is turned off, the force F is not generated, and the conductive ball 3 is separated from the concave portion 19 by its own weight.

[0016]

The present invention has been configured as described above.
It is possible to obtain a conductive ball holding device which operates at high speed and has few troubles.

[Brief description of the drawings]

FIG. 1 is a side view of a conductive ball mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a bottom view of the head according to the embodiment of the present invention;

FIG. 3 is an enlarged side view of a concave portion according to the embodiment of the present invention.

FIG. 4 is an enlarged perspective view of a concave portion according to another embodiment of the present invention.

FIG. 5 is an enlarged side view of a concave portion according to another embodiment of the present invention.

[Explanation of symbols]

 3 Conductive Ball 9 Head 11 Depression 13 Anode 14 Cathode I Current B Magnetic Field Line

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/60 B23P 21/00 305 H05K 3/34 501

Claims (4)

(57) [Claims] 1. A recess for holding a conductive ball, at least two terminals in contact with the conductive ball in the recess,
A conductive element comprising: a current supply unit for supplying a current to the terminal; a magnetic line generating unit for applying a magnetic line in a direction perpendicular to the direction of the current; and a head holding at least the concave portion and the terminal. Ball holding device. 2. The conductive ball holding device according to claim 1, wherein said recess is formed by recessing a part of said head. 3. The conductive ball holding device according to claim 1, wherein said concave portion is formed by said terminal projecting from said head. 4. The conductive ball holding device according to claim 1, wherein said magnetic force line generating means is a permanent magnet provided integrally with said head.