JP3875367B2 - How to detect the remaining amount of metal balls - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a metal ball remaining amount detection method.
[0002]
[Prior art]
As shown in FIG. 4, a metal ball storage device for supplying a metal ball 3 such as solder or gold to a substrate or a chip in order to form protruding electrodes (bumps) on the substrate or chip is formed from a ball storage case 1. The suction head 8 is used to supply a predetermined position in an aligned state. A large number of metal balls 3, 3... Housed in the ball housing case 1 jump in the ball housing case 1 by a jumping mechanism 2 such as a gas ejection nozzle, and the suction head 8 is in a jumping state. Adsorb and hold. In FIG. 4, reference numeral 20 denotes a flowing gas valve electromagnetic valve for controlling the jump height of the metal ball 3 and the like.
[0003]
[Problems to be solved by the invention]
By the way, it is desirable that the amount of the metal balls 3 housed in the ball housing case 1 is maintained at a substantially constant amount. If the amount of the metal ball 3 is excessive, another metal ball 3 is crushed by the weight of the metal ball 3 or the metal ball 3 does not jump when the mechanical jump mechanism 2 is used. If it is too small, the amount of the jumping metal ball 3 is reduced, and the suction reliability at the suction head 8 is lowered.
[0004]
However, in the above-described conventional example, during operation of the apparatus, the metal ball 3 jumps in the ball housing case 1, and further, the ball housing case 1 is open to the outside air and irradiated with outside air light and diffusely reflected. For this reason, it is difficult to check the remaining amount of the metal ball 3, and it is difficult to maintain the amount of the metal ball 3 in the ball housing case 1 at a constant amount.
[0005]
The present invention has been made to solve the above-described drawbacks, and an object of the present invention is to provide a method for detecting the remaining amount of a metal ball that can easily detect the remaining amount of the metal ball 3 in the ball housing case 1.
[0006]
[Means for Solving the Problems]
According to the present invention, the object is
A metal ball remaining amount detecting method for detecting the remaining amount of a metal ball 3 that is housed in a ball housing case 1 and jumps in the ball housing case 1 by a jump mechanism 2,
Observe the ball jumping region 10 in the ball housing case 1 in a low light environment where the light amount in the ball housing case 1 is reduced with respect to the outside,
This is achieved by providing a metal ball remaining amount detecting method for detecting the remaining amount from the color density of the ball jumping region 10.
[0007]
The metal ball 3 is a minute sphere that is used when a protruding electrode is formed on an element or solder coating is applied to an element or a mounting substrate. For forming the protruding electrode on the element, a metal ball or Solder balls are used, and solder balls are used for solder coating on the mounting substrate.
[0008]
The applicant has experimented with various methods for detecting the remaining amount of the various metal balls 3 in the ball housing case 1, and the brightness between the inside of the ball housing case 1 and the observation position (outside of the ball housing case 1) is equal. However, the amount cannot be confirmed due to irregular reflection from outside light, but in the ball housing case 1 darkened to the outside, each metal ball 3 is very small, so that it is in a foggy state. It has been found that the concentration of the atomized atmosphere changes depending on the amount of the metal ball 3 jumping. When there is a solder ball in the ball housing case 1, the ball jumping area 10 in the ball housing case 1, that is, the space of the ball housing case 1 in which the metal ball 3 jumps is milky white, and the gold ball is It turns yellow.
[0009]
That is, by observing the color density of the ball jump area 10, the jump amount of the metal ball 3 can be known, and the remaining amount of the metal ball 3 in the ball housing case 1 can be detected indirectly. Therefore, in the present invention, the color density of the ball jumping region 10 is observed from the outside, and the metal ball 3 may be supplied when the color of the ball jumping region 10 becomes light.
[0010]
Note that the jump mechanism 2 may be a mechanical device using a diaphragm or the like, or a gas device as shown in FIG. In addition, the observation of the color density of the ball jumping region 10 is sufficient simply to darken the inside of the ball housing case 1 with respect to the outside, and it is not necessary to completely block outside light.
[0011]
In the invention according to claim 1, the remaining amount of the metal ball 3 is detected by the color density of the ball jump region 10, but can also be detected by reflected light as in the invention according to claim 2. That is, the invention according to claim 2 is a method for detecting the remaining amount of a metal ball that is stored in the ball housing case 1 and detects the remaining amount of the metal ball 3 jumping in the ball housing case 1 by the jumping mechanism 2. And
Irradiate the observation light into the ball housing case 1 whose light amount is reduced with respect to the outside,
In this method, the remaining amount of the metal ball 3 is detected based on the amount of light reflected from the ball jumping area 10. Since the amount of observation in the present invention is the amount of reflected light, there is an advantage that detection by a measuring instrument is simpler than color density and automation is easy. In this case, if the observation light is intermittent light, the amount of processing data can be reduced. A strobe or the like can be used as a light source for intermittent light. Further, it is possible to detect the remaining amount of the metal ball 3 by measuring the transmitted light amount of the observation light from the ball jumping region 10 (Claim 3). In this case, the transmitted light amount increases as the remaining amount decreases.
[0012]
The metal ball storage device using the above method includes a jumping mechanism 2 for jumping the metal ball 3 as in the invention according to claim 4, and a ball storage case 1 having a low light intensity compared to the outside,
Illumination means 4 for irradiating observation light into the ball housing case 1;
A light amount measuring means 5 provided on the inner wall of the ball housing case 1 for measuring the brightness in the ball housing case 1;
The calculation unit 6 may be configured to calculate the remaining amount of the metal ball 3 in accordance with the output from the light amount measurement unit 5.
[0013]
If the ball supply means 7 for supplying the metal ball 3 into the ball housing case 1 in accordance with the output from the calculation means 6 is provided (Claim 5), complete automatic operation becomes possible.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the present invention. The ball housing case 1 has a light shielding wall that shields the inside of the ball housing case 1 from the light source in the installation room, and is darkened with respect to the room (outside the ball housing case 1). In this embodiment, the amount of light in the ball housing case 1 is adjusted to be about 2 lux to 5 lux with respect to the amount of light in the room of 900 lux. The light shielding wall is formed by coloring the wall surface facing the light source in the room of the ball housing case 1 or covering the open part with a light shielding material.
[0015]
A vibration plate (jumping mechanism 2) is disposed on the bottom wall of the ball housing case 1, and a gold or solder ball (metal) placed on the vibration plate by appropriately applying vibration to the vibration plate. Jump the ball 3) into the air. The jumped metal ball 3 is captured by the suction head 8 and conveyed to a predetermined position, and then placed on a printed circuit board or a pad of a semiconductor element. The solder ball is reflowed to form a solder bump or a solder coating layer. Once formed, the gold balls are bonded onto the pads of the semiconductor element to form bumps.
[0016]
The remaining amount of the metal ball 3 in the ball housing case 1 formed as described above is observed at the portion (ball jump region 10) where the metal ball 3 jumps from the observation window 11 provided on the wall surface of the ball housing case 1. Is done. When the metal ball 3 is a solder ball, the ball jumping area 10 is milky white, and when the metal ball 3 is a gold ball, the ball jumping area 10 is yellow. It turns out that the remaining amount of the ball has decreased, and the metal ball 3 is supplied. The concentration is checked visually. For example, if the relationship between the concentration and the remaining amount of the ball is obtained in advance, and a plurality of concentration samples are prepared, the concentration of the sample is compared with the observed concentration. Timing can be accurate.
[0017]
In the above, the case where the inside of the ball housing case 1 is darkened and the concentration of the ball jumping region 10 is observed by light leakage into the ball housing case 1 has been described, but in addition to this, as shown in FIG. The illumination means 4 can be installed in the ball housing case 1 that is blocked from outside light, and the remaining amount of the ball can be detected using strobe light or intermittent light emitted from the illumination means 4 as observation light. In this case, the ball jump area 10 is observed from the illumination means 4 side to determine the remaining amount from the amount of light reflected from the metal ball 3, or the ball jump area 10 is observed from the opposite side to the illumination means 4 to determine the ball jump area. The remaining amount of the ball can be determined from the 10 transmitted light amounts.
[0018]
Although it is possible to visually determine the remaining amount of the ball based on the reflected light amount or the transmitted light amount, it can be mechanized by configuring a metal ball housing device as shown in FIG. That is, in this embodiment, the metal ball storage device includes a ball storage case 1 that is shielded from external light, and a diaphragm that is a jumping mechanism 2 is disposed at the bottom of the ball storage case 1. Further, an illumination means 4 is provided on the wall surface of the ball housing case 1 to irradiate observation light into the ball housing case 1.
[0019]
In this embodiment, which is disposed on the side opposite to the illumination unit 4, the amount of light transmitted through the ball jumping region 10 is measured and the measurement result is sent to the subsequent calculation unit 6. Between the light quantity measuring means 5 and the remaining amount of the ball, there is a relationship in which the transmitted light quantity, that is, the detected light quantity in the light quantity measuring means 5 is reduced if the remaining amount of the ball is large. It is measured in advance and stored as a table. The calculating means 6 outputs the remaining amount of ball while referring to the table value and displays it on an appropriate display device. It should be noted that the display value on the display device does not necessarily have to display a continuous amount, and an alarm can be generated only when the display value falls below a predetermined threshold.
[0020]
In this embodiment, the operator may confirm the display device and supply the metal ball 3, but the ball supply means 7 is provided and the metal ball 3 is placed in the ball housing case according to the calculation result from the calculation means 6. When it is made to supply in 1, complete automatic operation can be performed.
[0021]
【The invention's effect】
As is apparent from the above description, according to the present invention, the remaining amount of the metal ball in the ball housing case can be detected easily and reliably.
[0022]
In addition, when the remaining amount is detected from the reflected light amount or transmitted light amount from the ball jumping area, it is easy to quantify and the detection accuracy can be further improved.
[Brief description of the drawings]
FIG. 1 shows the present invention.
FIG. 2 is a diagram showing a modification of FIG.
FIG. 3 is a view showing a metal ball housing device of the present invention.
FIG. 4 is a diagram showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ball storage case 10 Ball jump area 2 Jump mechanism 3 Metal ball 4 Illumination means 5 Light quantity measurement means 6 Calculation means 7 Ball supply means

Claims (5)

A method for detecting a remaining amount of a metal ball that is housed in a ball housing case and detects a remaining amount of a metal ball that jumps in the ball housing case by a jumping mechanism,
Observe the ball jumping area in the ball housing case in a low light environment where the light amount in the ball housing case is reduced with respect to the outside,
A method for detecting a remaining amount of a metal ball, wherein the remaining amount is detected from a color density of the ball jumping area. A method for detecting a remaining amount of a metal ball that is housed in a ball housing case and detects a remaining amount of a metal ball that jumps in the ball housing case by a jumping mechanism,
Irradiate the observation light into the ball housing case with the amount of light reduced from the outside,
A method for detecting a remaining amount of a metal ball, wherein the remaining amount of the metal ball is detected based on a reflected light amount from a ball jumping area. The metal ball remaining amount detection method according to claim 2, wherein the remaining amount of the metal ball is detected based on a transmitted light amount of the ball jump area instead of the reflected light amount. With a jumping mechanism that jumps metal balls, the ball housing case has a low light intensity compared to the outside, and
Illuminating means for irradiating observation light into the ball housing case;
A light amount measuring means provided on the inner wall of the ball housing case for measuring the brightness in the ball housing case;
A metal ball housing apparatus comprising: a calculating unit that calculates a remaining amount of the metal ball in accordance with an output from the light amount measuring unit. 5. The metal ball storage device according to claim 4, further comprising ball supply means for supplying a metal ball into the ball storage case in accordance with an output from the calculation means.

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