JP5189338B2 - Method and apparatus for measuring static electricity of chip-type electronic components - Google Patents

Description

  The present invention relates to a method and an apparatus for measuring the amount of electrostatic charge of a chip-type electronic component taped by an electronic component carrier.

  Chip-type electronic components such as chip capacitors and chip resistors are supplied to an electronic component mounting machine by an electronic component carrier. Here, the electronic component carrier means that a top tape is attached to the upper surface of a carrier tape having a plurality of through holes formed at intervals in the longitudinal direction, and a bottom tape is attached to the lower surface of the carrier tape. Means something that is stored.

  Supplying chip-type electronic components to the electronic component mounting machine by the electronic component carrier is performed by setting a component supply cassette (chip-type electronic component supply device) in which the electronic component carrier is set on the electronic component mounting machine. The component supply cassette feeds the carrier tape and peels off the top tape by supplying power from the mounting machine.

  In other words, the chip-type electronic component housed in the through hole of the carrier tape where the top tape has been peeled off from the carrier tape and the top tape has been removed from the top surface is placed on the electronic component mounting machine side together with the carrier tape while being housed in the carrier tape. It is fed and sucked and held by the suction head of the electronic component mounting machine.

  However, when the suction head sucks the chip-type electronic component, there is a problem that the position of the chip-type electronic component is shifted with respect to the suction head and a suction mistake occurs. This is because static electricity is generated when the top tape is peeled off from the carrier tape, so the chip-type electronic components housed in the through-holes in the carrier tape are charged with static electricity and float in the through-holes in the carrier tape. It is considered that the cause is that an electronic component sticks to a carrier tape or a bottom tape.

  In order to cope with such a problem, it is necessary to accurately grasp the electrostatic charge amount of the chip-type electronic component. However, although some methods for measuring the charge amount of non-contact static electricity have been proposed in the past (see, for example, Patent Document 1), a method for measuring the charge amount of static electricity by placing a probe on an object. Was common.

JP-A-8-186050

  However, since the size of the chip-type electronic component is 1 mm in length, 0.5 mm in width, 0.15 mm in height, etc., the measurement object is small, the probe cannot be applied to the object, and accurate electrostatic There was a problem that the amount of charge could not be measured.

  In addition, the non-contact type measurement method (Patent Document 1) has a problem that an accurate charge amount of static electricity cannot be measured because the charge amount per chip-type electronic component is very small.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method and an apparatus for accurately and inexpensively measuring the amount of electrostatic charge per chip-type electronic component. To do.

The present invention provides an electronic component transport body in which a top tape and a bottom tape are attached to the upper surface of a carrier tape having a plurality of through-holes containing chip-shaped electronic components, and supply of the chip-shaped electronic components per unit operation time. A plurality of the chip-shaped electrons dropped from the carrier tape by setting the component supply cassette with a known capacity and operating the component supply cassette for a predetermined operation time to feed out the carrier tape while peeling off the top tape. A step of storing a component in a Faraday cup; a step of measuring a potential difference between the potential of the Faraday cup and a ground potential by an electrometer; an output of the electrometer; and the predetermined operation of the component supply cassette previously input The chip type electronic component per one based on the number of drops of the chip type electronic component according to time It relates electrostatic measuring method of the chip-type electronic part and a step of calculating by the computer to charge of static electricity.

  With such a configuration, it is possible to measure the potential difference between the potential of the Faraday cup in which a plurality of electrostatic chip-shaped electronic components generated when the top tape is peeled from the carrier tape and the ground potential. Based on this potential difference and the number of chip-type electronic components housed in the Faraday cup, the amount of electrostatic charge of each chip-type electronic component can be accurately measured by a computer.

Further, the present invention provides the carrier tape while peeling off the top tape of the electronic component transport body in which the top tape is attached to the upper surface of the carrier tape having a plurality of through holes containing the chip-type electronic components and the bottom tape is attached to the lower surface. A component supply cassette to be sent out, a Faraday cup that is positioned below the component supply cassette and stores the plurality of chip-type electronic components dropped from the carrier tape, and a potential difference between the potential of the Faraday cup and the ground potential is measured An electrometer, and a calculator for calculating a static charge amount of the chip-type electronic component per unit based on an output of the electrometer, wherein the component supply cassette includes the chip-type electronic component per unit operation time a known supply capacity of, operating a predetermined operation time, the computer, the component supply cassettes previously entered A static charge amount of the chip-type electronic component per piece is calculated based on the number of drops of the chip-type electronic component corresponding to the predetermined operation time and an output of the electrometer. The present invention relates to a static electricity measuring apparatus for chip-type electronic components.

  With such a configuration, it is possible to measure the potential difference between the potential of the Faraday cup in which a plurality of electrostatic chip-shaped electronic components generated when the top tape is peeled from the carrier tape and the ground potential. Then, it is possible to provide a static electricity measuring device capable of accurately measuring the amount of static electricity of each chip-type electronic component by a computer based on the potential difference and the number of chip-type electronic components housed in the Faraday cup.

  The present invention can provide a method and an apparatus for accurately and inexpensively measuring the amount of electrostatic charge per chip-type electronic component.

   Hereinafter, the present invention will be described in detail with reference to examples of the present invention.

The present invention will be described with reference to FIGS.
1 is a perspective view of an electronic component carrier, FIG. 2 is a plan view of a carrier tape, FIG. 3 is a front view of the carrier tape, FIG. 4 is a front view of a component supply cassette, FIG. 5 is a perspective view of a Faraday cup, and FIG. FIG. 3 is a front view of an electrostatic measurement device. For ease of explanation, FIG. 6 is a sectional view of only the Faraday cup.

(Electronic parts carrier)
As shown in FIGS. 1 and 2, the electronic component carrier 1 has a resin (for example, PET and PE) on the upper surface of a paper carrier tape 2 in which a plurality of through holes 5 are formed at intervals in the longitudinal direction. A top tape 1 made of a two-layer structure is affixed, and a bottom tape 4 made of acetate is affixed to the lower surface of the carrier tape 2 as shown in FIG. The component 6 is accommodated.

  Further, feed holes 7 are formed at equal intervals in the longitudinal direction at the end of the carrier tape in the short direction, and the electronic component carrier is wound around the reel 8.

(Parts supply cassette)
As a component supply cassette as an electronic component supply device, one supplied from an electronic component mounter manufacturer, such as the one described in JP-A-9-186487, can be used. One example will be described below.

  FIG. 4 is a view showing a state in which the electronic component carrier 1 wound on the reel 8 is set in the component supply cassette 9.

  A shaft 10 as a reel set portion is fixed to the rear end portion of the main body 16 of the component supply cassette 9. By inserting a hole 11 formed in the central portion of the reel 8 into this shaft 10, the component supply cassette is inserted. A reel 8 can be attached to 9.

  The electronic component carrier 1 pulled out from the reel 8 is attached to the tip end portion 26 of the main body 16 and wound around a sprocket (not shown) that feeds the electronic component carrier 1 by a predetermined pitch.

  Specifically, a plurality of engagement blades provided on the sprocket are inserted into the feed holes 7 of the electronic component carrier. Then, the electronic component carrier 1 is pulled out from the reel 8 by the operation of the sprocket that rotates intermittently by the driving force of the driving mechanism generated based on air, electricity, etc. supplied from an electronic component mounting machine (not shown).

  A plate 12 is attached to the front end portion 26 of the main body 16 of the component supply cassette 9, and the top tape 3 attached to the upper surface of the electronic component carrier 1 drawn out from the reel 8 by the plate 12 is used as a carrier. It is peeled off from the upper surface of the tape 2.

  The top tape 3 peeled off from the upper surface of the carrier tape 2 is taken up by a take-up reel 13 attached to a substantially central portion of the main body 16.

  The carrier tape 2 from which the top tape 3 has been peeled off by the plate 12 is bent in an arc shape along the shape of the sprocket attached to the tip portion 26 of the main body 16 of the component supply cassette 9, and the carrier tape 2 of the main body 16 of the component supply cassette 9 is It is discharged from the lower part of the center.

  The electronic component carrier 1 is carried (intermittent sprocket drive) and the peeled top tape 3 is taken up by the take-up reel 13 using a driving mechanism such as an air cylinder (not shown) attached to the main body 16.

(Faraday Cup)
As shown in FIGS. 5 and 6, the Faraday cup is a box made of a cylindrical conductor having an opening 18.
As shown in FIG. 6, the Faraday cup 17 includes an outer cup 27 made of a conductive metal material, and a conductive metal material placed therein via a plurality of support posts 29 made of an insulator such as PTFE. It is comprised from the inner cup 28 which consists of. For this reason, the capacitance of the Faraday cup 17 is the capacitance between the outer cup 27 and the inner cup 28.
Since the potential of the Faraday cup 17 rises in proportion to the sum of the charges of the plurality of chip-type electronic components 6 housed in the inner cup 28, the charge of the chip-type electronic component 6 that has entered from the opening 18 will be described later. It can be measured with an electrometer.

(Static measurement device)
As shown in FIG. 6, the chip-type electronic component static electricity measuring apparatus according to the present invention has an electronic component carrier in which a top tape 3 is bonded to a carrier tape 2 having a plurality of through holes 5 in which chip-type electronic components 6 are housed. A component supply cassette 9 that feeds out the carrier tape 2 while peeling off the top tape 3, a Faraday cup 17 that is positioned below the component supply cassette 1 and stores a plurality of chip-type electronic components 6 that have dropped from the carrier tape 2, An electrometer 21 that measures the potential difference between the potential of the Faraday cup 17 and the ground potential, and a calculator 22 that calculates the electrostatic charge amount of each chip-type electronic component 6 based on the output of the electrometer 21. It is what you have.

  The component supply cassette 9 is fixed to the support base 20 at an angle of 45 to 70 degrees with respect to the horizontal, and operates for a certain time by a start switch (not shown), that is, the electronic component transport body 1 is moved from the reel 8 to the tip portion. A predetermined number is sent out toward H.26.

  In the electronic component carrier 1 sent out by the operation of the component supply cassette 9, the top tape 3 is peeled off at the distal end portion 26 of the main body 16, and the carrier tape 2 is bent in an arc shape along the shape of the distal end portion 26. Sent out. Therefore, the chip-type electronic component 6 accommodated in the through hole 5 of the carrier tape 2 falls from the carrier tape 2 at the front end portion 26 of the component supply cassette 9.

  The Faraday cup 17 is fixed to the support base 20 via the insulating sheet 19 so that the opening 18 is positioned below the front end portion 26 of the main body 16 of the component supply cassette 9. All chip-type electronic components 6 dropped from the carrier tape 2 are stored in the Faraday cup 17.

  Here, the component supply cassette 9 automatically stops after operating for a predetermined time. For example, if the component supply cassette 9 has a capability of supplying 280 components per minute, the operation time is set to 30 seconds. If set, 140 chip-type electronic components 6 are stored in the Faraday cup 17.

  The Faraday cup 17 is connected to an electrometer 21 by a cable 24, and the electrometer is grounded (grounded) by a cable 25. Therefore, the potential difference between the potential of the Faraday cup 17 in which the plurality of chip-type electronic components 6 are accommodated and the ground potential can be measured by the electrometer 21.

  Since the electrometer 21 is connected to the computer 22 by a cable, the potential difference (V) between the potential of the Faraday cup 17 in which the plurality of chip-type electronic components 6 are accommodated and the ground potential is determined by the A / D converter. To the computer 22 automatically.

Further, the calculator 22 includes a total sum (C) of the capacitance of the measurement system including the Faraday cup 17, the electrometer 21 and the cable 24, and the number of chip-type electronic components 6 dropped according to the operation time of the component supply cassette 9. Since (the number N of Faraday cups 17 stored) is input in advance, the electrostatic charge amount (Q) per chip-type electronic component 6 can be calculated by the following calculation formula.
Q = C × V / N

  When the operation time is 30 seconds, the electrostatic charge amount Q per chip-type electronic component is C × V / 140. The calculated amount of static electricity per chip-type electronic component 6 is displayed on the display 23.

(Measurement result 1)
The results of actually measuring chip-type electronic components using the above-described static electricity measuring device are shown below.

  The top tape and the bottom tape are subjected to a conductive treatment, and the carrier tape is a chip-shaped electronic component housed in an electronic component carrier that has not been subjected to a conductive treatment, after dropping 140 pieces (30 seconds) into the Faraday cup 17. Table 1 shows the potential of the Faraday cup. RK73B1E series 1005R manufactured by Koa Co., Ltd. was used as the chip-type electronic component.

  Here, the conductive treatment refers to, for example, forming a tape using a conductive resin, or applying a conductive layer or the like that prevents static electricity to the surface of the tape.

  From this table, it can be seen that the potential of the chip-type electronic component is slightly biased to the positive side. In addition, the average value of five measurements = 0.123 (V) can be set as the average potential of the Faraday cup.

  The capacitance of the Faraday cup is 10 (pF), the capacitance of the electrometer is 20 (pF), and the capacitance of the cable is 264 (pF). The charge amount Q is Q = (10 + 20 + 264) × 0.123 ÷ 140 = 0.258 (pC).

(Measurement result 2)
In addition, the top tape was subjected to a conductive treatment, and the carrier tape and the bottom tape were dropped into Faraday cup 17 by 140 chip-type electronic components (30 seconds) housed in an electronic component carrier not subjected to the conductive treatment. The potential of the later Faraday cup is shown in Table 2.

  As the chip-type electronic component, GRM155B11H series 1005C manufactured by Murata Manufacturing Co., Ltd. was used.

  From this table, it can be seen that the potential of this chip-type electronic component is biased to the positive side. In addition, the average value of the number of measurement times of 5 = 2.860 (V) can be made the average potential of the Faraday cup.

  The capacitance of the Faraday cup is 10 (pF), the capacitance of the electrometer is 20 (pF), and the capacitance of the cable is 264 (pF). Charge amount Q = (10 + 20 + 264) × 2.860 ÷ 140 = 6.006 (pC).

  The above-described embodiments are illustrated for explanation, and the present invention is not limited thereto, and those skilled in the art will recognize from the claims, the detailed description of the invention, and the description of the drawings. Modifications and additions are possible without departing from the technical idea of the present invention.

  For example, in the above-described embodiment, the support base 20 has the component supply cassette 9 and the Faraday cup 17 fixed together, but the component supply cassette 9 and the Faraday cup 17 may be fixed individually. good.

  In the above-described embodiment, 140 potential measurements are performed a plurality of times, and the electrostatic charge amount per chip-type electronic component is calculated using the average potential. However, 140 potential measurements are performed once. The electrostatic charge amount per chip electronic component may be calculated using the potential.

  Furthermore, although the above-mentioned Example showed what the some through-hole was formed in the carrier tape as an electronic component conveyance body, the thing by which the some recessed part was formed in the carrier tape may be sufficient. For example, embossed tape. In this case, the electronic component carrier does not require a bottom tape, and it is sufficient that the top tape is attached to the upper surface of the carrier tape. That is, the present invention can be grasped as follows.

(1) An electronic component transporter in which a top tape is attached to the upper surface of a carrier tape having a plurality of recesses containing chip-shaped electronic components is set in a component supply cassette, and the top tape is peeled off by the component supply cassette. Sending out the carrier tape and storing the plurality of chip-shaped electronic components dropped from the carrier tape in a Faraday cup;
Measuring the potential difference between the potential of the Faraday cup and the ground potential with an electrometer;
And a step of calculating, by a computer, the amount of electrostatic charge of the chip-type electronic component per unit based on the output of the electrometer.

(2) a component supply cassette that feeds out the carrier tape while peeling off the top tape of the electronic component transporter in which the top tape is attached to the upper surface of a carrier tape having a plurality of recesses containing chip-shaped electronic components;
A Faraday cup that is positioned below the component supply cassette and stores the plurality of chip-type electronic components dropped from the carrier tape;
An electrometer that measures the potential difference between the potential of the Faraday cup and the ground potential;
A static electricity measuring apparatus for a chip-type electronic component, comprising: a calculator for calculating an electrostatic charge amount of the chip-type electronic component per one based on an output of the electrometer.

The present invention can also be grasped as follows.
(3) The top end of the carrier tape is peeled off while the top tape is peeled off from the top of the carrier tape having a plurality of through holes containing the chip-type electronic components and the top tape is attached to the bottom surface of the carrier tape. A component supply cassette that is bent and sent out for a predetermined time,
A support base for fixing the component supply cassette by tilting the tip thereof downward;
A Faraday cup that is located below the front end of the component supply cassette and houses the plurality of chip-type electronic components dropped from the carrier tape;
An electrometer that measures the potential difference between the potential of the Faraday cup and the ground potential;
A static electricity measuring apparatus for a chip-type electronic component, comprising: a calculator for calculating a charge amount of static electricity of the chip-type electronic component per one based on an output of the electrometer.

  It is possible to measure the amount of static electricity charged by the chip-type electronic component in the component supply cassette.

It is a perspective view of an electronic component conveyance body. Example 1 It is a top view of a carrier tape. Example 1 It is a front view of a carrier tape. Example 1 It is a front view of a component supply cassette. Example 1 It is a perspective view of a Faraday cup. Example 1 It is a front view of an electrostatic measurement apparatus. Example 1

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic component conveyance body 2 Carrier tape 3 Top tape 5 Through-hole 6 Chip-type electronic component 9 Component supply cassette 17 Faraday cup 21 Electrometer 22 Computer 26 Tip

Claims (2)

The supply capacity of the chip-type electronic component per unit operation time is known for the electronic component transporter having the top tape and the bottom tape attached to the upper surface of the carrier tape having a plurality of through holes containing the chip-type electronic components. By setting the component supply cassette and operating the component supply cassette for a predetermined operation time, the carrier tape is fed out while peeling off the top tape, and the plurality of chip-type electronic components dropped from the carrier tape are separated from the Faraday cup. The process of storing in,
Measuring the potential difference between the potential of the Faraday cup and the ground potential with an electrometer;
An output of said potential meter, static electricity of the chip-type electronic part per based on said falling speed of the chip-type electronic part according to the predetermined operating time of the component supply cassettes previously entered charge And a step of calculating the quantity by a computer. A method for measuring static electricity of a chip-type electronic component. A component supply cassette that feeds out the carrier tape while peeling off the top tape of the electronic component transport body in which the top tape is attached to the upper surface of the carrier tape having a plurality of through holes containing chip-type electronic components and the bottom tape is attached to the lower surface;
A Faraday cup that is positioned below the component supply cassette and stores the plurality of chip-type electronic components dropped from the carrier tape;
An electrometer that measures the potential difference between the potential of the Faraday cup and the ground potential;
A calculator for calculating the amount of electrostatic charge of the chip-type electronic component per unit based on the output of the electrometer,
The component supply cassette has a known chip-type electronic component supply capability per unit operation time, and operates for a predetermined operation time.
The computer calculates the chip-type electronic component per piece based on the number of drops of the chip-type electronic component corresponding to the predetermined operation time of the component supply cassette inputted in advance and the output of the electrometer. A static electricity measuring device for chip-type electronic components, characterized by calculating the amount of static electricity charged.

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