JP4800135B2 - Electronic component mounting equipment - Google Patents

Description

  The present invention relates to an electronic component mounting apparatus.

  2. Description of the Related Art Conventionally, an electronic component mounting apparatus configured to suck and convey an electronic component with a suction nozzle and mount it at a predetermined position on a substrate is widely known. In this type of mounting apparatus, for example, as shown in FIG. 4, the transfer head 11 including the suction nozzle 18 is incorporated on the XY tables 12 and 13 so as to be movable. Reference numeral 19 denotes a conveyor which conveys the substrate 14 to the positioning unit 15. The positioning unit 15 clamps and positions the substrate 14. A parts feeder (part supply device) F is provided at the back of the positioning unit 15.

  The transfer head 11 that has moved XY onto the parts feeder F lowers the suction nozzle 18, stops the lowering when the tip of the suction nozzle 18 reaches the upper surface of the electronic component P, and generates negative pressure. The electronic component P is adsorbed by Thereafter, the suction nozzle 18 is raised to lift the electronic component P, and the XY movement is again performed to move to the mounting position of the predetermined positioning portion 15 on the substrate 14 to lower the suction nozzle 18. When the bottom surface of the electronic component P reaches the top surface of the substrate 14, the negative pressure is cut off, the suction nozzle 18 is raised, and the mounting operation of the electronic component P on the substrate 14 is completed.

  The suction nozzle 18 attached to the tip of the transfer head 11 has several types according to the size of the electronic component P and is exchanged according to the application. FIG. 5 shows a general holding structure for the suction nozzle 18. The suction nozzle 18 is operable in the vertical direction Z and the θ direction, and an air passage 23 is secured therein. When the suction nozzle 18 is lowered with the contact plate (not shown) applied to the lower surface of the nozzle holder 40, the engagement between the ball 25 and the groove 18A of the suction nozzle 18 is released, and the force for holding the suction nozzle 18 decreases. . However, at this time, the suction nozzle 18 cannot always be smoothly separated due to friction or the like. Therefore, a positive pressure for separating the suction nozzle is generated through the air passage 23 and the suction nozzle 18 is pushed downward to assist in removing the suction nozzle 18.

  6A and 6B show control modes of air during (1) normal time (when electronic parts are not picked up), (2) when electronic parts are picked up, and (3) when the suction nozzle is replaced. In the figure, an air flow is generated in a portion indicated by a thick arrow.

  In the normal time shown in (1) of FIG. 6, the air supplied from the air supply source 20 includes a positive pressure generating (on-off) valve 21 and a negative pressure generating (on-off) valve (ejector). Since both 22 are turned off, the air is stopped there and is not supplied to the suction nozzle 18. In addition, the code | symbol 23 of FIG. 6 is a throttle valve (the degree of a throttle is small).

  At the time of component suction shown in (2) of FIG. 6, the positive pressure generating valve 21 is kept off and the negative pressure generating valve 22 is turned on. Therefore, from the valve 22 to the suction nozzle 18 A negative pressure is generated in the air circuit A <b> 2, and the electronic component P can be sucked by the suction nozzle 18.

  At the time of replacement of the suction nozzle 18 shown in (3) of FIG. 6, only the positive pressure generating valve 21 is turned on, and the air supplied from the air supply source 20 reaches the suction nozzle 18 via the throttle valve 23. And assisting the removal of the suction nozzle 18.

  By the way, when the electronic component P such as a bare chip is mounted, a flux is often used for bonding the substrate 14 and the electronic component (bare chip) P. In general, the flux has a weaker adhesive strength than the solder paste or adhesive, and the electronic component P is mounted on the substrate 14 due to weak static electricity, negative pressure remaining between the suction nozzle 18 and the electronic component P, or generation of friction. There is a case where the problem of taking it home without being placed may occur.

  Patent Document 1 discloses a technique for adjusting the pressure of the air discharged from the suction nozzle by controlling the operation time (operation timing) of the electromagnetic valve that controls the positive pressure.

JP 2000-151192 A

  However, the technique disclosed in Patent Document 1 is an attempt to control a very short time (timing) during which the solenoid valve operates, and has a problem of lack of stability. That is, the positive pressure to be generated here is basically intended to quickly eliminate the negative pressure that has been generated so far when the electronic component is placed on the substrate. It is a delicate thing. For example, if the time for applying positive pressure is slightly shorter than the appropriate time, or if the application timing is too early even if the time is appropriate, the problem that the negative pressure remains and the electronic component P is brought home cannot be solved. . On the other hand, if the time for applying positive pressure is too long or too slow, a positive pressure that is too strong is generated and the mounting position and mounting angle of the electronic component P are shifted. P may be blown away.

  The present invention has been made to solve such a conventional problem, and the configuration of the apparatus is simple and low-cost, and the electronic component is securely mounted at an appropriate position without causing any trouble. It is an object of the present invention to provide an electronic component mounting apparatus that can be realized.

The present invention relates to an electronic component mounting apparatus configured to suck and transport an electronic component by a suction nozzle and to be mounted at a predetermined position on a substrate. On the other hand, a positive pressure generating means capable of generating a positive pressure for separating the suction nozzle, and at least the electronic component sucked by the suction nozzle at the time of mounting the electronic component, A weak positive pressure generating means capable of generating a weak positive pressure , and the weak positive pressure generated by the weak positive pressure generating means is constantly applied to the suction nozzle , It solves the above problems.

Further, the present invention provides an electronic component mounting apparatus configured to suck and transport an electronic component with a suction nozzle and attach it to a predetermined position on a substrate. On the other hand, a negative pressure generating means capable of generating a negative pressure for sucking an electronic component, and at least when mounting the electronic component, the electronic component sucked by the suction nozzle is less than the negative pressure for sucking the electronic component. A weak positive pressure generating means capable of generating a weak positive pressure whose absolute value is weak , and the weak positive pressure generated by the weak positive pressure generating means is constantly applied to the suction nozzle. This solves the same problem as above.

  In the present invention, when the electronic component is mounted, a “weak positive pressure” set to an optimum value is applied to prevent the electronic component from being taken home. This “weak positive pressure” qualitatively means “a positive pressure that is so weak that no problem occurs even if it is applied as it is”. More specifically, the “weak positive pressure” is a positive pressure that is much lower than the positive pressure for removing the suction nozzle (on the order of MPa) generated for the suction nozzle to be replaced when the suction nozzle is replaced. Pressure. For example, in an embodiment to be described later, the pressure for electronic component suction generated for the electronic component sucked by the suction nozzle is set to a positive pressure of 3 kPa with respect to a negative pressure of 70 kPa. If the weak positive pressure is too strong, the component mounting accuracy is lowered. If the weak positive pressure is too weak, the components are brought home. Therefore, the positive pressure is preferably 1 to 5 kPa.

  Therefore, the control itself can be greatly simplified, and even with a simple control system, it is possible to prevent parts from being blown off due to excessive application of strong positive pressure while preventing the electronic parts from being taken home. can do.

Further, the Te present invention odor, weak positive pressure generated by the weak positive pressure generating means, wherein that is configured to be constantly applied to the suction nozzle. This is the simplest additional configuration for the control system. However, since the “weak positive pressure” according to the present invention is weak, the configuration of “always applied” can be adopted, as will be described later. It is possible to perform a very rational joint work with the positive pressure for detaching the nozzle or the negative pressure for sucking the electronic components.

Also, good preferable embodiment of the present invention, the pressure generated by the weak positive pressure generating means is to be varied for each type of electronic component. As a result, it is possible to always mount an appropriate electronic component (without taking it away in a short time) regardless of the type of the electronic component.

  In addition, another preferred embodiment of the present invention further includes a pressure sensor that detects a pressure value of air that is actually generated in the suction nozzle, and detects the take-back of the electronic component based on the detected value of the pressure sensor. Then, the weak positive pressure applied to the same kind of electronic component is learned and corrected based on the detection value of the pressure sensor at this time. As a result, an optimal “weak positive pressure” can be applied to each electronic component.

  When a pressure sensor is installed, in addition to the configuration for learning and correcting an appropriate weak positive pressure in this way, the weak positive pressure is variably controlled in real time based on the detection value of the pressure sensor. You can also. As a result, the shortest and optimum placement control can be surely performed regardless of variations in individual electronic components.

  According to the present invention, an electronic component attracted to an appropriate position on a substrate can be reliably mounted with a simple and low-cost configuration without causing the electronic component to be taken home.

  Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

  Note that the basic configuration related to mounting electronic components in the mounting apparatus according to the present embodiment is the same as the conventional configuration already described. A different part is the structure regarding the air supply control demonstrated using FIG. Therefore, here, the configuration corresponding to this different part will be mainly described with reference to the drawing corresponding to FIG. Note that the same or similar parts as those shown in FIG. 6 are given the same reference numerals in the last two digits.

  FIG. 1 shows a configuration example of the first embodiment of the present invention.

  In the first embodiment, a positive pressure generating valve 121 that functions when the nozzle is replaced, and a first air circuit having a first throttle valve (a positive pressure generating means capable of generating a positive pressure for separating the suction nozzle) In addition to A101, a second air circuit (negative pressure generating means) A102 having a negative pressure generating valve 122 that functions during component adsorption, a third throttle valve 130 having a weak positive pressure generating second throttle valve 130 is provided. An air circuit (weak positive pressure generating means) A103 is provided.

  The positive pressure generating valve 121 is a binary valve that controls on / off of the flow of air supplied from the air supply source 120 into the first air circuit A101. Specifically, the first throttle valve 123 is a fixed orifice that allows a large flow rate (the degree of throttling is small). The negative pressure generating valve 122 discharges the compressed air supplied from the air supply source 120 from the discharge passage 122A through a nozzle (not shown) so that the negative pressure is turned on and off in the second air circuit A102. It is a so-called ejector to be generated. The second throttle valve 130 for generating a weak positive pressure reduces the pressure (or flow rate) of the air supplied from the air supply source 120 to a fine positive pressure that is optimal as a positive pressure applied when an electronic component is mounted. Specifically, it is a fixed orifice that allows only a small flow rate (a large degree of throttling). As a result, a “weak positive pressure” that is weaker than the positive pressure for separating the suction nozzle generated in the first air circuit A101 is generated. In this embodiment, the “weak positive pressure” is set to 3 kPa, for example, and its absolute value is far greater than the negative pressure (for example, 70 kPa) for sucking electronic components generated in the second air circuit A102. small.

  The first to third air circuits A101, A102, A103 are each branched from the branching portion 125 and connected to the suction nozzle 118 in a state of being joined at the joining portion 126. Of these, the third air circuit A103 does not have a valve for controlling on / off, and always bypasses both the air circuits A101 and A102 in parallel with the first and second air circuits A101 and 102. It is attached in such a manner as to generate a weak positive pressure.

  Next, the operation of the first embodiment will be described.

  Referring to (1) of FIG. 1, at the normal time, that is, before the electronic component P starts to be sucked, the air sent from the air supply source 120 is supplied with the positive pressure generating valve 121 and the negative pressure. Since the generating valve 122 maintains the off (shut off) state, air does not flow through the first air circuit A101 and the second air circuit A102 (no positive or negative pressure is generated).

  On the other hand, the air that has reached the second throttle valve 130 for generating a weak positive pressure from the air supply source 120 via the branching portion 125 is greatly reduced in pressure (or the flow rate thereof is reduced), and is moved to the third air circuit A103 side. It always flows in. Therefore, in a normal state, a state in which this weak positive pressure is always applied to the suction nozzle 118 is formed. Since this weak positive pressure is always generated at a constant pressure, the circuit is simple and low-cost, and switching to negative pressure when mounting electronic components can be performed stably as described later. it can. Furthermore, it can also be expected to fulfill the function of preventing fine dust and the like from adhering to the tip of the nozzle.

  Referring to (2) of FIG. 1, when the electronic component is attracted, the positive pressure generating valve 121 is turned off and the negative pressure generating valve 122 is turned on. As a result, the air supplied from the air supply source 120 is discharged from the discharge path 122A, and a negative pressure is generated in the second air circuit A102, so that the electronic components can be sucked by the suction nozzle 118. Note that a weak positive pressure is generated in the third air circuit 103 as in the example of (1) above, but the absolute value of this positive pressure (for example, 3 kPa) is generated in the second air circuit A102. It is set much smaller than the absolute value (for example, a negative pressure of 70 kPa). Therefore, as a result, the air flowing out to the third air circuit A103 side is drawn into the negative pressure generating valve 122 side via the second air circuit A102. Therefore, the suction nozzle 118 generates a negative pressure sufficient to suck the electronic component.

  Referring to (3) of FIG. 1, when the electronic component P is placed at a predetermined position on the substrate from this state, both the positive pressure generating valve 121 and the negative pressure generating valve 122 are turned off. And Thereby, the state is automatically switched to a state where only the weak positive pressure of the third air circuit A102 remains, and the electronic component P can be smoothly detached from the suction nozzle 118. The positive pressure generated / remaining due to this switching is “weak”. Therefore, even if there is a variation, it is necessary to set the suction nozzle 118 to rise after a certain period of time until the negative pressure reaches zero. , “Positive pressure supply start and stop” timing is not suitable, and there will be no problem of bringing back the electronic parts as they are, and the positive pressure is too strong and the electronic parts that have been adsorbed so far There is no problem that a used electronic component is blown away.

  Referring to (4) of FIG. 1, when the suction nozzle is replaced, a state is formed in which the positive pressure generating valve 121 is turned on and the negative pressure generating valve 122 is turned off. Thereby, the strong positive pressure for nozzle separation generated in the first air circuit A101 and the weak positive pressure generated in the third air circuit A103 are applied to the suction nozzle 118 in a merged state, and the suction nozzle is removed. Is done smoothly.

FIG. 2 shows a reference example of the present invention.

In this reference example , a valve 238 for generating weak positive pressure capable of turning on and off the application of “weak positive pressure” is added to the third air circuit A203 of the embodiment of FIG. Thereby, it is possible to prevent the weak positive pressure from constantly flowing through the third air circuit A203. The control is such that the weak positive pressure generating valve 238 is turned on before the negative pressure generating valve 222 is switched from off to on, and is turned off at the time when it is estimated that the electronic component is surely placed. 2 (2) and (3) in FIG. 2 can obtain substantially the same action as that obtained in FIGS. 1 (2) and (3).

The weak positive pressure generating valve 238 is turned off when the nozzle is replaced in FIG. 2 (4) in this reference example , but it may be turned on. Since other configurations and operations are basically the same as those of the previous embodiment, the same or similar parts are denoted by the same reference numerals as those in FIG. To do.

This reference example is excellent in terms of reducing energy loss because weak air does not always flow out of the suction nozzle at normal times.

FIG. 3 shows an example of the second embodiment of the present invention.

This second embodiment has only the first and second two air circuits A302 and A305. However, the first air circuit A305 is provided with an electric control pressure reducing valve 350 capable of adjusting the degree of throttling instead of the fixed throttle valve, and a positive pressure generating means capable of generating a positive pressure for removing the suction nozzle; It also serves as a weak positive pressure generating means capable of generating a positive pressure weaker than the positive pressure for separating the suction nozzle. That is, the functions of the first air circuits A101 and A201 and the functions of the third air circuits A103 and A203 in the previous embodiments and reference examples are combined. In the second embodiment, a pressure sensor 351 is further provided in the first air circuit A305, and the actual pressure of the air in the first air circuit A305 can be detected.

  In this embodiment, the control mode shown in (1) of FIG. 3 is normally used, the control mode shown in (2) of FIG. 3 is used when the electronic component P is attracted, and the control mode shown in FIG. The control mode shown in 3 (3) is used. In the present embodiment, since the pressure sensor 351 is incorporated, for example, the following two modes can be considered as more specific control modes at the time of mounting.

  The first control mode detects the return of the electronic component P based on the detection value of the pressure sensor 351 (a state in which the negative pressure is not eliminated even though the suction nozzle 318 is in the ascending process). Based on the detection value of the pressure sensor 351, the value of the weak positive pressure applied to the subsequent electronic component P of the same kind is learned and corrected. This learning correction is performed for each type of suction nozzle and / or each type of electronic component. In addition, when the time when the detection value of the pressure sensor 351 becomes positive is too early, the applied weak positive pressure is too strong, so learning correction is made so as to make it weaker. Incidentally, when the take-out is detected, the suction nozzle 318 is returned to the place where it should be placed again, and is again placed by applying “weak positive pressure” again.

  The second control mode is to variably control the weak positive pressure that is actually applied to the electronic component P based on the detection value of the pressure sensor 351 in real time. That the detected value of the pressure sensor 351 indicates a negative value means that the electronic component P is still sucked (not separated) at the tip of the suction nozzle 318. Therefore, in this case, the “weak positive pressure” is continuously applied. At this time, the weaker “weak positive pressure” is applied as the detection value of the pressure sensor 351 approaches “zero”.

  In the present invention, since the “weak positive pressure” is originally applied to the electronic component, there is no particular problem even if the “weak positive pressure” is applied a little longer in time (the stop timing of the positive pressure application). Strict configuration is not required). However, by adopting a configuration in which a “weak positive pressure” that changes from a slightly stronger value to a weaker value as the detection value of the pressure sensor 351 approaches zero in this way is provided without causing a malfunction, Regardless of the type of P and various variations, the residual negative pressure can be made zero in the shortest time.

  In both the first and second control modes, a large positive pressure is applied when the suction nozzle is replaced, and the nozzle replacement is assisted (see FIG. 3 (4)). .

Since the other configurations and actions are basically the same as the previous configuration example , the same or similar parts are denoted by the same reference numerals as those in FIG. 1 or FIG. Description is omitted.

  Note that the weak positive pressure learning correction using the detection value of the pressure sensor and the real-time correction are not necessarily performed, and the detection value may be simply used as an index for raising the suction nozzle. Furthermore, the pressure sensor itself is not necessarily an essential element, and only the feedforward pressure reduction control by the electric control pressure reducing valve may be performed.

  Widely applicable to electronic component mounting apparatuses.

Schematic air control circuit diagram showing the main part of the configuration example of the first embodiment of the present invention Schematic air control circuit diagram showing the main part of a reference example of the present invention Schematic air control circuit diagram showing the main part of the configuration example of the second embodiment of the present invention Main part schematic block diagram of the conventional (and embodiment of this invention) electronic component mounting apparatus Sectional view showing a configuration example near the suction nozzle 1 is a schematic air control circuit diagram corresponding to FIG.

Explanation of symbols

A101, A201 ... first air circuit (positive pressure generating means for nozzle replacement)
A102, A202, A302 ... second air circuit (negative pressure generating means)
A103, A203 ... Third air circuit (weak positive pressure generating means)
A305: first air circuit (positive pressure for nozzle replacement and weak positive pressure generating means)
118 ... Adsorption nozzle 120 ... Air supply source 121 ... Valve for generating positive pressure 122 ... Valve for generating negative pressure 123 ... First throttle valve 130 ... Second throttle valve 138 ... Valve for generating weak positive pressure 350 ... Electric control Pressure reducing valve 351 ... Pressure sensor

Claims (5)

In an electronic component mounting apparatus configured to suck and transport electronic components with a suction nozzle and to be mounted at a predetermined position on a substrate,
When replacing the suction nozzle, a positive pressure generating means capable of generating a positive pressure for separating the suction nozzle with respect to the suction nozzle to be replaced;
A weak positive pressure generating means capable of generating a positive pressure weaker than the positive pressure for separating the suction nozzle with respect to the electronic component sucked by the suction nozzle at least when the electronic component is mounted;
The equipped, and,
The electronic component mounting apparatus , wherein the weak positive pressure generated by the weak positive pressure generating means is constantly applied to the suction nozzle . In an electronic component mounting apparatus configured to suck and transport electronic components with a suction nozzle and to be mounted at a predetermined position on a substrate,
A negative pressure generating means capable of generating a negative pressure for sucking an electronic component with respect to the suction nozzle when sucking and conveying the electronic component;
At least when the electronic component is mounted, a weak positive pressure generating means capable of generating a weak positive pressure whose absolute value is weaker than the negative pressure for the electronic component suction with respect to the electronic component sucked by the suction nozzle;
The equipped, and,
The electronic component mounting apparatus , wherein the weak positive pressure generated by the weak positive pressure generating means is constantly applied to the suction nozzle . In claim 1 or 2 ,
The electronic component mounting apparatus, wherein the weak positive pressure generated by the weak positive pressure generating means is variable depending on at least one of the type of the suction nozzle and the type of electronic component. In any one of Claims 1-3 , Furthermore,
A pressure sensor for detecting the pressure value of the air currently applied to the suction nozzle;
The take-out of the electronic component is detected based on the detection value of the pressure sensor, and the weak positive pressure applied to the same kind of electronic component is learned and corrected based on the detection value of the pressure sensor at this time. An electronic component mounting apparatus. In any one of Claims 1-3 , Furthermore,
A pressure sensor for detecting the pressure value of the air currently applied to the suction nozzle;
An electronic component mounting apparatus, wherein the weak positive pressure that is actually applied to the electronic component is variably controlled in real time based on a detection value of the pressure sensor.

Images