JP2007281024A - Mounting device of electronic component and mounting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately inspect the thickness of a flux film to be transferred to a solder ball electrode of an electronic component by simplified structure. <P>SOLUTION: An electronic component provided with a ball electrode is sucked and picked up by a nozzle 101, and the solder ball electrode of the sucked electronic part is immersed in a flux unit 108 to transfer flux thereto. The surface on which the solder ball electrode of the electronic component is illuminated by an illumination 103, and the illuminated solder ball electrode illuminated by the illumination in the photographing part 104 is photographed to acquire a video signal. At the same time, the luminance of the solder ball electrode is detected by a luminance detector 105, and when the detected luminance of the solder ball electrode is higher than a predetermined threshold value, it is judged to be flux transfer failure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic component mounting apparatus and mounting method, and more particularly to an electronic component mounting machine and mounting method for inspecting and mounting after transferring a flux to a solder ball electrode such as BGA or CSP.

Generally, in solder bonding, flux is supplied to the surface of the solder alloy in order to remove the oxide film formed on the surface of the solder alloy, improve the wettability when the solder alloy melts, and ensure the bonding. Is essential. Therefore, in order to ensure the quality of the joint, it is essential to inspect whether the flux is supplied securely before placing the printed circuit board with electronic components in the furnace and performing soldering. It is a difficult issue.
In recent years, BGA (Ball Grid Array) and CSP (Chip Size Package) in which solder balls are arranged as electrodes at the bottom of the package in order to reduce the size of the device by mounting electronic components on the substrate at high density are more effective than the mounting area. Used for further reduction. As an inspection of the flux supply state for a package in which solder ball electrodes such as BGA and CSP are provided at the bottom of the package, Patent Document 1 performs image recognition of the solder ball electrode to which the flux has been transferred before mounting on the substrate. The diameter of the solder ball electrode to which the flux has been transferred is obtained from the image recognition result, and the difference from the diameter of the solder ball electrode itself is calculated from that value. An inspection method for not mounting is disclosed.
However, in such a conventional method, there are two major problems. First, there are problems associated with downsizing and increasing the density of packages. In recent years, the pitch between the electrodes has been further narrowed and the size of the solder ball electrode itself has been reduced. Accordingly, further improvement in inspection accuracy has been demanded. Specifically, since the diameter of the solder ball electrode provided in the package is also in the order of several hundreds to several tens of micrometers, accuracy in the order of several tens of micrometers is required for the inspection of the transfer amount of the flux. For this reason, it is increasingly difficult to determine the diameter by image recognition, and it is difficult to cope with the conventional method. The second problem is the shape of the solder ball electrode. The solder balls provided on the package are formed in a substantially spherical shape, but since this is formed by a method such as atomization, there are actually not a few ball electrodes that have a distorted shape such as irregularities on the surface. To do. Therefore, there is a possibility that a sufficient amount of flux transfer is not obtained even if the inspection condition is satisfied in a certain cross section. For example, even if the inspection condition is satisfied when the image is taken from directly below, the inspection condition may not be satisfied if the image is picked up from a point slightly shifted in angle. Therefore, it is difficult to ensure sufficient inspection accuracy in consideration of the non-uniformity of the shape.
JP 2003-60398 A

Accordingly, the present invention solves the problems of the prior art, and an electronic component mounting inspection apparatus and electronic component mounting capable of accurately inspecting the amount of flux supplied to solder ball electrodes such as BGA and CSP with a simple configuration. The purpose is to provide an inspection method.

The first solution of the present application includes a nozzle unit that sucks and picks an electronic component including a solder ball electrode, a flux unit in which a solder ball electrode provided on the sucked electronic component is immersed, and the electronic component. An illumination unit that illuminates the surface provided with the solder ball electrode, a luminance detection unit that images the surface of the electronic component provided with the solder ball electrode and detects luminance, and the solder ball detected by the luminance detection unit It is characterized by comprising a control unit that performs determination control of flux transfer failure when the luminance of the electrode is higher than a predetermined threshold value.

With this configuration, it is possible to detect the transfer state of the flux of the electronic component including the solder ball electrode with high accuracy, and it is possible to mount the electronic component in which the bonding failure due to insufficient flux is suppressed.
The second solution of the present application is that the nozzle height for sucking and picking an electronic component including a solder ball electrode and the solder ball electrode provided on the sucked electronic component are immersed, and the gate height is variable. A flux unit; an illumination unit that illuminates a surface of the electronic component provided with the solder ball electrode; a luminance detection unit that captures an image of the surface of the electronic component provided with the solder ball electrode; and the luminance detection It is characterized by comprising a control unit that performs determination control of flux transfer failure when the brightness of the solder ball electrode detected by the unit is higher than a predetermined threshold value.
With this configuration, it is possible to detect the transfer state of the flux of the electronic component including the solder ball electrode with high accuracy, and it is appropriate when the operating environment such as the ambient temperature of the apparatus changes and the influence of warpage or the like occurs. It is possible to mount an electronic component that secures a flux transfer amount and suppresses bonding failure due to insufficient flux.

  The third solving means of the present application is characterized in that it is possible to adjust the irradiation intensity of the illumination part in the first solving means and the second solving means of the present application. With this configuration, when conditions such as the type of flux to be used and the diameter of the solder ball electrode change, it is possible to set more appropriate detection conditions for flux transfer failure.

In the fourth solution of the present application, the control unit in the second solution performs control to change the gate height of the flux unit when a transfer failure occurs at a predetermined frequency or more, or to the operator It is configured to notify that the gate height is changed.
With this configuration, it is possible to detect the transfer state of the flux of the electronic component including the solder ball electrode with high accuracy, and to ensure an appropriate amount of flux transfer when the mounting conditions change from time to time, and joining due to insufficient flux It is possible to mount an electronic component in which defects are suppressed.

  The fifth solution of the present application includes a step of sucking and picking an electronic component including a solder ball electrode, a step of immersing a solder ball electrode provided on the sucked electronic component in a flux unit, and transferring a flux, Illuminating the surface of the adsorbed electronic component provided with the solder ball electrode, imaging the surface of the adsorbed electronic component provided with the solder ball electrode, detecting the brightness, and detecting the detected solder It is characterized by comprising a step of determining and controlling flux transfer failure when the brightness of the ball electrode is higher than a predetermined threshold value.

With this configuration, it is possible to detect the transfer state of the flux of the electronic component including the solder ball electrode with high accuracy, and it is possible to perform the mounting method of the electronic component that suppresses the bonding failure due to the insufficient flux.
The sixth solution of the present application includes a step of sucking and picking an electronic component including a solder ball electrode, a step of transferring a flux by immersing a solder ball electrode provided in the sucked electronic component in a flux unit, and Illuminating the surface of the adsorbed electronic component provided with the solder ball electrode, imaging the surface of the adsorbed electronic component provided with the solder ball electrode, detecting the brightness, and detecting the detected solder It comprises a step of determining and controlling flux transfer failure when the brightness of the ball electrode is higher than a predetermined threshold value, and a step of changing the gate height of the flux unit when flux transfer failure occurs more than a predetermined frequency. It is characterized by being.
With this configuration, it is possible to detect the transfer state of the flux of the electronic component including the solder ball electrode with high accuracy, and it is possible to perform the mounting method of the electronic component that suppresses the bonding failure due to the insufficient flux.
The seventh solution of the present application includes a step of sucking and picking an electronic component including a solder ball electrode, a step of transferring a flux by immersing a solder ball electrode provided on the sucked electronic component in a flux unit, and Illuminating the surface of the adsorbed electronic component provided with the solder ball electrode, imaging the surface of the adsorbed electronic component provided with the solder ball electrode, detecting the brightness, and detecting the detected solder A step of determining and controlling a flux transfer failure when the brightness of the ball electrode is higher than a predetermined threshold value, and a notification of changing the gate height of the flux unit when a flux transfer failure occurs more than a predetermined frequency. It is characterized by comprising steps.

  With this configuration, it is possible to detect the transfer state of the flux of the electronic component including the solder ball electrode with high accuracy, and it is possible to perform the mounting method of the electronic component that suppresses the bonding failure due to the insufficient flux.

  According to the electronic component mounting apparatus and electronic component mounting method of the present invention, it is possible to detect the transfer state of the flux of the electronic component including the solder ball electrode with high accuracy, and to suppress the bonding failure due to the lack of flux. Components can be mounted.

Embodiments of an electronic component mounting apparatus according to the present invention will be described below with reference to the drawings. In the first embodiment, the configuration and basic operation of an electronic component mounting apparatus will be described. In the second embodiment and below, various modifications will be described.
(First embodiment)
FIG. 1 is a block diagram showing the overall configuration of an electronic component mounting apparatus according to the present invention. The electronic component mounting apparatus according to the present embodiment includes a nozzle unit 101, a drive unit 102, an irradiation unit 103, an imaging unit 104, a luminance detection unit 105, a control unit 106, a table unit 107, and a flux unit 108.

The nozzle unit 101 has a nozzle for sucking an electronic component 109 provided with a solder ball electrode from a component supply feeder. The drive unit 102 has the nozzle unit in the X-axis direction, the Y-axis direction (note that the plane of the substrate 110 is the XY plane), the Z-axis direction (the axial direction perpendicular to the substrate 110), and the θ-axis direction (on the XY plane). The motor is driven in the rotation direction), and the nozzle portion is driven. Thereby, the nozzle unit 101 moves onto the flux unit 108, the flux is transferred to the solder electrode of the electronic component adsorbed on the nozzle unit 101, and moves onto the table unit 107 on which the substrate 110 is placed, Electronic components are mounted on the substrate 110. In the present embodiment, the drive unit 102 is configured to drive the nozzle unit in the X-axis direction, the Y-axis direction, the Z-axis direction, and the θ-axis direction. However, the present invention is not limited to this configuration. The unit 102 may be connected to the table unit 107 on which the substrate 110 is placed, and may be aligned in the X-axis direction, the Y-axis direction, the Z-axis direction, and the θ-axis direction by driving the table unit. The irradiation unit 103 uses a light source such as a light emitting diode (LED) to irradiate light onto the surface of the attracted electronic component on which the solder ball electrode is provided. The image pickup unit 104 is provided with an image pickup device such as a CCD for picking up an image of the surface on which the solder ball electrode of the electronic component irradiated with light by the irradiation unit 103 is provided, and the solder electrode of the electronic component is provided. The image signal of the given surface is acquired. The luminance detection unit 105 performs signal analysis from the image signal acquired by the imaging unit 104 and calculates the luminance level of the solder ball electrode portion of the electronic component 109. This luminance level calculation method is arbitrary. For example, the luminance in a state where the flux is transferred may be a relative luminance level normalized by the luminance in a state where the flux is not transferred at all, or may be an absolute luminance level such as cd / m 2 which is a unit of luminance. The control unit 106 controls the alignment of the driving unit 102, and based on the luminance level of the solder ball electrode portion of the electronic component 109 detected by the luminance detection unit, the state of flux transfer to the solder ball electrode of the electronic component 109 And whether or not the electronic component 109 is to be mounted on the substrate 110 is determined. The flux unit 108 is filled with a flux for removing an oxide film formed on the surface of the solder alloy, and the nozzle unit 101 is moved in the X-axis direction and the Y-axis direction by the driving unit 102, thereby the flux unit. The magnetic flux is transferred by moving the solder ball electrode part of the electronic component 109 by being moved up and down in the Z-axis direction while being positioned above 108.

Next, a graph showing the relationship between the transfer film thickness of the flux and the detected luminance level is shown in FIG. FIG. 2 shows a state in which the detected luminance level decreases as the flux transfer film thickness increases. From this relationship, the lower limit value of the flux transfer film thickness that provides sufficient wettability at the time of melting is measured in advance, and a brightness that becomes a certain threshold value is set in consideration of this, so that the solder of the electronic component 109 can be obtained. The brightness level of the ball electrode portion can be measured to determine whether the flux transfer state is good or bad.
Next, the operation of the electronic component mounting apparatus according to this embodiment will be described. FIG. 3 shows an operation flowchart of the electronic component mounting apparatus according to this embodiment. The operation of the electronic component mounting apparatus according to this embodiment will be described below with reference to FIG. First, the electronic component 109 is supplied from the feeder, and the nozzle unit 101 sucks the electronic component 109 (step 1). Next, the control unit 106 controls the drive unit 102 to move the nozzle unit 101 in the X-axis direction and the Y-axis direction so that the nozzle unit 101 that has attracted the electronic component 109 is positioned on the flux unit 108. Then, the flux is transferred to the solder ball electrode provided on the electronic component 109 by moving up and down in the Z-axis direction (step 2). Next, the irradiation unit 103 irradiates light onto the surface on which the solder ball electrode of the electronic component 109 to which the flux has been transferred is provided, and also the solder ball of the electronic component 109 irradiated with light by the irradiation unit 103 by the imaging unit 104. The surface on which the electrodes are provided is imaged and an image signal is acquired (step 3). Then, the brightness level of the solder ball electrode is calculated from the acquired image signal, and when the brightness level of the solder ball electrode portion is equal to or greater than a certain threshold, the control unit 106 determines that the transfer of the flux is defective and outputs a control signal. Based on the output, control is performed so that the electronic component 109 is not mounted on the substrate 110 (step 4). When the brightness level of the solder ball electrode is equal to or less than a certain threshold value, the same brightness level is detected for the next solder ball electrode. It is determined that the component 109 can be mounted (step 5). In this embodiment, the transfer state of each solder ball is determined. However, the determination is not performed for all the solder balls, and the transfer state is determined only for representative electrodes for efficiency. You may comprise. In addition, the type of flux to be filled in the flux unit is not particularly limited, but by adding a pigment to the flux, the brightness change accompanying the change of the flux transfer film thickness becomes steep, so even if a pigment is added to the flux Good.

FIG. 4 shows the relationship between the luminance level detected when the intensity of the light irradiated by the irradiation unit 103 is changed and the flux transfer film thickness. From FIG. 4, the brightness level difference between the thin film thickness and the thick film pressure is significant depending on the light intensity. Therefore, by changing the intensity of light emitted from the irradiation unit, it is possible to flexibly cope with changes in conditions such as the type of flux used. As described above, according to the present embodiment, since the transfer state of the flux can be determined without directly measuring the film thickness of the flux, it is possible to easily and accurately determine the transfer state of the flux without the need for high-precision image recognition at the tens of micrometers level. Is possible.
(Embodiment 2)
FIG. 5 is a block diagram showing the overall configuration of the electronic component mounting apparatus according to the second embodiment.
In addition, the same code | symbol is attached | subjected about the same part as the electronic component mounting apparatus in 1st embodiment of FIG. In the second embodiment, the flux unit 401 is connected to the control unit 406 in addition to the configuration of the first embodiment. FIG. 6 shows a schematic diagram of the flux unit in this embodiment. FIG. 6A is a plan view of the flux unit 408, and FIG. 6B is a cross-sectional view of the flux unit 408. In such a reciprocating squeegee type flux unit, the flux on the bottom surface of the flux unit is scraped off by the scraping squeegee in the forward path, and the flux is deposited to a certain thickness by the film forming squeegee in the return path. This flux film thickness is determined by the gate height which is the distance between the film forming squeegee lower end and the flux tank bottom. The transfer amount when the flux is immersed in the flux film is greatly influenced by the film thickness. The flux unit in the present embodiment is configured such that the gate height is variable by changing the squeegee or controlling the position.
Further, as in the first embodiment, the control unit 406 determines whether or not the flux transfer is good according to the output of the luminance detection unit, and when the flux transfer failure is more than a predetermined frequency, Control is performed to change the thickness.
Next, the operation of the electronic component mounting apparatus according to this embodiment will be described. FIG. 7 shows an operation flowchart of the electronic component mounting apparatus according to this embodiment. First, the supply of the electronic component 109 is received, and the nozzle unit 101 sucks the electronic component 109 (step 1). Next, the control unit 406 controls the drive unit 102 to move the nozzle unit in the X-axis direction and the Y-axis direction so that the nozzle unit 101 that has attracted the electronic component 109 is positioned on the flux unit 109. The flux is transferred to the solder ball electrode of the electronic component 109 by moving up and down in the Z-axis direction (step 2). Next, the irradiation unit 103 irradiates light onto the surface on which the solder ball electrode of the electronic component 109 to which the flux has been transferred is provided, and also the solder ball of the electronic component 109 irradiated with light by the irradiation unit 103 by the imaging unit 104. The surface on which the electrodes are provided is imaged and an image signal is acquired (step 3). Then, the brightness level of the solder ball electrode part is calculated from the acquired image signal, and when the brightness level of the solder ball electrode is equal to or higher than a certain threshold value, the control unit 406 determines that the transfer of the flux is defective and outputs a control signal. Based on the output, control is performed so that the electronic component 109 is not mounted on the substrate 110 (step 4). When the brightness level of the solder ball electrode is equal to or less than a certain threshold value, the same brightness level is detected for the next solder ball electrode. It is determined that the component 109 can be mounted (step 5). Further, the control unit 406 controls the gate height of the film formation squeegee in the flux unit when the transfer failure occurs at a constant frequency to secure the flux transfer amount (step 6).
With this configuration, it is possible to easily and accurately determine the flux transfer state without the need for high-accuracy image recognition, and the amount of flux transfer can be adaptively controlled. It is also possible to deal with a case where the amount of flux transferred changes due to warpage or the like in the electronic component. In this embodiment, the flux unit is connected to the control unit 406 and the height of the gate is automatically controlled. However, when a transfer failure occurs at a certain frequency or more without connecting the control unit to the flux unit. The operator may be notified, the gate height may be adjusted manually such as by changing the squeegee, and the flux transfer amount may be secured.

  As described above, the electronic component mounting apparatus and the electronic component mounting method according to the present invention can prevent a bonding failure by detecting a solder ball electrode flux transfer defect of an electronic component with high accuracy, and are lighter. It can greatly contribute to the manufacture of small and highly functional electronic devices.

The block diagram of the electronic component mounting apparatus of 1st embodiment of this invention Diagram showing the relationship between the transfer film thickness of the flux and the detected brightness level Operation flow diagram of electronic component mounting apparatus in first embodiment of the present invention The figure which shows the relationship between the luminance level at the time of changing the intensity | strength of the light which the irradiation part 103 irradiates, and a flux transfer film thickness The block diagram of the mounting device of the electronic component of 2nd embodiment of this invention The block diagram of the flux unit in the second embodiment of the present invention Operation flow diagram of electronic component mounting apparatus according to second embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Nozzle part 102 Drive part 103 Irradiation part 104 Imaging part 105 Luminance detection part 106 Control part 107 Table part 108 Flux unit 109 Electronic component 110 Substrate 406 Control part 408 Flux unit 601 Scraping squeegee 602 Deposition squeegee 603 Flux tank

Claims (7)

Nozzle portion for picking up and picking up electronic components including solder ball electrodes, flux unit in which solder ball electrodes provided on the picked-up electronic components are immersed, and surface of the electronic components on which the solder ball electrodes are provided An illumination unit that illuminates the surface of the electronic component, a luminance detection unit that detects the luminance of the surface on which the solder ball electrode of the electronic component is provided, and a predetermined threshold value for the luminance of the solder ball electrode detected by the luminance detection unit An electronic component mounting apparatus having a control unit that performs determination control of a flux transfer defect when it is higher. A nozzle unit that picks up and picks up an electronic component including a solder ball electrode, a flux unit in which a solder ball electrode provided on the picked-up electronic component is immersed, and a variable gate height, and the electronic component An illumination unit that illuminates the surface provided with the solder ball electrode, a luminance detection unit that images the surface of the electronic component provided with the solder ball electrode and detects luminance, and the solder ball electrode detected by the luminance detection unit An electronic component mounting apparatus having a control unit that performs determination control of a flux transfer failure when the luminance of the light is higher than a predetermined threshold. The electronic component mounting apparatus according to claim 1, wherein irradiation intensity of the illumination unit is changeable. The control unit notifies the operator that the gate height of the flux unit is changed or the gate height is changed when the flux transfer failure occurs at a predetermined frequency or more. Item 3. The electronic component mounting apparatus according to Item 2. A step of adsorbing and picking an electronic component having a solder ball electrode; a step of immersing a solder ball electrode provided on the adsorbed electronic component in a flux unit; and transferring a flux; and a solder of the adsorbed electronic component Illuminating the surface on which the ball electrode is provided, imaging the surface of the attracted electronic component on which the solder ball electrode is provided, detecting the luminance, and the detected luminance of the solder ball electrode is predetermined. An electronic component mounting method including a step of determining and controlling a flux transfer defect when the value is higher than a threshold. A step of adsorbing and picking an electronic component having a solder ball electrode; a step of immersing a solder ball electrode provided on the adsorbed electronic component in a flux unit; and transferring a flux; and a solder of the adsorbed electronic component Illuminating the surface on which the ball electrode is provided, imaging the surface of the attracted electronic component on which the solder ball electrode is provided, detecting the luminance, and the detected luminance of the solder ball electrode is predetermined. An electronic component mounting method comprising: determining and controlling a flux transfer failure when higher than a threshold value; and changing a gate height of the flux unit when a flux transfer failure occurs more than a predetermined frequency. A step of adsorbing and picking an electronic component having a solder ball electrode; a step of immersing a solder ball electrode provided on the adsorbed electronic component in a flux unit; and transferring a flux; and a solder of the adsorbed electronic component Illuminating the surface on which the ball electrode is provided, imaging the surface of the attracted electronic component on which the solder ball electrode is provided, detecting the luminance, and the detected luminance of the solder ball electrode is predetermined. An electronic component mounting method comprising the steps of: determining and controlling a flux transfer failure when higher than a threshold; and notifying that the gate height of the flux unit is changed when a flux transfer failure occurs more than a predetermined frequency .

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