WO2008018526A1

WO2008018526A1 - Soldering inspection method, soldering method, and soldering apparatus

Info

Publication number: WO2008018526A1
Application number: PCT/JP2007/065580
Authority: WO
Inventors: Yoshiomi Munesawa; Seiichi Kitano; Tsuyoshi Kobayashi
Original assignee: National University Corporation Okayama University
Priority date: 2006-08-11
Filing date: 2007-08-09
Publication date: 2008-02-14
Also published as: CN101501444B; CN101501444A; JP3962782B1; JP2008045956A

Abstract

A soldering inspection method which is performed while accurately detecting solder melted by a solder melting means such as a soldering iron. A soldering method and a soldering apparatus are also provided. In a soldering method and a soldering apparatus for performing soldering by supplying solder to a solder melting means such as a soldering iron disposed in a soldering region, solder melted by the solder melting means is photographed sequentially by means of a camera in predetermined timing, image data by light, which is reflected from the solder and has a wavelength longer than that of red, is generated, differential image data is generated sequentially by taking the difference of at least two image data taken in different photography timing, compound image data is generated by compounding the differential image data by superposing sequentially, the area of solder in the soldering region of the compound image data is detected, and then the amount of solder supplied to the solder melting means is detected based on the area of solder.

Description

Specification

Soldering inspection method, soldering method, and soldering apparatus

Technical field

The present invention relates to a soldering inspection method, a soldering method, and a soldering apparatus, and in particular, automatically supplies solder to a solder melting means such as a soldering iron that melts solder. Thus, the present invention relates to a soldering inspection method, a soldering method, and a soldering apparatus that can automatically perform soldering.

Background art

[0002] In recent years, when electronic components are mounted on a mounting board, a paste-like solder is applied in advance to a predetermined position of the mounting board, and a predetermined position on the mounting board is required via the paste-like solder. The electronic component is placed, and the solder is melted by performing a reflow process in which the mounting substrate is heated to a temperature higher than the melting temperature of the solder, and the electronic component is soldered to the mounting substrate.

[0003] However, a member that is always subjected to stress, such as an electrode body in contact with a battery electrode, is bonded to the mounting substrate, or a so-called power electronics component used at high power is bonded to the mounting substrate. In order to take advantage of the stress relaxation property of solder, it is necessary to join using a relatively large amount of solder. In reflow processing, solder is fed while supplying thread solder that has been processed into a thread shape. It had to be soldered while being raised into a mountain shape by melting.

[0004] As described above, since a relatively high skill is required to raise the solder into a chevron shape, until recently, it was often performed manually by a worker using a soldering iron. Since the feeding accuracy has been improved, the solder can be supplied smoothly, so an automatic soldering device has been developed, and manual soldering replaces soldering by the automatic soldering device. As a result, productivity is improved.

[0005] When soldering with an automatic soldering apparatus, it is necessary to monitor whether the soldering is performed accurately, and soldering is performed by measuring the temperature distribution in the soldering area with an infrared sensor. A monitoring device that can monitor the status in real time has been proposed. (For example, refer to Patent Document 1).

[0006] As described above, when the soldering state is monitored in real time by the infrared sensor, the soldering state is detected by a CCD camera (hereinafter simply referred to as a CCD camera) using a silicon photodiode array as an image sensor. The ability to improve the detection accuracy of solder compared with the case of monitoring Since it is relatively expensive, it was desired to use a CCD camera that can be introduced at a lower cost.

[0007] When the soldering state is monitored with a CCD camera, at least first image data and second image data are generated by photographing the soldering state with a predetermined time difference, and this first By generating the difference image data by taking the difference between the first image data and the second image data, the soldering iron melts between the first image data generation timing and the second image data generation timing. The amount of solder that has been detected can be detected, and the soldering state can be monitored based on the detected amount of solder.

[0008] Note that, in the generation of the difference image data, at least one of the first image data and the second image data is generated by photographing at a timing immediately after the start of melting of the solder by the soldering iron or immediately before the start. It is common to generate difference image data by using the difference between this image data as basic image data and using the image data generated by sequential shooting as the other image data. A difference S may be generated by taking a difference from three or more appropriate image data. Patent Document 1: Japanese Patent Application Laid-Open No. 07-270239

Disclosure of the invention

Problems to be solved by the invention

However, the solder melted by a solder melting means such as a soldering iron generally has a spherical shape due to its extremely high surface tension. Therefore, when the melted solder is photographed with a CCD camera, The surface of the melted solder that is in front of the camera becomes a plane that can be regarded as a flat surface, and even if the solder is further melted, the surface change has become extremely small.

[0010] Therefore, the portion of the surface that can be regarded as approximately a flat surface is extracted in the differential processing for generating the differential image data because no change with time is seen like the substrate portion other than the soldering region. The solder specified by the difference image data cannot be This shows all the solder melted by the field melting means! / ,!

[0011] In other words, the CCD camera cannot accurately detect the solder melted by the solder melting means, so the soldering state cannot be completely monitored! /, And! / was there.

[0012] Moreover, since smoke generated during soldering is reflected in an image taken by a CCD camera, there is a problem that the soldering state cannot be monitored due to the smoke. In particular, when soldering using so-called lead-free solder, a larger amount of smoke is generated, making it difficult to accurately photograph the solder in the soldered portion with a CCD camera.

[0013] In view of such a current situation, the present inventor has conducted research and development to perform soldering while reliably monitoring the soldering state even in the case of soldering using lead-free solder, thereby forming the present invention. Has been reached.

Means for solving the problem

[0014] In the soldering inspection method of the present invention, in the soldering inspection method in which the solder melting means for melting the solder is disposed in a soldering area where soldering is performed and the solder is supplied to the solder melting means. A step of sequentially generating image data of light having a wavelength longer than red, reflected from the solder by sequentially shooting the solder melted by the solder melting means at a predetermined timing with a camera, and shooting of the image data A step of sequentially generating difference image data by taking a difference between at least two pieces of image data having different timings, a step of sequentially superposing the difference image data on each other and generating a composite image data, and a composite image A step of detecting the solder area in the data soldering region and a step of determining whether or not the soldering is correctly performed based on the solder area. It was a child and a flop.

[0015] Further, in the soldering method of the present invention, in the soldering method in which the solder melting means for melting the solder is disposed in the soldering area where soldering is performed and the solder is supplied to the solder melting means, the solder melting is performed. The step of sequentially shooting the solder melted by the means at a predetermined timing with a camera and sequentially generating image data reflected from the solder and having a longer wavelength than red, and the timing of shooting among the image data At least two different images The difference image data is sequentially generated by taking the difference of the data, the difference image data is sequentially superimposed and synthesized to generate the synthesized image data, and the solder in the soldering area of the synthesized image data And a step of detecting the amount of solder supplied to the solder melting means based on the area of the solder.

[0016] Further, in the soldering apparatus of the present invention, the solder is supplied to the solder melting means in the soldering apparatus for soldering the component to a predetermined position of the substrate by melting the solder with the solder melting means for melting the solder. The generation timing of the image data differs from the solder supply device and the camera that sequentially generates image data of light having a longer wavelength than red, reflected from the solder melted by the solder melting means, at a predetermined timing. Difference image data is sequentially generated by taking a difference between at least two pieces of image data, and the generated difference image data is sequentially superimposed on each other to be combined to generate combined image data. A control unit for detecting the area of the solder melted by the melting means is provided.

Furthermore, the soldering apparatus of the present invention is also characterized by the following points. That is,

(1) The wavelength of light having a longer wavelength than red is in the range of 670 to UOOnm.

(2) At least a wavelength of 670 or more; having light shielding means for shielding light other than UOOnm.

(3) Shading means power S, filter attached to the camera.

(4) Light shielding means force S, at least a cover body covering the substrate and camera

(5) A light source for projecting light having a wavelength longer than that of red toward the solder melted by the solder melting means is provided.

(6) The light source is placed close to the camera.

(7) The solder melting means is a soldering iron.

(8) The solder melting means is a focused laser beam spot.

(9) The laser beam spot is formed by the output light of the laser diode.

(10) The light source is a laser diode or a light emitting diode.

(11) The wavelength of the light projected from the light source is the output light of the laser diode as the solder melting means. If it is longer than the wavelength of this output light.

(12) The wavelength of the light emitted from the light source is shorter than the wavelength of the output light when the solder melting means is the output light of the laser diode.

The invention's effect

[0018] In the present invention, image data is generated by sequentially photographing the solder melted by the solder melting means for melting the solder in the soldering region at a predetermined timing with a camera, and at least two image data having different photographing timings. The difference image data is sequentially generated by taking the difference between the generated difference image data, and the generated difference image data is sequentially superimposed and combined to generate composite image data. By detecting the solder from the combined image data, the difference image data is generated. Undetected solder that occurs during data generation can be supplemented with other differential image data, and the area of the solder can be reliably detected from the composite image data.

In addition, the camera generates image data using light having a wavelength longer than that of the red color reflected from the solder melted by the solder melting means, so that smoke generated during soldering is reflected in an image photographed by the camera. It is possible to generate image data obtained by accurately photographing the solder melted by the solder melting means that cannot be inserted.

[0020] Therefore, even when a camera is used, the amount of solder in the soldering area can be accurately detected, and the solder that can inspect the force of soldering with an appropriate amount of solder can be inspected. Additional inspection methods can be provided. Further, it is possible to provide a soldering method and a soldering apparatus capable of soldering with an appropriate amount of solder.

Brief Description of Drawings

FIG. 1 is an explanatory diagram of a method for detecting the area of solder.

FIG. 2 is a schematic explanatory diagram of the soldering apparatus of the first embodiment.

FIG. 3 is a flowchart of a soldering process by the soldering apparatus of the first embodiment.

FIG. 4 is a schematic explanatory diagram of a soldering apparatus according to a second embodiment.

Explanation of symbols

[0022] A1 Soldering device

A2 Soldering equipment

F Finoleta 10 base

11 Place

12 Cover body

13 Camera

14 Lai

15 Soldering iron

16 Thread solder

17 Solder feeder

18 Control unit

20 Mounting board

21.

BEST MODE FOR CARRYING OUT THE INVENTION

[0023] The soldering inspection method, soldering method, and soldering apparatus of the present invention are soldered using a relatively inexpensive imaging device such as a CCD camera rather than an expensive infrared sensor! By monitoring the solder of the solder, it is possible to detect the end of soldering or the occurrence of soldering abnormality by making it possible to confirm whether soldering is performed with an appropriate amount of solder! It is. In the following, an imaging device using a semiconductor imaging device consisting of a silicon photodiode, such as a CCD camera or CMOS camera, is simply referred to as a “camera”.

[0024] In particular, the camera is capable of detecting light in the infrared region, and an image is obtained by light having a wavelength longer than that of red reflected from solder melted by a solder melting means such as a soldering iron or a laser beam spot. The data is being generated.

[0025] By using light having a wavelength longer than that of red as described above, the influence of smoke generated during soldering can be reduced and the soldering state can be monitored.

[0026] That is, the smoke generated during soldering is composed of particles having a particle size distribution centered around 300 nm due to the performance of the dust collection filter provided in the duct provided for the removal of the smoke. It is inferred that Particles of this size cause light scattering called so-called mi-scattering in the visible light wavelength range, and appear as whitish smoke with scattering. It is what.

[0027] Therefore, when the camera performs photographing in the visible light range, smoke generated during soldering is also photographed, and there is smoke between the solder melted by the solder melting means and the camera. As a result, the solder was hidden behind the smoke and was unable to capture a clear picture.

[0028] However, it has been found that in the near-infrared region, which has a longer wavelength than visible light, light scattering due to smoke generated during soldering is mainly Rayleigh scattering. In this Rayleigh scattering, the intensity of the scattering decreases in proportion to one fourth power of the wavelength, so the scattering is suppressed. Is possible.

[0029] In this way, by generating image data with light having a wavelength longer than that of red, the effect of smoke generated during soldering is reduced, and the use of a camera in the soldering region is reduced. The status can be monitored reliably, soldering can be done with the proper amount of solder! /, And the end of soldering can be judged. It is possible to detect abnormalities such as solder not being melted

[0030] It should be noted that light having a wavelength longer than that of red is the first time that in the case of smoke generated as the solder melts, the intensity of Rayleigh scattering due to smoke becomes smaller than the reflected light from the solder from around 670 nm. Since it was confirmed experimentally, it is desirable to use light with a wavelength longer than 670 nm.

[0031] Furthermore, when a conventional camera with a built-in CCD image sensor was used to perform image processing up to a wavelength of several meters, even a wavelength up to the sensitivity region of a CCD image sensor composed of a silicon photodiode array was obtained. Since it was first experimentally found that image data can be generated sufficiently, it was confirmed that at least l lOOnm, the wavelength in the sensitivity range of silicon photodiodes with a band gap of 1.17 eV, could be used. .

[0032] Therefore, it is desirable to use infrared light of at least 670 nm or more; UOOnm as light having a wavelength longer than that of red. This makes it possible to significantly reduce the cost and to melt the soldering apparatus. Therefore, it is possible to increase the accuracy in accordance with the higher sensitivity of the photographed solder.

[0033] On the other hand, in soldering, a surface tension acting on the solder melted by the solder melting means. Since the melted solder tends to spheroidize due to the force, the amount of solder can be estimated from a two-dimensional image of the solder obtained by photographing the solder melted by the solder melting means with a camera. . Therefore, the soldering apparatus only needs to monitor the solder melted by the solder melting means with the camera.

[0034] However, in order to detect the amount of solder melted by the solder melting means from the image photographed by the camera, the first image data is obtained by photographing the state before the supply of solder to the solder melting means with the camera. Then, the supply of solder to the solder melting means is started, and a state in which a predetermined amount of solder is melted is photographed with a camera to generate second image data. The first image data and the second image data Difference image data is generated by taking the difference between and the amount of solder that is detected from the difference image data. In this case, the soldering iron or the soldering means that is the solder melting means in the first image data is soldered There is a risk of errors due to the influence of leads and the like.

Therefore, when it is desired to accurately detect the amount of solder melted by the solder melting means, image data composed of an image in a state before starting the supply of solder to the solder melting means is used as the first image data. Is not suitable.

[0036] In such a case, in the analysis by the normal difference processing, at least two images obtained by continuously capturing images at a time interval as short as possible in order to suppress extraction of changes other than the change of the observation target. Force using data When the object to be observed is solder, as described above, the amount of change is small in the difference processing for the area where the solder exists! Cannot be extracted correctly! /, An area will be generated! /, Ru.

[0037] That is, in the case of solder, the surface of the melted solder that is the front face of the camera becomes a plane that can be regarded as a flat surface, and even if the solder is further melted, the surface change is extremely small. For this reason, the threshold cannot be exceeded during binarization in difference processing, and as shown in Fig. 1 (c) and Fig. 1 (d), an undetected area L where solder cannot be detected occurs in the center. It has become.

[0038] Therefore, the present inventor sequentially generates image data with a camera while performing soldering, and at the same time, the difference between at least two image data having different shooting timings among the generated image data. As shown in Fig. 1 (a) to (d), the difference image data? & 13 Pd is generated sequentially, and these difference image data Pa, Pb, Pc, Pd are sequentially superimposed on each other. The synthesized image data Pe is generated as shown in FIG.

[0039] In this way, difference image data? & 13 (: (By combining 1 and generating composite image data? 6, the undetected area L can be eliminated with other difference image data, and by using the composite image data Pe, solder melting is performed. The amount of solder melted by the means can be accurately detected.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 is a schematic diagram of the soldering apparatus A1 according to the first embodiment. In the following, the power to explain the solder melting means as a general soldering iron. Recently, solder melting means using a laser light source such as a laser diode is also known, and a laser light source is provided instead of the soldering iron. Any solder melting means that can sequentially melt the supplied solder using a solder melting device may be used.

[0041] In the soldering apparatus A1, the base 10 provided with the mounting portion 11 on which the mounting substrate 20 on which the required electronic components 21 are temporarily mounted is mounted, and the mounting substrate 20 is soldered to be soldered. A camera 13 for photographing the area, a light 14 for illuminating the soldering area, a soldering iron 15 as a solder melting means disposed in the soldering area, and a solder for supplying the thread solder 16 toward the soldering iron 15 A solder supplier 17 as supply means, and a control unit 18 for controlling the solder supplier 17 and analyzing the output signal of the camera 13 are provided. In FIG. 2, 19 is a guide body that guides the yarn solder 16 toward the soldering iron 15.

[0042] Although not shown, the soldering apparatus A1 is provided with a transfer device that transfers the mounting board 20 to the mounting unit 11 and transfers the mounting board 20 that has undergone the soldering process to a subsequent process. Specifically, the transfer device is provided with a rectangular lift body (not shown) that moves in the transfer direction and can be moved up and down. The lift body has a tip that contacts the mounting substrate 20 from below. A plurality of support columns (not shown) are provided in contact with each other. When the mounting board 20 is transferred to the mounting portion 11, the lifting body is lifted to raise the support pillar in contact with the mounting board 20, and in that state, the lifting body is moved in the horizontal direction for mounting. The mounting substrate 20 is placed on the placement unit 11 by transferring the substrate 20 to the placement unit 11 and lowering the lifting body. With the same transfer device, the mounting substrate 20 of the mounting portion 11 can be transferred to a subsequent process. [0043] In this embodiment, the mounting portion 11 includes a plurality of pillars 11a projectingly contacting the upper surface of the base 10, and the mounting bodies 20 are placed in a horizontal state by arranging the pillars 11a at predetermined intervals. Can be supported.

As the camera 13, a CCD camera capable of photographing in the infrared region is used. This CCD camera can use what is generally used as a surveillance camera, for example. When using a commercially available CCD camera, an infrared cut filter may be built in depending on the case. It is desirable to remove this infrared cut filter before use.

[0045] Further, the camera 13 is equipped with a filter F that transmits only light having a longer wavelength than red. The filter F is preferably a filter that blocks light outside the wavelength range of 670 to UOOnm and transmits light with a wavelength of 670 to 1100 nm, and is preferably the highest in the infrared light range of 800 to 900 nm. It is desirable to use a filter that has transmittance. This filter F prevents light in the visible light range from entering the image sensor of the camera 13, and suppresses the reflection of smoke generated during soldering!

[0046] The light 14 is provided to increase the amount of reflected light composed of light having a longer wavelength than that of the red color from the solder melted by the soldering iron 15. The light 14 has a longer wavelength than that of the red light. The one that irradiates is used. In particular, the light 14 is preferably irradiated with light having a wavelength longer than 600 nm, and more preferably irradiated with light having a wavelength of about 800 to 900 nm. Even if the light 14 is not irradiated, the light 14 is not necessarily provided if the amount of light reflected from the solder by light having a longer wavelength than red is sufficiently large.

[0047] In some cases, it is not necessary to use a light of a special light source. For example, by simply using a continuous spectrum light such as a tungsten lamp, a halogen lamp, or sunlight, the light amount of the infrared component is simply increased. Good. In particular, in the case of a tungsten lamp or a halogen lamp, the light 14 may be used as a state in which the ratio of the infrared component is increased by using it below the rated current.

[0048] When the solder melting means is a solder melting means using a laser light source, halation is caused by the laser light spot melting the solder and the light emitted from the light 14, and the camera 13 It may be difficult to generate appropriate image data. [0049] Therefore, for example, when irradiating a 670 nm red laser beam by a GalnP laser diode as a laser light source, the light 14 is irradiated with 780 nm light using a GaAlAs laser diode, or GaAs It is desirable to irradiate light of 800 to 900nm using a system diode.

[0050] Alternatively, when using a GaAlAs or GaAs laser diode as a laser light source and irradiating a 78 Onm or 800 nm laser beam, a light emitting diode such as GaAs or GalnAs is used for the light 14. 850 ~; It is desirable to irradiate UOOnm light.

That is, the light 14 serving as the light source can prevent the occurrence of halation by irradiating light having a wavelength different from that of the output light of the laser light source of the solder melting means. Note that the wavelength of light emitted from the light 14 may be as short as possible only when it is longer than the wavelength of the output light of the laser light source. desirable.

[0052] Further, when the output of the laser light source is extremely large, an appropriate light shielding body such as a filter or a polarizing plate that can shield light other than the wavelength 670 to light other than UOOnm as much as possible or completely is used. And solder that is the subject.

[0053] The camera 13 and the light 14 are arranged apart from the position immediately above the placement unit 11 instead of being arranged at a position directly above the placement unit 11. It is desirable not to hit light 14. Further, since the camera 13 needs to photograph the solder melted by the soldering iron 15, it is disposed at an obliquely upper position of the mounting portion 11.

Furthermore, in the present embodiment, the light 14 is attached to the camera 13 and arranged as close to the camera 13 as possible. Therefore, the light 14 can be easily arranged, and the force lens 13 can easily obtain a strong reflected light from the solder, so that the camera 13 can reliably photograph the solder.

[0055] The soldering iron 15 is mounted on a lifting device (not shown) so that the soldering iron 15 can be raised and lowered. The soldering iron 15 is lowered after the mounting board 20 is placed on the placing portion 11, so that the supplied thread solder can be melted. Yes. If soldering at multiple locations is required on one mounting board 20, the lifting device may be provided with moving means in the X and Y directions so that the position of the soldering iron 15 can be moved appropriately. The substrate 20 may be moved as appropriate using an XY table or the like. [0056] The solder supplier 17 can feed the thread solder 16 processed into a thread shape by a predetermined amount at a predetermined timing. The thread solder 16 fed out from the solder feeder 17 is placed in the guide body 19 and fed to the soldering iron 15 at the joint.

The control unit 18 can execute an appropriate program. In this embodiment, the control unit 18 is composed of a personal computer, analyzes the output signal of the camera 13, and finishes the feeding of the thread solder 16 from the solder supplier 17. The timing is detected, and a control signal for stopping the operation of the solder supplier 17 is output in accordance with the detection of the end timing.

[0058] In the following, the solder joining process by the soldering apparatus A1 will be described based on the flowchart of FIG.

First, in the soldering apparatus A1, the mounting board 20 is transferred and placed on the placement unit 11 (step S

1) Light having a longer wavelength than red is irradiated onto the soldering region of the mounting board 20 with the light 14 as the light source (step S2).

[0060] Next, in the soldering apparatus A1, supply of the thread solder 16 is started by the solder supplier 17 (step S3), and photographing of the soldering area by the camera 13 is started (step S4). At this time, smoke S is generated due to soldering S, and shooting using light having a wavelength longer than red, suppresses smoke from appearing in the image taken by camera 13. Use the power S to obtain clear images.

The camera 13 sequentially photographs the soldering area at a predetermined timing, and inputs an output signal to the control unit 18 of the soldering apparatus A1. The control unit 18 sequentially generates image data from the input output signal of the camera 13. Further, the control unit 18 takes the difference between the first image data generated from the output signal of the camera 13 and the second image data whose shooting timing is later than the first image data. (Step S5).

[0062] The first image data and the second image data have different shooting timings, so that only the solder shape in the soldering area is different. In the difference image data, the change in the solder shape is extracted. The Rukoto. In the difference image data of the present embodiment, the area where the difference value between the first image data and the second image data is smaller than a predetermined threshold is “0”, and the area above the threshold is “1”. Yes.

[0063] Next, the control unit 18 sets the image data provided for temporarily storing the image data. The stored stored image data is read from the data memory (step S6). The stored image data is composite image data generated by superposing and combining the difference image data as will be described later. The image data memory stores image data that is “0” in all areas as a default!

[0064] The control unit 18 performs a logical OR process on the difference image data generated from the first image data and the second image data and the saved image data (synthesized image data) read from the image data memory. Thus, the composition is performed by superimposing the difference image data to generate new composite image data (step S7).

[0065] After the composite image data is generated, the control unit 18 detects the area of the solder melted by the soldering iron 15 in the soldering area from the composite image data (step S8). Specifically, “1” areas in the combined difference image are counted.

[0066] The control unit 18 compares the detected solder area with a preset end condition threshold (step S9), and when the detected solder area is smaller than the end condition threshold (step S9). In step S9: NO), the composite image data generated in step S7 is stored in the image data memory (step S10), the process returns to step S5, and the previous second image data and the second image data are used. Also, the difference image data is generated from the third image data whose shooting timing is later, and new difference image data is generated.

[0067] Then, the control unit 18 combines the difference image data with the stored image data (synthesized image data) stored in the image data memory read out in step S6, thereby generating new synthesized image data. (Step S7), the solder area is detected from this composite image data.

As described above, the control unit 18 sequentially generates the difference image data, and sequentially generates the combined image data by synthesizing the generated difference image data, so that the soldering iron 15 in the soldering area 15 Control that stops the operation of the solder feeder 17 when the area of the melted solder can be detected correctly and the solder area becomes larger than the preset threshold value of the end condition in step S9 (step S9: YES). A signal is being output (step Sll).

[0069] After that, in the soldering apparatus A1, the mounting substrate 20 is removed from the mounting portion 11, and the process proceeds to a subsequent process. (Step SI 2).

[0070] In the soldering apparatus A1 of the present embodiment, the camera 13 equipped with the filter F that transmits only light having a wavelength longer than red is used to photograph the solder melted by the soldering iron 15. In addition to reducing the effects of smoke generated by soldering, the state of solder can be monitored, and by detecting the area of the solder based on composite image data generated by overlaying difference image data, Solder can be detected with high accuracy.

Therefore, in the soldering apparatus A1 of the present embodiment, it is possible to perform soldering with the minimum necessary solder, and to shorten the soldering work time.

[0072] Moreover, since the soldering apparatus A1 of the present embodiment can detect the soldering abnormality by detecting the solder with high precision, it also serves as an inspection apparatus, and the soldering part after soldering The inspection process can be eliminated, and the manufacturing cost can be reduced by shortening the manufacturing process.

Here, the detection of the soldering abnormality at the time of soldering may be a shape abnormality detected from an image photographed by the camera 13, or the feeding time of the thread solder 16 by the solder feeder 17. It is possible to determine that an abnormality has occurred when this feeding time exceeds a predetermined time. In the present invention, a state in which such an abnormality has not occurred is regarded as a state in which correct soldering is performed.

FIG. 4 is a schematic diagram of a soldering apparatus A2 according to the second embodiment. In the soldering apparatus A2 of the second embodiment, the cover that covers the mounting substrate 20 mounted on the mounting portion 11 that does not mount the filter F on the camera 13 like the soldering apparatus A1 of the first embodiment. The body 12 is provided. The configuration is the same as that of the soldering apparatus A1 of the first embodiment except that a cover body 12 is provided instead of the filter F, and the same reference numerals are used for the same parts as the soldering apparatus A1 of the first embodiment. Detailed description will be omitted.

[0075] The cover body 12 is composed of a sheet-like filter that transmits only light having a wavelength longer than that of red. In this embodiment, a cover formed in a box shape with a transparent acrylic plate is longer than red. A sheet-like filter that transmits only light having a wavelength was pasted and formed. The sheet-shaped finerator is preferably one that has the highest transmittance in the infrared light region of 800 to 900 nm.

[0076] The cover body 12 is large enough to cover not only the mounting substrate 20 placed on the placement portion 11 but also the camera 13. The solder supply device 17 and, in some cases, the control unit 18 may be covered with the cover body 12.

In this way, by covering the mounting substrate 20 and the camera 13 with the cover body 12, the light that passes through the cover body 12 and is incident on the cover body 12 is converted into light having a wavelength longer than that of red, and then a soldering iron. The reflected light from the solder melted by 15 can be made light having a longer wavelength than red. As a result, it is possible to suppress the reflection of smoke generated by soldering when the solder is photographed by the camera 13, and to reliably photograph the solder.

In the present embodiment, a light 14 that irradiates light having a wavelength longer than red is provided in the cover body 12, and the amount of light that passes through the cover body 12 and enters the cover body 12 is not sufficient. In this case, the light emitted from the light 14 is used to ensure that the camera 13 can photograph the solder. The light 14 is preferably irradiated with light having a wavelength longer than 600 nm, and is preferably irradiated with light having a wavelength of about 800 to 900 nm.

[0079] Further, when the light 14 is provided in the cover body 12 in this way, the cover body 12 is not necessarily required to transmit light having a wavelength longer than that of red, and the cover body 12 is integrated with a light shielding plate that completely shields light. May be configured.

[0080] In the case of a laser beam spot formed by the output light of the laser diode that the solder melting means is not the soldering iron 15, the camera 13 has at least a filter for cutting light with a wavelength of 670 to UOOnm and necessary. It is desirable to install a light shielding body such as a polarizing plate according to the conditions.

In the present embodiment, the cover body 12 can be moved up and down by a lifting device (not shown). When the mounting board 20 is transferred to the mounting portion 11, the cover body 12 is retracted upward to transfer the mounting board 20. The cover 12 is lowered to cover the mounting board 20 during soldering.

Note that the present invention is not limited to the case where an elevating device is provided in the cover body 12. A feeding opening (not shown) for introducing the mounting substrate 20 into the cover body 12 in a part of the wall surface of the cover body 12. In addition, a delivery opening (not shown) for delivering the mounting board 20 after soldering to the outside of the cover body 12 may be provided so that the mounting board 20 can be taken in and out of the cover body 12. .

[0083] Furthermore, the cover body 12 is provided with an exhaust device such as an exhaust fan (not shown) to prevent the smoke generated by soldering from filling the cover body 12. Better Yes.

[0084] By covering the soldering area with the cover body 12 in this manner, the influence of visible light can be eliminated, so that the influence of smoke generated by soldering can be easily eliminated. However, in this case, since the operator cannot visually recognize the soldering area, when the visibility of the soldering area is required, the soldering device A1 of the first embodiment is used. It is desirable to use the finoleta F.

[0085] Alternatively, the filter F and the cover body 12 are used in combination, and the cover body 12 suppresses extraneous light from entering the soldering area while ensuring a certain degree of visibility, and the filter F is longer than red. The light blocking effect by the filter F may be improved by making light in a wavelength band incident on the image sensor of the camera 13.

Industrial applicability

The soldering inspection method, soldering method, and soldering apparatus of the present invention can reliably monitor the solder in the soldering area without using an expensive infrared sensor, and can be a low-cost soldering inspection method. A soldering method and a soldering apparatus can be provided.

Claims

The scope of the claims

The solder melting means for melting the solder is arranged in the soldering area where the soldering is performed, and the soldering inspection method performed by supplying the solder to the solder melting means,

The solder melted by the solder melting means is sequentially photographed at a predetermined timing with a camera, and image data is sequentially generated by light having a longer wavelength than red, which is reflected from the solder. Sequentially generating difference image data by taking a difference between at least two image data having different timings; and

A step of detecting a solder area in the soldering region of the composite image data;

A method for inspecting soldering, comprising: determining whether soldering is correctly performed based on the area of the solder! /.

Soldering means for melting solder is arranged in the soldering area where soldering is performed, and the soldering method is performed by supplying solder to the solder melting means.

A step of detecting a solder area in the soldering region of the composite image data; A soldering method characterized by comprising:

[3] In a soldering apparatus for soldering a part to a predetermined position of a substrate by melting the solder with a solder melting means for melting the solder,

A solder feeder for supplying solder to the solder melting means;

A camera that sequentially generates image data of light having a wavelength longer than red reflected from the solder melted by the solder melting means at a predetermined timing;

Among the image data, differential image data is sequentially generated by taking a difference between at least two image data having different generation timings, and the generated differential image data is sequentially superimposed and synthesized. And a control unit that generates data and detects an area of the solder melted by the solder melting means from the composite image data.

[4] The soldering apparatus according to [3], wherein a wavelength of light having a wavelength longer than that of red is in a range of 670 to UOOnm.

5. The soldering apparatus according to claim 4, further comprising light shielding means for shielding light having a wavelength of at least 670 to 11 nm.

6. The soldering apparatus according to claim 5, wherein the light shielding means is a filter attached to the camera.

7. The soldering apparatus according to claim 5, wherein the light shielding means is a cover body that covers at least the substrate and the camera.

[8] The soldering apparatus according to [6] or [7], wherein a light source that projects light having a wavelength longer than red toward the solder melted by the solder melting means is provided.

9. The soldering apparatus according to claim 8, wherein the light source is disposed close to the camera.

10. The soldering apparatus according to claim 5, wherein the solder melting means is a soldering iron.

11. The soldering apparatus according to claim 5, wherein the solder melting means is a focused laser beam spot.

[12] The laser beam spot is formed by output light of a laser diode. The soldering apparatus according to claim 11.

13. The light source is a laser diode or a light emitting diode.

The soldering apparatus according to 8.

14. The solder according to claim 13, wherein the wavelength of light emitted from the light source is longer than the wavelength of the output light when the solder melting means is output light of a laser diode. Attachment device.

15. The solder according to claim 13, wherein the wavelength of light projected from the light source is shorter than the wavelength of the output light when the solder melting means is output light of a laser diode. Attachment device.