JP6503112B2 - Soldering correction device - Google Patents

Description

  The present invention relates to a soldering correction device applied to a soldering defect of a workpiece on which a component is mounted.

  An electronic component that inserts and solders a component lead into a through hole of a substrate is called an insert component. For soldering of the insert, a flow soldering apparatus is generally used. In the soldering process, soldering defects occur due to various causes. For this reason, inspection after the mounting process was essential. As one of inspection methods, a non-contact optical inspection (hereinafter referred to as an appearance inspection) which is used to determine the quality of soldering using a video camera, a laser, an X-ray or the like is known.

  If a soldering defect is found in the inspection, the content of the defect either repairs or discards. Although the inspection process is becoming more automated, most of the corrections for bridges, non-wetting, etc. are done by workers, which is a cause of cost increase. In addition, differences in the skills of correction work among workers affect the quality of the final product. In particular, in the correction process of the inserted parts, most of them are repaired by workers. Under the visual inspection with a microscope, soldering is currently performed on defective parts one by one. As described in Patent Document 1 or Patent Document 2, correction by a robot soldering apparatus has been proposed without manual operation.

JP-A-5-152736 JP-A-5-235535

  However, although the work can be automated, it is necessary to contact the lead of defective parts one by one at each point and re-sold, and it takes a considerable amount of correction time. Furthermore, the soldering correction apparatus is different from the soldering process (apparatus), and not only the development of the soldering correction apparatus itself is necessary, but also the work in another process is performed in the process. It is not possible to centrally manage it, and the floor area in the factory is also expanded. Furthermore, in the case where a flux coating device and a preheater are provided in the front stage of the soldering device to satisfactorily correct a defect in soldering, depending on the type of defect, it may not be necessary to apply flux or preheating.

  Therefore, an object of the present invention is to provide a soldering correction apparatus in which such problems are eliminated.

The present invention relates to an appearance inspection apparatus which inspects a soldering defect with respect to a workpiece on which an insertion part is soldered by molten solder, and stores information on the location of the soldering defect;
A trace soldering apparatus which causes the molten solder to selectively jet to the portion specified by the information on the location of the soldering defect while one of the work and the jet nozzle that jets the molten solder moves relatively;
A preheater placed in front of the trace soldering machine to preheat the workpiece;
And a flux applying apparatus disposed in front of the preheater and applying a flux to a location designated by the information on the location of the soldering defect,
Each of the preheater and the flux application device is a soldering correction device in which operation / non-operation control is selectively performed according to the type of the soldering defect .

  According to at least one embodiment, the correction can be performed by means of a trace soldering apparatus commonly used in the soldering process. Therefore, it is not necessary to develop and design a soldering correction device separately. Furthermore, since the defect position found by the visual inspection apparatus is sequentially corrected, the correction time can be shortened. Furthermore, since the flux application device and the preheater are provided at the front stage of the soldering device to control their operation / non-operation, it is possible to satisfactorily correct the soldering failure. In addition, the effect described here is not necessarily limited, and may be any effect described in the present invention. Further, the contents of the present invention are not interpreted as being limited by the effects illustrated in the following description.

It is a basic diagram which shows the outline of one embodiment of this invention. It is a basic diagram which shows the structural example of the part of the correction apparatus in one embodiment of this invention. It is a schematic diagram used for description of the trace soldering apparatus in one embodiment of this invention. It is sectional drawing and top view which are used for description of a soldering defect. It is sectional drawing and top view which are used for description of a soldering defect. It is the top view and sectional drawing of an example of a workpiece | work (substrate). It is a partially expanded sectional view and an enlarged plan view of FIG. It is a flowchart used for description of the flow of an example of the process of one embodiment of this invention. It is a flowchart used for description of the flow of the other example of the process of one embodiment of this invention.

Hereinafter, embodiments of the present invention will be described. The description will be made in the following order.
<1. One embodiment>
<2. Modified example>
Although one embodiment described below is a preferred embodiment of the present invention, and various technically preferable limitations are added, the scope of the present invention is particularly set forth in the following description. As long as there is no statement to the effect of limiting, it shall not be limited to these embodiments.

<1. One embodiment>
"Overall configuration of one embodiment and trace soldering apparatus"
FIG. 1 shows the overall configuration of a system according to an embodiment of the present invention. The workpiece W is carried into a flux coating apparatus (hereinafter, appropriately referred to as a fluxer) 1. In the component insertion step (not shown), for example, the lead of the insertion component is inserted into the through hole on the substrate on which the chip component or the like is surface-mounted. The substrate on which the insert is attached is the work W. The fluxer 1 is, for example, a spray fluxer that applies the flux only to the necessary places.

  A preheater 2 and a soldering device 3 are arranged inline with respect to the fluxer 1. The workpiece W is placed on a conveyor and transported to each device. The preheater 2 preheats the work W, and the work W is heated to about 100 ° C., for example.

  The soldering device 3 is a device that performs flow soldering. One example of the flow soldering method performed in the soldering apparatus 3 is a flow method in which the workpiece W is passed over the jetted solder to perform soldering. In the case of the flow method, it is possible to use a method capable of selective soldering in which the solder is jetted only to the necessary area without jetting the solder over the entire surface of the workpiece W. Furthermore, not limited to the flow method, a dip method may be used in which the back surface of the workpiece is dipped in a solder bath in which the solder is melted to perform soldering.

  Furthermore, as a soldering apparatus 3, a suitable apparatus is a trace soldering apparatus. The trace soldering apparatus has a configuration capable of soldering only the location of the insertion part in a predetermined sequence (path), and jets molten solder which can flexibly correspond to the total length and number of insertion part leads. With jet nozzle

  FIG. 3 is a view for schematically explaining a trace soldering apparatus. As shown in FIG. 3A, the jet nozzle 22 and the solder bath 23 are provided on the XY table 21. The XY table 21 is displaceable in the X and Y directions by a servomotor (not shown). Furthermore, the jet nozzle 22 is also displaceable in the Z (upper and lower) direction. When the workpiece W is positioned above the jet nozzle 22 so as to face the XY table 21, the jet nozzle 22 is displaced upward, and the molten solder jetted from the jet nozzle 22 causes the lead protruding from the back surface of the workpiece W It is soldered to a predetermined place on the substrate.

  The leads are soldered at the positions of the plurality of insertion parts in an operation according to the insertion parts according to a preset order. Although the jet nozzle 22 is displaced in the XY direction in the example of FIG. 3, the jet nozzle 22 may be fixed and the workpiece W may be displaced in the XY and Z directions.

  The jet nozzle 22 has a nozzle 22a and a cylinder 22b concentrically surrounding the nozzle 22a, as shown in FIG. 3B. The molten solder supplied from the solder bath 23 spouts from the opening at the tip end of the nozzle 22a to the upper part, contacts the soldering point on the back surface of the workpiece W, and is soldered. The molten solder spilled from the nozzle 22a returns to the lower solder bath 23 from the opening of the cylinder 22b. The solder tank 23 is provided with a rotating blade for forming a flow of solder, a power source (motor), and the like, and circulates the molten solder.

  As shown in FIG. 3C, the leads 26 of the insertion component 25 are inserted into the substrate 24. The jet nozzle 22 moves in a direction parallel to the array direction on one side of the leads 26, and the solder 27 jetted from the nozzle 22a corrects the soldering of the leads 26. Once the soldering correction of one lead is complete, the same soldering correction is made to the other lead. As described later, by making the moving direction of the jet nozzle 22 parallel to the generating direction of the bridge, the bridge can be corrected well.

  Referring back to FIG. 1, the mounted work W is transported to the first visual inspection apparatus 4 by the soldering apparatus 3, and the inspection of the soldering defect is performed without contact. The appearance inspection apparatus 4 can use an automatic determination method in which a video camera captures an image of the mounting surface of the workpiece W and a human looks at an image to determine a defect or digital signal processing of the image. In FIG. 1, the soldering apparatus 3 and the appearance inspection apparatus 4 are separately shown above and below, in order to clearly show the features of the present invention. That is, the visual inspection apparatus 4 is arranged inline with the soldering apparatus 3, and the workpiece W is continuously conveyed from the soldering apparatus 3 to the visual inspection apparatus 4.

  The correction device 5 is disposed inline with the appearance inspection device 4. The coordinates (referred to as defect position information 7 as appropriate) of the position of the insertion defect of the soldering defect found by the appearance inspection device 4 of the previous stage are supplied to the correction device 5. The correction device 5 corrects the soldering defect in accordance with the received defect position information 7.

  The corrected workpiece W is transported to the second appearance inspection apparatus 6 and final inspection is performed. The visual inspection apparatus 6 can use the same one as the visual inspection apparatus 4. The workpiece carried out of the appearance inspection apparatus 6 is subjected to the next process. The workpiece whose soldering defect is found by the final appearance inspection apparatus 6 may be again subjected to a correction process and repaired, or may be discarded, as described later. In the case of being repaired, the defect position information obtained by the appearance inspection device 6 is used. In the embodiment of the present invention, the preheater 2, the soldering apparatus 3, the appearance inspection apparatus 4, the correction apparatus 5, and the appearance inspection apparatus 6 may be configured as separable modules.

  A configuration example of the correction device 5 will be described with reference to FIG. FIG. 2A is an example in which the correction device 5 is configured by the trace soldering device 8. Defect position information 7 obtained by the appearance inspection device 4 is supplied to the trace soldering device 8. The trace soldering apparatus 8 solders only the part of the insertion part which is badly soldered as described with reference to FIG. The soldering operation (path, etc.) of the trace soldering apparatus 8 is determined based on the defect position information.

  FIG. 2B is an example in which the correction device 5 is configured by the trace soldering device 8 and the fluxer 9. The fluxer 9 is, for example, a spray fluxer, and the defective position information is supplied to the fluxer 9, and the flux is applied only to the defective portion.

  FIG. 2C is an example in which the correction device 5 is configured by the trace soldering device 8, the fluxer 9 and the preheater 10. The fluxer 9 is, for example, a spray fluxer, and the defective position information is supplied to the fluxer 9, and the flux is applied only to the defective portion. The workpiece W from the fluxer 9 is preheated by the preheater 10 and supplied to the trace soldering device 8. The trace soldering apparatus 8, the fluxer 9 and the preheater 10 may be configured as separable modules.

  Which configuration in FIGS. 2A, 2B and 2C is to be used as the correction device 5 can be selected in consideration of the type of soldering failure. However, the correction device 5 configured as shown in FIG. 2C is installed, and control is performed to selectively activate / deactivate (pass only) each of the fluxer 9 and the preheater 10 according to the type of the soldering defect. Ru.

"Specific example of work and example of defective soldering"
4 and 5 show a specific example of the work W. FIG. The sectional view on the AA line of work W shown in Drawing 4A is shown in Drawing 4B. In the example of the work W, a portion surrounded by a line L1 is a mounting area of the surface mounting component, and a portion surrounded by a line L2 is a mounting region of the insertion part. For example, after the surface mount component is soldered by a reflow device, the insert component is attached to the substrate 24 in the component insertion process. Flow soldering then solders the leads of the insert.

  The cross section of the mounting area of the insert (the part shown by encircling line L2) is enlarged and shown in FIG. 5A. Furthermore, a plan view of the area is shown in FIG. 5B. The leads 26a, 26b, 26c of the insert parts 25a, 25b, 25c are inserted into the through holes of the substrate 24, and the leads 26a, 26b, 26c are soldered to the substrate 24 by flow soldering. FIG. 5 is a diagram in the case where no soldering failure occurs.

  FIG. 6A is a cross-sectional view and a plan view showing a bridge (short) which is an example of a soldering failure. For example, if the three leads 26b1, 26b2, 26b3 on one side of the insert 25b are inserted into the through holes in the substrate 24 and the leads 26b1, 26b2, 26b3 are soldered on the substrate by the solder 27, then the leads 26b1 and 26 b 2 is shorted by the solder 27. The short circuit is eliminated by the correction device 5 described above.

  FIG. 6B is a cross-sectional view and a plan view showing non-wetting (unsoldered) which is another example of the soldering failure. For example, the solder 27 is not sufficiently attached to the lead 26b1 of the insertion part 25b. The correction device 5 supplies solder to the lead 26b1 to eliminate non-wetting (unsoldered).

  FIG. 7 is a cross-sectional view (FIG. 7A), a plan view (FIG. 7B), and a partially enlarged cross-sectional view C (FIG. 7C) showing a blowhole (eyeball) which is another example of the soldering failure. For example, the solder 27 is attached to the lead 26b3 of the insertion part 25b, but a small spherical blowhole 28 is formed in part of the soldered portion. The correction device 5 re-solds the lead 26b3 and eliminates the blowhole 28.

"Flow of correction process"
The flowchart of FIG. 8 shows an example of the flow of the correction process (correction process) according to the embodiment of this invention. At each step, the following processing is performed.
Step ST1: The mounted work is input to the visual inspection apparatus 4.
Step ST2: The appearance inspection by the appearance inspection apparatus 4 is performed.
Step ST3: It is checked whether there is a defect in soldering.
Step ST4: If it is determined in step ST3 that there is no defect in soldering, the process proceeds to the next step.

Step ST5: In step ST3, if it is determined that there is a defect in soldering, the coordinates of the defect are stored as defect position information.
Step ST6: The correction device 5 corrects the defect portion using the defect position information.
Step ST7: The appearance inspection apparatus 6 determines the presence or absence of the final defect. If it is determined that there is no defect, the process proceeds to the next step (step ST4). If it is determined that there is a defect, the work is again input to the appearance inspection apparatus 4, and the above-described process is repeated.

If it is determined in step ST7 that there is a defect, as shown in FIG. 9, a defective work may be placed in the stocker and discarded.
Furthermore, the process of FIG. 8 may be combined with the process of FIG. 9 to discard a work that remains defective even if it is corrected twice or more.

"Evaluation of corrective action"
The results of experiments conducted on the correction of the soldering defects according to the embodiment of the present invention described above are shown in the following table.

  Table 1 shows, for example, the results of correction using the trace soldering apparatus 8 as the correction apparatus 5 for the workpiece W in which a bridge (short) is intentionally generated for six insertion parts. ing. In Table 1, the bridge NG indicates the number of places that could not be corrected among the six places. The smaller this number is, the better the correction is made.

  In Table 1, the nozzle type represents the diameter (10 mm, 3 mm, 7 mm) of the opening of the nozzle 22 a of the jet nozzle 22 and the manner of the jet of molten solder. The notation of single flow means a type in which the solder 27 spouts from about a half of the opening, as shown in FIG. 3C. Furthermore, Table 1 shows the results when the solder temperature is changed to 260 ° C. and 300 ° C., and the results when the moving speed of the jet nozzle 22 is changed to 3 mm / s and 10 mm / s. There is.

Furthermore, * in the remarks column indicates the following description.
"100% bridge generation only when solder is jetted in the direction perpendicular to the bridge generation direction in the same plane"
This means that bridge correction is possible if the jet wave is applied in the opposite direction parallel to the bridge generation direction and in the opposite direction with respect to the continuous reed.

From the results of Table 1, the following is shown.
• If the temperature is high and the nozzle speed is slow, it is easy to bridge in flux wither.
-If the speed is high, the time to melting is short or bridging is likely to occur when moving.

From the results of Table 1, the following can be seen.
• A smaller diameter jet nozzle is more capable of bridge correction than a standard soldering nozzle.
・ According to the result of φ3 single-flow nozzle, if the jet direction of molten solder (moving direction of nozzle) and the bridge generation direction are parallel and the wave of the jet is applied to the continuous lead in the opposite direction, bridge correction Is possible (see FIG. 3C).

  As can be understood from the description of the embodiment of the present invention described above, according to the embodiment of the present invention, the defective soldering point can be easily corrected in a short time without relying on the skill of the worker. It becomes possible. Furthermore, by providing the inspection process on the primary side of the trace soldering process and transferring the position data of the defective part, it becomes possible to automate the correction of the defective part, and all the works are regarded as good items in the automatic soldering apparatus It can be flowed to the process. Furthermore, since only defective parts can be selectively and automatically corrected, it is possible to minimize the heat load on the work, which can contribute to the further improvement of the quality of the final product.

<3. Modified example>
As mentioned above, although embodiment of this invention was described concretely, it is not limited to each above-mentioned embodiment, A various deformation | transformation based on the technical idea of this invention is possible. Further, the configurations, methods, processes, shapes, materials, numerical values, and the like described in the above-described embodiment are merely examples, and different configurations, methods, processes, shapes, materials, numerical values, and the like may be used as necessary. May be Furthermore, the configurations, methods, processes, shapes, materials, numerical values, and the like of the above-described embodiments can be combined with one another without departing from the spirit of the present invention.

W ··· Work 1, 9 · · · Fluxer 2, 10 · · · Preheater 3 · · · Soldering device 4, 6 · · · Appearance inspection device 5 · · · Correction device 7 · · · Defect position information 8 · · · · · · Trace soldering device 21 · · · XY table 22 · · · jet nozzle 24 · · · board 25, 25a, 25b, 25c · · · · insert parts

Claims (4)

An appearance inspection apparatus which inspects a soldering defect with respect to a workpiece on which an insertion part is soldered by molten solder and stores information of the portion of the soldering defect;
A trace soldering apparatus which causes the molten solder to selectively jet to the portion designated by the information on the portion of the soldering defect while one of the work and a jet nozzle to jet the molten solder moves relatively. ,
A preheater disposed in front of the trace soldering apparatus to preheat the workpiece;
And a flux applying device disposed in front of the preheater and applying flux to a location designated by the information on the location of the soldering defect,
A soldering correction device wherein each of the preheater and the flux coating device is selectively operated / not controlled depending on the type of soldering failure .   The soldering correction device according to claim 1, further comprising another appearance inspection device which inspects the presence or absence of a soldering defect with respect to a work corrected by the trace soldering device.   3. The soldering correction device according to claim 1, wherein in the trace soldering device, relative movement directions of the work and the jet nozzle are parallel to a generation direction of a bridge.   3. The soldering correction device according to claim 2, wherein a workpiece whose soldering defect is detected by the other appearance inspection device is returned to the appearance inspection device.

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