JPH08166218A - Board inspection method and its device - Google Patents

Abstract

PURPOSE: To provide a board inspection method and its device in which a part mounting board passed through a flow-soldering process is not turned upside down and its soldered surface facing downward can be inspected. CONSTITUTION: A board 1 on which a surface mounting part 4 and a lead insertion part 6 are mounted is soldered by applying solder 7 to the mounting position of the respective parts 4, 6 in a flow-soldering process. The board 1 passed through the flow-slodering process is sent to an inspection process in the state that the soldered surface faces downward without being turned upside down. In the inspection process, light is applied to the soldered surface of the board 1 from the lower side by a lighting system 9, and the reflected light is picked up from the lower side by an image pick-up device 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board inspection method and apparatus for observing the soldering surface of a component mounting board that has undergone a flow soldering process to inspect the quality of soldering.

[0002]

2. Description of the Related Art In recent years, a board inspection device for inspecting the quality of a soldering portion of each component using an image processing technique has been put into practical use on a component mounting board on which a large number of components are mounted. Usually, in manufacturing a component mounting board, a predetermined component is mounted at a predetermined position on a printed wiring board, soldering is performed at a mounting position of each component, and then each of the component mounting boards is tested by the board inspection device. The soldering points are inspected, and the good component mounting boards are transferred to the box packing process, and the defective component mounting boards are transferred to the solder correcting process.

FIG. 8 shows a flow from mounting of components to inspection. FIGS. 8 (1) to 8 (5) show the component mounting process, and FIG.
(6) is a flow soldering process, FIG. 8 (7) is a substrate reversal process, and FIG. 8 (8) is an inspection process. In the component mounting step, first, the adhesive 2 is applied to each mounting position of the surface mount component on one surface of the substrate 1 (FIG. 8 (1)), and then the mounter 3 is used.
Then, the surface mount component 4 is mounted at the application position of each adhesive (FIG. 8 (2)). Next, the substrate 1 is heated by the heater 5 to cure the adhesive, and each surface mount component 4 is fixed to the substrate 1 (FIG. 8C). Next, after the substrate 1 is turned upside down (FIG. 8 (4)), the mounter 3 guides the lead insertion component 6 to each mounting position of the lead insertion component on the other surface of the substrate 1 and leads to the lead insertion hole of the substrate 1. The lead of the insertion part 6 is inserted (FIG. 8 (5)).

The substrate 1 on which the surface mount component 4 and the lead insertion component 6 have been mounted is sent to the flow soldering process shown in FIG. 8 (6), and the solder 7 is applied to the mounting positions of the components 4 and 6. And solder. The component mounting board 1 that has undergone this flow soldering step is turned upside down in the board turning step shown in FIG. 8 (7) so that the soldering surface is directed upward, and then sent to the inspection step shown in FIG. 8 (8). To be

In the inspection step, the board inspection device 8 inspects the soldering points of the components 4 and 6 for the quality of soldering. The board inspecting device 8 includes an illuminating device 9 and an imaging device 10. The illuminating device 9 irradiates the soldering surface of the substrate 1 with light from above and reflects the reflected light from above with the imaging device 10. Take an image. This imaging device 1
The image obtained by 0 is sent to an image processing device (not shown) and subjected to predetermined image processing to judge whether or not the soldering is good at all the soldering points.

[0006]

However, in the above-described board inspection method, in order to inspect the component mounting board that has undergone the flow soldering process, the board reversing step for turning the component mounting board upside down and sending it to the inspection step is performed. is necessary. For this reason, not only the total number of steps is increased, but also it is necessary to provide a board reversing mechanism for reversing the board between the flow soldering line and the inspection line, which complicates the board manufacturing line and manufactures a component mounting board. There is a problem of high cost.

The present invention has been made in view of the above problems, and a board inspection method capable of inspecting a soldering surface facing downward without turning upside down a component mounting board that has undergone a flow soldering process, and It is an object of the present invention to provide the apparatus, thereby reducing the number of steps, simplifying the board manufacturing line, and reducing the board manufacturing cost.

[0008]

According to a first aspect of the present invention, there is provided a board inspection method, wherein a component-mounted board that has undergone a flow soldering process is carried into an inspection position with its soldering surface facing downward, and then the board is mounted on the board. By illuminating the soldering surface from below and imaging the reflected light from below,
It is characterized by inspecting the quality of soldering.

A substrate inspection apparatus according to the invention of claim 2 is
A board transfer mechanism that supports and carries in and out the component mounting board with the soldering surface facing downwards with respect to the inspection position, and irradiates light from below toward the soldering surface of the board carried in the inspection position. The illuminating device, the imaging device that images reflected light from the soldering surface of the substrate from below, and the stage mechanism that integrally moves the illuminating device and the imaging device in parallel with the substrate.

According to a third aspect of the present invention, in the board inspecting apparatus, the illuminating apparatus has a plurality of annular light sources which have different diameters and emit different colors of light. Seen from different elevation angles.

According to a fourth aspect of the present invention, in the substrate inspecting apparatus, the substrate transporting mechanism carries in the substrate to a standby position upstream of the inspection position, a unloading mechanism for unloading the inspected substrate, and the standby. The substrate delivery mechanism is configured to send the substrate at the position to the inspection position and at the same time to deliver the inspected substrate at the inspection position to the carry-out mechanism.

[0012]

Function: The component mounting board is illuminated from below and the reflected light is imaged from below to inspect the quality of soldering. Therefore, even a component mounting board that has undergone the flow soldering process It is possible to inspect the soldering surface without turning the board upside down.

According to another aspect of the substrate inspection apparatus of the present invention, when the substrate is carried into the inspection position by the substrate transport mechanism with the soldering surface facing downward, the lighting device applies light from below toward the soldering surface of the substrate. The reflected light is imaged from below by the imaging device. In this case, since the stage mechanism moves the illumination device and the image pickup device integrally in parallel with the board, the entire soldering surface of the board can be inspected. The inspected substrate is carried out from the inspection position by the substrate transfer mechanism.

In the board inspection apparatus of the third aspect, since the respective light sources for irradiating light of different colors are arranged in directions of different elevation angles when viewed from the position on the center line, the image pickup device for the reflected light on the soldering surface. When the image is taken by, a hue pattern according to the soldering state can be obtained.

In the board inspection apparatus according to the fourth aspect, the board is carried into the standby position upstream of the inspection position by the carry-in mechanism and waits for the inspection. When the inspection of the board previously sent to the inspection position is completed, the inspected board is sent out to the carry-out mechanism by the transfer mechanism, and at the same time, the board at the standby position is sent to the inspection position.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an outline of a substrate inspection method according to the present invention. FIG. 1 (1) shows a flow soldering process, and FIG.
(2) is an inspection process. The process up to the flow soldering process, that is, the component mounting process is shown in FIG.
Since it is the same as the conventional example shown in (5), illustration and description thereof are omitted here.

The board 1 on which the surface mounting component 4 and the lead insertion component 6 are mounted in the component mounting process is soldered to the mounting positions of the respective components 4 and 6 in the flow soldering process shown in FIG. It is made to act and soldering is performed.
The substrate 1 that has undergone this flow soldering process is sent to the inspection process shown in FIG. 1 (2) as it is with the soldering surface facing downward without being turned upside down.

In this inspection step, the board inspection device 8 inspects the soldering points of the components 4 and 6 for the quality of soldering. The substrate inspection device 8 includes an illumination device 9 and an image pickup device 10.
Light is radiated from below toward the soldering surface and the reflected light is imaged from below by the imaging device 10. The image obtained by the image pickup device 10 is sent to an image processing device (not shown) to be subjected to predetermined image processing, and the quality of soldering is determined at all soldering points.

The illuminating device 9 is composed of three annular light sources 9A, 9B and 9C having different diameters and irradiating red light, green light and blue light at the same time. Each light source 9
A, 9B, and 9C are aligned with each other and positioned in different elevation directions when viewed from the position on the center line. Imaging device 10
Is positioned on the center line of the lighting device 9, and when the reflected light on the soldering surface is imaged by the imaging device 10,
A hue pattern corresponding to the soldering state can be obtained. This hue pattern is compared with a reference pattern in an image processing apparatus (not shown) to judge the quality of soldering.

FIG. 2 specifically shows the structure of the substrate inspection apparatus 8 according to an embodiment of the present invention. This board inspection device 8 is provided with a box-shaped case 13 having a board inlet 11 and a board outlet 12 on both sides, and the board 1 is conveyed to the board inlet 11 by a flow soldering process. The first board transfer mechanism 14 transfers the inspected board 1 to the board outlet 12 to the correction step and the box packing step.
Substrate transfer mechanisms 15 are connected respectively.

Inside the box-shaped case 13, an intermediate base 16 is horizontally provided at the center of the height.
The substrate transfer mechanism 20 is disposed on the upper side of the substrate transfer mechanism 2
The upstream end of 0 is connected to the first substrate transfer mechanism 14, and the downstream end is connected to the second substrate transfer mechanism 15. An opening 17 serving as an inspection position is formed in the center of the intermediate base 16, the substrate transfer mechanism 20 is laid above the opening 17, and the lighting device 9 and the imaging device are provided below the opening 17. The devices 10 are respectively arranged upward.

The illumination device 9 and the image pickup device 10 are
It is integrally supported by a stage mechanism 60 including an X-axis table portion 61 and a Y-axis table portion 62. The X-axis table portion 61 supports the Y-axis table portion 62 so as to be movable in the X direction, and the Y-axis table portion 62 integrally supports the imaging device 10 and the illumination device 9 so as to be movable in the Y direction. The X-axis table unit 61 and the Y-axis table unit 62 include motors 63 and 64 that operate based on control signals. By driving the motors 63 and 64, the X-axis table unit 61 moves in the X direction and the Y direction. The axis table portion 62 moves the illumination device 9 and the imaging device 10 integrally in the Y direction.

In FIG. 2, 18a and 18b are monitors for displaying an image of the soldering surface of the substrate 1 imaged by the image pickup device 10, various data relating to teaching and inspection, and the like. Further, 19 is a piano wire stretched along the substrate transport path in the substrate transport mechanism 20, and the piano wire 19 is located in the center of the width of the substrate transport path, so that the substrate 1 to be transported does not warp. Support the underside of.

FIG. 3 shows a schematic structure of the substrate transfer mechanism 20. In the figure, 16 is the intermediate base, 17 is an opening provided in this intermediate base 16, and this opening 17
Two rails 21 and 22 which slidably support both end edges of the substrate 1 are horizontally and parallelly installed at a position above.
The substrate transfer mechanism 20 includes the rails 21 and 22, a carry-in mechanism 23 that carries in the substrate 1 introduced from the substrate introduction port 11 to a standby position at an upstream end of the opening 17 which is an inspection position, and an inspected device. A unloading mechanism 24 that unloads the substrate 1 from the substrate outlet 12, and a substrate 1 that is in the standby position is sent to the center of the opening 17 that is the inspection position, and at the same time, the inspected substrate 1 that is in the inspection position is unloading mechanism. It is composed of a substrate transfer mechanism 25 (not shown in FIG. 3) for sending to 24.

The carry-in mechanism 23 drives two conveyor belts 26 stretched along the rails 21 and 22 at the upstream end of the opening 17, and a pulley 27 around which each conveyor belt 26 is wound. And a motor 1 and a substrate 1
Both edges are supported on the upper surfaces of both conveyor belts 26 and are conveyed toward the opening 17. The carry-out mechanism 24 is stretched along the rails 21 and 22 at the downstream end of the opening 17.
The conveyor belt 29 includes a book and a motor 31 that drives a pulley 30 around which the conveyor belts 29 are wound. Transported in a direction away from you. In the figure, 32 is an operation handle, and this operation handle 3
By rotating 2 the width of the rails 21 and 22 can be adjusted according to the width of the board to be inspected.

FIG. 4 shows the structure and operation of the substrate transfer mechanism 20. In the figure, reference numeral 25 is the substrate transfer mechanism described above, and the mechanism is shown in detail in FIG. The substrate transfer mechanism 25 of the illustrated example fixes a cylinder guide 33 between the inspection position and the standby position along one rail 22, and a piston (not shown) that reciprocates inside the cylinder guide 33. A frame 34 is attached, and the frame 34 is configured to reciprocate along the cylinder guide 33.

The frame 34 includes side plates 35,
36, the shaft 42 is rotatably supported by the side plates 35, 36, and the claw plates 37, 38 are attached to the ends of the shaft 42 protruding to the outside of the side plates 35, 36, respectively. A motor 39 capable of forward and reverse rotation is fixed to the one side plate 35, and a drive gear 40 is attached to the motor shaft of the motor 39, and a driven gear 41 meshing with the drive gear 40 is attached to the shaft 42. There is. The claw plates 37 and 38 are arranged with a space slightly larger than the length of the substrate 1, and one claw plate 37 hooks the substrate 1 standing by at the standby position and sends it to the inspection position, and the other claw plate 37. The plate 28 functions to hook the substrate 1 at the inspection position and send it to the carry-out mechanism 24.

At the standby position of the substrate 1 along the other rail 21, a sensor 43 for detecting that the substrate 1 has reached the standby position, and a detection operation of this sensor 43 actuate to restrain the substrate 1 at the standby position. And a stopper 44 that operates. As shown in FIG. 6, the stopper 44 has a column 45 vertically provided on the intermediate base 16, and a drive shaft 46 supported on an upper end of the column 45 and a regulation plate 48 via a movable plate 47.
It is made by attaching. The intermediate base 16 has a cylinder 4
9 is swingably supported, and the drive shaft 46 is connected to the tip of a rod 50 of the cylinder 49 via a link 51. When the rod 50 of the cylinder 49 moves up and down, the movable plate 47 moves up and down to move the regulating plate 48.
Moves in and out of the substrate transport path.

At the inspection position of the substrate 1 along the same rail 21, a substrate fixing mechanism 70 for fixing the substrate 1 sent to the inspection position is arranged. As shown in FIG. 7, the board fixing mechanism 70 has two columns 71 and 72 vertically provided on the intermediate base 16 with an interval substantially equal to the length of the substrate 1 between them. Fixed pins 76 and 77 are attached to both ends of a drive shaft 73 supported between upper ends via movable plates 74 and 75, respectively. A cylinder 78 is swingably supported on the intermediate base 16, and a link 79 is attached to a tip of a rod 80 of the cylinder 78.
The drive shaft 73 is connected via. When the rod 80 of the cylinder 78 moves up and down, the movable plates 74 move up and down, so that the fixed pins 76 and 77 are engaged with and disengaged from the fixed holes 81 and 82 formed in the substrate 1. In FIG. 4, reference numeral 83 is a sensor for detecting that the substrate 1 has been sent from the substrate transfer mechanism 25 to the carry-out mechanism 24.

Next, the operation of the board inspecting apparatus 8 having the above structure will be described. When the lower surface of the substrate 1 is soldered by the flow soldering process, the substrate 1 is transported to the substrate inspection device 8 by the first transport mechanism 14 with the soldering surface facing downward, and the substrate transport mechanism 20. Loading mechanism 23
Be delivered to. The carry-in mechanism 23 carries in the substrate 1, and when the substrate 1 reaches the standby position, the sensor 43 detects this, and in response to the detection operation, the stopper 43 operates to temporarily stop the substrate 1 at the standby position. . FIG. 4 (2) shows this state.

Next, the substrate transfer mechanism 25 is actuated to cause the claw plates 37 and 38 to project into the substrate transfer path, and the stopper 4
After the return movement of 3 and the release of the substrate 1, the piston moves inside the guide cylinder 33. As a result, the one claw plate 37 hooks the rear end of the substrate 1 and guides the substrate 1 to the inspection position. FIG. 4C shows this state.

Next, the board fixing mechanism 70 is operated and the fixing pins 76 and 77 are engaged with the fixing holes 81 and 82 of the board 1, whereby the board 1 is fixed at the inspection position, while the board transfer mechanism 25 is operated. After that, the soldering surface of the substrate 1 is inspected. At this time, the next substrate 1 is loaded into the standby position and is on standby for inspection. FIG. 4 (4) shows this state.

On the soldering surface of the substrate 1, a plurality of inspection areas are preliminarily allocated, and the stage mechanism 60 automatically moves the illumination device 9 and the image pickup device 10 to each inspection area in sequence. The illuminating device 9 irradiates the soldering surface with light from below, and the imaging device 10 images the reflected light from below, and the inspections for each inspection region are sequentially performed.

When the inspection of the board 1 is completed in this way, the board fixing mechanism 70 returns to release the board 1.
After the substrate transfer mechanism 25 operates and the claw plates 37 and 38 project to the substrate transport path, the piston inside the guide cylinder 33 moves. As a result, one claw plate 37 hooks the rear end of the waiting substrate 1 to feed the substrate 1 to the inspection position, and the other claw plate 38 hooks the rear end of the inspected substrate 1 to carry out the substrate 1. It is sent to the mechanism 24. FIG. 4 (5) shows this state. When the sensor 83 detects the delivery of the substrate 1 to the unloading mechanism 24, the unloading mechanism 24 operates to let the inspected substrate 1 out of the substrate inspecting device 8. Less than,
Similarly, loading, inspection, and unloading of the substrate 1 are repeatedly performed.

In the above embodiment, the substrate inspection device 8 is an automatic inspection device that automatically inspects the substrate 1 in accordance with a pre-teached procedure. However, the present invention is not limited to this, and an image of the inspection area is displayed on the monitor. Of course, the present invention can also be applied to a visual inspection device in which an operator visually inspects.

[0036]

As described above, according to the present invention, the component mounting board that has undergone the flow soldering process is carried into the inspection position with the soldering surface facing downward, and then the component mounting board is exposed to light from below toward the soldering surface of the board. Is irradiated and the reflected light is imaged from below to inspect the quality of soldering,
Inspecting a board that has undergone the flow soldering process does not require the step of flipping the board up and down as in the past, reducing the number of steps and eliminating the need for a board reversing mechanism. Can be simplified and the manufacturing cost of the substrate can be reduced.

According to the invention of claim 3, since the respective light sources of the illuminating device for irradiating the light of different colors are arranged in the directions of different elevation angles, the reflected light on the soldering surface is picked up by the image pickup device, so that the soldering is performed. It is possible to obtain a hue pattern according to the state, and it is possible to perform accurate and highly accurate board inspection.

According to the fourth aspect of the present invention, the substrate is carried into the standby position upstream of the inspection position by the carry-in mechanism to stand by for inspection, and when the inspection of the substrate previously sent to the inspection position is completed, the transfer mechanism causes Since the inspected substrate is sent out to the unloading mechanism to be unloaded, the substrate at the standby position is sent to the inspection position, so that the substrate can be efficiently inspected.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of a substrate inspection method of the present invention.

FIG. 2 is a partially cutaway perspective view showing the structure of the board inspection apparatus according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of a substrate transfer mechanism.

FIG. 4 is a plan view showing the configuration and operation of a substrate transfer mechanism.

FIG. 5 is a perspective view showing a configuration of a substrate delivery mechanism.

FIG. 6 is a perspective view showing the structure of a stopper.

FIG. 7 is a perspective view showing a configuration of a substrate fixing mechanism.

FIG. 8 is an explanatory diagram showing an outline of a conventional board inspection method.

[Explanation of symbols]

 1 Substrate 8 Substrate Inspection Device 9 Illumination Device 9A, 9B, 9C Light Source 10 Imaging Device 20 Substrate Transfer Mechanism 23 Carry-in Mechanism 24 Carry-out Mechanism 25 Substrate Transfer Mechanism 60 Stage Mechanism

Front Page Continuation (72) Inventor Hideaki Takahara 24, Yamanouchi Yamanoshitamachi, Ukyo-ku, Kyoto City, Kyoto Prefecture OMRON Life Science Research Institute

Claims (4)

[Claims] 1. A component-mounted board that has undergone a flow soldering process is carried into an inspection position with the soldering surface facing downward, and then illuminated from below toward the soldering surface of the board, and its reflected light is reflected. A board inspecting method for inspecting the quality of soldering by imaging from below. 2. A board transfer mechanism for supporting and carrying in and out a component mounting board with the soldering surface facing downward with respect to the inspection position; and a soldering surface for the board carried in at the inspection position. An illumination device that irradiates light from below, an imaging device that images reflected light on the soldering surface of the substrate from below, and a stage mechanism that integrally moves the illumination device and the imaging device in parallel with the substrate are provided. Board inspection equipment. 3. The illuminating device comprises a plurality of annular light sources having different diameters and irradiating light of different colors, which are arranged in different elevation angles when viewed from a position on the center line with their centers aligned. Claim 1 according to claim 1, which is configured
The board inspection apparatus described in 1. 4. The board transfer mechanism carries in a board to a standby position upstream of an inspection position, a carry-out mechanism for carrying out an inspected board, and sends a board in the standby position to the inspection position. At the same time, the board inspection device according to claim 1, further comprising a board transfer mechanism for sending out the inspected board at the inspection position to the carry-out mechanism.