JP4019293B2 - Lighting device in mount inspection section - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination device for an inspection unit that inspects whether or not a ball is correctly mounted on a workpiece in a ball mounting device, and mainly performs image processing inspection of solder balls mounted on a BGA (ball grid array) substrate. It was developed mainly for lighting devices related to ball inspection illumination and substrate inspection illumination used when performing the above.
[0002]
[Prior art]
Solder ball mount inspection and BGA substrate inspection are required for solder ball mount misalignment inspection. The inspection of the BGA substrate is performed in order to determine the inclination of the BGA substrate, correct the inclination, and detect the misalignment of the solder ball. Specifically, a landmark or alignment attached to the BGA substrate is detected. This is done by recognizing the mark.
[0003]
Conventionally, in order to perform these two inspections, since the solder ball and the substrate are different in appearance, two images are captured with different illumination for each BGA substrate. At that time, as shown in Japanese Patent Laid-Open No. Hei 8-153997, one using two kinds of lighting devices, or as shown in Japanese Patent Publication No. 2-16012, the condition of one lighting device is inspected. There was something that could be varied according to the site.
[0004]
However, using two lighting devices for solder ball mount misalignment inspection requires a large mounting space for the illumination light source, and on the other hand, one lighting device can be varied according to the conditions of the illumination. However, there is a problem that it takes time to capture an image and lacks stability.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to reduce the mounting space of an illumination light source by attaching ball inspection illumination and alignment mark inspection illumination in the same illumination device, and performing both inspections with one illumination device. This is intended to shorten the entire inspection time without requiring fine adjustment of the optical system required in some cases.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention provides the same illumination device for the first illumination that irradiates the workpiece with a continuous light from a substantially vertical direction and the second illumination that irradiates the workpiece with a strobe light at a slight angle. The illumination device in the mount inspection part of the ball mount device is characterized in that it is disposed inside and irradiated with the second illumination while irradiating with the first illumination when inspecting the ball mount position of the workpiece .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described together with illustrated examples. FIG. 1 is a schematic view showing the entire ball mount apparatus. The ball mounting apparatus shown in FIG. 1 is a BGA solder ball mounting apparatus.
[0008]
The BGA solder ball mounting apparatus includes a flux supply unit 1 for transferring flux to a BGA substrate 9 of a BGA frame 8, a ball mount unit 2 for mounting solder balls 12 on the BGA substrate 9 of the BGA frame 8, and a ball mount. The mount inspection unit 3 inspects whether the BGA frame 8 is correctly performed by the CCD camera 5 and the transport unit 4 that transports the BGA frame 8 from the flux supply unit 1 to the ball mount unit 2 and the mount inspection unit 3.
[0009]
As shown in FIG. 2, the BGA frame 8 having a plurality of BGA substrates 9 (workpieces) to be mounted by the BGA solder ball mounting apparatus has six BGA substrates 9 formed therein. Is an alignment mark 11 attached to the BGA substrate 9, and 12 in the drawing is a solder ball 12 mounted on the BGA substrate 9.
[0010]
The BGA frame 8 is supplied onto a conveyor (not shown) of the transport unit 4 by a loading device not shown. The conveyor conveys the BGA frame 8 to the flux supply unit 1. After transferring the flux, the BGA frame 8 is conveyed to the ball mount unit 2. In the ball mount portion 2, the solder ball 12 is mounted on each BGA substrate 9. After completing the mounting of the solder balls 12, the BGA frame 8 is transported to the mount inspection unit 3.
[0011]
The mount inspection unit 3 inspects whether or not the solder ball 12 is correctly mounted at a predetermined position on the BGA substrate 9. The mount inspection unit 3 is a unit in which the CCD camera 5 and the illuminating device 16 are integrated, and is disposed on the traveling frame 13 above the transport unit 4 so as to be movable in the horizontal and horizontal directions. The moving range is a range in which all the BGA substrates 9 in the BGA frame 8 can be detected.
[0012]
In the illuminating device 16, two illuminations, a first illumination and a second illumination, are provided. The first illumination is continuous light illumination 6 provided on the top of the inclined surface in the illumination device 16, and is illumination for inspecting the alignment mark 11 on the BGA substrate 9. Since the alignment mark 11 is easily recognized by irradiation from a substantially vertical direction, the continuous light illumination 6 as the first illumination irradiates the alignment mark 11 from the substantially vertical direction. In FIG. 3, continuous light illumination 6 is provided in two steps on the upper part of the inclined surface in the illumination device 16 and on the upper part in the substantially vertical direction of the alignment mark 11 of the BGA substrate 9.
[0013]
The second illumination is the strobe light illumination 7 provided at the lower part of the inclined surface in the illumination device 16, and is illumination for ball inspection. Since the solder ball 12 is easy to recognize by oblique irradiation, the strobe light illumination 7 as the second illumination irradiates the solder ball 12 with a slight angle. In FIG. 3, the strobe light illumination 7 is provided at the lower part of the inclined surface in the illumination device 16 and obliquely above the solder ball 12 mounted on the BGA substrate 9.
[0014]
Note that the number and the number of steps of the continuous light illumination 6 or the strobe light illumination 7 can be changed as necessary. It is also conceivable to attach a diffusion plate or change the illumination angle.
[0015]
As the illumination light sources of the continuous light illumination 6 and the strobe light illumination 7, white LEDs are used. By using a white LED as the illumination light source, the amount of light is increased. This is because the red LED that is normally used is insufficient in light quantity, and as a result, a large number of illumination light sources are required and a large space for mounting is prevented. Note that continuous light and strobe light are distinguished by differences in electrical circuits.
[0016]
FIG. 4 is an explanatory view showing another embodiment of the illumination device 16. The continuous light illumination 6 is provided side by side at the upper horizontal position, and two steps are provided at the lower part of the inclined surface. Is the strobe light illumination 7. The continuous light illumination 6 is configured so as to be surely positioned at the upper part in the vertical direction of the alignment mark 11 attached to the BGA substrate 9.
[0017]
Next, an inspection procedure in the mount inspection unit 3 will be described. In the BGA frame 8 in which a plurality of BGA substrates 9 shown in FIG. 2 are formed, the mount inspection unit 3 first stops the leading BGA substrate 9 within the image capturing range 10 of the CCD camera 5. Here, the image of the alignment mark 11 is captured by the continuous light illumination 6. Subsequently, the relative movement between the BGA frame 8 and the CCD camera 5 is started at the same time when the image of the solder ball 12 is captured by the strobe light illumination 7. Specifically, the CCD camera 5 moves.
[0018]
When the second BGA substrate 9 reaches the image capture range 10 of the CCD camera 5, the strobe light illumination 7 is turned on to capture an image of the solder ball 12 of the second BGA substrate 9. The timing of capturing an image while moving the CCD camera 5, that is, the timing of turning on the strobe light illumination 7, inputs the pitch of the BGA substrate 9 in advance, observes the movement of the CCD camera 5 with an encoder, and emits the encoder. It is managed by the number of pulses.
[0019]
The relative movement stops when the last solder ball 12 of the BGA substrate 9 is recognized. After the stop, the image of the alignment mark 11 is captured by the continuous light illumination 6. The mount inspection unit 3 calculates the inclination of the entire BGA frame 8 by using the alignment marks 11 of the first and last BGA substrates 9 after capturing the image, and takes the inclination into consideration, and the position of the solder balls 12 on the BGA substrate 9. Is calculated to determine whether the mounting position of the solder ball 12 is good or bad.
[0020]
In this inspection procedure, the inspection is performed on the premise that there is no variation in the inclination of the BGA substrate 9 on the BGA frame 8, but when the difference in inclination between the individual BGA substrates 9 is too large to be ignored, the BGA frame 8 The alignment marks 11 of all the BGA substrates 9 can be taken in and individual inclinations can be taken into consideration.
[0021]
【The invention's effect】
Since the present invention is configured as described above, the following effects are exhibited.
First, the present invention includes a first illumination that irradiates the workpiece with a continuous light from a substantially vertical direction and a second illumination that irradiates the workpiece with a strobe light at a slight angle. This makes it possible to properly recognize the alignment mark on the BGA substrate and to properly recognize the solder ball by the second illumination, and at the same time, because two types of illumination are provided in the same illumination device. The installation space can be reduced.
[0022]
Secondly, by using a first illumination suitable for recognizing alignment marks arranged in one illumination device and a second illumination suitable for solder ball inspection, both conventional inspections are performed with one illumination device. This eliminates the need for fine adjustment of the optical system, which is necessary in the case of, and makes adjustment easy and reliable. Furthermore, since it is not necessary to finely adjust the optical system, the entire inspection time can be shortened.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the whole mounting apparatus. FIG. 2 is a plan explanatory view of a BGA frame. FIG. 3 is an explanatory view showing an embodiment of an illuminating apparatus. [Explanation of symbols]
1. . . . . . 1. Flux supply unit . . . . . 2. Ball mount part . . . . . 3. Mount inspection unit . . . . . 4. Transport unit . . . . . CCD camera 6. . . . . . Continuous light illumination7. . . . . . Strobe light illumination8. . . . . . BGA frame9. . . . . . BGA substrate 10. . . . . 10. Image capture range . . . . Alignment mark 12. . . . . Solder balls 13. . . . . Traveling frame 16. . . . . Lighting device

Claims (1)

The first illumination that irradiates the workpiece with a continuous light from a substantially vertical direction and the second illumination that irradiates the workpiece with a strobe light at a slight angle are arranged in the same illumination device, and the ball mounting position of the workpiece is determined. An illumination device in a mount inspection unit of a ball mount device, wherein the illumination is performed with the second illumination while irradiating with the first illumination when inspecting .

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