JPH0528496B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a wire bonding apparatus, and more specifically, a monitor scope provided on the bonding head side monitors a positioning recognition mark formed on the surface of a substrate. In particular, the present invention relates to a wire bonding device characterized by a means for irradiating a recognition mark.

<Prior Art> FIG. 5 shows the basic configuration of a wire bonding apparatus to which the present invention is directed.

This device is equipped with an XY table 1 that can be moved and adjusted in a horizontal plane by a pair of motors Mx and My, and is equipped with a bonding head 2 and a monitor scope 3. The formed recognition mark is monitored by the monitor scope 3, and the image signal from the monitor scope 3 is transmitted to the pattern recognition unit 6 via the camera control unit 5, and pattern recognition processing is performed according to the procedure stored in the microcomputer 7. , while displaying the results on the monitor television 8, driving and controlling the motors Mx and My via the XY control circuit 9 and motor braking circuit 10.
The structure is such that the bonding head 2 is positioned horizontally with respect to the substrate on the heater block 4.

Conventionally, as shown in FIG. 6, a fine recognition mark A (generally a cross shape is used) formed on the surface of the substrate 11 by etching or the like is placed on the heater block 4 using a monitor scope 3. In order to monitor the marks, light from illumination lamps 12, 12 provided above the substrate 11 is irradiated onto the mark formation location, and reflected light from the surface of the substrate 11 is taken into the monitor scope 3.

<Problems to be Solved by the Invention> However, the conventional example having such a configuration has the following problems.

In the means for monitoring the reflected light from the substrate 11 as described above, the clarity of the image taken by the monitor scope 3 may be affected by changes in illuminance due to voltage fluctuations of the illumination lamps 12, changes in the illumination direction, etc. This tends to change greatly, and the image signal binarized based on this changes significantly, making it difficult to stably perform pattern recognition.

The present invention aims to solve the above-mentioned problems found in conventional means by improving the illumination means.

<Means for Solving the Problems> In order to achieve the above object, the present invention has a configuration in which an illumination device that can irradiate light from below the substrate to the location where the recognition mark is formed is provided on the heater block side. .

<Function> Since the substrate is generally made of thin ceramic, it has some degree of translucency, and if light of an appropriate intensity is irradiated from below, the recognition mark can be clearly marked by the light transmitted to the substrate surface. It can be captured as an image with great contrast.

Moreover, even if the luminous intensity of the irradiated light changes somewhat, the image produced by this transmitted light hardly appears as a change in contrast, and a clear image can always be obtained.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIGS. 1 and 2 show an example of a characteristic component of the present invention.

In this example, the heating resistor 13 is used as the substrate 11.
and a thermal printing head equipped with an IC chip 14 (only one is shown in the figure). The heater block 4 is made of a metal material such as stainless steel, and has an electric heater 15 inserted therein.

And, corresponding to directly below monitor scope 3,
A hole 16 passing vertically is formed between the heater block 4, and an optical fiber head 18, which is an example of a lighting device 17, is inserted into the hole 16 from below. Note that the light source is placed in a thermally safe location.

During the wire bonding process, the substrate 11
The recognition mark A formed on the surface of the hole is almost hole 1.
The substrate 11 is mounted on the heater block 4 so as to be positioned above the substrate 6, and the transmitted light of the light irradiated from the optical fiber head 18 to the lower surface of the substrate 11 is taken into the monitor scope 3, and the It performs positioning control.

Alternative Embodiment 1 FIG. 3 shows a case where the heater block 4 is made of a heat-resistant and transparent material such as quartz glass.
9 is formed from the bottom surface, and an optical fiber head 18 is inserted into this hole 19.

If the surface of the heater block 4 is continuous above the hole 19 in this way, the heat distribution on the surface can be maintained uniformly.

Alternative Example 2 This example shows a case where a general optical system is used for the illumination device 17, in which light from a light source located below (not shown) is condensed by a lens 20, and the hole 2 of the heater block 4 is
1 to the lower surface of the substrate 11.

<Effects of the Invention> As described above, according to the present invention, the illumination device irradiates the recognition mark formation location with light from below the substrate and monitors the transmitted light to the substrate surface. The recognition mark can always be captured as a clear image even with slight changes in light intensity or angle, resulting in good pattern recognition and stable relative positioning between the board and bonding head. It has become possible to do this with high precision and accuracy.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the main part of the wire bonding apparatus according to the present invention, FIG. 2 is a longitudinal sectional front view thereof, FIG. 3 is a longitudinal sectional front view showing another embodiment of the main part, and FIG. FIG. 5 is a side view showing the general basic structure of the wire bonding apparatus, and FIG. 6 is a front view showing the main part of a conventional example. A...Recognition mark, 3...Monitor scope, 4
... Heater block, 11 ... Substrate, 18 ... Optical fiber head, 20 ... Lens.

Claims (1)

[Claims] 1. The recognition mark formed on the surface of the substrate loaded on the heater block is monitored with a monitor scope provided on the bonding head side, and the connection between the substrate and the bonding head is determined based on the pattern recognition results. A wire bonding apparatus configured to correct and control a relative position, wherein an illumination device is disposed on the heater block side and is capable of irradiating light from below the substrate to a location where a recognition mark is formed. 2. The wire bonding device according to claim 1, wherein the lighting device uses an optical fiber.