JPS6146997B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for automatically aligning, for example, an IC component to a printed board or the like.

BACKGROUND ART In various manufacturing fields, it is essential to overlap an object to be aligned with an object to be aligned. For example, in the field of circuit board manufacturing, if the object to be aligned is a printed wiring board and the object to be aligned is the lead of a semiconductor integrated circuit package, the lead is completely overlapped with the specified location of the printed wiring and soldered. This work is essential. Since there are usually several dozen leads, it is quite difficult to position and overlap them with high precision beyond the specified locations of the corresponding printed wiring. Conventionally, this type of alignment work has generally been performed manually using a microscope. However, manual work has problems in terms of accuracy, and in mass production, there is also a problem in terms of yield. Therefore, there has been an increasing demand for automating this type of positioning work. For this reason, a positioning method using a microprocessor or the like has been proposed.

An example of this positioning method will be explained with reference to FIG.

A bonding pad 2 for bonding a component lead 3 is formed on a printed wiring board 1, and the purpose is to automatically align the lead 3 of a component 4 onto this bonding pad 2.

First, without placing the component 4 on the printed board 1, the pad portion 2 of the printed board 1 is photographed using an imaging device 5 composed of a CCD (charge, coupled device), etc., and is stored in a storage means. Next, the component 4 is placed on the printed board 1, and the bonding pad portion 2 and the lead portion 3 of the component are simultaneously photographed using the photographing device 5. The result determining device 6 operates the drive device 7 to move the component 4 in the direction of the arrow so that the lead portion of the component that protrudes from the joint pad portion 2 (does not overlap) is minimized.

The above is an example of the principle of the automatic component positioning method.

In Figure 1, when the number of leads of a component is large, it is necessary to lower the magnification of the optical system to photograph a wide range from one end of the lead to the other with the imaging device, which reduces the decomposition rate and improves performance. You will not be able to get a good video signal.

To solve this problem, it is necessary to limit the area photographed by the imaging device to a portion of the lead of the component, but since the lead at the edge of the component is likely to be deformed, it is necessary to photograph the lead in the center of the component. It is preferable to align the

However, when the leads L1 to Ln of the component should be aligned on the bonding pads P1 to Pn as shown in Figure 2a, if they are aligned one pitch apart as shown in Figure 2b, the leads Since the pitch intervals are equal, they overlap with a one-pitch difference, making it impossible for an automatic positioning device to detect this error. Therefore, an object of the present invention is to provide a positioning method that solves this problem, and the purpose is to align the lead terminals of a component in which a large number of lead terminals are arranged, and the printed circuit board on which the component is mounted. In the method of automatically aligning the lead terminal of the above component with the corresponding bonding pattern,
This is achieved by arranging the lead terminals and bonding patterns of the component so that the intervals between them are unequal with respect to the adjacent lead terminals and bonding patterns, and aligning the component approximately at the center thereof.

Next, details of the present invention will be explained with reference to the drawings.

FIG. 3 is an example in which some of the leads of a component are made twice the distance between other leads.

Figure 3a shows the normal alignment state.
If there is a one-pitch deviation, the lead will come to the part where there is no bonding pad, as shown in Figure 3b, so the pitch deviation can be easily detected.

Figure 4 is an example in which the lead spacing of a part of the component is set to 1.5 times the lead spacing of other parts, and in this case as well, if there is a deviation of one pitch from the normal alignment state of Figure 4a, the result will be as shown in Figure 4b. , the bonding pad and the lead do not overlap at all, making it possible to detect pitch deviation.

In Figure 5, the lead width of a part of the component is twice the lead spacing of other parts, and in this case as well, the normal alignment shown in Figure 5a is correctly aligned as shown in Figure 5b. Pitch deviation can be detected.

In addition to the above three examples, various methods of arranging the component leads can be considered, such as a method of sequentially increasing the lead pitch and a method of alternately changing the pitch width.

As explained above, the alignment method of the present invention has the advantage that pitch deviation can be easily detected and alignment accuracy can be improved.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the parts automatic positioning device, Figure 2
The figure is an explanatory diagram of the conventional part positioning method, Figure 3~
FIG. 5 shows an explanatory diagram of a component positioning method according to an embodiment of the present invention. In the figure, 1 is a printed board, 2 is a joint pad,
3 is a lead, 4 is a component, 5 is a photographing device, 6 is a determination device, and 7 is a drive device.

Claims (1)

[Claims] 1. In a method of automatically aligning the lead terminals of a component in which a large number of lead terminals are arranged and a bonding pattern provided on a printed circuit board on which the component is mounted and corresponding to the lead terminals of the component, An automatic positioning method characterized by arranging lead terminals and bonding patterns so that the intervals between them are unequal with respect to adjacent lead terminals and bonding patterns, and aligning the parts approximately at the center thereof.