JP2758474B2 - Electronic component manufacturing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electronic component when mounting an electronic component such as a semiconductor package on a printed circuit board or the like.

[Prior Art] When mounting an electronic component such as a semiconductor package on a printed circuit board or the like, it is necessary to inspect and correct the component and mount the electronic component on the circuit board in order to eliminate defective products. .

In recent years, mounting machines have been required to have higher mounting accuracy.

Hereinafter, the above-described conventional electronic component correction method will be described with reference to the drawings.

FIG. 6 shows a QFP (Quad Flat Package) requiring recognition correction, in which the lead pitch of the side B varies.

FIG. 2 shows a flowchart of a conventional method of correcting an electronic component, in which variations in lead pitch are corrected only by rotation correction.

[Problems to be Solved by the Invention] However, in the conventional correction method using only the rotation correction, only the side B varies, which affects the accuracy of the other three sides A, B, and C. As a result, there is a problem that accurate mounting of electronic components is hindered.

The present invention solves such a problem of the prior art. By adding a translational correction to the rotation correction, in such a component, the correction is performed only by the movement in the A-C direction, and the variation is corrected. The purpose is to minimize the effect of the above.

[Means for Solving the Problems] To achieve the above object, the present invention comprises the following constitutions. That is, the present invention is a method of inspecting and correcting a rectangular packaged electronic component having leads, and mounting the electronic component on a circuit board, comprising: a vertical correction angle θy of the electronic component; Is measured, and the variation in the lead pitch of the electronic component is determined when the difference between the vertical correction angle θy and the horizontal correction angle θx is large.
The rotation is corrected by the smaller of θx or θy, and |
The electronic component manufacturing method is characterized in that the electronic component is corrected by moving the electronic component in parallel by θx−θy |.

[Operation] According to the configuration of the present invention, when performing component correction, if there is only one side of the lead pitch variation in a component having a variation in the lead pitch, the movement correction is performed in parallel in addition to the normal rotation correction. Since it is performed, the parts other than the side where the lead pitch varies and the opposite side can be mounted with high precision, and the opposite sides can also be maintained with high precision, so that the quality of the completed substrate is improved and discarded as a defective shape part The number of components that have been removed is also reduced, and the reliability of the mounting machine is significantly improved.

EXAMPLES Hereinafter, an example of the present invention will be described more specifically with reference to the drawings.

In FIG. 1, 1 is a captured image, and 2 is a QFP image to be recognized and corrected. The captured image is
For example, this is performed using a CCD (solid-state imaging device).

Hereinafter, the operation of one embodiment of the present invention will be described with reference to FIGS. 1 to 5 (however, FIGS. 2 to 4 are flowcharts).

First, the part is moved onto the camera, and an image is captured from the camera.

Next, after extracting the outline of the component, the lead is detected,
Capture the coordinates of each lead. At this time, the side where the read variation is large is stored.

Next, the average value is calculated from the coordinates of the leads on each side, the facing sides AC and BD are connected to each other, and the intersection is defined as P
And

Next, a line connecting each of them and a vertical correction angle θy
And the deviation (θx−θy) of the correction angle θx in the horizontal direction is obtained.

Next, rotation correction is performed by an angle θx between the line AC connecting the sides not including the side B having the largest variation and the horizontal direction.

Next, if | θy−θx |> A, then {(θx + θy} /
2) Perform rotation correction by −θx and end the correction. A
Is obtained from FIG.

In FIG. 5, reference numeral 3 denotes a land pattern, and 4 denotes a lead. A supplementary drawing for obtaining A when a is the width of the land pattern and B is the lead width of the electronic component is obtained as follows.

Assuming that the width of the land pattern 3 is a and the width of the lead 4 is b, the deviation x of the symmetrical lead may satisfy the following expression.

x ≦ 2 (ab)... [I] If the expression [I] is satisfied, the QFP can be mounted on the land pattern. Assuming that the radius of the QFP is r, the deviation of the lead at the symmetric position can be expressed by the following equation.

x = rtan | θx−θy | (II) From equations [I] and [II], only parallel correction is required if 2 (ab) ≧ rtan | θx−θy | (III) is satisfied.

Here, if | θx−θy | = A, then A ≦ tan ⁻¹ {2 (ab) / r}.

Next, if | θx−θy | <A, rtan |
It is moved and corrected by θx−θy | / 2.

Finally, the correction processing ends, and the process proceeds to the next processing.

[Effects of the Invention] As described above, the present invention measures the vertical correction angle θy and the horizontal correction angle θx of the electronic component, and determines the variation in the lead pitch of the electronic component to correct the vertical correction angle θ.
When the difference between y and the horizontal correction angle θx is large, θx
Or rotation correction by the smaller of θy, and | θx
By moving the electronic component in parallel for -θy | and correcting it, by introducing parallel correction information in addition to the rotation correction information, the component can be corrected with high accuracy at the time of position correction. The effect described above can be achieved.

In addition, expensive QFs that have been discarded as shape defects until now
If P also satisfies the range of variation shown in FIG. 5, it will not be discarded, and the loss cost due to defective shape will be reduced.

Therefore, an efficient manufacturing method can be obtained as a whole.

[Brief description of the drawings]

FIG. 1 is a diagram showing a recognition-corrected image according to an embodiment of the present invention, and FIGS.
FIG. 4 is a flowchart of one embodiment of the present invention, FIG. 5 is a diagram for calculating an equation for determination in correction of one embodiment of the present invention, and FIG. 6 is a QFP requiring recognition correction. Fig. 7
The figure is a flowchart of the prior art. 1... A captured image, 2... QFP image to be recognized and corrected.

Claims (1)

(57) [Claims] 1. A method of inspecting and correcting a rectangular packaged electronic component having leads and mounting the electronic component on a circuit board, wherein the electronic component has a vertical correction angle θ.
and the correction angle θx in the horizontal direction are measured. When the difference between the correction angle θy in the vertical direction and the correction angle θx in the horizontal direction is large, θx or θ
rotation correction by the smaller of y and | θx−θy |
Wherein the electronic component is moved in parallel to correct the electronic component.