JPS6114737A - Lead warpage detector - Google Patents

Abstract

PURPOSE:To eliminate the conventional physical adjustment by obtaining the position of a fiber for a good lead by a calibration before detecting, and setting the judging range for the position by a program. CONSTITUTION:When an IC1 moves under an optical fiber array 3 and a photoreceptor 5 receives a light from the end of a lead, an output varies. A control circuit 6 has a function of counting the variation in the outputs of the respective fibers of the array 3, and when the lead of the IC1 passaes under the array 3, the reflected light from the end of the lead passes the interior of the fiber in the array 3, and the count of the fiber increases by ''1''. When the ICs of the prescribed number are moved in this manner, the number of the passed leads can be known for the position of the fiber. The distribution of the counted result for the position of the fiber is obtained to provide the position of the fiber for the maximum value. Then, the circuit 6 sets the good judgement range in both directions for the position of the fiber obtained from a calibration to judge whether it is good or not by moving the IC in this state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to visual inspection of integrated circuits (hereinafter abbreviated as IC).

[Prior art]

When automatically mounting an IC into a hole in a printed circuit board, the ICI glue lead 1a may be bent in the horizontal direction as shown in Figure 3, or the lead 1a may be bent in the width direction as shown in Figure 4. Otherwise, the leads will not fit into the holes in the printed circuit board, resulting in mounting problems.

Therefore, it is necessary to inspect the lead bends.

Conventionally, as shown in FIG. 5, a fiber 2 with a certain width is placed adjacent to the tip of the lead 1a, and
If the fiber receives the reflection from the tip of the lead as it moves below the fiber 2, it is determined to be good, and if it does not, it is determined to be defective. In FIG. 5, lead la is good, lead la is good, and lead la is good.

becomes defective.

[Problem that the invention seeks to solve]

In this case, it is necessary to manufacture a dedicated fiber in response to changes in the standard for bending angles, and the accuracy of the fiber width is also a problem.

Furthermore, the position of the fiber 2 in FIG. However, due to IC movement conditions, etc., good product lead 1
The position of a1 may be relatively shifted to the left or right. In that case, it was necessary to readjust the position of the fiber 2 each time, and the adjustment was also difficult.

An object of the present invention is to provide an apparatus that eliminates the conventional physical adjustment by determining the fiber position with respect to the non-defective lead 1a□ by calibration before inspection and setting a determination range for that position by a program. be.

[Means for solving problems]

As shown in FIG. 1, the present invention is an integrated circuit using an optical fiber array 3, 3, etc., which has a structure in which N optical fibers (N is an integer) in which a light emitting part and a light receiving part are integrated are arranged in a straight line. (hereinafter referred to as IC) 1 is arranged in a direction perpendicular to the lateral direction of the lead 1a and adjacent to the tip of the lead 1a, and a light emitting element 4 is provided on the light emitting side of the optical fiber array 3. A light receiving element 5 corresponding to each fiber is installed on the light receiving side, and the number of leads passing through each fiber is 1.
The method calculates the position of each fiber and its distribution from the counting results, determines the fiber position corresponding to the maximum value, and determines the determination range in both directions for the fiber position determined above to inspect lead bending of integrated circuits. It is equipped with a control circuit 6 that performs the following operations.

[Effect]

The present invention uses a control circuit to determine the lead distribution based on the result of counting the number of leads in an optical fiber array and the position data of each fiber, determines the fiber position corresponding to the maximum value, and makes judgments in both directions for the determined fiber position. Inspect IC lead bending by determining the range.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, one end of the optical fibers J, J2 is connected to the light emitting element 4a and the light receiving element 5a, respectively, and the other end (light emitting part and light receiving part) of the optical fiber J, J2 is connected to the light emitting element 4a and the light receiving element 5a, respectively. ICI's lead 1a is an optical fiber array 3 having a structure in which N optical fibers (N is an integer) are arranged in a straight line.
The lead is disposed perpendicular to the lateral direction of the lead and adjacent to the tip of the lead.

Furthermore, the number of leads passing through each fiber is counted, the value of each fiber and the distribution of the counting results are determined, the position of the fiber corresponding to the maximum value is determined, and the judgment range is determined in both directions for the determined fiber position. The light-receiving element 5 is connected to a control circuit 6 that inspects the lead bending of the IC.

Next, the operation of the device will be explained.

The operation is divided into a calibration operation for checking the movement state of the IC and a test operation for performing an inspection using the calibration result.

First, the calibration operation will be explained.

As shown in FIG. 1, optical fiber arrays 3, 3 are arranged adjacent to the lead tip portions. Light from the light emitting element 4 is incident on the lead tip through the fiber.

If there are no lead tips under the optical fiber arrays 3, 3, no light will enter the light receiving side, so the output of the light receiving element 5 will not change, but if the IC moves under the optical fiber array 3, When the light receiving element 5 receives light from the tip of the lead, the output changes. The control circuit 6 has a function of counting the changes in the output of each fiber of the optical fiber array 3, and when the IC lead passes under the optical fiber array 3, the reflected light from the lead tip is reflected inside the optical fiber array 3. passes through a certain fiber and increases the count for that fiber by 1.

When a certain number of ICs are moved in this way, the number of leads that have passed can be determined for each fiber position. The distribution of the counting results for this fiber position is determined, and the fiber position for the maximum value is determined. This is a calibration operation.

Next, the control circuit 6 sets a non-defective judgment range in both directions with respect to the fiber position determined by the calibration operation, and in this state, moves the IC to perform a pass/fail judgment. This is a test operation.

〔Effect of the invention〕

As explained above, the present invention appropriately selects the pass/fail judgment range with respect to the lead center position in the calibration operation, thereby eliminating the need to manufacture many types of fibers that meet the standards as in the past, and ensuring the position of the good lead. Even when there is a relative shift due to the movement state, the calibration operation determines the good lead position, eliminating the need to readjust the fiber position as in the conventional case. Therefore, by using the lead bending inspection device of the present invention, there is an advantage that physical changes and complicated adjustments are not required.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a structural diagram of an optical fiber used in the present invention, and Figs. 3 and 4 are I
FIG. 5, which shows lead bending at C, is a configuration diagram of a conventional device. 1...IC (integrated circuit), 1a...lead, 3...
・Optical fiber, 4... Light emitting element, 5... Light receiving element,
6...Control diagram Figure 2

Claims (1)

[Claims] (1) N
An optical fiber array (N is an integer) arranged in a straight line is arranged perpendicularly to the lateral direction of the leads of the integrated circuit and adjacent to the tip of the leads. Install a light emitting element on the light emitting side and a light receiving element corresponding to each fiber on the light receiving side, count the number of leads that have passed through each fiber, calculate the distribution from the position of each fiber and the counting results, and calculate the maximum A lead bend detection device comprising: a control circuit for inspecting lead bends of an integrated circuit by determining a fiber position corresponding to the value and determining a determination range in both directions for the determined fiber position.