JPH02114104A - Apparatus for inspecting lead terminal of ic package - Google Patents

Abstract

PURPOSE:To enhance the reliability of inspection by eliminating the difficulty in discriminating the projection image of a lead terminal by illuminating the lead terminal from just-above and diagonally-above positions by the first and second illumination devices and calculating the coordinate values of the taken images. CONSTITUTION:In order to obtain the projection images of a lead terminal in different directions, the first and second illumination devices LGT 1, LGT 2 respectively illuminating the lead terminal from a just-above position and a position having a predetermined inclination and a camera CMR successively taking the first and second projection images due to the illumination devices LGT 1, LGT 2 are provided. At first, the lead terminal is illuminated by the illumination device LGT 1 and the image thereof is taken by the camera CMR and the coordinate value thereof is calculated by an image processing part. Next, the lead terminal is illuminated by the illumination device LGT 2 and the image thereof is taken by the camera CMR and the coordinate value of said image is calculated by the image processing part. Further, the levitation quantity of the lead wire is calculated from the trigonometric functions of the coordinate values and compared with a reference value to judge the quality of the levitation of the lead terminal.

Description

[Detailed Description of the Invention] [1 Remarks] Regarding an inspection device for lead terminals of an IC package, the purpose of this invention is to solve the difficulty of identifying projected images of lead terminals and improve the reliability of inspection. The package lead terminal inspection apparatus includes first and second illumination sections that illuminate one from directly above and the other at a predetermined tilt in order to obtain projected images of the lead terminal from different directions; an imaging unit that sequentially photographs first and second projected images by a second illumination unit; a shutter mechanism unit that switches illumination of the first and second illumination units; an image processing section that calculates the coordinate values of the imaging of the image, calculates the vertical lift of the lead terminal from these coordinate values, and compares it with a reference value, and a control section that controls the operation of the shutter mechanism section and the image processing section. be done.

[Industrial application field]

The present invention relates to inspection of lead terminals of IC packages, and particularly to an apparatus for inspecting floating lead terminals.

Various tC packages are used in information equipment.

An IC package has a large number of legs (lead terminals), and it is desirable that these lead terminals are lined up in a line to avoid deformation such as floating as much as possible in view of their positional relationship with the socket. For this reason, strict inspections are carried out by manufacturers before shipment, but with the recent increase in demand, improvements in inspection efficiency and reliability are desired.

[Conventional technology]

FIGS. 7(a) and 7(c) are layout diagrams of main parts of a conventional inspection device for inspecting floating lead terminals of an IC package. Figure 7 (a) is a view of the inspection device viewed from above, (b)
is a side view. In the figure, fCP is an IC package, LT is a lead terminal, LGT1 and LGT2 are lighting devices, and CMR is a camera. Two lighting devices LGT1
, LGT2 simultaneously illuminate the lead terminals from the front, and the camera CMH images the reflected light from the lead terminals.

This is an image of the tip part (■) of the lead terminal. Each machine inspects the float■
Find the coordinate value in the Y-axis direction of
This is done by finding the difference between this center of gravity coordinate value and each machine (2) and comparing it with the standard value.

[Problem to be solved by the invention]

FIG. 9 is a diagram showing a conventional actual image. The shaded area is an actual image of the beam-F terminal. As shown in FIG. 7(b), in this case, the camera focuses on the image of the tip part ■, but in addition to the image of ■, it simultaneously captures the image of the falling part ■ and the image of the bending part ■. become. In the type where the length d of the bent portion of the REIT terminal is short, the reflected light is mixed because the focal points are close together, and as shown in the figure, the identification of these images becomes unclear and it is difficult to obtain accurate barycenter coordinate values. Yes, it is interfering with inspection.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lead terminal inspection device that can solve the difficulty of identifying projected images of lead terminals and improve the reliability of inspection.

[Means to solve the problem]

As shown in the basic configuration diagram in FIG. 3, the present invention is a tC package lead terminal inspection device, in which one side is illuminated from directly above and the other side is illuminated at a predetermined inclination in order to obtain projected images of the lead terminals from different directions. The first and second lighting sections (LG
Tl, LGT2), and a imaging unit (CMR) that sequentially photographs first and second projected images by the first and second illumination units.
), a shutter mechanism section (3) that switches the illumination of the first and second illumination sections, and a shutter mechanism section (3) that switches the illumination of the first and second illumination sections;
An image processing unit (4) calculates the vertical lift of the lead terminal from these coordinate values and compares it with a reference value.
), and a control section (5) that controls the operations of the shutter mechanism section and the image processing section.

[For production] FIGS. 1(a) and 1(b) are layout diagrams of main parts of the present invention.

As shown in the figure, first, the lead terminal LT is illuminated from directly above by the first illumination device LGTI, and its projected image is captured by the camera CMR to obtain the coordinate values of the image. Next, the second illumination device LGT2 similarly illuminates the lead terminal from diagonally above, and the coordinate values of the image are determined. Then, the float of the lead terminal is calculated from the trigonometric function of the two coordinate values.

FIG. 2 is a projected image of the lead terminal taken by a camera. In the figure, the solid line is the image obtained by the illumination device LGTI,
The dotted line is an image obtained by illumination device LGT2.

S is the amount of deviation of the projected image caused by floating of the lead terminal. From this amount of deviation, the image processing section (4) calculates the floating of the lead terminal, as will be described later.

〔Example〕

FIG. 3 is a basic configuration block diagram of the lead terminal inspection device of the present invention. In the figure, 1 indicates two lighting units (LGTI
, LGT2), 2 is the imaging unit (camera) (CMR)
, 3 is a shutter mechanism section, 4 is an image processing section, and 5 is a control section consisting of a microcomputer. The illumination unit l has first and second illumination devices for obtaining projected images of the lead terminals from different directions, and the camera 2 receives the first and second projected images by the first and second illumination devices. The shutter mechanism section 3 intermittents the illumination light of the first and second illumination devices, and the image processing section 4 sequentially photographs the first and second illumination lights by the camera.
The coordinate values of the captured image are determined, and the vertical lift of the lead terminal is calculated from these coordinate values and compared with a reference value. FIG. 4 is a basic processing flowchart of the apparatus shown in FIG. First, the lead terminal is illuminated by the illumination device LGTI, its image is obtained by a camera (1), and the coordinate values of the image are calculated (2).

Next, the lead terminal is illuminated by the illumination device LGT2, its image is obtained by the camera (3), and the coordinate values of the image are calculated (4). Then, the floating amount of the lead terminal is calculated from the trigonometric function of these coordinate values using the method described later (5), and compared with a reference value to determine whether the lead terminal floating is good or bad (6).

FIG. 5 is a layout diagram of an embodiment of the lighting device and camera of the present invention. In the figure, 51 is a microcomputer-based position control device that controls the position of the lighting device, 52 is an optical fiber that guides the irradiation light, 53 is an adjustment device that adjusts the angle of the lighting device LGT2, and 54 is an IC package (ICP).
It is a vacuum pad that absorbs. As described above, the projected image of the illumination device LGTI and the projected image of the illumination device LGT2 are sequentially captured by the camera and the coordinate values are determined by the image processing unit.

FIGS. 6(a) and 6(b) are diagrams showing projected images of the present invention.

(a) shows the float seen from the side of the beam terminal, and (b) shows the float seen from the top. In (a), the shaded area is an image of the tip of the lead terminal, in (b), the solid line is an image projected by the illumination device LGTI, and the dotted line is an image projected by the illumination device LGT2.

Here, the width of the projected image by the illumination device LGTI is a, the width of the projected image by the illumination device LGT2 is a゛, the arbitrary setting value of the float height is X, the amount of deviation is S, the plate thickness of the lead terminal is H, I
t (The incident angle of the light device LGT2 is assumed to be θ.

In such a relationship, the incident angle θ of the lighting device LGT2
is θ-Lan-'(a-a')/H...1
It can be expressed as 1).

As is clear from equation (1), the amount of deviation S is 5=x−t
Since it can be expressed as an θ・・・・・・・・・(2),
The deviation ls of the projected image is related to the float X, and if the float X is set to a predetermined allowable reference value, the lead terminal float can be inspected by looking at the range of S from equation (2). For example, S≦X・tan θ is determined to be a good product, and S>x・tan θ is determined to be a defective product.

In this case, as described above, the image processing unit 4 calculates equations (1) and (2).

〔Effect of the invention〕

As explained above, according to the present invention, inspection can be performed regardless of the length of the bent portion of the lead terminal, there is no need to identify the projected light, and the position of the illumination device can be easily adjusted, thereby increasing inspection efficiency. It is possible to improve performance and reliability.

[Brief explanation of drawings]

1(a) and 1(b) are main part layout diagrams of the first and second lighting devices, IC packages, lead terminals, and cameras according to the present invention, and FIG. 2 is an image taken by the camera of FIG. 1. Figure 3 is a basic configuration block diagram of the lead terminal inspection device of the present invention, Figure 4 is a processing flowchart of the device shown in Figure 3, and Figure 5 is the illumination device and camera of the present invention. 6(a) and 6(b) are diagrams showing projected images of the lead terminal of the present invention as seen from the side and top surfaces, and FIG. 7(
a) and (b) are layout diagrams of the main parts of conventional IC package lead terminal inspection, Figure 8 is a diagram showing the conventional depiction of the tip, and Figure 9 is a diagram showing the actual conventional imaging. be. (Explanation of symbols) 1. LGT1, LGT2...Lighting device, 2. CM
R...Camera, 3...Shutter mechanism section, 4
...Image processing unit, 5...Control unit, ICP...
・IC package, LT...lead terminal. Layout of essential parts of the present invention Figure 112I Figure 3 Processing flowchart of the device Figure 2: Diagram showing the projected image on the camera Figure '$2FjJ Basic configuration block diagram of the present invention) Figure 83 Configuration diagram of essential parts of an embodiment of the present invention Figure 5 (a) Y (b) Diagram showing a projected image according to the present invention Figure 5 (Q) Conventional layout diagram of main parts #I7 Figure

Claims (1)

[Scope of Claims] 1. A lead terminal inspection device for an IC package, comprising first and second lamps that illuminate one side from directly above and the other at a predetermined inclination in order to obtain projected images of the lead terminals from different directions.
lighting units (LGT1, LGT2), and the first and second illumination units (LGT1, LGT2);
an imaging unit (CMR) that sequentially photographs first and second projection images by the illumination unit; a shutter mechanism unit (3) that switches the illumination of the first and second illumination units; An image processing unit (4) that calculates the coordinate values of the first and second imaging, calculates the vertical lift of the lead terminal from these coordinate values, and compares it with a reference value, and controls the operation of the shutter mechanism unit and the image processing unit. An IC package lead terminal inspection device, comprising: a control section (5) for controlling;