JPH01140049A - Inspecting apparatus for external appearance - Google Patents

Abstract

PURPOSE:To simplify a construction by a method wherein a distance between a lead surface of an integrated circuit and a distance detector is sampled at a prescribed time interval and each lead width, each lead space and a distance from the center of each lead width to the distance detector is determined. CONSTITUTION:A distance detector 5 having a light-projecting element and a light-sensing element, a positioning mechanism 6 for positioning vertically to the lead 2a surface IC 2, a processing element 4 processing data on a distance between a lead 2a and the detector 5, etc. are provided. The upper and lower limits of the distance between the detector 5 and the lead 2a are set and each distance data are discriminated. Moreover, a lead width, a lead space and a sampling time are determined, a pitch direction of the lead 2a is detected through comparison with a set value, while a surface direction of the lead 2a is detected by comparing data positioned in the center of the lead width with a set value. Accordingly, inspections of the pitch direction of the lead 2a and the surface direction thereof are conducted simultaneously, and thus a construction can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the visual inspection of integrated circuit (hereinafter abbreviated as IC) packages, and particularly to the inspection of lead shapes.

[Conventional technology]

Conventionally, this type of lead shape inspection has been carried out using a transmission method, in which light is emitted from the top surface of the IC 2 near the tip of the lead 2a using a projector 1, and the light is received by a receiver 3 on the bottom surface of the IC 2, as shown in FIG. In the detection method, the IC 2 is moved at a constant speed to detect the presence or absence of the lead 2a as a temporal change, and the processing unit 4 converts the presence or absence of each lead 2a into the lead width or lead interval and calculates only the pitch direction of the leads. I was doing an inspection.

[Problem that the invention seeks to solve]

The above-described conventional inspection method has the disadvantage that it is possible to inspect only the pitch direction of the lead, and inspection in the planar direction of the lead must be performed using a different inspection method.

An object of the present invention is to provide an appearance inspection device that solves the above problems.

[Differences between the Invention and the Prior Art] The present invention differs from the conventional inspection apparatus described above in that the inspection in the lead pitch direction and the lead surface direction can be performed using the same apparatus.

[Means for solving problems]

The present invention provides a distance detector in which a light emitting part and a light receiving part are integrated;
It includes a mechanism for moving the integrated circuit or the distance detector at a constant speed, and a storage section that samples distance data between the lead surface of the integrated circuit and the distance detector at regular time intervals and stores the data. This is an external appearance inspection device characterized by having a processing section for determining the lead width, the interval between each lead, and the distance between the center of the width of each lead and a distance detector.

〔Example〕

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

(Embodiment 1) In FIG. 1, the present invention includes a distance detector 5 in which a light emitter and a light receiver are integrated, and a distance detector 5 that is perpendicular to the surface of the lead 28 of an IC (integrated circuit) 2. It includes a positioning mechanism 6 located at , a mechanism 7 that moves the IC 2 at a constant speed, and a storage section that samples distance data between the IC lead surface and the distance detector at regular time intervals and stores the data. It is equipped with a processing section 4 for determining the width of each read lead, the interval between each lead, and the distance between the center of each lead width and the distance detector.

FIG. 1 is a perspective view of Embodiment 1 (in the case of a flat package) of the present invention.

Now, assume that the moving mechanism 7 moves directly below the distance detector 5 at a constant speed. Regarding data collection at this time, the distance detector 5 is sampled in a sufficiently short time compared to the time it takes to pass through each lead 2a of the IC 2, and the distance detector 5 is sampled for the sampling time from when the moving mechanism 7 starts passing under the distance detector 5 until it finishes passing. and distance data at the lead 2a moat are stored in the processing section 4.

Next, the detection method will be explained using FIG. 2 (side view of the IC).

First, find the ideal distance between the distance detector 5 and the lead 28 surface in advance, set the upper and lower limits for that value, read out the stored data, and check whether each distance data is within the range. Compare to see if there are any.

The data area that contains the data is the lead part, and the data area that does not contain the data is between the leads or the lead missing part. BASE indicates the reference position of the distance detector.

Now, sequentially examine the distance data P□ to P4 from when the distance detector 5 started passing, and find the change point from the state without a lead to the state with a lead (TR,, TR,, TR, ,
TR, ) and the change point from the leaded state to the leadless state (TF, , TF, , TF3. TF4
), and each lead width (wz 9wt tW3
tw4) and lead spacing (Ql.

Q2. Find Q, ).

If the correlation between the lead width, lead spacing, and sampling time is determined in advance, the lead spacing (L, Qz
, Qg) with a preset standard, the lead pitch direction can be inspected.

Mata, lead width (S2.l'2, l'3, lI'4
) located at the center of the data (I+1.H2, H3, H4
) and compare it with a preset standard to inspect the surface direction of the lead.

(Example 2) Next, as Example 2, an example in which the present invention is applied to a dual in-line package is shown in FIG. The detection method is the same as described above.

In the embodiment, the IC 2 is moved at a constant speed, but the distance detector 5 may be moved at a constant speed.

〔Effect of the invention〕

As explained above, the present invention uses a distance detector in which a light emitting part and a light receiving part are integrated in the detection part, so that the pitch direction of the lead and the surface direction of the lead can be inspected simultaneously with the same device. , it has the advantage of being lower in price than conventional devices and can be achieved with a simple configuration.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of Embodiment 1 of the present invention, Fig. 2 is a side view of Embodiment 1 of the present invention, Fig. 3 is a perspective view of Embodiment 2 of the invention, and Fig. 4 is a perspective view of the conventional example. It is a diagram. 2...Integrated circuit 2a...Lead 4...
Processing unit 5...Distance detector 7...Movement mechanism BASE...Reference position P of distance detector,, P2. P,,P,...Distance data between the distance detector and each lead interval H,,H2,H,,H,...Distance data between the distance detector and each lead LD1. LD2. L
D, , LD4...IC leads TR1, TR,,
TR, , TR, . . . Change time from the lead interval portion to the lead portion TF, TF, , TF, , TF4 . . . Change time from the lead portion to the lead interval portion w, , w2. lol,
, w, . . . Required time in the lead section Q1. Q,
, Q, ... Required time within the lead spacing section Patent applicant
NEC Corporation Representative Patent Attorney Kanno Naka', Ge~;- Figure 1

Claims (1)

[Claims] (1) A distance detector with an integrated light emitting part and a light receiving part, a mechanism for moving the integrated circuit or the distance detector at a constant speed, and distance data from the lead surface of the integrated circuit to the distance detector for a certain period of time. It includes a storage section for sampling at intervals and storing the data, and a processing section for reading out the data and determining the width of each lead, the interval between each lead, and the distance between the center of the width of each lead and the distance detector. Characteristic appearance inspection equipment.