JPH01295143A - Lead curvature detecting device - Google Patents

Abstract

PURPOSE:To detect whether or not there is a lead in real time by adding data in a specific area in one line from a line sensor camera which picks up an image of an integrated circuit moving at a constant speed and comparing the sum with an optionally set value. CONSTITUTION:The IC moves right below the line sensor camera LS in a direction DIR at a constant speed. The start point STA and final point STP of the specific area in one line of the line sensor camera LS are set and addition data in this area is stored in a storage circuit MEMO. When the IC moves in the direction DIR at the constant speed and finishes moving, histograms H1...Hi for leads P1...Pi are obtained in the storage circuit MEMO. An optional value HTH is set for the addition result and used to decide whether or not there is a lead. Here, the lead width is Pr1-Pf1...Pri-Pfi, and the lead interval is Pf1-Pr2...Pf(i-1)-Pri. For the purpose, the lead width and lead interval are set previously and compared with certain criteria to make a normal/abnormal decision.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC visual inspection device, and particularly to an inspection device in the pitch direction of leads.

[Conventional technology]

Conventionally, this type of inspection method involves passing the IC leads at a constant speed in the DIR direction through a transmission type sensor section FS (the upper part of the page is the emitter and the lower part of the page is the receiver) as shown in Figure 3. , lead P1 to P, switching time (L, 1
．． L, 2. ...Lr+...), and lead P1~
Time to switch from presence to absence of P (L = t, L +?
,,...L fl...) is determined, and the lead spacing (Lr
2 1. rl), (L, -3Lr2)...(
Lr++++++-L□)... was sought. Furthermore, an area sensor is used to photograph the lead part, a window is provided in the lead part, and processing is performed based on the lead data within the window. S Tl+ shows no measurement line.

[Problem to be solved by the invention]

The conventional transmission sensor inspection method described above detects only one point on the lead, and therefore has the disadvantage that it cannot detect a lead that is bent in the middle, such as lead P4 in FIG.

Furthermore, the area sensor inspection method requires a large window in order to improve detection accuracy, which has the disadvantage of increasing inspection time.

An object of the present invention is to provide a lead bending detection device that solves the above problems.

[Differences between the invention and the prior art]

The present invention differs from the conventional inspection method described above in that it enables real-time data collection and processing, and also realizes a detection method that grasps the characteristics of the entire lead.

[Means to solve the problem]

In order to achieve the above object, the lead bend detection device of the present invention includes means for binarizing one line of output from a line sensor camera that images an integrated circuit moving at a constant speed, and A means for setting an area, a means for adding data in a specific area, a means for storing the addition result, and a means for comparing the addition result of each line with an arbitrarily set value to detect the presence or absence of a lead. It has the following.

〔Example〕

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

(Example 1) FIG. 1 is a block diagram, not showing Example 1 of actual noodles of the present invention.

In the figure, the present invention includes a line sensor camera LS that images an integrated circuit package (hereinafter referred to as IC) that moves at a constant speed, including leads P and ~Pl, and a line sensor camera LS that captures the output of one line from the line sensor camera LS. A binarization circuit COMP that performs binarization, a control circuit CTRL that controls a specific area for one line of output from the line sensor camera LS, and a control port I.
? An adder circuit ADD that adds data in a specific area according to the signal of 8cTRL, and a memory port Fl that stores its output.
@M EMO and a determination circuit JG that compares the addition result of each line with an arbitrarily set value and determines the presence or absence of a lead.

In the embodiment, it is assumed that the IC is moving directly below the line sensor camera LS in the DIR direction at a constant speed. It is assumed that data is continuously collected at fixed time intervals from when the line sensor camera LS or IC is detected until the IC finishes passing. Furthermore, from the starting point STA to the final point STP of a specific area of one line of the line sensor camera LS
is set, and the addition data in this area is stored in the memory circuit MEM.
Store in O.

Now, the IC is moving at a constant speed in the direction of DIR, and when it finishes moving, the memory circuit MEMO contains a histogram of H2 for lead P1, a histogram of H2 for lead P2, etc.
A histogram of lead H for lead P is obtained. This state is the histogram H3 for lead P in FIG. 1, which shows the horizontal axis frequency distribution of H with respect to the vertical axis constant time interval. P r 1+ to p rl indicate the point from no lead to present, P, l to Pf1 indicate the point from presence to no lead, respectively, ) ('rH indicates an arbitrary setting value.

Here, an arbitrary value H7, . is set for the addition result, and whether or not to read is determined based on this value. Here, the lead widths are prl~prl, Pr2~p, , , ,
p rl~P2. , and the lead spacing is Pf1 to P r
2. P12~Pr3+'...Pf3~Prll+
It becomes l+.

Therefore, the lead width and lead interval are set in advance and compared with certain criteria to determine the quality.

(Example 2) FIG. 2 is a principle diagram showing a second embodiment of the present invention.

-4 In Example 1, the explanation was made for one lead of the IC, but
Considering the size of the IC package, the number of bits per line of the line sensor camera, and the accuracy, it may be possible to detect data from both leads simultaneously6. Therefore, in this embodiment, the line sensor camera LS is specified. Area 5T
Two types of AI~5TP1 and 5TA1~5TP2 are provided,
The left and right leads of the IC are managed independently. This embodiment has the advantage that the left and right leads of the IC can be inspected at the same time.

〔Effect of the invention〕

As explained above, the present invention can shorten inspection time by collecting data in real time, and can also determine characteristic bends of individual leads, which can be expected to improve quality. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention, FIG. 2 is a principle diagram showing a second embodiment of the present invention, and FIG. 3 is a principle diagram showing a conventional example. LS...Line sensor camera COMP...Binarization circuit CT RL...Control circuit ADD...Addition circuit M
'EMO...Memory circuit JG...Judgment circuit STA
, 5TAI, 5TA2...Start point of specific area STP, 5TPI, 5TP2... End point of specific area IC...Integrated circuit package DIR...IC movement direction P+, P2, P3, P4, P+・...IC leads H+, H2, H3, H4, H+...Histogram P rl+ P r2+ P r3+ P
r4+ P rl"'Lead's point from nothing to existence p H, P t2. P f3+ P tl, P t
+...Point from presence to absence of lead H'ro...Arbitrary setting value Patent applicant: NEC Corporation

Claims (1)

[Claims] (1) means for binarizing one line of output from a line sensor camera that images an integrated circuit moving at a constant speed;
A means for setting a specific area within a line, a means for adding data in the specific area, a means for storing the addition result, and a means for comparing the addition result of each line with an arbitrarily set value to determine whether or not there is a lead. 1. A lead bending detection device comprising: means for detecting.