JP2916447B2 - IC package lead pin inspection method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC package lead pin inspection method and apparatus, and more particularly, to an IC package lead pin inspection method and apparatus for inspecting the alignment of lead pins of a flat IC package.

[0002]

2. Description of the Related Art Generally, a QFP (Quad) shown in FIG.
Flat type IC package 1 such as Flat Package)
0 includes a main body 11 and a number of lead pins 12 arranged on the side surface of the main body 11. The lead pin 12 is
As shown in the drawing, an extension 121 protruding from the package body 11 in the lateral direction, an inclined portion 122 inclined downward at a predetermined angle from the extension 121, and a lateral direction again from the inclined portion 122. And an extended end 123.

When the IC package 10 is mounted on a printed circuit board (not shown), if the alignment of the position, direction, interval, height, etc. of the lead pins 12 is not uniform, the lead pins 12 can be accurately mounted on the circuit board. Cannot contact. That is, if the alignment of the lead pins 12 is not uniform,
When the IC package 10 is mounted on a board, as shown in FIG. 2, lead pins 12 that cannot contact the circuit board 1 are generated, so that appropriate soldering is not performed. Therefore, I
Before the C package is mounted on the board, the alignment of the lead pins is inspected. The alignment of the lead pins can be determined by measuring the coplanarity indicating the degree to which the lead pins are located on the same plane. be able to.

Referring to FIGS. 3 and 4, a conventional lead pin inspection device for measuring the coplanarity includes a suction nozzle 111 for sucking the IC package 10 and an IC that is sucked by the suction nozzle 111. A light-emitting sensor 120 and a light-receiving sensor 130 which are provided to face each other across the row of the lead pins 12 of the package 10;
A controller 140 that detects the alignment state of the lead pins 12 by measuring the amount of light emitted from the light source 20 and passing between the lead pins 12 and reaching the light receiving sensor 130.
It is comprised including.

[0005] The I sucked by the suction nozzle 111
The C package 10 is moved and aligned between the light emitting sensor 120 and the light receiving sensor 130. In this state, light is emitted from the light emitting sensor 120 to the light receiving sensor 130. At this time, if the alignment state of the lead pins 12 is not uniform and the height deviation is large, the amount of light shielded by the lead pins 12 increases, and the amount of light reaching the light receiving sensor 130 decreases. Therefore, the coplanarity of the lead pins 12 of the IC package 10 can be measured by measuring the amount of light reaching the light receiving sensor 130.

However, the conventional IC as described above
In a package lead pin inspection apparatus, an accurate inspection result cannot be obtained unless the side surfaces of the body of the IC package to be inspected and the arrangement lines of the tip ends of the lead pins are basically parallel to each other. However, in the actual inspection process, it is not easy to satisfy the above conditions, so that the accuracy of the inspection is reduced.

Further, as shown in FIG. 5, the IC package 10 is not parallel to the optical axis by the suction nozzle 111 and has an angle.
(θ), even if the alignment state of the lead pins 12 is uniform, the inclined portions 122 of the lead pins 12
A region (B) where light is blocked is formed by (see FIG. 1). Therefore, the amount of light received by the light receiving sensor 130 decreases. According to the conventional lead pin inspection method, the absolute value of the amount of light received by the light receiving sensor is compared with a reference value to determine whether or not the alignment state of the lead pins is good. In some cases, it is determined as defective regardless of the alignment state of the lead pins, and the reliability of the inspection is reduced.

[0008]

SUMMARY OF THE INVENTION The present invention has been devised to solve the above-mentioned problems, and has a flat type I-type.
It is an object of the present invention to provide a method and an apparatus for inspecting lead pins of an IC package, which improve the precision and efficiency of inspection for alignment of lead pins of a C package.

[0009]

According to an aspect of the present invention, there is provided an IC package lead pin inspection apparatus movably and rotatably provided for picking up an IC package to be inspected. At least three pairs of light-emitting sensors and light-receiving sensors provided so as to face each other across the lead pin row of the package, and the amount of light emitted from each light-emitting sensor and reaching each of the light-receiving sensors after passing between the lead pins A controller for checking the alignment of the lead pins by measuring
The optical axis formed by each of the light emitting and light receiving sensors is
It intersects at an angle to each other.

According to another aspect of the present invention, there is provided a method of inspecting a lead pin of an IC package, the lead pin including at least three pairs of light-emitting and light-receiving sensors provided so as to face each other across the lead pin row of the IC package. In a method for inspecting a lead pin of an IC package using an inspection device, a step of positioning an IC package between the light emitting and light receiving sensors, and a step of emitting light from the light emitting sensor and passing between lead pins of the IC package to the light receiving sensor. Measuring the amount of light that reaches, obtaining a function with the angle between each optical axis formed by each of the light emitting sensor and the light receiving sensor and the amount of light blocked by the lead pin as a variable, and minimizing the function. Determining a value and a minimum optical axis angle, and comparing a maximum received light amount corresponding to the minimum optical axis angle with a reference value. Characterized in that it comprises a step of inspecting the alignment of the lead pin to.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in more detail with reference to the accompanying drawings. FIG.
Referring to FIG. 7, a lead pin inspection apparatus according to the present invention includes a suction nozzle 211 movably provided to suck and pick up an IC package 10, and a lead pin of the IC package 10 sucked by the suction nozzle 211. At least three pairs of light-emitting sensors 221/2 provided so as to correspond to each other in the arrangement direction with 12 rows interposed therebetween.
22.223 and light receiving sensors 231,232,233
After the light emitted from the light emitting sensors 221, 222, 223 and passed between the lead pins 12, the amount of light reaching the light receiving sensors 231, 232, 233 is measured to check the alignment of the lead pins 12. Controller 24
0.

The optical axis formed by the light emitting sensors 222 and 232 and the light receiving sensors 223 and 233 is inclined by an angle (θ) with respect to the optical axis formed by the light emitting and light receiving sensors 221 and 231. Therefore, the respective optical axes intersect at one point (F). Reference numeral 2 in FIG.
Reference numeral 10 denotes a head unit that supports the suction nozzle 211 so that it can get on and off and rotate.
When the inspection of one lead pin 12 is completed, the head unit 210 moves or rotates the suction nozzle 211 to inspect the lead pin on the other side.

On the other hand, the head section 210 is, for example, XY
It is provided so that it can be moved freely by a robot or an articulated robot. Reference numerals 220 and 230 are support members for supporting the light-emitting sensors 221, 222, 223 and the light-receiving sensors 231, 232, 233, respectively.

The IC of the present invention having the above-described configuration
In operation of the package lead pin inspection device, when the IC package 10 to be inspected is aligned on a station (not shown) of a normal component supply device such as a bowl feeder or a linear feeder, the IC package 10 is provided at the station. The head unit 110 is moved to the station by a signal of a sensor (not shown).
The IC package 10 descends to adsorb and pick up the IC package 10.

The IC package 10 thus adsorbed
The light emission sensor 2 is
21, 222, 223 and light receiving sensors 231, 232.2
It is aligned with the inspection area between 33. According to a feature of the present invention, even if the IC package 10 is not accurately sucked by the suction nozzle 211, the plurality of light receiving sensors 231, 232.2, and
The maximum light receiving point can be searched for using the received light amount received by the variable 33 as a variable. This will be described in more detail with reference to FIG. 8, which shows a lead pin inspection apparatus having three pairs of light emission and light reception sensors.

As shown in FIG. 8, the IC package 10
Is not accurately adsorbed by the suction nozzle 211, the light amounts reaching the light receiving sensors 231, 232, and 233 are different. Therefore, the following quadratic function is defined by using the angles θ ゜, 0 °, -θ の of each optical axis and the respective light shielding amounts F (θ ゜), F (0 °), F (-θ ゜) as variables. You can ask. F (θ) = aθ ² + b
θ + c

Here, a, b, and c are coefficients determined by the angle of the optical axis and the light shielding amount. From the above function,
When the minimum light shielding angle θ = −b / 2a, the minimum light shielding amount (L) is
As shown in FIG. 9, it was found that cb ² / 4a, which indicates the maximum light receiving angle. If the minimum light shielding angle θ = −b / 2a does not exist between −θ ゜ and θ ゜, a smaller value of F (θ ゜) and F (-θ ゜) becomes the minimum light shielding amount. .

The minimum light receiving angle is a maximum light receiving angle, and the maximum light receiving angle is a value representative of the coplanarity of the lead pin to be inspected. Will be inspected. That is, according to the present invention, regardless of the installation state of the IC package, a function is obtained by using values measured by a large number of light emission and light reception sensors as variables, and the maximum light reception angle and the maximum light reception amount are searched for from the functions, and the values are obtained. Inspect the alignment of the lead pins. Therefore,
Since the maximum amount of received light is always constant, the inspection reliability of the lead pin can be improved. In the present embodiment,
Although a quadratic function is induced by three pairs of light-emitting and light-receiving sensors, a higher-order function may be induced when a plurality of light-emitting and light-receiving sensors are employed.

[0019]

As described above, the method and apparatus for inspecting the lead pins of an IC package according to the present invention can improve the precision and efficiency of the inspection of the lead pins regardless of the positional error of the IC package sucked by the suction nozzle.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a general flat type IC package.

FIG. 2 is a schematic cross-sectional view showing a state in which a flat type IC package is mounted on a substrate.

FIG. 3 is a schematic perspective view showing a conventional IC package lead pin inspection apparatus.

FIG. 4 is a side view showing the conventional IC package lead pin inspection apparatus shown in FIG. 3;

FIG. 5 is a schematic plan view for explaining the operation of the conventional IC package shown in FIG.

FIG. 6 is a perspective view showing an IC package lead pin inspection apparatus according to the present invention.

FIG. 7 is a plan view showing a lead pin inspection device for an IC package according to the present invention.

FIG. 8 is a schematic plan view for explaining the operation of the IC package lead pin inspection device according to the present invention.

FIG. 9 is a graph showing a function obtained by the IC package lead pin inspection method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 IC package 11 Main body 12 Lead pin 121 Extension part 122 Inclined part 123 End part 130 Light receiving sensor 211 Suction nozzle 211, 222, 223 Light emitting sensor 231, 232, 233 Light receiving sensor

Claims (5)

(57) [Claims] 1. A supporting means movably and rotatably provided for picking up an IC package to be inspected, at least three pairs of light emitting sensors provided so as to face each other across a lead pin array of the IC package, and a light receiving sensor, after passing between the lead pins are emitted from the respective light-emitting sensor, seen including a controller for checking the alignment of the lead pins by measuring the amount of light reaching the the respective light receiving sensors, each The optical axes formed by the light emitting and receiving sensors are mutually
A lead pin inspection device for an IC package characterized by intersecting at an angle . 2. A lead pin inspection system of an IC package according to claim 1, characterized in that intersecting the optical axis at a single point. 3. A lead pin inspection method for an IC package using a lead pin inspection device including at least three pairs of light emission and light reception sensors provided so as to face each other across a lead pin row of the IC package, wherein the light emission and light reception sensors are provided. Positioning the IC package between; and measuring the amount of light emitted from the light emitting sensor and passing between the lead pins of the IC package and reaching the light receiving sensor; and forming the light emitting sensor and the light receiving sensor. Obtaining a function with the angle between each optical axis to be controlled and the amount of light blocked by the lead pin as a variable; obtaining a minimum value and a minimum optical axis angle of the function; and a maximum corresponding to the minimum optical axis angle. Inspecting the alignment of the lead pins by comparing the amount of received light with a reference value. The lead pin inspection method. 4. The lead pin inspection system of an IC package according to claim 3, characterized in that intersecting the optical axis at a single point. Wherein said light emitting and light receiving sensors are each three pairs, the lead pin testing of the IC package of claim 3, wherein the function is a quadratic function.