JP2648058B2 - Coplanarity measurement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coplanarity measuring method for measuring coplanarity of a lead terminal, which is a kind of visual inspection of a semiconductor device.

[0002]

2. Description of the Related Art FIG. 4 is a schematic plan view of an apparatus to which a conventional coplanarity measuring method for measuring coplanarity of a lead terminal of a semiconductor device is applied, and FIG.
FIG. 5 is an enlarged cross-sectional view of the case where the IC 3 to be measured is mounted on the device and cut along the line AA in FIG. 4.

The measurement stage 1 is made of a transparent resin 12 that transmits light and a non-transparent resin 13 that does not transmit light. The non-transparent resin 13 is formed so as to cover the lower part from the front end (the front end 11a of the measurement stage 1) of the side surface of the transparent resin 12.

Reference numeral 31 denotes a molded part of the IC 3 to be measured, and 32 denotes a lead terminal of the IC 3 to be measured. 21, 22, 23,
Reference numeral 24 denotes a camera for capturing an image of the lead terminal 32 of the IC 3 to be measured and measuring the coplanarity of the lead terminal 32, and is installed facing each side surface of the IC 3 to be measured.

Next, the operation will be described. First, the measured in order to measure the coplanarity of the lead terminals 32 I
C3 is mounted on the measurement stage 1. Then, light 4 is irradiated from below the measurement stage 1. Light 4 is transparent resin 1
2, but not through the non-permeable resin 13. Therefore, when the measurement stage 1 is viewed from the camera 21 direction,
As shown in FIG. 6, a shadow 32a of the lead terminal 32 and a shadow 13a of the non-transparent resin 13 are formed. Upper end of the shade 13a, i.e. non-transmissive resin 13 as above end 11a of the measuring stage 1 coincides with the reference line for the coplanarity measurement is provided. This image is captured by the camera 21 as a binarized image and the coplanarity 5 (the lower end of the shadow 32a and the measurement stage 1)
Calculating the above end 11a (i.e., baseline) distance between). If the coplanarity 5 is within a predetermined value, it is a good product, and if it is not larger than the predetermined value, it is a defective product.

[0006]

Since the conventional coplanarity is measured as described above, there are the following two problems.

First, if the coplanarity 5 is large as shown by the shadow 32a on the left side of FIG. 7, the coplanarity can be easily measured, but if the coplanarity 5 is small as shown on the right side, the interference of the light 4 will occur. The dark portion 32b is formed in the coplanarity 5 portion due to the shortage of the transmission amount, and the coplanarity 5 is erroneously measured.

[0008] Second, as shown in FIG.
3 (the flatness of the reference line 11b) is the impermeable resin 1.
3 by variations in manufacturing the upper end 11 of the measuring stage 1
This is a problem in that coplanarity cannot be measured correctly due to deviation from a. Note X is the reference line 11b and the upper end 1
1a.

The present invention has been made to solve the above problems, and has as its object to provide a coplanarity measuring method with high coplanarity measuring accuracy.

[0010]

A first aspect of the coplanarity measuring method according to the present invention is a coplanarity measuring method for measuring coplanarity of a lead terminal by setting a semiconductor device on a transparent stage. the baseline for the measurement is provided by downwardly a predetermined distance from the upper end of the transparent stage, the measured distance between the lead terminal and the reference line, the predetermined distance from the measured distance between the lead terminal and the reference line Is subtracted to calculate the coplanarity of the lead terminal.

[0011] A second aspect of the coplanarity measuring method according to the present invention is a coplanarity measuring method for measuring coplanarity of a lead terminal of a semiconductor device.
The amount of variation in the flatness of the reference line for coplanarity measurement is determined in advance for each lead terminal, the distance between the reference line and each lead terminal is measured, and the distance between each of the lead terminals and the reference line is measured. by correcting based on the measured distance to the variation amount of the corresponding and calculates the coplanarity of the respective lead terminals.

[0012]

[Action] In a first aspect of the coplanarity measurement method according to the present invention, provided below a predetermined distance from the upper end of the transparent stage reference line for coplanarity measurement, the distance between the lead terminals and the reference line The coplanarity of the lead terminal is calculated by measuring and subtracting the predetermined distance from the measured distance between the lead terminal and the reference line. Light for coplanarity measurement is sufficiently transmitted between the lines.

In a second aspect of the coplanarity measurement method according to the present invention, the variation in flatness of a reference line for coplanarity measurement is determined in advance for each lead terminal, and the reference amount is determined for each lead terminal. measure the distance between the line, since to calculate the coplanarity of the lead terminals by correcting based on the corresponding rose <br/> with weight measurement distance between each lead terminal and the reference line, the The measurement distance can be corrected based on the variation amount.

[0014]

FIG. 1 is a partially enlarged sectional view of a coplanarity measuring apparatus to which one embodiment of a coplanarity measuring method according to the present invention is applied. 5 is different from the conventional apparatus shown in FIG. 5 in that the position of the non-permeable resin 13 is lower than that in FIG.
This is to provide a reference line 11b intentionally lower than 1a and to increase the distance between the reference line 11b and the lead terminal 32. Other configurations are the same as those of the conventional device shown in FIG.

The basic operation is the same as in the prior art. Light 4 is irradiated from below the measurement stage 1. Since the light 4 is blocked by the presence of the non-transparent resin 13, a shadow 13b is formed. Since the position of the non-transparent resin 13 is lower than that of the conventional device, the appearance position of the shadow 32b is also lower than that of the conventional shadow 32a. Therefore, the reference line corresponds to the upper end of the shade 13b 11b
Of the measuring stage 1 by the distance 7a in FIG.
It is at a position lower than a. Therefore, the lower end of the shadow 32 a of the lead terminal 32 taken into the camera 21 and the reference line 11
The distance 7 with respect to b increases as shown in FIG. That is,
The coplanarity calculated based on the image captured by the camera 21 is larger than the original coplanarity 5. Upper end 1 of the reference line 11b is measurement stage 1
Since the coplanarity 5 is lower than 1a by the distance 7a, the original coplanarity 5 is obtained from (coplanarity 5) = (measured value 7)-(distance 7a).

According to the above embodiment, there is always a difference of 7 mm or more between the upper end 11a of the measurement stage 1 and the reference line 11b. For this reason, since the light 4 always passes by a certain amount or more, the space between the lower end of the shadow 32a and the reference line 11b does not become dark, and the coplanarity 5 can be measured accurately.

Next, another embodiment of the method for measuring coplanarity according to the present invention will be described. Reference line 11b corresponding to the upper end of the non-transmissive resin 13 is non-transmissive resin 13
Variations on the manufacture of the assumed that deviates from the upper end 11a of the measuring stage 1 as shown in FIG. In this case, in this embodiment, first, the upper end 11a of the reference line 11b
Is measured in advance. Then, the measured values are stored as correction values in a memory, for example, in a one-to-one correspondence with each of the lead terminals 32 as shown in FIG. Then, the coplanarity is actually measured for each lead terminal 32 in the same manner as in the related art, and then the correction value corresponding to the measurement lead terminal 32 is read from the memory, and the measured value is automatically measured in the measuring device based on the correction value. To calculate the true coplanarity. By doing so, it is possible to eliminate the influence of manufacturing variations of the non-permeable resin 13 and to increase the coplanarity measurement accuracy. In this embodiment, the correction values are stored in the memory, and the correction values are read out from the memory to perform the correction. However, the correction values may be listed, and the correction may be performed artificially based on the table. Further, in the above-described embodiment, the reference of the flatness variation amount is the tip 11a of the measurement stage 1, but may be a horizontal line at any position.

[0018]

According to a first aspect of the coplanarity measurement method according to the present invention as described above, according to the present invention, by a predetermined distance from the upper end of the transparent stage a reference line for the coplanarity measurement provided below, lead The distance between the lead terminal and the actual reference line is calculated by measuring the distance between the terminal and the reference line and calculating the copsenality of the lead terminal by subtracting the predetermined distance from the measured distance between the lead terminal and the reference line. Is not reduced, and light for coplanarity measurement is sufficiently transmitted between the lead terminal and the reference line. As a result, coplanarity can be accurately measured.

According to the second aspect of the coplanarity measuring method, the amount of variation in the flatness of the reference line for measuring coplanarity is obtained in advance for each lead terminal, and the amount of variation in the flatness is determined for each lead terminal. distance was measured. Thus to calculate the coplanarity of the lead terminals by correcting on the basis of the corresponding amount of variation of the measured distance between the lead terminals and the reference line, based on the measured distance to the amount of variation Can be corrected. As a result, coplanarity can be accurately measured.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining one embodiment of a coplanarity measuring method according to the present invention.

FIG. 2 is a diagram for explaining an embodiment of a coplanarity measuring method according to the present invention.

FIG. 3 is a diagram for explaining another embodiment of the method for measuring coplanarity according to the present invention.

FIG. 4 is an external plan view of a conventional coplanarity measuring device.

FIG. 5 is a partially enlarged sectional view of FIG. 4;

FIG. 6 is a diagram for explaining a conventional coplanarity measuring method.

FIG. 7 is a diagram for explaining a problem of a conventional coplanarity measuring method.

FIG. 8 is a diagram for explaining a problem of a conventional coplanarity measuring method.

[Explanation of symbols]

 11a Ideal reference line 11b Actual reference line 32 Lead terminal

Claims (2)

(57) [Claims] 1. A coplanarity measurement method to set the semiconductor device on a transparent stage measures the coplanarity of the lead terminals, the reference line for the coplanarity measurement downward by a predetermined distance from the upper end of the transparent stage And measuring a distance between the lead terminal and the reference line, and calculating a coplanarity of the lead terminal by subtracting the predetermined distance from a measured distance between the lead terminal and the reference line. Liability measurement method. 2. A coplanarity measuring method for measuring coplanarity of a lead terminal of a semiconductor device, wherein a variation amount of flatness of a reference line for coplanarity measurement is obtained in advance for each lead terminal. the distance between the reference line is measured every calculated coplanarity of the respective lead terminals by correcting, based the on corresponding <br/> the variation amount of the measured distance between the reference line and each of the lead terminals A coplanarity measurement method.