JPH05203415A - Method for setting check area on plural lands - Google Patents

Abstract

PURPOSE:To obtain a means which is suitable for setting a group of check areas on a plurality of lands. CONSTITUTION:At the time of setting a plurality of check areas CA corresponding to a plurality of lands 12 on a substrate 1 one to one by taking the lands 12 in the visual field V of a camera, the check areas CA are arranged based on the data used at the time of forming the lands 12 and an arbitrary area CA is selected out of the check areas CA. Then the selected area CA is moved to and superimposed upon one of the lands 12 from its original position HP by scanning in the visual field V and the shifted amount (DELTAX', DELTAY') of the area CA to the superimposed position CP from the original position HP is found. The other check areas CA are respectively superimposed upon the other lands 12 by the shifted amount (DELTAX', DELTAY').

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for setting a check area for a plurality of lands, and more particularly to a land for a chip such as a mini transistor or a rectangular chip such as a resistor or a capacitor among lands formed on a substrate. The present invention relates to a means that is preferably used when visual inspection of the soldering state is carried out by taking in a plurality of fields of view.

[0002]

2. Description of the Related Art In order to inspect whether or not the leads of a chip, such as an IC, an LSI, a capacitor chip and a resistor, are bonded to a land of a substrate by soldering, and then the leads of the chip are well bonded to the land. In addition, a visual inspection of the solder is conducted in the vicinity of the overlapping portion of the chip lead and the land.

Conventionally, such visual inspection has been performed by visual inspection by an operator, but in recent years, automatic inspection by a camera has begun. In order to carry out automatic inspection by this camera, it is necessary to set a check area within the field of view of the camera. Moreover, it is necessary to set a large number of check areas corresponding to a large number of lands on a one-to-one basis and align each of these check areas with a predetermined position of the corresponding land.

Here, when setting the check area for performing the above-mentioned automatic inspection, conventionally, the substrate on which the chip is actually mounted is selected as the master substrate from among the substrates on which the chip is actually mounted, and the operator selects it. While checking the camera image of this master board on a monitor, etc., scan the check area, align each check area with each of the solders of the multiple overlapping parts, and set the coordinates of the check area. Had set.

[0005]

However, there is a problem that the above-mentioned means is extremely complicated and requires a great deal of labor and time. Furthermore, the shape and position of the solder bonded to the board vary widely, so even if you select a master board and set a check area based on this, this check area will actually It does not always match well with the solder of another substrate, and there is a risk that the appearance of the solder may be erroneously determined due to a mismatch.

By the way, the land of the substrate is formed by a precise means such as etching, and the reliability of its positional accuracy is extremely high.

In view of the above points, the present invention makes it possible to accurately set the check area for the visual inspection of the solder at a high speed with reference to the land of the board. An object of the present invention is to provide a suitable means for taking a plurality of lands in the field of view and setting a check area group corresponding to these lands on a one-to-one basis.

[0008]

To this end, the present invention takes in a plurality of lands of a substrate in the field of view of a camera and sets a plurality of check areas corresponding to these lands one to one. The process of arranging a plurality of check areas based on the data when the plurality of lands are formed, the process of selecting an arbitrary check area among the check areas, and the selected check area The process of scanning from the original position within the field of view and overlapping it with the land, the process of obtaining the shift amount from the original position of this check area to the overlapping position, and the other check areas only with this shift amount A process of moving and polymerizing on each of the plurality of lands is configured.

[0009]

According to the above structure, the check area is accurately set by using the land with high reliability of position accuracy, and the shift amount of the selected check area is used for the movement of other check areas. Therefore, it is not necessary to scan each of the plurality of check areas one by one, and the setting of the check areas can be completed at high speed.

[0010]

Embodiments will be described with reference to the drawings. FIG. 1 is a plan view of the substrate 1.

A portion A is a group of lands 12 to which leads 14 of square chips such as resistors and capacitors and chips 13 such as minitransistors are soldered 15. Also, part B is S
The lead 24 of the OP chip 23 is a group of lands 22 to which solder 25 is attached. The section B is composed of a land row B1 and a land row B2 formed in parallel. Further, the C portion is a land 32 group to which the leads 34 of the QFP chip 33 are soldered. In the C portion, the land row C1 and the land row C3 are formed in parallel in the lateral direction (X direction), and the land row C2 is formed.
And the land row C4 are formed in parallel in the vertical direction (Y direction).

These lands 12, 22, 32 are precisely formed on the substrate 1 by etching, and the reliability of their shape dimensions and positional relationship is extremely high. In addition,
The X-axis and the Y-axis shown in the figure are the lands 12, 22, 3
2 are the horizontal axis and the vertical axis of the land coordinate system XY.

By the way, the chips 13, 23 and 33 are
Positions are corrected in a chip mounter (not shown) with reference to the land coordinate system XY, and then the leads 14, 2 are
4, 34 are mounted on the lands 12, 22, 32. Here, in the chip mounting process, mount data and chip data are given in advance as known data. Of these, the chip data includes chip size data for each product type and the number of leads. The dimension data of this chip mounter (in particular, the distances 11, ..., 16 between the vertical and horizontal leads 34 tip portions) are referred to when the check area CC is set for the group 32 of lands 32 described later.

In all the embodiments described below, the land coordinate system XY and the check area coordinate system X'-Y 'are set to be parallel to each other without any displacement in the rotational direction.

(Embodiment 1) FIG. 2 shows a land 1 of the above-mentioned section A.
The image which captured the 2nd group in the visual field V of a camera (not shown) is shown.
CA is a check area. Since the reliability of the positional relationship of the lands 12 is extremely high, the check area coordinate system X '
The distance (X1, X2, Y1 in FIG. 2) between the check areas CA in −Y ′ is determined by using the design data for forming the land 12 as it is.

A method of setting the check area CA for the portion A will be described. First, as described above, a plurality of lands 12 are incorporated in the visual field V. Next, these land 12
It is determined whether or not all of the check marks overlap one-on-one with the entire check area CA. Whether or not one check area CA has overlapped with the land is determined by the fact that the check area CA gradually becomes brighter due to the reflected light from the land 12 as the check area CA is moved (this is more specific). Specifically, it is sufficient to confirm that the number of pixels (not shown) in the check area CA (not shown) that have reacted to light has increased and then converged (hereinafter referred to as polymerization confirmation). This means for confirming polymerization is also used in the examples relating to parts B and C described later.

Now, in the above, all check areas CA
If is overlapped with the land 12, the setting is completed. If not, as shown in FIG. 3, any one check area CA is selected from the plurality of check areas CA. Then, the selected check area CA is scanned from the original position HP within the field of view V on the check area coordinate system X′-Y ′. When this scanning is performed and the overlapping confirmation can be performed, the shift amount (ΔX ′, ΔY ′) from the original position HP to the position CP where the overlapping confirmation can be performed is stored in the check area coordinate system X′-Y ′.

Next, another shift area CA is set in the check area coordinate system X'-Y ', and this shift amount (Δ
X ', ΔY') shift. As a result, when it is possible to confirm the overlap in all the check areas CA, the setting is completed. If not, the selected check area CA does not overlap the land 12 (for example, as shown in FIG.
In the above, the check area CA on the upper left has overlapped with the land 12 on the right side thereof (for example). However, it is certain that the land 12 is superposed on one of the plurality of lands 12, and the positional relationship between the lands 12 is known as described above. Therefore, the superposition can be easily corrected to confirm the superposition in all the check areas CA. In the present embodiment, the case where the entire check area CA is checked for superposition is explained, but in the case shown in FIG. 2, it is necessary and sufficient to check the superposition of the upper left and lower right check areas CA, for example. The process for the area CA may be omitted. That is, the present means is not limited to the case of performing the polymerization confirmation for all the check areas CA, and includes the case of performing the polymerization confirmation for only the necessary and sufficient check areas CA.

As described above, in this embodiment, at least one check area CA among the plurality of check areas CA may be scanned to obtain the shift amount, and it is not necessary to scan the plurality of check areas CA one by one. Therefore, the labor and time required for setting the check area can be significantly reduced, and the setting can be completed at high speed.
Moreover, since the distance between the check areas CA is set based on the data of the land 12 having high reliability, even if most of the scanning is omitted as described above, the set check area CA will be the land. It is unlikely that the polymer does not polymerize well into 12.

(Embodiment 2) FIG. 4 shows an image in which the group of lands 22 in the portion B of FIG. 1 is taken into the visual field V of the camera. This B
The group is a land group of the SOP chip 23, and the land 22 groups are arranged in parallel so that each of the leads 24 group of the SOP chip 23 can be mounted. In addition, the X'axis of the check area coordinate system X'-Y 'on the visual field V side of the camera is
The land 22 is set parallel to the column direction. CB is a check area.

A method of setting the check area CB in the X'axis direction (land row direction) of the check area coordinate system of the land 22 group will be described. First, of the number m of lands 22 formed in a row, an appropriate number n (n = 4 in this embodiment) is set.

Next, in the check area CB, the start position S1 (X ',
Y ') = (X'0, Y'C). Then, the check area CB is directed toward the row of the lands 22 and scanning is performed in parallel with the row direction of the lands 22 (in the X ′ axis direction). Then, if the above-mentioned overlap confirmation can be confirmed for the first land 22 and the check area CB, the coordinates (X ′, Y ′) at this time = (X ′
1, Y′C) is stored. The same process is repeated for the second and subsequent lands, and the n-th land 22 set as described above is repeated.
When the superposition of the check area CB is confirmed, the scanning of the check area CB is finished.

The first coordinate (X'1, Y'C)
Shift amount S from the to the n-th coordinate (X'4, Y'C)
The pitch P = SX ÷ (n−1) between the lands 22 is obtained from X (SX = (X′4−X′1)).

Based on this pitch P, the set coordinates (land row direction) in the coordinate system X'-Y 'of the check area CB are (X', Y ') = (X'1, Y'C). ，
(X'1 + P, Y'C), ..., (X'1 + P (m-
1), Y'C).

First, in the same manner as above, the check area C
B is 1 at the start position S1 (X ′, Y ′) = (X′0, Y′C) on the outer side of the land 22 (on the left side in FIG. 4).
The coordinates (X ', Y') of the th land 22 = (X'1,
Y′C) is stored and the start position S2 (X ′, Y ′) = (X′X,
Y′C) (where X′X> X′M), the coordinates (X ′, Y ′) of the m-th land 22 = (X′M, Y′C)
And the pitch P = (X′M−X′0) ÷ (m−1)
The pitch P may be obtained from the above to determine the set coordinates in the coordinate system X′-Y ′ of the check area CB.

As described above, only a part of the 22 rows of lands is actually measured by checking the overlap of the check areas CB, and the coordinates (land row direction) of all the check areas CB are set. Can be set. As described above, the accuracy of the position and shape of the land 22 row is very high. Therefore, even if only a part of the land 22 row is actually measured and the other land 22 is omitted, the coordinates of the special check area CB The accuracy does not decrease.

(Embodiment 3) FIG. 5 shows the land 2 of the B section.
Longitudinal direction of 2 groups (Y'axis direction of check area coordinate system)
5 is an explanatory diagram of a setting method of a check area CB of FIG.

First, based on the shape data of the SOP chip 23, the upper row B1 and the lower row B2 of the land 22 are respectively set.
An interval t in the Y'axis direction between the check areas CB and CB 'to be superposed is determined. That is, this interval t
Leads 24 and 2 extending in opposite directions from both sides of the
It is set to be approximately the same as the distance between the tip portions of No. 4. And Y '
2 in the axial direction (longitudinal direction of the land) with this interval t
Two check areas CB ′, CB are taken, and these check areas CB ′, CB are respectively shown in FIG.
Scan until the upper row B1 and the lower row B2 can be confirmed as overlapping.
Thereby, based on the shape data of the chip 23, one of the two check areas CB and CB ′ spaced at a distance t in the longitudinal direction of the land 22 is overlapped with the land 22 in the upper row B1. At the same time, the other check area CB is overlapped with the land 22 in the lower row B2.

Here, when it is possible to confirm the overlap, it is certain that the check areas CB 'and CB are overlapped on the upper row B1 and the lower row B2 of the lands 22 at the intervals t, respectively. However, the check areas CB ′ and CB are located in the upper row B1 and the lower row B2 of the land 22 and the SOP chip 2
3 is not always in the matching position with respect to the tip of the lead 24 or the solder 25. Therefore, next, a method of aligning the check areas CB ′ and CB with this matching position, that is,
A method of setting the coordinates of the check areas CB and CB 'in the Y'axis direction (land longitudinal direction) will be described.

First, in the check area coordinate system X'-Y ', the lower edge 22a of the land 22 in the upper row B1 and the lower row B are shown.
X'at a convenient position between the upper edge 22b of the second land 22 and
A reference line 1 parallel to the axis is provided. In addition, check area C
When B and CB 'are in contact with the reference line 1, the check areas CB and CB' are completely off the land 22.

Here, the check areas CB and CB 'are
Although they are overlapped at appropriate positions on the lands 22 in the lower row B2 and the upper row B1 with the above interval t, the coordinates (X ′, Y ′) = (X′1, Y ′S) at that time are stored. I'll do it.
Next, the check area CB overlapping the land 22 in the lower row B2 is moved upward in the longitudinal direction of the land 22,
First, it is completely removed from the land 22 and aligned with the reference line l, and then the check area CB is moved downward so that the check area C is attached to the upper edge 22b of the land 22 in the lower row B2.
Match the upper edge CB1 of B. The coordinates at that time (X ',
Y ') = (X'1, Y'E) is stored.

Similarly, with respect to the check area CB 'overlapping the land 22 in the upper row B1, the coordinates (X', Y ') = (X'4, which are appropriately overlapped with the land 22 first).
Y'S ') is stored, then the check area CB' is moved downward until it contacts the reference line l, and then the lower edge CB'2 of this check area CB 'is the lower edge 22a of the land 22 in the upper row. Move upward until it touches. The coordinates (X ', Y') = (X'4, Y'E ') at that time are stored.

Then, the shift amount SY is obtained from the following equation. SY = {(Y'E-Y'S) + (Y'E'-Y'S ')} / 2 Next, each of the check areas CB and CB' is checked area coordinate system X'by this shift amount SY. -In Y ', move in the Y'axis direction. Then, the check areas CB and CB ′ are located at the tips of the leads 23 of the SOP chip 23 and the positions matching the solder 25. In addition,
In the above description, the reference line 1 is provided and the check areas CB and CB ′ are moved until they come into contact with the line 1. However, the present means is not limited to this, and the check areas CB and CB ′ are once moved from the land 22. It may be removed, and the positions where the check areas CB and CB ′ are removed may be changed for convenience.

That is, the two check areas CB and C
Each of B ′ is moved in one direction in the longitudinal direction of the land 22 to be temporarily removed from the land 22, and is moved in the opposite direction to the above-mentioned one direction so that the end edges 22a and 22b of the land 22 are aligned with each other. From the shape data of the chip 23, the coordinates of the check areas CB and CB ′ in the longitudinal direction of the land 22 are set.

According to the third embodiment, with respect to the longitudinal direction of the land 22, the check areas CB and CB 'can be set quickly and easily with reference to the land 22. Also S
Since the shape data of the OP chip 23 is also taken into consideration, the SOP chip 2 in which the length of the lead 25 is different from that of the land 22 group of the same type
In the case of mounting No. 3, it is possible to deal flexibly and accurately by changing the interval t.

In the third embodiment, the method of temporarily removing the check areas CB and CB 'from the land 22 when setting the coordinates of the check areas CB and CB' in the Y'axis direction (land longitudinal direction) has been described. .. However, this means is not limited to this, and the check areas CB, C
Without removing B ′ from the land 22, the edge 22 of the land 22
This also includes the case of obtaining the positions of a and 22b. In this case, the check area CB is moved as shown by a broken line arrow S in the partially enlarged view of the lower part of FIG. 5 (on the side of the row B2). Specifically, first, the check area CB is (X ',
Y ′) = (X′1, Y ′S) at the land 2
The number of pixels that captures 2 is counted, and then the check area CB is moved parallel to the Y ′ axis (the arrow S), and when the number of pixels before the movement is slightly reduced, the check area C
It is sufficient to stop the movement of B and obtain the Y ′ coordinate Y′E of that position. Of course, regarding the land row B1 in the upper part of FIG.
Similarly, the Y'coordinate Y'E can be obtained. The following processing is as described above.

(Embodiment 4) FIG. 6 shows an image in which the group of lands 32 of the portion C in FIG. 1 is taken in the visual fields V1, V2, V3 and V4 of the camera. The C section is a group of lands 32 of the QFP chip 33, and the group of lands 32 is the QFP chip 3
The land rows C1, C2, C3, and C4 arranged in parallel and facing each other are arranged so as to be orthogonal to each other vertically and horizontally so that each of the three leads 34 can be mounted. Further, the X'axis (horizontal axis) and the Y'axis (vertical axis) of the check area coordinates X'-Y 'are set to be parallel to these land rows C1, C2, C3, C4.

Then, a land row C1 parallel to the X'axis,
For each of the land rows C4 parallel to the Y ′ axis, the check area C in the land row direction is provided as in the second embodiment.
Set C. As a result, including the measured values of the land 32, the X ′ coordinate sequence (X′1, X′2, ..., X ′) shown in FIG.
5) and the Y'coordinate sequence (Y'1, Y'2, ..., Y'5) can be obtained. Note that S3 and S4 are start positions. That is, the check areas CC are set at the start positions S3 and S4 on the outer sides of the land rows C4 parallel to the vertical axis Y ′ and the land row C1 parallel to the horizontal axis X ′. Scan in the direction.

Next, the coordinates of the check area CC in the longitudinal direction of the land row in FIG. 6 are set. That is, from the dimension data of the QFP chip 33, the distances 11 and 1 shown in FIG.
Calculate 2,13,14,15.

The Y'coordinate of the check area CC of the visual field V1 is Y'0 which is separated from Y'1 by 12 in the negative direction,
The X'coordinate of the check area CC of the visual field V2 is X'0, which is separated from X'1 by 11 in the negative direction. Also, the field of view V
The X'coordinate of the check area CC of No. 4 becomes X'6 which is separated from X'5 by 13 in the positive direction, and the Y'coordinate of the check area CC of the visual field V3 is separated from Y'5 by 15 in the positive direction. It becomes Y'6. This means that the coordinates of the check area CC could be set after actually measuring the lands 32 for all of the lands 32 of the QFP chip 33.

That is, from the coordinates when the check area CC overlaps with a part of each of the land rows C1 and C4,
The pitch P between the lands 32 is obtained, and based on this pitch P, the land row direction of the check area CC group corresponding to the land row C4 parallel to the vertical axis Y'and the land row C1 parallel to the horizontal axis X '. The coordinates are set. Then, the coordinates in the longitudinal direction of the check area CC group are set from the coordinates in the land row direction of the check area CC group and the dimension data of the chip 33.

In the present embodiment, the check area CC is scanned in a direction (column direction) which traverses the 32 rows of lands to obtain the actually measured values of the lands 32, and the dimensional data of the QFP chip 33 is referred to for checking the check areas. CC was set. Therefore, in general, the check area can be set quickly and easily without visually observing the C portion including a large number of lands 32.

[0043]

As described above, according to the present invention, a plurality of lands of a substrate are taken in the field of view of a camera and a plurality of check areas corresponding to these lands are set one by one. The process of arranging the individual check areas based on the data when the plurality of lands are formed, the process of selecting an arbitrary check area among the check areas, and the selected check area are also included. The process of scanning the above field of view from the position of and to overlap with the land, the process of obtaining the shift amount from the original position of this check area to the overlap position, and other check areas are moved by this shift amount. Since a process for superimposing on each of the above-mentioned multiple lands was configured, the land with high reliability of position accuracy can be used to accurately perform the check error. There is set, and since it is possible to omit the scanning of the check area other than the selected check area, it is possible to set a plurality of check areas in one-to-one correspondence to the plurality of lands quickly.

[Brief description of drawings]

FIG. 1 is a plan view of a substrate of the present invention.

FIG. 2 is an explanatory diagram of the check area CA.

[Figure 3] Enlarged view

FIG. 4 is an explanatory diagram of the check area CB.

FIG. 5 is an explanatory diagram of the check area CB.

FIG. 6 is an explanatory diagram of the check area CC.

[Explanation of symbols]

 V field of view 1 substrate 12 land CA check area ΔX ′ shift amount ΔY ′ shift amount HP original position CP overlapping position

Claims (1)

[Claims] 1. When capturing a plurality of lands of a substrate in a field of view of a camera and setting a plurality of check areas corresponding to these lands on a one-to-one basis, the plurality of check areas are set to the plurality of check areas. The process of arranging based on the data when the land was formed, the process of selecting an arbitrary check area from the above check areas, and scanning the selected check area from its original position within the above field of view. On the land, and the process of obtaining the shift amount from the original position of this check area to the overlapped position, and other check areas are moved by this shift amount to each of the above lands. A method for setting a check area for a plurality of lands, characterized by comprising a process of overlapping.