JP3089786B2 - Check area setting method for multiple lands - Google Patents

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 of a plurality of lands, and more particularly, to a method of setting a land for a chip such as a square chip such as a resistor or a capacitor or a mini transistor among lands formed on a substrate. The present invention relates to a means which is preferably used when a plurality of pieces are taken in a visual field and the appearance of a soldered state is inspected.

[0002]

2. Description of the Related Art After bonding chip leads such as ICs, LSIs, capacitor chips, and resistors to lands on a substrate by soldering, it is necessary to inspect whether the chip leads are well bonded to the lands. In addition, a solder appearance inspection is performed in the vicinity of a portion where a chip lead and a land overlap.

Conventionally, such visual inspection has been carried out by visual inspection by an operator, but in recent years, automatic inspection by a camera has begun. When performing an automatic inspection using this camera, it is necessary to set a check area within the field of view of the camera. In addition, it is necessary to set a large number of check areas corresponding to one land on a large number of lands, and to match each of these check areas to a predetermined position of the corresponding land.

Here, when setting a check area for performing the above-mentioned automatic inspection, conventionally, a board on which a chip is properly mounted among boards on which the chip is actually mounted is selected as a master board, and an operator is required to select the master board. While checking the camera image of the master board with a monitor or the like, the check area is scanned, and each check area is aligned with each of a large number of the solders of the overlapping portion, and the coordinates of the check area are adjusted. Was 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 size and position of the solder adhered to the board vary widely, so even if a master board is selected and a check area is set based on this, this check area will actually Therefore, the appearance of the solder may be erroneously determined due to poor matching.

The lands of the substrate are formed by precise means such as etching, and the reliability of the positional accuracy is extremely high.

In view of the above, the present invention allows a check area for inspecting the appearance of solder to be set at high speed and accurately with reference to the land of the board. It is an object of the present invention to provide a means suitable for taking in a plurality of lands in a field of view and setting a check area group corresponding to these lands on a one-to-one basis.

[0008]

For this purpose, the present invention relates to a method in which a plurality of lands of a substrate are taken into the field of view of a camera and a plurality of check areas corresponding to these lands one-to-one are set. A process of arranging a plurality of check areas based on data when the plurality of lands are formed; a process of selecting an arbitrary check area from the check areas; and a process of selecting the selected check area. The process of scanning within the field of view from the original position to overlap the land, the process of obtaining the shift amount from the original position of this check area to the overlapped position, and the other check area by this shift amount A process of moving and polymerizing each of the plurality of lands is configured.

[0009]

According to the above arrangement, a check area is accurately set by using a land having high positional accuracy reliability, and the shift amount of the selected check area is used for movement of another check area. 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 a high speed.

[0010]

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

Part A is a group of lands 12 to which leads 14 of a chip 13 such as a square chip such as a resistor or a capacitor or a chip 13 such as a mini-transistor are soldered 15. Part B is S
A group of lands 22 to which the leads 24 of the OP chip 23 are soldered 25. This part B is composed of a land row B1 and a land row B2 formed in parallel. The portion C is a group of lands 32 to which the leads 34 of the QFP chip 33 are soldered. This C portion includes a land row C1 and a land row C3 formed in parallel in the horizontal direction (X direction) and a land row C2.
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 the shape, dimensions and positional relationship is extremely high. In addition,
The X-axis and Y-axis shown are the lands 12, 22, 3
2 is the horizontal axis and the vertical axis of the land coordinate system XY.

Incidentally, the chips 13, 23, 33 are:
The positions of the leads 14 and 2 are corrected in the chip mounter (not shown) with reference to the land coordinate system XY.
4 and 34 are mounted so as to rest on the lands 12, 22 and 32. Here, in the chip mounting process, mount data and chip data are given in advance as known data. Among them, the chip data includes dimensional data of the chip for each type, the number of leads, and the like. The dimension data of the chip mounter (especially the distances 11,..., 16 between the end portions of the vertical and horizontal leads 34, etc.) is referred to when a check area CC is set for a group of lands 32 in the C section described later.

In all of the embodiments described below, the land coordinate system XY and the check area coordinate system X'-Y 'are set in parallel without a shift in the rotation direction.

(Embodiment 1) FIG.
An image obtained by capturing two groups in a visual field V of a camera (not shown) is shown.
CA is a check area. Since the reliability of the positional relationship between 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 at −Y ′ is determined by using the design data for the formation of the land 12 as it is.

A method for setting the check area CA for the section A will be described. First, as described above, a plurality of lands 12 are taken in the visual field V. Next, these lands 12
Is determined to have overlapped one-to-one with all of the check area CA. Whether one check area CA overlaps with the land is determined by the fact that as the check area CA is moved, the check area CA gradually becomes brighter due to the reflected light from the lands 12 and this brightness becomes constant (more specifically, Specifically, it is sufficient to confirm that the number of pixels (not shown) in the check area CA that responded to light converge after increasing (hereinafter, referred to as polymerization confirmation). This means for confirming the polymerization is also used in Examples relating to Part B and Part C described later.

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

Next, the other check area CA is set in the check area coordinate system X'-Y ', and the shift amount (.DELTA.
X ′, ΔY ′). As a result, when the overlap is confirmed for all the check areas CA, the setting is completed. If not, the selected check area CA is not landed on the land 12 (for example, FIG. 2).
In this case, the upper left check area CA overlaps with the land 12 on the right side of the check area CA). However, it is certain that the lands 12 have overlapped on any one of the lands 12, and the positional relationship between the lands 12 is known as described above. In the present embodiment, the case where the overlap check is performed for the entire check area CA has been described. However, in the case shown in FIG. 2, it is necessary and sufficient to check the overlap for the upper left and lower right check areas CA, for example. The processing for the area CA may be omitted. That is, this means is not limited to the case where the overlap check is performed for all the check areas CA, but also includes the case where the overlap check is performed only for the necessary and sufficient check area CA.

As described above, in this embodiment, it is sufficient to scan at least one of the plurality of check areas CA to determine 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 greatly reduced, and the setting can be completed at a high speed.
In addition, 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 is not changed. There is little danger that the polymer will not be polymerized well.

(Embodiment 2) FIG. 4 shows an image in which the lands 22 of the portion B in FIG. This B
The unit is a land group of the SOP chip 23, and the land 22 group is arranged in parallel so that each of the lead groups 24 of the SOP chip 23 can be placed. Also, the X 'axis of the check area coordinate system X'-Y' on the visual field V side of the camera is
The lands 22 are kept parallel to the row 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 lands 22 will be described. First, an appropriate number n (n = 4 in the present embodiment) is set among the number m of the lands 22 formed in a row.

Next, the check area CB is moved to the start position S1 (X ',
Y ′) = (X′0, Y′C). Then, the check area CB is directed to 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, when the above-mentioned overlap is confirmed for the first land 22 and the check area CB, the coordinates (X ′, Y ′) at this time = (X ′)
1, Y'C). Hereinafter, the same processing is repeated for the second and subsequent lands, and the n-th land 22 set as described above is set.
When the overlap of the check area CB is confirmed, the scanning of the check area CB is finished.

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

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

First, as described above, check area C
B at the start position S1 (X ′, Y ′) = (X′0, Y′C) outside the row of the lands 22 (left side in FIG. 4).
The coordinates (X ′, Y ′) of the second 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 set coordinates in the coordinate system X′-Y ′ of the check area CB may be determined.

As described above, only a part of the 22 rows of lands is actually measured by confirming the overlap of the check areas CB, and the coordinates (land row direction) of all the check areas CB are set. Can be set. Note that, as described above, the accuracy of the position and the shape of the land 22 rows is extremely high, so even if only a part of the land 22 row is actually measured and the actual measurement of the other lands 22 is omitted, the coordinates of the special check area CB are omitted. Accuracy does not decrease.

(Embodiment 3) FIG.
Longitudinal direction of two groups (Y 'axis direction of check area coordinate system)
It is an explanatory view of a setting method of a check area CB.

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
An interval t in the Y′-axis direction between the check areas CB and CB ′ to be overlapped is determined. In other words, this interval t is
Leads 24, 2 extending in opposite directions from both sides of the
4 is set substantially equal to the distance between the tip portions. And Y '
In the axial direction (land longitudinal direction),
One of the check areas CB ′ and CB is taken, and these check areas CB ′ and CB are
The scanning is performed until the polymerization is confirmed in the upper row B1 and the lower row B2.
Thereby, based on the shape data of the chip 23, one of the two check areas CB and CB 'separated by the interval t in the longitudinal direction of the land 22 overlaps one of the check areas CB' with the land 22 in the upper row B1. At the same time, the other check area CB is superimposed on the land 22 of the lower row B2.

Here, when the overlap is confirmed, it is certain that the check areas CB 'and CB are overlapped in the upper row B1 and the lower row B2 of the land 22 at the above-mentioned interval t. However, when the check areas CB ′ and CB are in the upper row B1 and the lower row B2 of the land 22, the SOP chip 2
The third lead 24 is not always located at the leading end of the lead 24 or at the position corresponding to the solder 25. Then, next, a method of aligning the check areas CB ′ and CB with this code position, that is,
A method of setting the coordinates of the check areas CB, 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
X 'at a convenient position between the upper edge 22b of the second land 22 and X'.
A reference line 1 parallel to the axis is provided. Check area C
When B, CB 'touches the reference line 1, the check areas CB, CB' are completely off the land 22.

Here, the check areas CB, CB '
Although they are superimposed 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. Keep 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, the lands 22 are completely removed from the lands 22 and are aligned with the reference line l. Then, the check area CB is moved downward, so that the check areas C
Align the upper edge CB1 of B. The coordinates (X ',
Y ′) = (X′1, Y′E).

Similarly, for the check area CB 'overlapping the land 22 in the upper row B1, coordinates (X', Y ') = (X'4) appropriately overlapping the land 22 first.
Y'S '), and then moves the check area CB' downward until it touches the reference line l. Then, the lower edge CB'2 of the check area CB 'is changed to 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 shifted by the shift amount SY in the check area coordinate system X ′. At −Y ′, the lens is moved in the Y ′ axis direction. Then, the check areas CB and CB ′ are located at the ends of the leads 23 of the SOP chip 23 and at positions corresponding to the solders 25. In addition,
In the above description, the reference area 1 is provided, and the check areas CB, CB 'are moved until the reference area 1 comes into contact with the reference line 1. However, the present invention is not limited to this, and once the check areas CB, CB' are The positions where the check areas CB and CB 'deviate may be changed for convenience.

That is, the two check areas CB, C
Each of B ′ is moved in one direction in the longitudinal direction of the land 22 and is once removed from the land 22, and is moved in the opposite direction to the one direction, so that the position of the edge 22 a, 22 b of the land 22 is From the shape data of the chip 23, the coordinates of the check areas CB and CB 'with respect to the longitudinal direction of the land 22 are set.

According to the third embodiment, the check areas CB and CB 'can be set quickly and easily with respect to the longitudinal direction of the land 22 with reference to the land 22. Also S
Since the shape data of the OP chip 23 is also taken into account, the SOP chips 2 having different lengths of the leads 25 in the same kind of lands 22 are used.
3 can be flexibly and accurately handled by changing the interval t.

In the third embodiment, the method of temporarily removing the check areas CB, CB 'from the land 22 when setting the coordinates of the check areas CB, CB' in the Y 'axis direction (land longitudinal direction) has been described. . However, the present 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
The case where the positions of a and 22b are obtained is also included. In this case, the check area CB is moved as shown by a broken arrow S in the partially enlarged view below (the land row B2 side) in FIG. Specifically, first, the check area CB is (X ′,
Y ′) = (X′1, Y ′S), land 2
The number of pixels capturing 2 is counted, and then the check area CB is moved parallel to the Y ′ axis (the same arrow S).
The movement of B may be stopped, and the Y 'coordinate Y'E at that position may be obtained. Of course, 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 lands 32 of the portion C in FIG. 1 are captured in the visual fields V1, V2, V3 and V4 of the camera. The C portion is a group of lands 32 of the QFP chip 33, and the group of lands 32 is
In this arrangement, the land rows C1, C2, C3, and C4, which are in parallel with each other, are provided so as to be able to mount each of the three leads 34. The X'-axis (horizontal axis) and the Y'-axis (vertical axis) of the check area coordinates X'-Y 'are set so as to be parallel to these land rows C1, C2, C3, and C4.

And 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 set in the same manner as in the second embodiment.
Set C. Thus, 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 rows 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 dimensional data of the QFP chip 33, the distances 11 and 1 shown in FIG.
Find 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 l2 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 visual field V
The X 'coordinate of the check area CC of No. 4 is X'6 which is 13 away from X'5 in the forward direction, and the Y' coordinate of the check area CC of the visual field V3 is 15 away from Y'5 in the forward direction. Y'6. As a result, the coordinates of the check area CC can be set for the entire land 32 group of the QFP chip 33 after the actual measurement of the land 32.

That is, from the coordinates when the check area CC overlaps a part of each of the land rows C1 and C4,
The pitch P between the lands 32 is determined, and based on the 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' is determined. Coordinates are set. 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 (row direction) crossing the 32 rows of lands to obtain the actual measurement value of the lands 32, and the check area CC is referred to by referring to the dimension data of the QFP chip 33. CC settings were made. Therefore, the check area can be quickly and easily set for the portion C composed of a very large number of lands 32 without visual observation.

[0043]

As described above, according to the present invention, a plurality of land areas of a substrate are taken in the field of view of a camera and a plurality of check areas corresponding to these land areas are set one-to-one. The process of arranging the 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 process of selecting the selected check area The process of scanning within the field of view from the position above and overlapping the land, the process of calculating the shift amount from the original position of this check area to the overlapped position, and the other check areas are moved by this shift amount. The process of superimposing on each of the above-mentioned lands has been configured by using the lands with high reliability of position accuracy. 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 the 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.

FIG. 3 is an enlarged view of the same.

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 Polymerized position

Claims (1)

(57) [Claims] When a plurality of substrate lands are taken into the field of view of a camera and a plurality of check areas corresponding to these lands are set on a one-to-one basis, the plurality of check areas are divided into the plurality of check areas. A process of arranging based on the data when the land is formed, a process of selecting an arbitrary check area from the check areas, and scanning the selected check area from the original position in the field of view. A process of calculating the shift amount from the original position of the check area to the position where the check area overlaps, and moving the other check areas by this shift amount to each of the plurality of lands. A check area setting method for a plurality of lands, comprising a process of superimposing.