JPH05203417A - Method for setting check area on longitudinal and transversal parallel lands - Google Patents

Abstract

PURPOSE:To obtain a means which is suitable for setting a check area group corresponding to a land group for QFP chips. CONSTITUTION:The axes of ordinates Y' and abscissas X' of the coordinate system of check areas CC are set in parallel with land rows C2 and C4 and C1 and C3 formed in parallel with each other in the longitudinal and transversal directions. Then the check areas CC are set at starting positions S3 and S4 on the outside of the land rows C1 and C3 which are arranged in parallel with the axis of abscissas X'. By scanning the check areas CC in the direction of the land rows, the pitch P between the lands 32 is found from the coordinates where the check areas CC overlap parts of the land rows. Based on the pitch P, the coordinates of the check area CC group corresponding to the individual lands 32 in the land rows C1 and C2 parallel to the axis of abscissas X' one to one are set. Then the coordinates of the check area CC group in the length direction of the lands are set from the coordinates of the check area CC group in the direction of land rows and dimensional data of chips 33 mounted on the land rows C1, C2, C3, and C4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check area setting method for vertical and horizontal parallel lands, and in particular, among lands formed on a substrate, a plurality of lands for QFP chips are taken into the field of view of a camera and soldered. The present invention relates to means that are preferably used when visually inspecting a condition.

[0002]

2. Description of the Related Art A chip electrode such as an IC or LSI is bonded to a land of a substrate by soldering, and then an electrode of the chip is used to inspect whether or not the chip electrode is well bonded to the land. A visual inspection of the solder is performed in the vicinity of the overlapping portion between the solder 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. In particular, the number of lands for the QFP chip may be more than several hundreds formed with a narrow pitch, and it is almost impossible to visually inspect as described above. 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. Further, the land for the QFP chip is a vertical and horizontal parallel land in which four land rows are formed in parallel vertically and horizontally due to the shape of the QFP chip.

In view of the above points, the present invention makes it possible to accurately and accurately set a check area for visual inspection of solder at a high speed based on the land of the board. In addition, it is an object of the present invention to provide a suitable means for taking in a land group for a QFP chip and setting a check area group corresponding to the land group for the QFP chip on a one-to-one basis.

[0008]

To this end, the present invention provides a process of setting the vertical axis and the horizontal axis of the coordinate system of the check area parallel to the land rows formed in parallel in the vertical and horizontal directions, and The process of placing a check area at the start position on the outer side of each land row of the land row and the land row parallel to the horizontal axis, and scanning this check area in the direction of each land row, The process of obtaining the pitch between lands from the coordinates when the check areas overlap with each other, and based on this pitch, each land in the land row parallel to the vertical axis and each land row parallel to the horizontal axis The process of setting the coordinates in the land column direction of the check area groups corresponding to the lands of 1 to 1 and the coordinates in the land column direction of the above check area groups and the implementation in these land columns From the chip size data constitute a process of setting the land longitudinal coordinates of the checking area group.

[0009]

According to the above structure, the check area is set accurately by using the land having high reliability in position accuracy.

Further, it is not necessary to scan the check area in the land row direction for all the land rows,
Since most of them can be omitted, the setting can be done quickly, and the coordinates in the land row direction of the check area are set based on the measured data of the land row.
The accuracy of this coordinate can be kept high.

In addition, in the longitudinal direction of the land, the coordinates of the check area are set from the coordinates of the land direction of the check area obtained as described above and the chip size data without scanning the check area. The time and labor required for setting the check area can be significantly reduced.

[0012]

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 a square chip such as a resistor and a capacitor or a chip 13 such as a mini transistor are soldered. 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.

Incidentally, 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 (particularly the distances l1, ..., L6 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 of the embodiments described below, the land coordinate system XY and the check area coordinate system X'-Y 'are set in parallel without any deviation in the rotational direction.

(Embodiment 1) FIG. 2 shows the land 1 of the section A above.
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 part 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 within the field of view V from its original position HP 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 (ΔX'
, ΔY ′). As a result, when it is possible to confirm the overlap in all the check areas CA, the setting is completed. Otherwise, check area C selected above
It means that A has been superposed on the land 12 that should not be superposed (for example, in the case where the upper left check area CA is superposed on the right lateral land 12 in FIG. 2). 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 of the portion B in 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') outside the row of the lands 22 (on the left side in FIG. 4).
) = (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 22 of the lands 22 (in the X ′ axis direction). Then, when 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 memorized. After that, the same processing is repeated for the second and subsequent lands, and when the n-th land 22 and the check area CB set as described above are confirmed to overlap, the scanning of the check area CB is ended.

The first coordinate (X '1, Y'C)
Shift amount S from the nth coordinate to (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 is (X', Y ') = (X'1, Y'C). ，
(X'1 + P, Y'C), ..., (X'1 + P (m-
1), Y'C).

First, as in the 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).
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
The 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 ′ and CB are taken, and these check areas CB ′ and CB are respectively shown in FIG.
Scan until the upper row B1 and the lower row B2 can be confirmed as overlapping.
As a result, based on the shape data of the chip 23, one of the two check areas CB and CB ′ having 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 above-mentioned 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 with each other at appropriate positions on the lands 22 in the lower row B2 and the upper row B1 at the intervals 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, regarding the check area CB 'overlapping the land 22 in the upper row B1, first, the coordinates (X', Y ') appropriately overlapping the land 22 = (X' 4,
Y'S '), then the check area CB' is moved downward until it contacts the reference line l, and the lower edge CB '2 of this check area CB' is then 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 moved by the shift amount SY in the check area coordinate system X '. At -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 also moved in the opposite direction to the above-mentioned one direction so that the positions of the edges 22a and 22b of the land 22 are changed. 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. Further, since the shape data of the SOP chip 23 is also taken into consideration, when mounting the SOP chips 23 having different lengths of the leads 25 on the same type of land 22 group, it is possible to flexibly and accurately respond by changing the interval t. ..

In the third embodiment, a 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) will be described. did. However, this means is not limited to this, and the check area CB,
The edge 2 of the land 22 without removing the CB 'from the land 22
This also includes the case of obtaining the positions of 2a 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), the number of pixels that capture the land 22 is counted, and then the check area CB is moved in parallel with the Y ′ axis (the arrow S), before moving. When the number of pixels is slightly decreased, the movement of the check area CB is stopped and the Y ′ coordinate Y ′ E of the position may be obtained. Of course, the Y ′ coordinate Y ′ E can be similarly obtained for the land row B1 in the upper part of FIG. 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 into 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, as in the second embodiment, the check area C in the land row direction is provided.
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, 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 l1 and l2 shown in FIG.
, L3, l4, l5 are obtained.

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 l1 in the negative direction. Also, the field of view V
The X'coordinate of the check area CC of No. 4 is X'6 which is separated from the 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 the Y'5 by 15 in the positive direction. 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) that traverses the 32 rows of lands to obtain the actually measured values of the lands 32, and the dimension data of the QFP chip 33 is referred to to check the 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.

[0045]

As described above, according to the present invention, the process of setting the vertical axis and the horizontal axis of the coordinate system of the check area in parallel with these land rows, the land rows parallel to the vertical axis, and the above The process of setting a check area at the start position outside each land row of the land rows parallel to the horizontal axis, and scanning this check area in the direction of each land row, and a check area is formed in part of these land rows. A process of determining the pitch between lands from the coordinates at the time of stacking, and based on this pitch, a pair of lands is formed on each land in the land row parallel to the vertical axis and each land in the land row parallel to the horizontal axis. The process of setting the land area direction coordinates of the check area group corresponding to one, the land area direction coordinates of the above check area group, and the dimensional data of the chips mounted on these land areas. From data, to constitute a process of setting the land longitudinal coordinates of the checking area group. In this way, the coordinates of the land area in the check area are set based on the data obtained by actually measuring the land with high positional accuracy, and the coordinates of the longitudinal direction of the check area are calculated by adding the chip dimension data to these coordinates. Since the setting is made, the accuracy of the set coordinates of the check area can be kept high.
Further, since it is sufficient to scan the check area for a part of the land row direction, it is possible to omit most of the land row direction scan and the land longitudinal direction scan. Moreover, the setting of check areas for a large number of lands can be completed in a short time.

[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 Board 32 Land 33 Chip C1 Land Row C2 Land Row C3 Land Row C4 Land Row CC Check Area X'Horizontal Axis of Check Area Coordinate System Y'Vertical Axis of Check Area Coordinate System S3 Start Position S4 Start Position P Pitch

Claims (1)

[Claims] 1. A check area is provided when a plurality of land rows formed in parallel in the vertical and horizontal directions on a substrate are taken into the field of view of a camera and a check area corresponding to each land of these land rows is set one-to-one. The process of setting the vertical axis and the horizontal axis of the coordinate system in parallel with these land rows, the land rows parallel to the vertical axis, and the start positions on the outer side of each of the land rows parallel to the horizontal axis. The process of setting the check area at, the process of scanning this check area in the direction of each land row, and determining the pitch between lands from the coordinates when the check area overlaps a part of these land rows, and this pitch Based on the above, each land in the land row parallel to the vertical axis and each land in the land row parallel to the horizontal axis have a one-to-one correspondence with the land row direction of the check area group. Of the check area group and the process of setting the coordinate of the check area group in the longitudinal direction of the land from the dimension data of the chips mounted on these land rows. A check area setting method for vertical and horizontal parallel lands, which is characterized in that