JP2004055739A - Needle position correcting method and potting equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly accurately position the dripping position of resin by a needle upon effecting underfill potting or the like. <P>SOLUTION: The needle is put on an X-Y coordinate table to position the same at a plurality of preset coordinate positions (X1, Y1), (X1+Px, Y1),..., and resin is dripped from the needle at respective positioned coordinate positions for the measurement of the positions. The resins A1-A9 for measuring the dripped positions are photographed by a camera whereby the coordinates of the actual dripped positions of respective resins A1-A9 are obtained. Then, deviations ▵x1, ▵y1, ▵x2, ▵y2,... between the actual dripping coordinate positions and the coordinate positions of the needle upon dripping, the resin are obtained from the difference between the actual dripping coordinate positions and the coordinate positions of the needle upon dripping the resin, and then the average value of the deviations is obtained whereby the correction of the needle position with respect to the camera is made. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention makes it possible to apply a needle position correcting method capable of controlling a resin drop position from a needle used when underfill potting a semiconductor chip with high accuracy, and to apply the needle position correcting method, thereby enabling highly accurate potting. Related to potting equipment.
[0002]
[Prior art]
There is a potting system for potting a semiconductor chip or the like mounted on a strip-shaped thin substrate (called a tape substrate) with a thermosetting resin such as an epoxy resin.
[0003]
The main processing steps of this potting system include, in a two-dimensional coordinate table (here, XY coordinates) a needle filled with a liquid epoxy resin having appropriate viscosity for a semiconductor chip mounted on a tape substrate. A potting step of controlling the movement of the resin by a predetermined amount in the X-axis direction and the Y-axis direction, positioning the resin dropping position with high precision, and dropping a viscous liquid resin from the tip thereof. And a resin curing step of thermally curing the resin potted by the potting step.
[0004]
As a potting method in the above-described potting step, there is a potting method called underfill. As shown in FIG. 6, the underfill potting is performed by dropping a liquid resin 10 having appropriate viscosity from the needle 1 onto a base portion of the side surface 11a of the semiconductor chip 11 with respect to the tape substrate 12, thereby reducing surface tension. This is a potting method in which resin enters a gap between the back side of the semiconductor chip 11 (the surface opposite to the surface of the tape substrate 12) and the tape substrate 12, and the bottom surface of the semiconductor chip 11 is fixed to the tape substrate 12.
[0005]
In such underfill potting, it is necessary to position the needle 1 for dripping the resin with high precision. The inner diameter of the needle 1 is as fine as about 0.2 mm to 0.5 mm. In the case of the underfill described above, the position of the needle 1 with respect to the semiconductor chip 11 to be potted is set such that the interval P from the side surface 11a of the semiconductor chip 11 to the outer surface of the tip of the needle 1 is only about 0.1 mm. Therefore, the position control requires high accuracy.
[0006]
As shown in FIG. 6, the needle 1 is attached to the head 3 together with, for example, a CCD camera (hereinafter simply referred to as a camera 2) as an imaging device. Based on the image data output from the camera 2, the mounting position (position on the XY coordinates) of the semiconductor chip 11 with respect to the tape substrate 12 is detected, and the needle 1 is moved to the drop position on the XY coordinates. The movement of the head 3 is controlled so that the liquid resin is dropped from the needle 1 at the drop position. Thereafter, the needle 1 is moved along the four side surfaces of the semiconductor chip 11.
[0007]
At this time, the distance between the camera 2 and the needle 1 needs to be kept at a preset value. That is, on the XY coordinate table, if the position of the optical axis of the camera 2 and the position of the center of the tip of the needle 1 are held at predetermined distances in the X-axis direction and the Y-axis direction, If the position of the camera is controlled on the XY coordinate table on the basis of the positional relationship between the optical axis of the camera 2 and the center of the tip of the needle 1, the needle 1 can be accurately positioned at the coordinate point where it should be dropped. it can.
[0008]
However, if the positional relationship of the center of the tip of the needle 1 with respect to the optical axis of the camera 2 is distorted (if the position of the needle 1 is displaced), the drop position will be displaced by the displacement. For this reason, it is important that the position of the needle 1 with respect to the camera 2 is accurately set.
[0009]
However, the needle 1 may be replaced due to long-time use or the like, and when a new needle 1 is attached, the needle 1 may be slightly tilted depending on how the needle 1 is attached. Further, not only when the needle 1 is replaced, but also when the potting operation on the semiconductor chip 11 is repeated by the same needle 1 for a long period of time, the resin adheres to the tip of the needle 1, which causes a shift in the subsequent dropping position. There are cases.
[0010]
Therefore, conventionally, in order to accurately set the position of the needle 1 with respect to the camera 2, the position of the needle 1 is measured using various methods, and the position of the needle 1 with respect to the camera 2 is set based on the measurement result. I am trying to do it.
[0011]
As a method of measuring the position of the needle 1 for determining the position of the needle 1, for example, although not shown, two sets of photoelectric conversion elements including a light emitting element and a light receiving element that receives the light are used. There is a method of arranging the photoelectric conversion elements so that the light from each light emitting element is orthogonal to each other, and measuring the position of the needle 1 by positioning the tip of the needle 1 at the orthogonal point of the light.
[0012]
[Problems to be solved by the invention]
However, in such a position measuring method, when the position of the needle 1 is measured again after performing the potting operation for a while, if the measurement is performed in a state where the resin or the like adheres to the tip of the needle 1, There is a problem that an accurate measurement result cannot be obtained because the adhered resin is an obstacle.
[0013]
In addition, this type of position measurement method measures the position of the needle 1 itself. That is, the position of the dropped resin when the resin is actually dropped by the needle 1 is not measured. Therefore, as a result of measuring the position of the needle 1, even if it is determined that the measurement result is appropriate, the resin is not always dropped at a desired accurate position when the resin is actually dropped.
[0014]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a needle position correcting method capable of controlling a resin drop position with high accuracy, and a potting apparatus capable of performing high-precision potting by applying the needle position correcting method.
[0015]
[Means for Solving the Problems]
In order to achieve the above-described object, a needle position correcting method of the present invention is a needle position correcting method of a resin coating device that applies a resin onto a tape from a needle, and calculates a needle calculation position calculated from predetermined parameters. In the needle position correction method of correcting the needle application position where the resin is actually applied, the resin is applied in a point-like manner from a needle to a preset position, and the plane center of gravity of the resin is determined from the outer shape of the point-applied resin. Is calculated, and the position of the center of gravity is set as the needle application position, and the needle calculation position corresponding to the preset position is corrected by the needle application position corresponding to the preset position.
[0016]
As described above, since the needle calculation position calculated from the predetermined parameter is corrected by the needle application position where the resin is actually applied, for example, when replacing the needle, the needle position with respect to the imaging device is appropriately adjusted. And the positional relationship between the imaging device and the needle can always be properly maintained. In this needle position correction method, it is preferable that the preset position at which the resin is applied includes a plurality of positions, and that the average value of the needle calculation positions corresponding to the position is corrected by the average value of the needle application positions corresponding to the position. . This makes it possible to determine the displacement of the needle position with respect to the imaging device with high accuracy.
[0017]
Further, the needle position correction method of the present invention is attached to a head together with an imaging device, and calculates a difference between a position on the two-dimensional coordinate of an optical axis of the imaging device and a position on a two-dimensional coordinate of the center of the tip of the imaging device. In a needle position correction method for performing position correction on a two-dimensional coordinate with respect to an imaging device of a needle for dropping viscous liquid resin from the tip thereof, position control is performed based on the distance, Is positioned at a plurality of coordinates set in advance on the two-dimensional coordinates, and each of the positioned positions is used as a theoretical dropping position coordinate for measuring the resin from the needle for each theoretical dropping position coordinate. The coordinates of the actual drop position of each resin are determined by dropping and imaging the dropped resin for position measurement with an imaging device. The deviation between the actual droplet position coordinates and the theoretical dropping position coordinates of the needle calculated, so that correct the needle position relative to the imaging device by utilizing this deviation.
[0018]
As described above, the positional deviation between the needle position on the two-dimensional coordinate table and the actual drop position coordinate (if the two-dimensional coordinate is the XY coordinate, the positional deviation in the X-axis direction and the Y-axis direction The position of the needle with respect to the imaging device can be properly corrected, for example, at the time of replacement of the needle. Can always be properly maintained.
[0019]
Also, the deviation between the actual drop position of the needle and the theoretical drop position coordinates is the theoretical drop position coordinates and the actual drop position for each resin dropped at the theoretical drop position coordinates. It is preferable to determine the difference from the coordinates and obtain an average of the determined differences. This makes it possible to determine the displacement of the needle position with respect to the imaging device with high accuracy.
[0020]
Also, when calculating the average of the difference, of the resin for position measurement at a plurality of locations dropped on the theoretical dropping position coordinates, the resin for position measurement dropped first is the calculation target when calculating the average. Preferably, it is outside.
[0021]
The reason why the resin for position measurement dropped first is excluded from the calculation when calculating the average is in consideration of the instability of the rising of the resin dropping operation by the needle. In other words, the resin dropped first may have an inappropriate shape or resin amount, so for the first dropped resin, it is better to exclude from the target for calculating the average of the deviation, to obtain a more accurate average of the deviation This makes it possible to obtain a more accurate average of the deviation.
[0022]
Further, it is preferable that the respective resins for position measurement are arranged in a 3 × 3 matrix on two-dimensional coordinates.
[0023]
In this way, by setting the drop positions in a matrix of nine (3 × 3) positions, displacements corresponding to various potting positions can be checked. Further, by setting nine dropping positions, it is possible to obtain a highly reliable value as an average value without complicating the calculation.
[0024]
Further, the potting apparatus of the present invention moves the imaging device and the needle to a preset position on the two-dimensional coordinate table while maintaining a space between the tape substrate feeding mechanism and the tape substrate feeding mechanism for feeding the tape substrate on which the semiconductor is mounted. A movable means, and a potting controller for performing drive control of the movable means and performing a control necessary for performing a potting operation, and the tip of the needle with respect to a position on the two-dimensional coordinate of an optical axis of the imaging apparatus. The difference between the positions on the two-dimensional coordinates of the center is defined as the distance between the imaging device and the needle, and the position of the needle is controlled based on the distance, and the viscous liquid resin is dropped from the needle tip to pot the semiconductor. In the two-dimensional coordinate of the center of the tip of the needle with respect to the two-dimensional coordinate of the optical axis of the imaging device , After being corrected by the needle position correction method described above, based on the position information of the corrected, and to perform the potting position control of the needle by controlling the driving of the moving means.
[0025]
Thus, for example, even when replacing the needle or after using the needle for a long time, the needle position can be corrected, so that the positional relationship between the imaging device and the needle can always be appropriately maintained, and high-precision potting can be performed. It can be performed.
[0026]
In addition, potting is underfill potting, and when applying resin to a semiconductor with a needle, the resin is applied by moving the needle in one direction from the start position of application in a single stroke. Is preferred.
[0027]
As described above, potting can be performed only by moving the needle in one direction in one stroke, so that the needle can be easily controlled, and air bubbles and the like are hardly generated in the dropped resin.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described. The contents described in this embodiment include both the needle position correcting method of the present invention and a potting device that performs potting by applying the needle position correcting method. Further, the same members as those described in the related art are denoted by the same reference numerals, and description thereof will be omitted or simplified.
[0029]
FIG. 1 shows components necessary for explaining a needle position correcting method according to the present invention. A head 3 on which a needle 1 and an imaging device 2 (referred to as a camera 2) such as a CCD are attached, and the head 3 Here, as the two-dimensional coordinate table, a head drive unit 4 that can move to an arbitrary coordinate position on an XY coordinate table (not shown), and a liquid resin such as an epoxy resin having appropriate viscosity from the needle 1 ( In this embodiment, a resin dropping position measuring jig 5 such as a glass plate used for trial dropping of a resin), a function of processing an image captured by the camera 2 and a head driving unit 4 are controlled. And a potting control unit 6 that performs control necessary for performing a potting operation, such as a function to perform a potting operation.
[0030]
In addition, among these components, the head 3 to which the needle 1 and the camera 2 are attached, the head driving unit 4, the potting control unit 6, and the like are conventionally provided in the potting apparatus. In the present invention, in addition to these components, a resin dropping position measuring jig 5 is prepared, and the resin is actually dropped from the needle 1 onto the resin dropping position measuring jig 5, and the resin is dropped. The position of the needle 1 with respect to the camera 2 is measured based on the resin position, and the position of the needle 1 with respect to the camera 2 is corrected based on the measurement result. Hereinafter, an embodiment of the needle position correcting method of the present invention will be described.
[0031]
Although the camera 2 and the needle 1 are attached to the head 3 as described above, it is necessary to accurately maintain the distance d between the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1. This distance d can be obtained as the distance in the X-axis direction and the distance in the Y-axis direction on the XY coordinate table of the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1 on the XY coordinate table.
[0032]
Specifically, this distance d is determined by dropping the resin at a position (referred to as a reference position) set on a tape substrate traveling table on which the tape substrate travels in a potting apparatus, and the dropped resin is positioned at the center of the image monitor. It is obtained by teaching the position to be reflected in
[0033]
At this time, the coordinates of the optical axis 2a of the camera 2 on the XY coordinate table are obtained, and then the optical axis 2a is moved to its reference position (for example, the center of the depression). , The coordinate value of the optical axis 2a in that state is obtained. By obtaining the two coordinate values in this manner, the distance between the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1 is defined as the distance between the center 1a of the tip of the needle 1 and the optical axis 2a of the camera 2 in the X-axis direction. , Y-axis direction.
[0034]
Here, as shown in FIG. 2, the distance d between the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1 is separated by X1 in the X-axis direction and Y1 in the Y-axis direction in the XY coordinate table. Position.
[0035]
The distance d between the tip center 1a of the needle 1 and the optical axis 2a of the camera 2 determined as described above is used in a needle position correction method described below.
[0036]
In the needle position correcting method according to the present embodiment, first, a resin dropping position measuring jig 5 (hereinafter, referred to as a glass jig 5) made of glass or the like is installed at a predetermined position, and a needle is attached to the glass jig 5. From 1 drop resin. FIG. 3 shows the state of the dropped resin. The resin is dropped on the glass jig 5 nine times in total. Here, a total of nine dripped resins are arranged on the glass jig 5 in a 3 × 3 matrix, that is, three in the X-axis direction and three in the Y-axis direction on the XY coordinates. You. The dropped resin has a circular shape as shown in FIG.
[0037]
In FIG. 3, for each of the dropped circular resins (hereinafter referred to as dropped resins), for convenience of description, the upper dropped resin is denoted by A1, A2, and A3 in order from the left. The same applies to the middle drop resin in the order of A4, A5, and A6 from the left, and the lower drop resin in the same manner to the left in order of A7, A8, and A9.
[0038]
Note that the original center coordinates of the dropping resin A1 on the XY coordinate table in FIG. 3 are (X1, Y1), and the dropping interval of each dropping resin is in the X-axis direction on the XY coordinate table. Is Px, and the Y-axis direction is Py.
[0039]
That is, the original center coordinates (X1, Y1) of the dripping resin A1 are the tip center 1a of the needle 1 when the optical axis 2a of the camera 2 is aligned with a reference position on the XY coordinate table. Are the position coordinates on the XY coordinate table. That is, in this case, as described above, the tip center 1a of the needle 1 is located at a position Xm away from the optical axis 2a of the camera 2 in the X-axis direction and Ym away in the Y-axis direction. The coordinates where A1 is dropped, that is, the original center coordinates (X1, Y1) of the dropped resin A1 are Xm in the X-axis direction and Xm in the Y-axis direction from the coordinates of the optical axis 2a of the camera 2 on the XY coordinate table. It can be said that the coordinates are theoretical drop position coordinates separated by Ym. Therefore, hereinafter, the original center coordinates (X1, Y1) of the dripping resin A1 are referred to as theoretical dropping position coordinates.
[0040]
The coordinates of the other dripping resins A2, A3,..., A9 are obtained by setting the needle 1 to Px in the X-axis direction based on the theoretical dropping position coordinates (X1, Y1) on the XY coordinate table. , In the Y-axis direction when moved by Py.
[0041]
To explain with some examples, first, after the resin is dropped at the theoretical dropping position coordinates (X1, Y1), the needle 1 is moved by Px in the X-axis direction to obtain the coordinates of (X1 + Px, Y1). The resin that the needle 1 drops the resin at the coordinates at that position is the dropped resin A2. Further, the needle 1 is moved by Px in the X-axis direction and is positioned at the coordinates of (X1 + 2Px, Y1), and the resin dropped by the needle 1 at that position is the dripping resin A3.
[0042]
Further, the needle 1 is moved by Py in the Y-axis direction with the coordinates (X1, Y1) as a base point, and is positioned at the coordinates (X1, Y1 + Py). The resin A4 is obtained by further moving the needle 1 by Py in the Y-axis direction and positioning it at the coordinates (X1, Y1 + 2Py), and dropping the resin at the coordinate position by the needle 1 is the dripping resin A7.
[0043]
In addition, the coordinates described corresponding to each of the dripping resins A1, A2,..., A9 in FIG. 3 are the theoretical dropping position coordinates described herein.
[0044]
Then, each of the dripping resins A1, A2,..., A9 is photographed one by one by the camera 2, and the respective dripping resins A1, A2,. The coordinates of the position of the center of gravity of A9 are obtained. The dripping resins A1, A2,. The coordinates obtained from the image of A9 (the coordinates of the position of the center of gravity of each dripping resin) are the actual dripping positions dropped by the needle 1.
[0045]
In this manner, the drop position coordinates (theoretical drop position coordinates on the XY coordinate table) of the nine drop resins A1, A2,... The actual drop position coordinates for the nine drop resins thus obtained are obtained. After that, the deviation between the theoretical drop position coordinates and the actual drop position coordinates (X-axis position deviation and Y-axis position deviation) is determined.
[0046]
Here, for example, the deviation in the X-axis direction between the theoretical dropping position coordinates of the dropping resin A1 and the actual dropping position coordinates in the X-axis direction is obtained as Δx1, and the deviation in the Y-axis direction is Δy1, and the theoretical dropping position of the dropping resin A2 is obtained. It is assumed that the deviation between the coordinates and the actual drop position coordinates in the X-axis direction is determined as Δx2, and the deviation in the Y-axis direction is determined as Δy2. Further, the deviation in the X-axis direction between the theoretical dropping position coordinates of the dropping resin A3 and the actual dropping position coordinates is determined as Δx3, and the deviation in the Y-axis direction is determined as Δy3. It is assumed that the displacement of the drop position coordinates in the X-axis direction is determined as Δx4 and the displacement in the Y-axis direction is determined as Δy4.
[0047]
Further, the deviation in the X-axis direction between the theoretical dropping position coordinates of the dripping resin A5 and the actual dropping position coordinates is determined as Δx5, and the deviation in the Y-axis direction is determined as Δy5. It is assumed that the displacement of the drop position coordinates in the X-axis direction is determined as Δx6 and the displacement in the Y-axis direction is determined as Δy6. Further, the deviation in the X-axis direction between the theoretical drop position coordinates of the dripping resin A7 and the actual drop position coordinates is determined as Δx7, and the deviation in the Y-axis direction is determined as Δy7. It is assumed that the displacement of the drop position coordinates in the X-axis direction is determined as Δx8 and the displacement in the Y-axis direction is determined as Δy8.
Further, it is assumed that the deviation between the theoretical drop position coordinates and the actual drop position coordinates of the dropping resin A9 in the X-axis direction is Δx9, and the shift in the Y-axis direction is Δy9.
[0048]
These deviations are caused by positioning the needle 1 at a certain coordinate on the XY coordinate table, and comparing the position on the XY coordinate table when the resin is dropped and the actual position of the dropped resin. It is a gap.
[0049]
For example, taking the dropping resin A1 as an example, the resin is dropped with the needle 1 positioned at the coordinate position (X1, Y1) on the XY coordinate table. When the position of the center of gravity is obtained, the position coordinates of the center of gravity are (X1 + Δx1, Y1 + Δy1). In other words, when the needle 1 is positioned at the coordinate position (X1, Y1) on the XY coordinate table and the resin is dropped, the actual dropping position is relative to the theoretical dropping position coordinates (X1, Y1). This means that there is a shift of Δx1 in the X-axis direction and Δy1 in the Y-axis direction.
[0050]
This is because the distance between the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1 should originally be set to Xm in the X-axis direction and Ym in the Y-axis direction on the XY coordinate table. Actually, it means that Xm + Δx1 in the X-axis direction and Ym + Δy1 in the Y-axis direction. Therefore, when potting the semiconductor chip, if the dropping position of the needle 1 is controlled in consideration of the deviation, the potting can be performed at an accurate position.
[0051]
In this case, nine drops were tried on the glass jig 5 by the needle 1 and the respective resin A1, A2,. Since the displacement in the X-axis direction and the displacement in the Y-axis direction with respect to A9 are determined, the average of the nine displacements is determined, so that the average deviation of the tip center 1a of the needle 1 with respect to the optical axis 2a of the camera 2 can be calculated. You can ask. Here, if the average of the displacements in the X-axis direction is represented by Δx and the average of the displacements in the Y-axis direction is represented by Δy, the average of these displacements in the X-axis direction is represented by Δx, and the average of the displacements in the Y-axis direction is represented by Δy.
Δx = (Δx1 + Δx2 + Δx3 +... + Δx9) / 9 (1)
Δy = (Δy1 + Δy2 + Δy3 +... + Δy9) / 9 (2)
You can ask.
[0052]
That is, no matter which coordinates on the XY coordinate table, the needle 1 drops resin at that position, and the resin drops at a position shifted by Δx in the X-axis direction and Δy in the Y-axis direction. That is to be done.
[0053]
Therefore, the interval between the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1 on the XY coordinate table is corrected using the average of the deviation. If the distance between the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1, that is, the average distance in the X-axis direction on the XY coordinate table is represented by, and the average distance on the Y-axis coordinate is represented by Y,
X = Xm + Δx (3)
Y = Ym + Δy (4)
It can be expressed as. X and Y are the distance between the optical axis 2a of the camera 2 and the actual drop position of the needle 1, that is, the optical axis 2a of the camera 2 and the tip center 1a of the needle 1 are actually represented in the XY coordinate table. The value is registered in the potting control unit 6 as a value indicating a position separated by X in the X-axis direction and Y in the Y-axis direction.
[0054]
As a result, the distance between the optical axis 2a of the camera 2 and the actual drop position of the needle 1 becomes accurate. Therefore, the head 3 on which the camera 2 and the need 1 are attached is driven and controlled on the XY coordinate table with the camera 2 as a reference, so that the drop position of the needle 1 can be positioned with high accuracy. The above-described operation of correcting the position of the needle 1 is performed when the needle 1 is replaced with respect to the head 3 or when the dripping of the needle 1 is readjusted due to long-term use.
[0055]
By performing such position correction of the needle 1, even if the needle 1 is attached with a slight inclination when the needle 1 is attached, the position of the needle 1 with respect to the camera 2 is determined based on the actual drop position. The deviation of the interval can be obtained accurately. Therefore, it is possible to obtain an accurate distance between the camera 2 and the needle 1 in consideration of the obtained deviation. By registering the distance between the camera 2 and the needle 1, the semiconductor chip can be used when performing actual potting. The resin can be dropped at a highly accurate potting position.
[0056]
By the way, in the example described above, when determining the displacement of the needle position, as shown in FIG. 3, nine dripping resins A1, A2,. With respect to all A9, the position coordinates are obtained by the camera 2, and the respective dropped resins A1, A2,. For each A9, deviations Δx1, Δx2,..., Δx9 on the X coordinate and deviations Δy1, Δy2,. However, since the rising of the resin dropping operation of the needle 1 is unstable, the shape and amount of the dropped resin may not be appropriate for the first dropped resin A1. For the first dripping resin A1, the deviation may not be determined. Further, even if the deviation is obtained, the average deviation is obtained by using the deviation obtained by the other eight dropping resins A2, A3,..., A9 without using the deviation. Is also good.
[0057]
If Δx1 and Δy1 are obtained for the dropping resin A1, in the above-described equations (1) and (2), Δx1 = 0 and Δy1 = 0, and Δx2 + Δx3 +. .. + Δy9 are also divided by 8, and Δy is obtained by dividing Δy2 + Δy3 +... + Δy9 by 8.
[0058]
Next, a potting apparatus to which such a needle position correction method can be applied will be described.
[0059]
FIG. 4 shows a potting system incorporating the potting device of the present invention. This potting system is roughly composed of a tape substrate supply device 21, a potting device 22, a resin curing device 23, and a tape substrate winding device 24. The potting device 22 will be described here.
[0060]
The potting device 22 forwards (in the direction of arrow a) a tape-shaped tape substrate 12 made of resin on which a number of semiconductor chips 11 (see a circular frame Z indicated by broken lines in the drawing) sent from the tape substrate supply device 21 are mounted. It has a feed roller 221 as a tape substrate feed mechanism and a tension roller 222 for applying tension to the tape substrate 12, and a thermosetting resin such as an epoxy resin for the semiconductor chip 11 mounted on the surface of the tape substrate 12. And a potting section 223 for potting.
[0061]
As described with reference to FIG. 1, the potting unit 223 can move the head 3 on which the needle 1 and the camera 2 are attached, and move the head 3 to an arbitrary coordinate position on an XY coordinate table (not shown). And a potting control unit 6 that performs various controls necessary for performing a potting process, such as a function of processing an image captured by the camera 2 and a function of controlling the head drive unit 4. are doing.
[0062]
The potting device 22 in the potting system configured as described above pots the resin on the semiconductor chip 11 mounted on the tape substrate 12 (here, underfilling) with respect to the tape substrate 12 sent from the tape substrate supply device 21. Potting). When performing this potting, the camera 2 captures an image of a preset portion of the semiconductor chip 11, obtains the position coordinates of the semiconductor chip 11, and determines the dropping position of the needle 1 based on the obtained position coordinates. After that, the head 3 is driven to drive and control the head 3 so that the tip center 1a of the needle 1 is at the obtained dropping position.
[0063]
For example, two diagonal corners 11b and 11c of the semiconductor chip 11 on the tape substrate 12 are detected, the positions of the corners 11b and 11c are measured, and the position of the semiconductor chip 11 is obtained. The corners 11b and 11c of the semiconductor chip 11 can be detected by performing pattern matching processing or edge detection processing on the image data captured by the camera 1. As shown in FIG. 5, the corners 11b and 11c are captured by the camera 2 so as to be substantially at the centers of the captured images 13 and 13 of the camera 2.
[0064]
In this manner, if the position of the semiconductor chip 11 is known, the driving of the head 3 is controlled thereafter, so that the needle 1 can be positioned at the coordinates to be potted and potting can be performed.
[0065]
Here, the above-described position correction of the needle 1 has already been performed, and X and Y (actual position coordinates of the needle 1 with respect to the camera 2) obtained by the above-described equations (3) and (4) are used for potting control. It is assumed that it is registered in the unit 6.
[0066]
Thus, if the head 3 is moved to a preset potting position on the XY coordinate table, the resin from the needle 1 is dropped on the potting position with high precision.
[0067]
Note that the potting performed here is underfill potting as described above, and as described with reference to FIG. 6, the center 1 a of the tip of the needle 1 is positioned at the base of the side surface 11 a of the semiconductor chip 11 with respect to the tape substrate 12. The resin is dropped.
[0068]
In the present embodiment, since the accuracy of the potting position is improved, the needle 1 moves in one direction (the direction of arrow X) along one side surface 11a of the semiconductor chip 11, as shown in FIG. Just move it in one stroke. As described above, since the accuracy of the potting position is improved, even if the resin is dropped only while the needle 1 is moved along only the one side surface 11a having the width, the dropped resin is removed by the semiconductor chip due to the capillary phenomenon. 6, the resin flows into a small gap formed between the back surface of the tape substrate 12 and the front surface of the tape substrate 12, and the resin further flows out from the side surface 11d on the opposite side of the semiconductor chip 11 and the side surface 11e in the transport direction. As shown, the semiconductor chip 11 covers all the side surfaces 11a, 11d, 11e, and 11f.
[0069]
The advantages of potting by dropping the resin while moving the needle 1 in one direction in a single stroke as described above include the simplification of the potting operation and the fact that bubbles are hardly generated in the applied resin. Can be In this one-stroke application, in this embodiment, the application amount to one semiconductor chip 11 is 4 mmg, the application pressure of the needle 1 at the time of application is 2.1 kpa (kilopascal), and the epoxy resin is used. Has a viscosity of 0.5 Pas (Pascal second) and a cycle time of 6.0 seconds. The application pressure is preferably from 0.85 to 3.43 kpa, and the viscosity is preferably from 0.2 to 0.7 Pas.
[0070]
When performing such underfill potting, the distance between the tip side surface of the needle 1 and the side surface of the semiconductor chip 11 is about 0.1 mm as described in FIG. 6, and the inner diameter of the needle 1 is 0.1 mm. Since each is an extremely fine numerical value such as 2 mm to 0.5 mm and its outer diameter is 0.4 mm to 0.8 mm, the position of the needle 1 with respect to the semiconductor chip 11 when the resin is dropped is extremely high precision. Positioning is required.
[0071]
In order to determine the potting position of the needle 1 with high accuracy, it is necessary to appropriately maintain the distance between the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1 as described above. Therefore, in order to realize this, the position correction of the needle 1 as described above is effective. This position correction of the needle 1 can be performed as necessary, for example, when the needle 1 is replaced or when the position of the needle 1 needs to be readjusted after a long-term resin application operation.
[0072]
The distance between the optical axis 2a of the camera 2 and the center 1a of the tip of the needle 1 in the X-axis direction and the distance in the X-axis direction on the XY coordinate table of the needle 1 with respect to the camera 2 Since the calculation is performed based on the actually dropped position, a proper value can be obtained, and by registering the interval, highly accurate position control of the needle 1 can be performed. For this reason, the semiconductor chip 11 can be securely fixed to the tape substrate 12, and a problem that the semiconductor chip 11 peels off from the tape substrate 12 can be prevented.
[0073]
It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the needle position correcting method of the present invention is an example in which the glass jig 5 causes the needle 1 to drop resin in a matrix form at nine locations in each of three locations in the axial direction and the Y-axis direction. However, this is not limited to nine locations. For example, the resin may be dropped in a matrix at two locations in the X-axis direction and the Y-axis direction, respectively, or in four locations in the X-axis direction and the Y-axis direction, respectively. Can be dropped in a matrix, and the number thereof can be set arbitrarily.
[0074]
In the above-described embodiment, the needle 1 and the camera 2 are attached to one head 3, and the needle 3 is driven to move the needle 1 and the camera 2 integrally on the two-dimensional seating table. As described in the example, the needle 1 and the camera 2 do not necessarily have to be attached to one head 3. In other words, if the configuration is such that both can be moved while maintaining a preset interval, the needle 1 and the camera 2 do not necessarily need to be attached to one head 3, and they are provided separately. You can also.
[0075]
In addition, the one-stroke application in only one direction described in the above-described embodiment is suitable not only for the above-described needle position correction method but also for the case where the correction is performed by another position correction method. It will be. This one-stroke application can also be applied to a potting device that does not perform position correction, as long as the position accuracy of the needle 1 is maintained at a high level.
[0076]
Further, in the potting device 22 of the above-described embodiment, the case where the head 3 including the camera 2 and the needle 1 is one, that is, the one-head system has been described as an example, but this is limited to the one-head system. is not. For example, a potting apparatus in which a plurality of heads such as a two-head system are provided, and each head performs potting on the semiconductor chip 11 on the tape substrate 12 may be used. When performing the needle position correction in such a potting apparatus, the above-described needle position correction method may be applied to each head.
[0077]
【The invention's effect】
As described above, according to the needle position correction method of the present invention, the position difference between the needle position on the two-dimensional coordinate table and the actual drop position coordinates (when the two-dimensional coordinates are XY coordinates, , The displacement in the X-axis direction and the displacement in the Y-axis direction) to correct the distance between the imaging device and the needle. For example, when the needle is replaced, the needle position with respect to the imaging device is changed. Can be properly corrected, and the positional relationship between the imaging device and the needle can always be properly maintained. For this reason, the dropping position of the resin can be controlled with high accuracy.
[0078]
In addition, the potting device of the present invention can always maintain the positional relationship between the imaging device and the needle properly even at the time of replacement of the needle by applying the above-described needle position correction method, and can drop the resin. The position can be controlled with high precision, and highly accurate potting can be performed.
[Brief description of the drawings]
FIG. 1 is a diagram showing components necessary for describing an embodiment of a needle position correcting method according to the present invention.
FIG. 2 is a diagram illustrating a distance between an optical axis of a camera as an imaging device illustrated in FIG. 1 and a center of a tip of a needle as a distance in an X-axis direction and a distance in a Y-axis direction on XY coordinates.
FIG. 3 shows a theoretical drop position coordinate on an XY coordinate table of a total of nine 3 × 3 resins (drop resin) dropped in a matrix on a glass jig, and coordinates of an actual drop position. FIG. 7 is a diagram for explaining a deviation from the above.
FIG. 4 is a diagram showing a schematic configuration of a potting system in which the potting device according to the embodiment of the present invention is incorporated.
FIG. 5 is a view for explaining the movement of a needle when underfill potting is performed by the potting device shown in FIG. 4;
FIG. 6 is a diagram illustrating an example in which underfill potting is performed on a semiconductor chip mounted on a tape substrate.
[Explanation of symbols]
1 needle
1a Center of tip of needle
2 Camera (imaging device)
2a Optical axis of camera
3 head
4 Head drive unit
5 Glass jig (resin dropping position measurement jig)
6 Potting control unit
11 Semiconductor chip
12 Tape substrate
21 Tape substrate supply device
22 Potting equipment
23 Resin curing device
24 Tape substrate winding device
223 Potting unit

Claims (8)

A needle position correction method for a resin coating device for coating a resin from a needle on a tape, wherein the needle position correction for correcting a needle calculation position calculated from predetermined parameters with a needle coating position for actually applying the resin. In the method,
Applying the resin from the needle to the preset position in a point-like manner, calculating the plane center of gravity of the resin from the outer shape of the resin applied in the form of a point, and setting the plane center of gravity position as the needle application position, A needle position correction method, wherein the needle calculation position corresponding to the preset position is corrected by the preset needle application position corresponding to the preset position. The preset position where the resin is applied is composed of a plurality, and the average value of the needle calculation positions corresponding to the position is corrected by the average value of the needle application positions corresponding to the position. The method according to claim 1, wherein The difference between the position on the two-dimensional coordinates of the center of the tip of the imaging device and the position on the two-dimensional coordinates of the optical axis of the imaging device is defined as an interval with the imaging device, and position control is performed based on this interval. In a needle position correction method for performing position correction on the two-dimensional coordinates with respect to the imaging device of the needle for dropping a viscous liquid resin,
The needle is positioned at a plurality of predetermined coordinates on two-dimensional coordinates, and the position thus determined is set as a theoretical drop position coordinate, and the resin is measured from the needle for each theoretical drop position coordinate. The actual drop position coordinates of each resin are obtained by taking an image of the dropped resin for position measurement by the imaging device, and the actual drop position coordinates and the theoretical drop of the needle are dropped. A method of correcting a needle position, wherein a deviation from a position coordinate is obtained, and the deviation is used to correct a needle position with respect to the imaging device. The deviation between the actual dropping position of the needle and the theoretical dropping position coordinates is, for each resin dropped at the theoretical dropping position coordinates, the respective theoretical dropping position coordinates and the respective actual dropping position. 4. The needle position correcting method according to claim 3, wherein the difference is obtained by calculating a difference from the coordinates and averaging the obtained differences. When calculating the average of the difference, of the resin for position measurement at a plurality of locations dropped on the theoretical dropping position coordinates, the resin for position measurement dropped first is a calculation target when calculating the average. The needle position correcting method according to claim 4, wherein the needle position is set outside. 6. The needle position correcting method according to claim 3, wherein each of the resins for position measurement is arranged in a matrix of 3 × 3 on the two-dimensional coordinates. A tape substrate feeding mechanism for feeding a tape substrate on which a semiconductor is mounted; moving means for moving an imaging device and a needle to a preset position on a two-dimensional coordinate table while maintaining an interval between the two; And a potting control unit for performing control necessary for performing a potting operation, and a position on a two-dimensional coordinate of a center of a tip of the needle with respect to a position on a two-dimensional coordinate of an optical axis of the imaging device. Is the distance between the imaging device and the needle, the position of the needle is controlled based on this distance, and a potting device for potting the semiconductor by dropping viscous liquid resin from the tip of the needle. At
The position on the two-dimensional coordinate of the center of the tip of the needle with respect to the position on the two-dimensional coordinate of the optical axis of the imaging device has been corrected by the needle position correcting method according to any one of claims 1 to 6. After that, the potting position control of the needle is performed by controlling the driving of the moving means based on the corrected position information. The potting is underfill potting, and when applying resin to the semiconductor by the needle, the resin is applied by moving the needle in one direction from the resin application start position in one stroke. The potting device according to claim 7, wherein

Images