JP3534045B2 - Die bonding apparatus and die bonding method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die bonding apparatus and a die bonding method for linearly mounting a rectangular chip on a substrate.

[0002]

2. Description of the Related Art A thermal head substrate for a printer or an image sensor substrate for a scanner is formed by linearly mounting rectangular semiconductor chips on a substrate. In these types of substrates, it is required to keep the chip interval between adjacent chips within a predetermined allowable range. As a die bonding apparatus for such a substrate, there is known a die bonding apparatus that secures the interval accuracy between chips by recognizing the approaching portion with an adjacent chip with a camera during a mounting operation (Japanese Patent No. 2751536). (See the official gazette).

In this method, after a chip is mounted by a transfer head on an adhesive material previously applied to a substrate, the chip is held by the transfer head, and the approaching portion between this chip and an already mounted adjacent chip is placed. It is recognized by the camera and the positional deviation error of the interval between these chips is detected. Then, the transfer head is moved relative to the substrate while being pressed against the substrate to correct the positional deviation error.

[0004]

Recently, as the performance of printers and scanners has been improved, it has become necessary to more strictly manage the intervals between these chips. However, in the above-mentioned conventional die bonding apparatus, relative slip is liable to occur between the transfer head and the chip during the position correction operation after mounting the chip, and it is difficult to accurately move the chip on the adhesive material by the position correction amount. there were. Therefore, even after the position correction operation, the intervals between the chips cannot be maintained accurately, and there is a problem in that mounting defects occur.

Therefore, it is an object of the present invention to provide a die bonding apparatus and a die bonding method which keep the distance between chips accurate and have excellent mounting position accuracy.

[0006]

A die bonding apparatus according to claim 1, wherein a moving table on which a substrate is placed, a transfer head for transferring and mounting a rectangular chip on the substrate, and a transfer for holding the chip. Pressing means for pressing the head against the substrate, and moving for moving the substrate on the moving table relative to the chips held by the transfer head while the chip is pressed against the upper surface of the substrate by the pressing means. Means and
A camera for observing the approaching portion of the chip pressed against the substrate by the transfer head and the adjacent chip already mounted, and the magnitude of the pressing load of the pressing means are set by the adhesive material for bonding the chip to the substrate. press spread chip and the first pressing load of order to stabilize the posture of the chip, by the first pressing load
After stabilizing the posture of the
With the pressing load when correcting the displacement of the tip by the movement
And a control means for switching to a second pressing load lower than the certain first pressing load.

The die bonding apparatus according to claim 2 is
The die bonding apparatus according to claim 1, wherein the transfer head includes ridge lines of two opposing sides of the chip,
The chip has an inner wall surface that abuts the ridgeline of one side orthogonal to the two sides, and the other side of the chip has an opening projecting outward.

The die bonding method according to claim 3 is
A step of mounting a chip by a transfer head on a substrate to which an adhesive is applied in advance; and a step of pressing the transfer head against the substrate with a first pressing load by a pressing means to spread the adhesive and spread the chip. a step of attitude Ru to stabilize,
After that, a step of switching to a second pressing load lower than the first pressing load by controlling the pressing means, and an approaching portion between the chip pressed against the substrate by the transfer head and the already mounted adjacent chip Is observed with a camera, and based on this observation result, the chip pressed by the second pressing load is moved relative to the substrate to correct the position.

According to the present invention, the transfer head is pressed against the substrate by the pressing means with the first pressing load to spread the adhesive material, and then the pressing means is controlled to lower the first pressing load. By performing the position correction by relatively moving the chip with respect to the substrate in the state where the pressing load is switched to the two pressing loads, the relative slip between the chip and the substrate can be made favorable and the accurate position correction can be performed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 is a side view of a die bonding apparatus according to an embodiment of the present invention, FIG. 2A is a perspective view of a die collet of a die bonding apparatus according to an embodiment of the present invention, and FIG. 4 is an inverted perspective view of the die collet of the die bonding apparatus according to the first embodiment, FIG. 3 is a perspective view of the die bonding apparatus according to the embodiment of the present invention, and FIG.
5 is a flow chart of a die bonding operation of an embodiment of the present invention, FIG. 5 is a graph showing a pressing load in the die bonding operation of an embodiment of the present invention, and FIG. 6 is a die bonding of an embodiment of the present invention. It is explanatory drawing of operation.

First, the structure of the die bonding apparatus will be described with reference to FIG. In FIG. 1, a substrate 3 is placed on a moving table 1. The moving table 1 is driven by the table driving mechanism 2, and by driving the table driving mechanism 2, the moving table 1 moves in the horizontal direction.

A transfer head 6 which is moved by a head moving mechanism 7 is arranged above the moving table 1.
The transfer head 6 is provided with a die collet 10 capable of moving up and down to suck and hold the rectangular chip 5. The transfer head 6 is controlled by controlling the head moving mechanism 7 by the control unit 16.
Moves horizontally and the chip 5 is taken out from the chip supply unit (not shown) by the die collet 10. By moving the transfer head 6 holding the chip 5 onto the moving table 1 and lowering the die collet 10, the chip 5 is mounted on the substrate 3 to which the bond 4 which is an adhesive material for chip bonding is applied in advance. To be done.

The die collet 10 is connected to the load generating section 8, and the chip 5 is pressed against the substrate 3 by the load generating section 8 in the chip mounting operation of lowering the die collet 10 holding the chip 5. . Load generator 8
The pressing load of the chip 5 can be set to a predetermined value by controlling the pressure of the chip 5 by the control unit (control means) 16. The chip 5 is fixed and mounted on the substrate 3 by hardening the bond 4 while pressing the chip 5 against the substrate 3.

Next, the die collet 10 will be described with reference to FIG. The die collet 10 includes a pipe-shaped shank portion 9 and is detachably mounted by fixing the shank portion 9 to the mounting portion 8 a of the load generating portion 8.
As shown in FIG. 2B, the die collet 10 has a lower surface provided with a rectangular recess 10a for attracting chips. Of the four side wall portions of the recessed portion 10a, the three side wall portions 10b, 10c, and 10d remain, but the one side wall portion is removed to form the opening 10e.
The side walls 10b, 10c, 10d are formed with tapered inner wall surfaces 10f, 10g, 10h.

The die collet 10 is for adsorbing a rectangular chip which is a component such as a thermal head of a printer, and has a long inner wall surface 10g, 10h.
Is in contact with the ridgelines of two opposite long sides of the chip 5, and the short inner wall surface 10f is in contact with the ridgeline of one short side of the chip 5 orthogonal to the two sides, and the other of the chips 5 is The short side projects outward from the opening 10e. The imaginary line L is the contact line of the ridgeline of the chip 5. That is, this die collet 10 has three of the four ridgelines of the chip 5.
This chip 5 is positioned from three directions by abutting against the side.

FIG. 3 shows a state in which a long chip 5 is mounted on a substrate 3 by a die bonding apparatus equipped with this die collet 10. Moving table 1
The bond 4 is applied to the substrate 3 placed on the above,
The chip 5 is linearly mounted on the bond 4. On the upper surface of the chip 5, constituent parts of an electric circuit such as bright spots 5a and electrode parts are arranged in parallel at equal pitches. Further, on the substrate 3, constituent parts of an electric circuit such as the electrode parts 3b are formed at equal pitches. Reference numeral 3a is a position reference mark formed at the corner of the substrate 3. The die collet 10 is the transfer head 6
(FIG. 1), the chip 5 is taken out from the chip supply unit (not shown) and transferred and mounted on the substrate 3.

In FIG. 1, an image pickup section 11 is arranged above the moving table 1. The image pickup unit 11 includes a camera 12 and a lens barrel 13, and a mirror 14 is provided inside the lens barrel 13. By positioning the opening provided on the lower surface of the lens barrel 13 at the imaging site, the mirror 1
The light guided by 4 is made incident on the camera 12 to capture an image of the imaged region. The recognition unit 15 performs image processing on the captured image to recognize the approaching portion between the chip 5 that is the imaging region and the already mounted adjacent chip 5.

As a result, the position of the bright spot portion 5a of the chip 5 is recognized. Then, the position of the chip 5 is corrected based on the position of the bright spot portion 5a obtained here. That is, the chips 5 are aligned so that all the bright spots 5a of each chip 5 mounted in a straight line maintain good alignment and the pitch between the bright spots 5a is maintained at a predetermined pitch t. To be done.

The present apparatus has the above-mentioned structure. Next, the die bonding method will be described with reference to the drawings. Here, an operation for newly bonding the chip 5C to the substrate 3 in a state where the bond 4 has already been applied and the preliminarily mounted chips 5A and 5B have already been mounted is shown.

First, the transfer head 6 is moved onto a chip supply unit (not shown), and the die collet 10 holds the chip 5 by suction. Next, the transfer head 6 is moved onto the moving table 1, and the die collet 10 holding the chips 5 is attached to the substrate 3.
(ST1). Next, the die collet 10 is lowered to land the chip 5C on the bond 4 adjacent to the already mounted chip 5B (ST2).

Next, as shown in FIG. 5, at the timing t1 when the chip 5C lands, the load generator 8 presses the chip 5C against the substrate 3 with the first pressing load F1,
The bond 4 on the lower surface of the chip 5C is spread (ST3).
When the bond 4 is expanded and the posture of the chip 5C is stabilized, the load generation unit 8 is set to the control unit 16 at timing t2.
The pressure load of the chip 5C is reduced to the second pressure load F2 as shown in FIG. 5 (ST4).

After this, as shown in FIG.
The approaching portion of the mounted chip 5B adjacent to C is located below the imaging unit 11. Then, at timing t3, the approaching portion is imaged by the camera 12 through the lens barrel portion 13 and is recognized by the recognizing portion 15, and the positional deviation of the chip 5C is detected (ST5). That is, here, in FIG.
As shown in (c) respectively, chip 5B and chip 5C
The relative positional deviations Δx and Δy with respect to and are detected.

At a timing t4, the table driving mechanism 2 is driven to move the substrate 3 in the X direction and the Y direction.
The position shifts are corrected by moving Δx and Δy respectively in the directions (ST6). As a result, the chip 5C is bonded to the already mounted chip 5B while the alignment of the bright spots 5a is properly maintained and the pitch between the bright spots 5a is correctly maintained at the predetermined value t. Then, the die collet 10 is raised to complete the die bonding operation.

In the above bonding operation, the chip 5
The pressing load for pressing C against the substrate 3 is lower than this load after the chip 5C is stably pressed with the proper load (first pressing load) necessary to spread the bond 4. The positional deviation is corrected while being pressed by the second pressing load). Therefore, the slip of the chip 5C on the upper surface of the substrate 3 coated with the bond 4 is not hindered by an excessive pressing load. As a result, the chip 5C is surely moved by the amount of movement of the substrate 3 when the positional deviation is corrected, and accurate position correction is performed. Therefore, it is possible to accurately maintain the distance between the chips and perform die bonding with excellent mounting position accuracy. .

[0025]

According to the present invention, the transfer head is pressed against the substrate with the first pressing load by the pressing means to spread the adhesive material, and then the pressing means is controlled so that the pressure is lower than the first pressing load. The position is corrected by moving the chip relative to the substrate in a state where the pressure is switched to the low second pressing load, so that the relative slip between the chip and the substrate is improved and accurate position correction is performed. Therefore, it is possible to perform die bonding excellent in mounting position accuracy by accurately maintaining the interval between chips.

[Brief description of drawings]

FIG. 1 is a side view of a die bonding apparatus according to an embodiment of the present invention.

FIG. 2A is a perspective view of a die collet of a die bonding apparatus according to one embodiment of the present invention. FIG. 2B is an inverted perspective view of the die collet of the die bonding apparatus of one embodiment of the present invention.

FIG. 3 is a perspective view of a die bonding apparatus according to an embodiment of the present invention.

FIG. 4 is a flow chart of a die bonding operation according to an embodiment of the present invention.

FIG. 5 is a graph showing a pressing load in a die bonding operation according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a die bonding operation according to the embodiment of the present invention.

[Explanation of symbols]

1 Moving table 3 substrates 5 chips 6 Transfer head 8 load generator 10 die collet 12 cameras 15 Recognition part 16 Control unit

Claims (3)

(57) [Claims] 1. A moving table on which a substrate is placed, a transfer head for transferring and mounting rectangular chips on the substrate, pressing means for pressing the transfer head holding the chips against the substrate, and the pressing device. Moving means for moving the substrate on the moving table relative to the chip held by the transfer head in a state where the chip is pressed against the upper surface of the substrate by means, and a state of being pressed against the substrate by the transfer head. a camera for observing the approach portion of the Aitonaru chip of the chip and already mounted, the size of the pressure load of the pressing means, Ru stabilize the posture of the chip push the adhesive to bond to the substrate tip And a first pressing load for
After stabilizing the posture,
Therefore, it is the pressing load when correcting the displacement of the tip.
Die bonding apparatus characterized by comprising a control means for switching the second pressing load is lower than said first pressing force. 2. A die collet, which is provided in the transfer head and holds the chip by suction, contacts a ridge line of two opposite sides of the chip and a ridge line of one side orthogonal to the two sides. 2. The chip has a wall surface, and the other side of the chip has an opening projecting outward.
The described die bonding apparatus. 3. A step of mounting a chip by a transfer head onto a substrate to which an adhesive material has been applied in advance, and a step of pressing the transfer head against the substrate with a first pressing load to attach the chip to the adhesive material. Spread the tip to stabilize the posture of the tip
A step that was followed the steps of switching to the second pressing load is lower than said first pressing load by controlling the pressing means, the phase state of being pressed to the substrate chip and already mounted by the mounting head Tonariru A step of observing a portion approaching the chip with a camera, and a step of correcting the position by relatively moving the chip pressed by the second pressing load with respect to the substrate based on the observation result. Characteristic die bonding method.