JP2002151528A - Die bonding sheet sticking device and method of sticking die bonding sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sticking device which sticks a sheet functioning as a protective sheet at the time of dicing a semiconductor chip and also functioning as an adhesive for die bonding to the rear of a wafer. SOLUTION: This die bonding sheet sticking device is equipped with a wafer carrier which takes out a wafer stored in a wafer supplier and carries it, an alignment part which positions a wafer taken out of the wafer supplier, a sheet sticker which sticks a die bonding sheet equipped with a separation sheet and a base material having a heat sensitive adhesive layer to the rear of a wafer by heating it, and a sheet separator which separates the separation sheet of the die bonding sheet from the wafer where the die bonding sheet is stuck in the sheet sticker, and this sheet sticker is equipped with a cutting means which cuts the heat sensitive adhesive base material of the die bonding sheet into the external form of the wafer before sticking the die bonding sheet to the rear of the wafer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die which also functions as an adhesive for die bonding when a semiconductor chip is die-bonded to a lead frame after dicing in a manufacturing process of a small electronic component such as a semiconductor chip. The present invention relates to a die bonding sheet bonding apparatus and a die bonding sheet bonding method for bonding a bonding sheet to a back surface of a wafer.

[0002]

2. Description of the Related Art Conventionally, for example, to manufacture a semiconductor wafer such as silicon (hereinafter simply referred to as "wafer"), a large-diameter disk is manufactured, and a circuit pattern is formed on the surface thereof. After protecting the surface with a protective tape and grinding the back surface, attaching the back surface of the wafer to a ring frame via an adhesive sheet, peeling off the protective tape on the surface, and then using a dicing cutter It is cut and separated (diced) into a large number of chips in a dice pattern, and in this state, it is transferred to the next steps such as washing, drying, die bonding and the like.

[0003]

Conventionally, as a method of attaching an adhesive sheet to the back surface of a wafer, there is a method shown in FIG.
As shown in FIG. 5, the wafer W is placed on the holding table 200, and the pressure-sensitive adhesive sheet 202 including the base sheet 204 and the pressure-sensitive adhesive layer 206 is attached to the back surface W3 of the wafer W. The adhesive sheet 202 is cut by rotating the cutter 210 along the outer shape (outer circumference) W4 of the wafer W.

However, recently, semiconductor chips such as IC cards have been required to be thinner and thinner, and the demand for semiconductor chips as thin as about 300 μm in recent years to about 100 to 50 μm has been increasing. In order to obtain such a chip, an extremely thin wafer having the above thickness is required. In the case of such an ultra-thin wafer, when cutting the adhesive sheet 202 with such a cutter 210,
There is a possibility that the outer peripheral portion W4 of the wafer W may be damaged or the wafer may be cracked.

In order to prevent such damage and cracking of the wafer, conventionally, in another step, the adhesive sheet is cut in advance into the outer shape of the wafer, and this is adhered to the back surface of the wafer. There are also ways to do that. Conventionally, an ultraviolet-curable pressure-sensitive adhesive sheet is used as an adhesive sheet, and ultraviolet rays are applied to the ultraviolet-curable pressure-sensitive adhesive sheet when a semiconductor chip cut into many chips is die-bonded (transferred) to a lead frame. By,
Die bonding is performed using a suction collet while reducing the adhesive strength of the sheet.

Further, at the time of die bonding, an adhesive is separately applied to a lead frame, and a semiconductor chip is die-bonded thereon. However, in any case, such separate steps are required, complicated steps are required, and the cost is currently high. The present invention, after dicing,
When a semiconductor chip is die-bonded to a lead frame, a series of steps of attaching a die bonding sheet, which also functions as an adhesive for die bonding, to the backside of the wafer, is performed continuously without damaging or cracking the wafer. Another object of the present invention is to provide an apparatus for attaching a die bonding sheet to a wafer that can be automatically implemented.

[0007]

According to the present invention, there is provided a die bonding sheet sticking apparatus comprising: a wafer supply unit for accommodating a plurality of wafers; and conveyance means for taking out and conveying the wafer accommodated in the wafer supply unit. A wafer transfer unit, an alignment unit that performs wafer positioning of the wafer taken out of the wafer supply unit via a wafer transfer unit of the wafer transfer unit, and the wafer positioned at a predetermined reference position in the alignment unit. A sheet bonding part which is conveyed through a conveying means, and which adheres to the back surface of the wafer by heating a die bonding sheet composed of a base material having a release sheet and a heat-sensitive adhesive layer; and The peeling sheet of the die bonding sheet is formed from the wafer to which the die bonding sheet is attached at the attaching portion. And a sheet peeling portion having a sheet peeling means for peeling, before the sheet sticking portion, for attaching the die bonding sheet to the back surface of the wafer,
A cutting means for cutting a substrate having the heat-sensitive adhesive layer of the die bonding sheet in an outer shape of the wafer is provided.

[0008] With this configuration, an alignment for taking out and positioning a wafer from a wafer cassette accommodating a plurality of wafers, a die bonding sheet including a release sheet and a base material having a heat-sensitive adhesive layer are provided. It is possible to continuously and automatically execute a series of steps of attaching the wafer to the back surface, peeling off the release sheet of the die bonding sheet, and storing the wafer in the wafer cassette.

In addition, when the semiconductor chip is die-bonded to the lead frame after dicing, it also functions as an adhesive for die bonding. Therefore, unlike the conventional method, it is not necessary to apply an adhesive to the lead frame at the time of die bonding, and by simply heating the die bonding sheet, the semiconductor chip can be sucked and picked up by the suction collet, and the die bonding sheet can be formed. The heat-sensitive adhesive layer functions as an adhesive to the lead frame, and can be directly thermocompression-bonded.

Further, before attaching the die bonding sheet to the back surface of the wafer, the substrate having the heat-sensitive adhesive layer of the die bonding sheet in the outer shape of the wafer is cut. When the sheet is cut, there is no fear that the outer peripheral portion of the wafer is damaged or the wafer is cracked, and it is not necessary to cut the die bonding sheet in advance in a separate process as in the related art.

Further, in the die bonding sheet sticking apparatus of the present invention, the cutting means may be moved up and down from below the die bonding sheet so that the cutting means comes into contact with the substrate having the heat-sensitive adhesive layer. A base having a possible cutting blade device and a heat-sensitive adhesive layer of the die bonding sheet by pressing the die bonding sheet downward from above the die bonding sheet when the cutting blade device is raised to an upper position. And a cutting press device for cutting the material.

According to this structure, the substrate having the heat-sensitive adhesive layer of the die bonding sheet can be easily and accurately cut. In addition, the die bonding sheet bonding apparatus of the present invention may be configured such that the sheet bonding section mounts the wafer and includes a mount table provided with a heater for heating the wafer, and the die bonding section heated by the mount table. A die bonding sheet is pressed downward from above the sheet, and the back surface of the wafer placed on the mount table is bonded to a substrate having the heat-sensitive adhesive layer of the die bonding sheet. And a device.

With this configuration, the substrate having the heat-sensitive adhesive layer can be easily and reliably adhered to the back surface of the wafer by heating the die bonding sheet. Further, in the die bonding sheet sticking apparatus of the present invention, the mount table has an outer peripheral portion of the mount table protruding upward, and an adsorbing portion that adsorbs an outer peripheral portion of a surface of the wafer; Formed on the circumferential side,
An air blow space for supporting the surface of the wafer upward from below by compressed air.

Since the mount table does not come into contact with the circuit pattern on the surface of the wafer, the circuit pattern is not damaged, and the whole surface of the wafer is supported by the compressed air. In addition, the wafer is not cracked, broken, or damaged when pressed downward by the sticking and pressing device when sticking the die bonding sheet. In the die bonding sheet sticking device of the present invention, the sticking and pressing device includes a fixed roller and a pressing and moving roller, and the fixed roller holds an upstream side of the wafer of the die bonding sheet. The pressing and moving roller is configured to move to the downstream side so that the die bonding sheet is attached to the back surface of the wafer.

[0015] With this configuration, the fixed roller holds the die bonding sheet on the upstream side of the wafer, and the pressing and moving roller moves to the downstream side, so that the gap between the back surface of the wafer and the die bonding sheet is formed. Air is discharged from the downstream side, so that no air is introduced between the back surface of the wafer and the die bonding sheet.
The die bonding sheet can be securely adhered to the back surface of the wafer.

Further, in the die bonding sheet sticking apparatus of the present invention, the sheet peeling section includes the mount table on which the wafer is placed, and the mount table has an outer peripheral portion protruding upward. A suction unit that suctions an outer peripheral portion of the surface of the wafer; and an air blow space formed on an inner circumference side of the suction unit and supporting the surface of the wafer upward with compressed air from below. Features.

Accordingly, the circuit pattern does not come into contact with the circuit pattern on the surface of the wafer, so that the circuit pattern is not damaged, and the entire surface of the wafer is supported upward by the compressed air. When peeling off the release sheet, the wafer may crack, break,
No damage. Further, in the die bonding sheet sticking apparatus of the present invention, the sheet peeling means includes a fixed roller and a pair of peeling moving rollers, and the fixed roller holds a downstream side of the die bonding sheet, The die bonding sheet is wound and sandwiched between a pair of the peeling transfer rollers, and the peeling transfer roller moves to the upstream side of the die bonding sheet, so that the release sheet of the die bonding sheet is removed from the wafer. Characterized in that it is configured to peel off.

Thus, the peeling sheet of the die bonding sheet can be reliably and easily peeled from the wafer. Further, in the method for attaching a die bonding sheet according to the present invention, the die bonding sheet including the release sheet and the substrate having the heat-sensitive adhesive layer is attached to the back surface of the wafer. Before, a die bonding sheet cutting step of cutting a substrate having a heat-sensitive adhesive layer of the die bonding sheet in the outer shape of the wafer, and the die cut in the outer shape of the wafer in the die bonding sheet cutting step. The die bonding sheet is heated, so that the die bonding sheet is bonded to the back surface of the wafer, and the die bonding sheet is bonded from the wafer to which the die bonding sheet is bonded in the die bonding sheet bonding step. And a sheet peeling step of peeling the release sheet. To.

With this configuration, since the die bonding sheet is composed of the release sheet and the base material having the heat-sensitive adhesive layer, the die bonding sheet functions as a protective tape at the time of dicing. It also functions as an adhesive for die bonding when the semiconductor chip is die bonded.

Therefore, unlike the related art, it is not necessary to apply an adhesive to the lead frame at the time of die bonding, and the semiconductor chip can be sucked and picked up by the suction collet only by heating the die bonding sheet. The substrate having the heat-sensitive adhesive layer of the die bonding sheet functions as an adhesive to the lead frame, and can be directly thermocompression-bonded.

Further, before attaching the die bonding sheet to the back surface of the wafer, the base material having the heat-sensitive adhesive layer of the die bonding sheet is cut into the outer shape of the wafer. When the sheet is cut, there is no fear that the outer peripheral portion of the wafer is damaged or the wafer is cracked, and it is not necessary to cut the die bonding sheet in advance in a separate process as in the related art.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the die bonding sheet sticking apparatus according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a top view of the entire apparatus of the embodiment of the die bonding sheet sticking apparatus of the present invention, FIG. 2 is a view of the die bonding sheet sticking apparatus of FIG. 1 as viewed in the direction of arrows II-II, and FIG. FIG. 3 is a view of the die bonding sheet attaching device of FIG.

In FIG. 1, reference numeral 1 denotes an apparatus for attaching a die bonding sheet to a semiconductor wafer of the present invention (hereinafter, simply referred to as “applying apparatus 1”). Sticking device 1
As shown in FIG. 1, a wafer supply unit 10 for accommodating a plurality of wafers W, a wafer conveyance unit 20 for conveying the wafers W accommodated in the wafer supply unit 10, and a wafer supply unit 10 As shown in FIG. 4, an alignment unit 30 for positioning the wafer W taken out of the wafer W and a back surface W3 of the wafer W positioned by the alignment unit 30 (that is, a surface on which a circuit pattern is not formed),
A sheet to which a sheet (hereinafter, referred to as “die bonding sheet 2”) in which a release sheet is adhered to both sides of a substrate having a heat-sensitive adhesive layer on both sides (hereinafter, referred to as “thermosensitive adhesive substrate 7”) is attached. The sheet bonding unit 40 includes a sticking unit 40 and a sheet peeling unit 50 that peels off the peeling sheet 4 (4A) of the die bonding sheet 2 from the wafer W to which the die bonding sheet 2 is stuck by the sheet sticking unit 40.

As the die bonding sheet 2, for example, the substrate 6 can be made of PET (polyethylene terephthalate) resin, and the heat-sensitive adhesive layer 5 can be made of polyimide resin. However, the present invention is not limited thereto, and any substrate having a heat-sensitive adhesive layer may be used. As shown in FIGS. 1 and 3, in the wafer supply unit 10, a wafer carrier (wafer carrying container) 12 or a wafer supply box (not shown) in which wafers W are stacked and housed are mounted on a lifting drive motor 14.
And a drive device such as a ball screw mechanism 16, which is removably disposed on the wafer supply unit 10 so as to be vertically movable.
A plurality of shelves (not shown) each having a convex portion formed in the wafer carrier 12 contain a plurality of wafers W in each stage of the shelves. In addition, in FIG.
Upper and lower 2 used alternately to perform the operation of
One wafer carrier 12 is shown.

Further, although not shown, a wafer detection sensor (light transmission type or light reflection type sensor or the like) is attached to the wafer supply unit 10, and the wafer W is moved by the sensor while moving the wafer carrier 12 up and down. Each stage position,
The number of sheets and the like can be detected. Note that the wafer supply unit 10 may be a wafer supply box in which a buffer sheet is laid between wafers and stacked in order to protect a circuit surface.

As shown in FIG. 1, the wafer transfer section 20
This is a robot provided with a multi-axis movable arm 22. The movable arm 22 allows the robot to use arrows (1) to (4) shown in FIG.
In this order, the wafer W can be transferred between the wafer supply unit 10, the alignment unit 30, the mount table 42, and the sheet peeling unit 50.

The tip of the movable arm 22 has
A suction member 24 connected to a vacuum source (not shown) is provided, and the wafer W can be suction-fixed by a negative pressure by the suction member 24 that suctions the wafer W onto the movable arm 22. Wafer transfer unit 2 configured as above
No. 0 detects the step position, the number of wafers W of the wafer carrier 12 of the wafer supply unit 10, and moves the wafer transfer unit 20 up and down on the basis of the detection result, thereby storing the wafer W in the shelf of the wafer carrier 12. The held wafer W is moved to the suction member 2 of the movable arm 22 as shown by an arrow (1) in FIG.
4, the wafer W is suction-fixed and taken out.

Then, the wafer W taken out from the wafer supply unit 10 is fixed by suction to the suction member 24 at the tip of the movable arm 22 with the circuit surface facing upward, and the movable arm 22 turns the alignment unit 30 for positioning the wafer. The data is transferred onto the table 32 (arrow (2) in FIG. 1). In the alignment unit 30, although not shown, an orientation flat (orientation flat) portion or a V-notch portion whose peripheral edge is formed in a straight line as a reference portion formed on the wafer W is rotated by rotating the wafer W to a sensor (not shown). And performs alignment (positioning).

As described above, the wafer W, the alignment of which has been completed by the alignment unit 30, releases the suction of the turntable 32, is suction-fixed on the movable arm 22, and is further attached to the movable arm 22 (not shown). The wafer heating and bonding unit 4 of the sheet bonding unit 40 for bonding the die bonding sheet 2 to the back surface of the wafer W with the back surface of the wafer W turned upside down by turning the wafer W up and down by 180 ° by the reversing mechanism.
5 (see arrow (3) in FIG. 1).

As shown in FIGS. 1, 2 and 5, the sheet sticking section 40 is a wafer heating sticking section 45 for receiving the aligned wafer W carried by the movable arm 22.
And a sheet feeding section 44 for feeding out the die bonding sheet 2, a sheet cutting section 46 for cutting the die bonding sheet 2, and a sticking pressing section 48 for sticking the die bonding sheet 2 to the back surface of the wafer W. ing.

In the wafer heating / adhering section 45, the movable arm 2
2. The wafer W transferred by the
It is transferred to the top and held by suction. As shown in FIG. 1, FIG. 2 and FIG. 5, the mount table 42 is moved along the guide rail 60 by a driving mechanism such as a cylinder mechanism (not shown), as shown by an arrow A, at the standby position 41 (movement of the wafer W). It can be moved between the mounting position (dotted line position in FIG. 5) and the sticking position (solid line position in FIG. 5).

As shown in FIGS. 2 and 5, the sheet feeding section 44 has the die bonding sheet 2 wound around a feed roller 62, and the die bonding sheet 2 fed from the feed roller 62 is guided by a guide. Roller 6
4, via a peeling roller 66 and a tension roller 68, to a cutting / sticking position 70. At this time, the release sheet 4 of the die bonding sheet 2
B is sharply folded by the peeling roller 66 and peeled off from the die bonding sheet 2, and is wound around the peeling material winding section 75 via the guide roller 72.

The die bonding sheet 2 which has reached the cutting / sticking position 70 is vertically movable along a guide rail 74 in the sheet cutting section 46 as shown in FIG. 9) rises from below the die bonding sheet 2 as shown by an arrow B, and the cutting blade 78 formed in the outer shape of the wafer W rises to a position where it comes into contact with the heat-sensitive adhesive base 7 of the die bonding sheet 2. I do.

At this time, as shown in FIGS. 6 and 7, the sheet cutting / pressing device 82 which can move up and down along the guide rail 80 moves downward, and the cutting / pressing roller 84 provided thereunder is moved. Along the guide rail 86, the C direction,
That is, by moving in a direction perpendicular to the feeding direction of the die bonding sheet 2, the die bonding sheet 2 is pressed downward from above the die bonding sheet 2, and the heat-sensitive adhesive substrate 7 of the die bonding sheet 2 is
The wafer W is cut into an outer shape to form a cut 88 (FIG. 9). At this time, the cut 88
The precise position of the cutting blade device 76 is adjusted by driving the cylinder 90 by a control device (not shown).

At this time, the mount table 42
It is in the standby position 41 (the dotted line position in FIG. 5). After the cut 88 is formed in the heat-sensitive adhesive substrate 7 of the die bonding sheet 2 in the outer shape of the wafer W in this manner, the cutting blade device 7
6 moves downward and the sheet cutting and pressing device 82
Move to the standby position. At this time, the cutting pressure roller 84 also returns to the original position.

In this state, the mount table 42 at the standby position 41 (dotted line position in FIG. 5) moves to the sticking position (solid line position in FIG. 5) as shown by the arrow A in FIGS. I do. As shown in FIG. 8, the outer periphery of the mount table 42 projects upward, and the mount table 42 has an adsorbing portion 92 for adsorbing the outer peripheral portion W1 on the surface of the wafer W. An air blow space 94 is formed on the inner peripheral side of the air blower.

The suction portion 92 is about 3 m from the outer diameter of the wafer W.
Since it is formed with a width of about m and comes into contact with a portion of the wafer W where no circuit pattern is formed, the circuit pattern of the wafer W is not affected. The suction unit 92 is connected to a vacuum source (not shown).
The outer peripheral portion W1 of the wafer W is attracted by the action of the negative pressure.

The compressed air P is supplied to the air blow space 94 at a constant pressure through an air supply pipe 96 connected to an air supply source (not shown), and the compressed air P is supplied to the surface W2 of the wafer W at a constant pressure. It is supported entirely upward (arrow P in FIG. 8). In this state, the mount table 42 moves to the sticking position (solid line position in FIG. 5), and as shown in FIG. 8, the back surface W3 of the wafer W (that is, the surface on which the circuit pattern is not formed) Die bonding sheet 2 in which cut 88 is formed in the outer shape of wafer W
To the heat-sensitive adhesive base material 7. At this time, the accurate position of the back surface W3 of the wafer W is adjusted by driving the cylinder 98 by a control device (not shown) to adjust the amount of elevation of the mount table 42.

Note that the mount table 42 is provided with a heater 43, and the heat-sensitive adhesive layer 5 of the die bonding sheet 2 is heated via the wafer W to increase the adhesiveness. I have. Such a temperature is set to a temperature that does not affect the performance of the wafer W, depending on the type of the heat-sensitive adhesive. In this state, the die-bonding sheet 2 is pressed downward from above the die-bonding sheet 2 by the sticking pressing unit 48, and the back surface W <b> 3 of the wafer W mounted on the mount table 42 is heated by the heat-sensitive material of the die-bonding sheet 2. The adhesive is attached to the adhesive base material 7.

That is, as shown in FIG. 2, FIG. 5 and FIG. 8, the sticking / pressing portion 48 is composed of a fixed roller 102 and a pressing / moving roller 104 disposed downstream thereof. 102 is a die bonding sheet 2
The pressing movement roller 104 moves downstream in the direction of arrow D in FIG. 8 while pressing the die bonding sheet 2 downward from above while holding the upstream side of the wafer W. The heat-sensitive adhesive substrate 7 of the die bonding sheet 2 is attached to the die bonding sheet 2 (FIG. 8).

As described above, the fixed roller 102 holds the upstream side of the wafer W of the die bonding sheet 2, and the pressing moving roller 104 moves to the downstream side, so that the back surface W 3 of the wafer W and the die bonding sheet 2 Since the air between the heat-sensitive adhesive substrate 7 and the air is discharged from the downstream side,
The heat-sensitive adhesive substrate 7 of the die bonding sheet 2 is securely attached to the rear surface W3 of the wafer W without blowing air between the back surface W3 of the wafer W and the heat-sensitive adhesive substrate 7 of the die bonding sheet 2. can do.

At this time, since the entire surface W2 of the wafer W is supported upward by the air, the sticking pressing portion 48 is pressed downward by the pressing moving roller 104 by the bonding of the die bonding sheet 2. In the case of the wafer W
Is not cracked, broken or damaged. in this way,
After the heat-sensitive adhesive base material 7 of the die bonding sheet 2 is attached to the back surface W3 of the wafer W by the attachment pressing unit 48, the suction of the suction unit 92 of the mount table 42 is released, and the mount table 42 is removed. Attachment position (Fig. 5
Is moved from the solid line position) to the standby position 41 (the dotted line position in FIG. 5), and a new wafer W that has been aligned by the alignment unit 30 is again transferred to the mount table 42 by the movable arm 22 of the wafer transfer unit 20. Is conveyed.

On the other hand, with the heat-sensitive adhesive substrate 7 of the pre-cut die bonding sheet 2 adhered to the back surface W3 of the wafer W, the die bonding sheet 2 is placed on the downstream side while the wafer W is adhered. The sheet is conveyed to the sheet peeling section 50. In the sheet peeling section 50, the peeling sheet 4A of the die bonding sheet 2 is peeled from the wafer W to which the portion where the heat-sensitive adhesive base material 7 of the die bonding sheet 2 is precut in the sheet bonding section 40 is bonded. .

That is, as shown in FIGS. 2 and 10, the die bonding sheet 2 is provided with a pair of peeling moving rollers 108 as a sheet peeling means.
The die bonding sheet 2 is wound and pinched between the rollers 110, guided by a fixed roller 112, and wound around a scrap take-up roller 114. Also, as shown in FIGS. 1, 2 and 10, the die bonding sheet 2 has a mount table 42 of the sheet attaching section 40.
A mount table 116 having the same structure as that of the above is provided, and is configured to be able to move up and down (F direction) along a guide rail 118 by a driving mechanism such as a cylinder mechanism 120.

That is, the mount table 116 has an outer peripheral portion of the mount table 116 protruding upward, and is formed on an inner peripheral side of the adsorber 122 to adsorb the outer peripheral portion W1 on the surface of the wafer W. An air blow space 126 that supports the front surface W2 of the wafer W upward from below by compressed air P via an air supply pipe 124 is provided. However, the mount table 116 is not provided with a heater.

Therefore, in the sheet peeling section 50, as shown in FIG. 10, the heat-sensitive adhesive base material 7 of the die bonding sheet 2 is adhered to the back surface W3 of the wafer W, and the sheet peeling section 50 on the downstream side is used. The mount table 116 rises in the direction of the arrow F in FIG. 10 with respect to the die bonding sheet 2 conveyed to the outside, and the suction portion 122 of the mount table 116 suctions the outer peripheral portion W1 of the wafer W. Then, compressed air P is supplied at a constant pressure through an air supply pipe 124 connected to an air supply source (not shown),
The surface W2 of the wafer W is entirely supported upward at a constant pressure.

In this state, as shown by an arrow E in FIG.
The die bonding sheet 2 sandwiched between the pair of peeling movement rollers 108 and 110 by moving the upper and lower sides of the wafer W by the cuts (precut) 88 as shown by dotted lines in FIG. In a state where the heat-sensitive adhesive base material 7 is adhered to W3, the release sheet 4A is peeled off together with the cut waste of the pre-cut heat-sensitive adhesive base material 7. Then, the peeled release sheet 4A is guided by the fixed roller 112 and wound up by the winding roller 114.

At the time of this peeling, the whole surface of the surface W2 of the wafer W is supported upward by the compressed air P, so that when the peeling sheet 4A of the die bonding sheet 2 is peeled, the wafer W may be broken, No breakage or damage. After the peeling operation is completed, the mounting table 116
10 is lowered in the direction of arrow F in FIG. 10, the suction of the suction unit 122 is released, and the wafer W is suction-fixed on the movable arm 22 and housed in the shelf of the wafer carrier 12 of the wafer supply unit 10. Alternatively, a buffer sheet for protecting the circuit surface may be stacked in a wafer storage box (not shown) and stored in a wafer storage box for storing the wafer W while being laid between the wafers.

The above cycle is repeatedly performed. The wafer W in which the heat-sensitive adhesive base material 7 of the die bonding sheet 2 is adhered to the back surface W3 of the wafer W in this manner is transferred to respective steps such as a dicing step, cleaning, drying, and die bonding.

[0050]

According to the present invention, there is provided an alignment for taking out and positioning a wafer from a wafer cassette accommodating a plurality of wafers, and a die bonding provided with a release sheet and a base material having a heat-sensitive adhesive layer. It is possible to continuously and automatically perform a series of steps of attaching a sheet to the back surface of a wafer, peeling off a release sheet of a die bonding sheet, and storing a wafer in a wafer cassette.

Further, since the die bonding sheet is composed of a sheet having a release sheet and a base material having a heat-sensitive adhesive layer, it functions as a protective tape at the time of dicing and, after being diced, is attached to a lead frame. When die bonding a semiconductor chip, it also functions as an adhesive for die bonding. Therefore, unlike the conventional case, there is no need to apply an adhesive to the lead frame at the time of die bonding, and at the time of die bonding, the semiconductor chip is sucked and picked up by the suction collet simply by heating the die bonding sheet. In addition, the substrate having the heat-sensitive adhesive layer of the die bonding sheet functions as an adhesive to the lead frame, and can be directly thermocompression-bonded.

Further, before attaching the substrate having the heat-sensitive adhesive layer of the die bonding sheet to the back surface of the wafer, the substrate having the heat-sensitive adhesive layer of the die bonding sheet in the outer shape of the wafer is cut (precut). Therefore, when the die bonding sheet is cut with a cutter as in the related art, there is no risk that the outer peripheral portion of the wafer will be damaged or the wafer will be cracked. This is an extremely excellent invention which has many unique and remarkable functions and effects, such as no necessity of cutting.

[Brief description of the drawings]

FIG. 1 is a top view of an entire apparatus of an embodiment of a die bonding sheet sticking apparatus according to the present invention.

FIG. 2 is a perspective view of the die bonding sheet sticking apparatus II of FIG. 1;
FIG.

FIG. 3 shows the die bonding sheet attaching apparatus II of FIG.
FIG.

FIG. 4 is a partially enlarged sectional view of a die bonding sheet used in the present invention.

FIG. 5 is a schematic perspective view illustrating the operation of the die bonding sheet sticking apparatus of the present invention.

FIG. 6 is a front view of a sheet cutting section of the die bonding sheet sticking apparatus of the present invention.

FIG. 7 is a side view of the sheet cutting unit of FIG. 6;

FIG. 8 is a schematic cross-sectional view for explaining the operation of the sticking pressing unit of the die bonding sheet sticking apparatus of the present invention.

FIG. 9 is a schematic cross-sectional view illustrating the operation of a sheet cutting unit of the die bonding sheet sticking apparatus of the present invention.

FIG. 10 is a schematic sectional view illustrating the operation of a sheet peeling unit of the die bonding sheet sticking apparatus of the present invention.

FIG. 11 is a schematic cross-sectional view illustrating a conventional method for attaching a pressure-sensitive adhesive sheet.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sticking device (die bonding sheet sticking device) 2 die bonding sheet 4A, 4B release sheet 5 heat-sensitive adhesive layer 6 base material 7 heat-sensitive adhesive base material (base material having heat-sensitive adhesive layer) 10 wafer supply Unit 12 Wafer carrier 14 Elevating drive motor 16 Ball screw mechanism 20 Wafer transfer unit 22 Movable arm 24 Suction member 30 Alignment unit 32 Turntable 40 Sheet attaching unit 42, 116 Mount table 44 Sheet feeding unit 45 Wafer heating attaching unit 46 Sheet cutting section 48 Adhesion pressing section 50 Sheet peeling section 60 Guide rail 62 Feeding roller 64 Guide roller 66 Peeling roller 68 Tension roller 70 Cutting / sticking position 72 Guide roller 75 Peeling material winding section 76 Cutting blade device 78 Cutting blade 80 Guide rail 82 Sheet cutting Pressing device 84 Cutting / pressing roller 86 Guide rail 90 Cylinder 92 Suction unit 94, 126 Air blow space 96 Air supply pipe 98 Cylinder 102 Fixed roller 104 Pressing moving roller 108, 110 Peeling moving roller (sheet peeling means) 112 Fixed roller (sheet peeling) Means) 114 Scrap take-up unit 118 Guide rail 120 Cylinder mechanism 122 Suction unit 124 Air supply pipe 200 Holding table 202 Adhesive sheet 204 Base sheet 206 Adhesive layer 210 Cutter W Wafer W1 Outer periphery W2 Front surface W3 Back surface

Claims (8)

[Claims] 1. A wafer supply unit accommodating a plurality of wafers, a wafer conveyance unit provided with a conveyance unit for taking out and conveying the wafer accommodated in the wafer supply unit, and a wafer conveyance unit of the wafer conveyance unit And an alignment unit for positioning the wafer taken out of the wafer supply unit, and the wafer positioned at a predetermined reference position in the alignment unit is transported through a transport unit, and the release sheet and the heat-sensitive A die bonding sheet made of a base material having an adhesive layer, a sheet sticking portion to be stuck to the back surface of the wafer by heating, from the wafer to which the die bonding sheet is stuck at the sheet sticking portion, A sheet peeling unit having a sheet peeling unit that peels off the release sheet of the die bonding sheet, The sheet sticking unit includes a cutting unit that cuts a substrate having the heat-sensitive adhesive layer of the die bonding sheet in an outer shape of the wafer before attaching the die bonding sheet to the back surface of the wafer. A die bonding sheet sticking apparatus, comprising: 2. The cutting blade device, wherein the cutting means rises from below the die bonding sheet and comes into contact with a substrate having the heat-sensitive adhesive layer of the die bonding sheet, and is vertically movable; When the blade device is raised to the upper position, the die-bonding sheet is pressed downward from above the die-bonding sheet to cut only the substrate having the heat-sensitive adhesive layer of the die-bonding sheet. The die bonding sheet sticking apparatus according to claim 1, further comprising a device. 3. A mounting table in which the sheet sticking section mounts the wafer and includes a heater for heating the wafer; and the die bonding sheet from above the die bonding sheet heated by the mount table. And a sticking and pressing device that sticks the back surface of the wafer placed on the mount table to the substrate having the heat-sensitive adhesive layer of the die bonding sheet. The die bonding sheet sticking apparatus according to claim 1. 4. The mounting table, wherein an outer peripheral portion of the mount table protrudes upward, an adsorbing portion that adsorbs an outer peripheral portion of a surface of the wafer, and an inner peripheral side of the adsorbing portion. The die bonding sheet sticking apparatus according to claim 3, further comprising: an air blow space that supports the surface from above to below with compressed air. 5. The sticking / pressing device includes a fixed roller and a pressing / moving roller, wherein the fixing roller holds an upstream side of the wafer of the die bonding sheet, and the pressing / moving roller is downstream. The die bonding sheet bonding apparatus according to any one of claims 3 to 4, wherein the die bonding sheet is bonded to the back surface of the wafer by moving to the side. 6. The sheet peeling section includes the mount table on which the wafer is mounted, and the mount table has an outer peripheral portion of the mount table protruding upward, and adsorbs an outer peripheral portion of a surface of the wafer. 6. An air-blowing space formed on the inner peripheral side of the suction unit and supporting the surface of the wafer upward from below with compressed air. 3. The die bonding sheet sticking device according to 1.). 7. The sheet peeling means includes: a fixed roller;
A pair of peeling movement rollers, wherein the fixed roller holds the downstream side of the die bonding sheet, and the die bonding sheet is wound and sandwiched between the pair of peeling movement rollers, and the peeling movement roller is The die according to any one of claims 1 to 6, wherein the die peeling sheet of the die bonding sheet is peeled from the wafer by moving to an upstream side of the die bonding sheet. Bonding sheet sticking device. 8. A die bonding sheet provided with a release sheet and a base material having a heat-sensitive adhesive layer is bonded to the outer shape of the wafer before the die bonding sheet is attached to the back surface of the wafer. The die bonding sheet cutting step of cutting only the base material having the heat-sensitive adhesive layer of the sheet, and heating the die bonding sheet cut into the outer shape of the wafer in the die bonding sheet cutting step, A die bonding sheet sticking step of sticking to the back surface of the wafer; and a sheet peeling step of peeling the release sheet of the die bonding sheet from the wafer to which the die bonding sheet has been stuck in the die bonding sheet sticking step. And a method for attaching a die bonding sheet.