KR19980034139A - Wafer, die-bonding tape and manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape for wafer die bonding and a method of manufacturing the same, wherein an adhesive of an acrylic polymer component is easily attached to and detached from a wafer ring. Iii) there is no need to remove the tape from the wafer ring after the die bonding process and then clean the wafer ring separately.

Description

Wafer die attach tape and its manufacturing method

The present invention relates to a tape for wafer-die bonding, and more particularly, a component in which a portion of the tape contacted with the wafer ring is easily adhered to and detached from the wafer ring in order to prevent contamination of the tape with the adhesive on the wafer ring. It relates to a wafer die-bonding tape made of an adhesive of the present invention and a manufacturing method thereof.

In the semiconductor assembly process, a silver-epoxy adhesive is mainly used in the die bonding process in which the semiconductor chip separated from the wafer is attached to the die pad of the lead frame.

The silver-epoxy adhesive has high productivity because it can be applied continuously to the die pad by using a separate coating device, but in the process of applying the silver-epoxy adhesive, the adhesive is applied incorrectly in the coating device, or the adhesive is applied depending on the viscosity of the adhesive. There is a problem that voids occur within.

The problem is that the cracks due to peeling from the adhesive layer are generated in the reliability test, for example, the burn-in test, after the semiconductor chip is die bonded and the packaging is completed. have.

Therefore, in order to solve this problem, a method of solving the above-mentioned problems by using a pressure-sensitive adhesive of a wafer adhesive tape instead of a silver-epoxy adhesive has recently been studied.

More specifically, the wafer adhesive tape adhered to the bottom of the wafer fixes the wafer in the wafer cutting process, and after the wafer cutting process, when the semiconductor chip is separated from the adhesive tape, the adhesive layers of the semiconductor chip and the adhesive tape are separated together. By attaching directly to the die pad of the lead frame, it replaces the role of conventional silver-epoxy adhesives.

Therefore, since the above-mentioned adhesive tape is used for wafer and die bonding, it is hereinafter called wafer-die bonding tape.

1 is an exploded perspective view showing a state in which a wafer ring and a wafer are attached to a wafer die attach tape according to the prior art.

FIG. 2 is a cross-sectional view of FIG. 1, illustrating a state in which a semiconductor chip is separated from a wafer.

3 is a cross-sectional view showing a wafer die-bonding tape according to the prior art.

Referring to FIG. 1, the structure in which the wafer 10 is attached to the opening 25 of the wafer ring 20 using the wafer-die adhesive tape 30 according to the prior art is shown.

More specifically, the wafer ring 20 has an opening 25 into which the wafer 10 can be inserted.

The tape 30 is attached to the periphery of the opening 25 of the lower surface of the wafer ring 20, and the opening 25 of the upper surface of the wafer ring 20 opposite to the surface to which the tape 30 is attached is attached. The opposite side of the surface on which the circuit elements of the wafer 10 are formed is attached to the tape 30 through the tape 10.

2 and 3, the tape 30 to which the wafer 10 is attached includes a pressure-sensitive adhesive layer 31 having a lower surface of the wafer 10 attached thereto, and a base film supporting the pressure-sensitive adhesive layer 31. 33, Base Film).

In more detail with respect to the wafer-die adhesive tape 30, the tape 30 is a release film 35, an adhesive layer 31, and a base film 33 before being attached to the wafer ring 20. It consists of three floors.

Here, the release film 35 is formed on the pressure-sensitive adhesive layer 31 to protect the pressure-sensitive adhesive layer 31 until the wafer 10 bonding process is performed, and the component is polyester.

Therefore, in order to proceed with the process of adhering the wafer 10, the release film 35 on the upper surface of the pressure-sensitive adhesive layer 31 is removed.

The base film 33 serves to support the adhesive layer 31 in the state in which the wafer 10 is attached to the adhesive layer 31, and the component is polyolefin.

Herein, a process of separating the semiconductor chip 12 from the wafer 10 attached to the tape 30 will be described. The wafer ring 20 to which the wafer 10 is attached is cut off by a die cutting device and the wafer 10 Each of the semiconductor chips 12 is cut along a cutting line that divides the circuit elements 12 formed in the semiconductor chip 12.

Ultraviolet rays are irradiated to separate the separated semiconductor chips 12 from the tape 30.

When the ultraviolet rays are irradiated, the adhesive force between the pressure-sensitive adhesive layer 31 of the tape 30 and the base film 33 is weakened.

In more detail, the pressure-sensitive adhesive 31 is composed of thermosetting resin, UV curable resin, and acrylic polymer.

When the ultraviolet rays are irradiated on the back surface of the base film 33, the ultraviolet rays and the UV curable resin react with each other to cause a chemical reaction, thereby weakening the adhesiveness of the wafer adhesive pressure sensitive adhesive 31 to the base film 33. Separation of the wafer adhesive pressure sensitive adhesive 31 from the film 33 becomes easy.

Therefore, when the semiconductor chip 12 is separated from the tape 30 by the chip feeder 40, the adhesive 31 of the lower surface of the semiconductor chip 12 adheres and is separated from the base film 33 at the same time.

The semiconductor chip 12 having the adhesive 31 attached to the lower portion is directly die bonded to the die pad of the lead frame.

As the die bonding process is performed by separating the semiconductor chips from the wafer attached to the wafer ring as described above, the process is simplified and there is no need for a device for applying a separate adhesive, thereby reducing the manufacturing cost. There is an advantage that can be used as is.

However, since the adhesive of the tape is buried in the wafer ring when the tape is called in the wafer ring where the die bonding is completed, there is a disadvantage that a cleaning process for removing the adhesive from the wafer ring after the die bonding process is completed must be added.

Accordingly, an object of the present invention is to provide a tape for attaching a wafer and a die, in which the adhesive is not attached to the wafer ring by changing the tape manufacturing process.

1 is an exploded perspective view showing a state in which a wafer ring and a wafer are attached to a wafer die attach tape according to the prior art;

FIG. 2 is a cross-sectional view of FIG. 1 showing a state in which a semiconductor chip is separated from a wafer.

3 is a cross-sectional view showing a wafer die bonding tape according to the prior art.

4-9 is a plan view and sectional drawing which shows the manufacturing process of the tape for wafer-die bonding which concerns on this invention.

Fig. 10 is a cross sectional view showing a state in which a wafer ring and a wafer are attached to a wafer die-bonding tape according to the present invention, and a cross sectional view showing a state in which a semiconductor chip is separated from a wafer.

* Description of the main parts of the drawings *

10, 110: wafer 20, 120: wafer ring

30, 130: adhesive tape 31, 131, 132: pressure-sensitive adhesive

33, 133, 137: base film

35, 135 release film 40, 140 chip feeder

In order to achieve the above object, a portion of a wafer / die bonding tape adhered to the periphery of the opening of the wafer ring is formed of a wafer-die bonding formed of an adhesive layer used for a conventional wafer-adhesive tape that is easily adhered and detached from the wafer ring. A tape for use and a method for producing the same are provided.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

4-9 is a top view and sectional drawing which shows the manufacturing process of the tape for wafer-die bonding which concerns on this invention.

4 and 5, the manufacturing process of the wafer-die adhesive tape according to the present invention is provided with a tape consisting of three layers of a release film 135, pressure-sensitive adhesive layer 132 and the base film 137 In, the pressure-sensitive adhesive layer 132 and the base film 137 are cut except for the portion in contact with the wafer ring.

Here, since the opening formed in the conventional wafer ring has a circular shape, the portion of the tape attached to the wafer ring has a donor shape.

Therefore, the adhesive layer 132 and the base film 137 remaining on the upper surface of the release film 135 have a donor shape and are referred to as a wafer ring adhesive tape layer 136 because they are portions to be attached to the wafer ring. .

The adhesive layer 132 is an acrylic polymer, which is an adhesive 132 component of a conventional tape, which is easily attached to and detached from a wafer ring. The component of the release film 135 is made of polyester. to be.

The pressure-sensitive adhesive layer 132 is referred to as a wafer ring adhesive layer 132 in order to distinguish it from the pressure-sensitive adhesive layer to be described later.

6 and 7, the pressure-sensitive adhesive layer 131 and the base film 133 on the top surface of the wafer adhesive tape layer 136 and the release film 135 formed in the donor shape of FIG. 4. The formed tape 134 is laminated and attached.

By the lamination process, the wafer adhesive pressure-sensitive adhesive layer 131 is filled between the top surface of the donor-shaped wafer ring adhesive tape layer 136 and interposed therebetween to adhere to the top surface of the release film 135.

Here, the components of the pressure-sensitive adhesive 131 for wafer bonding are made of thermosetting resin, UV curable resin, and acrylic polymer.

In addition, a component of the base film 133 attached to the rear surface of the adhesive layer 131 for wafer bonding is polyolefin.

8 and 9, the tape on which the pressure-sensitive adhesive layer 131 for wafer bonding is formed may have a release film (ie, the outer side 138 of the donor-shaped wafer ring adhesive tape layers 132 and 137) may be exposed. When the wafer adhesive tape layer 134 is etched to the upper surface of 135, the wafer-die adhesive tape 130 is manufactured.

Of course, the release film 135 on the upper surfaces of the adhesive layers 131 and 132 is removed in order to proceed with the process of attaching the wafer.

10 is a cross-sectional view illustrating a state in which a wafer ring and a wafer are attached to an adhesive tape for a wafer according to the present invention, and a cross-sectional view illustrating a state in which a semiconductor chip is separated from a wafer.

Referring to FIG. 10, the wafer ring 120 and the wafer 110 are attached with the release film removed from the wafer-die bonding tape 130 shown in FIG. 9.

Here, the portion where the peripheral portion of the opening 125 of the wafer ring 120 and the wafer-die bonding tape 130 adhere to each other becomes the adhesive layer 132 for wafer ring adhesion.

The wafer 110 to be bonded through the upper surface of the opening 125 is attached to the wafer adhesive pressure-sensitive adhesive layer 131 between the wafer ring adhesive layer 132.

In addition, a cutting process of the wafer 110 is performed to cut the circuit elements 112 formed on the wafer 110 into respective semiconductor chips 112.

Then, the UV irradiation process mentioned in FIG. 2 is performed, and each semiconductor chip 112 separated thereafter is separated by the chip transfer machine 140, and the semiconductor chip 112 separated is a die of the lead frame. Adheres to the pad.

Here, the semiconductor chip 112 and the pressure-sensitive adhesive 131 of the lower surface of the semiconductor chip 112 are simultaneously separated in the process of separating using the chip feeder 140, and the die attaching process is performed.

Then, when the wafer-die bonding tape 130 is separated from the wafer ring 120 after the die attaching process is completed, the portion contacted with the wafer ring 120 is the pressure-sensitive adhesive layer 132 made of acrylic polymer. The adhesive 131 of the tape is attached to the ring 120 without being attached.

Therefore, according to the structure of the present invention, a portion which is cut into each semiconductor chip by a wafer cutting process, and which comes into contact with the wafer ring when separating the wafer / die bonding tape after the die bonding process is completed in the next process Since it is a component which is easy to isolate | separate from this adhesive bond layer for wafer ring adhesion, there exists an advantage that the process of cleaning a wafer ring according to the contamination of a wafer ring is not necessary separately.

Claims (10)

Release film; A wafer ring adhesive tape layer formed on an upper surface of the release film, the adhesive layer formed to correspond to a portion in contact with the lower surface of the wafer ring, and a base film laminated on the upper surface of the adhesive layer; A pressure-sensitive adhesive layer for bonding wafers filled between the upper surface of the base film and the substrate; And And a base film adhered to the wafer adhesive pressure-sensitive adhesive layer upper surface. The wafer and die bonding tape according to claim 1, wherein the wafer ring adhesive tape layer has a donor shape. The wafer die-bonding tape according to claim 1, wherein a component of the pressure-sensitive adhesive for wafer ring adhesion is an acrylic polymer. A three layer tape of release film, pressure-sensitive adhesive layer and base film is provided; Cutting the adhesive layer and the base film of the upper surface of the release film to a shape to be attached to a wafer ring; Attaching a pressure-sensitive adhesive layer for wafer adhesion and a base film supporting the pressure-sensitive adhesive layer to the cut surfaces of the pressure-sensitive adhesive layer and the base film; And a step of cutting the pressure-sensitive adhesive layer on the wafer and the base film formed on the outer sides of the cut pressure-sensitive adhesive layer and the base film. The method of manufacturing a wafer die-bonding tape according to claim 4, wherein a component of the pressure-sensitive adhesive for wafer ring adhesion is an acrylic polymer. No content A wafer ring having an opening formed in the middle thereof; Wafer die bonding layer comprising a wafer ring adhesive tape layer adhered to a peripheral portion of the lower surface of the opening, and a pressure-sensitive adhesive layer formed on the inside of the opening and filled between the wafer ring adhesive tape layers. tape; A wafer attached to a lower surface of the wafer adhesive pressure-sensitive adhesive layer exposed to the opening of the wafer ring and having a plurality of circuit elements formed on the upper surface thereof; Structure bonded to the tape. 8. The wafer ring adhesive pressure-sensitive adhesive layer according to claim 7, wherein the wafer ring adhesive tape layer is adhered to the wafer ring adhesive pressure-sensitive adhesive layer adhered to the periphery of the opening, and the lower surface of the wafer ring adhesive pressure-sensitive adhesive layer, and supports the wafer ring adhesive pressure-sensitive adhesive layer. A structure in which a wafer using a wafer-die bonding tape is attached to a wafer-die bonding tape. The wafer according to claim 7 or 8, wherein the pressure-sensitive adhesive layer for wafer adhesion is formed to the bottom surface of the wafer ring adhesive tape, and a base film is bonded to the bottom surface of the pressure-sensitive adhesive layer for wafer adhesion. A structure in which a wafer using a die attaching tape is bonded to a wafer die attaching tape. 8. The structure according to claim 7, wherein a component of the pressure-sensitive adhesive layer for wafer ring adhesion is an acrylic polymer. The wafer using the wafer-die adhesive tape is attached to the wafer-die adhesive tape.