JP2003173988A - Method for dicing semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for preventing cracks from generating in a step of dicing a semiconductor wafer, and further easily integrally bonding a small piece of a die bond sheet having the same dimension as a semiconductor chip to a back surface of the chip, and further to provide a method capable of solving the above-mentioned problems at a stroke. <P>SOLUTION: In a method for dicing a semiconductor wafer, a semiconductor wafer (1) that a die bond sheet (2) is bonded to a back side thereof is supported and fixed by bonding by using a laser micro-jet dicing tape (24) bonded fixedly to a ring frame (3). In this state, the semiconductor wafer (1), the die bond sheet (2) and an adhesive layer (8) of the laser micro-jet dicing tape (24) are fully cut and diced by a laser micro-jet dicing that a water jet (6) is caused to guide a laser beam (5). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dicing a semiconductor wafer.

[0002]

2. Description of the Related Art Recently, the need for miniaturization of mounted parts has further increased, and miniaturization technology for semiconductor packaging has been further advanced. Along with this, the semiconductor chips are inevitably made thinner and smaller, and at the same time, the technical needs for compact packaging of the thin and small semiconductor chips tend to increase. Conventionally, as for these semiconductor chips, a semiconductor wafer thinned by back grinding in a back grinding process is made into chips in a dicing process. next,
The chip-shaped semiconductor chip is coated with a pickup die bonder or the like on a continuously flowing lead frame with a necessary amount of liquid adhesive for each die bonding, and is die-bonded at that position.

In the dicing step among these steps, the semiconductor wafer 1 is cut by the dicing blade 13 as shown in the front view of FIG. 4, and at this time, the wafer 1 is cut by the blade 13. Due to the resistance, a small chip (chipping, chipping,
Hereinafter simply referred to as lacking. ) May occur. 12 in the figure
Is a dicing tape having an adhesive layer 12a for adhering the semiconductor wafer 1, and 3 is a ring frame.
(Note that, in the following description according to the drawings, the same reference numerals in the drawings mean the same things.) The occurrence of this lack has recently been noted as one of the important problems to be solved. . Although various studies have been conducted to reduce the occurrence of chipping, there is still no satisfactory method. Furthermore, this chipping tends to occur as the thickness of the wafer 1 becomes thinner, and the chipping tolerance level becomes stricter for small chips. Therefore, it is easily conjectured that the problem of this chipping will become more serious in the future as the thinning of semiconductor chips and the tendency of small chips continue to progress as described above.

Further, the thin film / small chip semiconductor chip 1'obtained by dicing is required to prevent chipping and be compactly packaged. This is due to the need for miniaturization of the package size, and it is desired that the package should be packaged in a size substantially the same as the size of the semiconductor chip. Usually, the semiconductor chip 1 ′ made into a chip is a die pad 1 of a lead frame 16 to which a liquid adhesive 17 is applied by a pickup die bonder or the like, as shown in FIG. 5 as an explanatory view.
5 is die-bonded. However, when a liquid adhesive is used, it is very difficult to control the required coating amount for each die bonding, and further, since the liquid adhesive is liquid, variations in dimensions when applied onto the die pad 15 are likely to occur. In this case, the size of the semiconductor chip 1'and the liquid adhesive 1
Since the size of 7 does not match, it is necessary to consider the difference in size between the two when packaging, and to package the semiconductor chip 1'with a size slightly larger than that of the semiconductor chip 1 '. As described above, this is not a desirable method because it is necessary to package the semiconductor chip in a size substantially the same as the size of the semiconductor chip.

On the other hand, there is a method of using a sheet-shaped adhesive (die bond sheet) as an adhesive for die bonding (for example, WO97 / 02595). Specifically, this is an epoxy resin, silicone resin, acrylic resin,
An adhesive sheet is prepared by filling an organic material such as polyimide resin with a metal filler or an inorganic filler. The method of use is to heat bond the adhesive sheet to the wafer. Then, processing such as dicing is performed in that state to form a chip and then die bonding. At this time, it is heated again to be completely cured. A widely known method of using this die bond sheet is to prepare a small piece of die bond sheet of the same size as the semiconductor chip and pre-mount it on the lead frame, or to attach it to the back surface of the chip one by one. Has been. However, in this case
The work is very complicated and is not preferable, and in addition, a slight deviation may occur when a small piece of the die bond sheet is attached to the lead frame or the back surface of the chip.
For these reasons, it is not the preferred method. Further, for example, as shown in the front view of FIG. 6, the die bond sheet 2 is previously bonded to the back surface of the semiconductor wafer 1, and then this is bonded and fixed to the dicing tape 12, and the semiconductor wafer is cut by the blade cut dicing device. There is a system in which 1 and the die bond sheet 2 are fully cut at the same time. In this method, the dicing chip 1'and the size of the die-bonding sheet 2'are perfectly matched, and the two can be bonded together without any deviation. However, in this case, not only the dicing tape 12 but also the die bond sheet 2 is interposed below the semiconductor wafer 1, so that the wafer 1 or the chip 1 ′ may be removed by the cutting resistance applied from the blade 13 during dicing. As compared with the case where the die bond sheet 2 is not provided, blurring is more likely to occur, so that chipping tends to occur remarkably, which is a problem.

Further, as a method of preventing the occurrence of chipping and solving the demands for compact packaging all at once, Japanese Patent Laid-Open No. Hei 2 (1998)
The method described in 001-156027 is proposed.
In the method proposed in Japanese Patent Application Laid-Open No. 2001-156027, after forming a groove having a cut depth shallower than the wafer thickness along a scribe line of a semiconductor wafer, the back surface of the wafer is protected with a protective tape on the pattern surface. Grinding to reduce the wafer thickness and dividing into individual chips. Then, a dicing die-bonding sheet composed of a base material and an adhesive layer formed thereon is attached to the ground surface, the protective tape is peeled off, and the adhesive layer exposed between the chips is fixed between the chips. In this method, the chips and the adhesive layer are separated from the base material by cutting with a dicing blade having a width narrower than the groove width formed in the above. In this method, the chips are individually divided by the backside grinding in the back grinding process, so it can be said that this is an effective means for preventing the occurrence of chipping. However, it has a drawback that the work is much more complicated than the conventional process such as performing the dicing process in two steps, and the width of the dicing blade used for cutting the adhesive layer is larger than the groove width between chips. It is said that the width of the dicing blade is preferably 30 to 90% of the groove width between chips, and in this case, the adhesive layer small piece of the dicing die bond sheet formed on the back surface of the chip is In some cases, it may not be a satisfactory method in this point as well, considering that it is necessary to package the semiconductor chip in almost the same size as the size of the semiconductor chip, because the size may be larger than the size of the cut chip.

[0007]

DISCLOSURE OF THE INVENTION The present invention prevents the occurrence of chipping in the process of dicing a semiconductor wafer, and further simply attaches a small piece of a die bond sheet having the same size as the size of the semiconductor chip to the back surface of the chip. It is an object of the present invention to provide a means for wearing and unifying, and an object of the present invention is to provide a method capable of solving the aforementioned problems all at once.

[0008]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the inventors of the present invention have fixed a semiconductor wafer having a die bond sheet bonded on the back side to a ring frame and fixed it. With the laser microjet dicing tape attached and supported and fixed, the semiconductor wafer, the die bond sheet, and the adhesive layer of the laser microjet dicing tape are fully filled by laser microjet dicing in which the laser beam is guided by the water jet. It has been found that the method of cut dicing solves the above-mentioned problems all at once, and the present invention has been completed based on this finding. That is, the present invention relates to (1) a semiconductor wafer, a die bond sheet, and a laser microjet dicing tape, which are bonded and supported by a laser microjet dicing tape on a semiconductor wafer to which a back surface side is attached. Full-cut dicing of a pressure-sensitive adhesive layer by laser microjet dicing in which a laser beam is guided by a water jet, and (2) semiconductor wafer dicing / dicing for laser microjet dicing. The laser beam guides the laser beam through the adhesive layer of the semiconductor wafer and the dicing die-bonding tape for laser microjet dicing while being supported by the tape. The method for dicing a semiconductor wafer, which is characterized in that full cut dicing is performed by the micro jet dicing, and (3) a tape for laser micro jet dicing or a die bond dicing tape for laser micro jet dicing is fixed by a ring frame. (1) or (2) characterized by
The present invention provides a method for dicing a semiconductor wafer as described in the above item.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the preferred embodiments of the present invention shown in the drawings. First, as shown in FIG. 7, the die bond sheet 2 is bonded to the backside ground surface of the semiconductor wafer 1 which has been backside ground in the back grinding step and adjusted to a predetermined thickness. At this time, the die bond sheet 2 is bonded to the back surface by thermocompression bonding with the pattern surface 17 of the wafer 1 facing downward, but it is necessary to protect the pattern surface 17 from the pressing force applied during thermocompression bonding. In this case, as shown in FIG. 8, the pattern surface protection tape 7 used at the time of grinding the back surface may be used as it is as a protection tape at the time of thermocompression bonding of the die bond sheet without being peeled off after the completion of grinding. The sheet 7 may be peeled off. Next, as shown in FIG. 9, the semiconductor wafer 1 in which the die bond sheet 2 is attached to the back surface of the laser microjet dicing tape 24 attached and fixed to the ring frame 3 is used for the laser microjet dicing. The bonding support is fixed so that it comes to the tape 24 side. The tape 24 has a base film 29,
It is composed of the adhesive layer 8. This operation can be easily performed by using a dedicated tape mounter or the like when attaching and fixing.

Next, the semiconductor wafer 1 fixed as described above is diced. This method will be described with reference to FIG. As shown in FIG. 1, a semiconductor wafer 1 to which a die bond sheet 2 is attached on the back side is attached to a laser microjet dicing tape 24 together with the ring frame 3, and a laser beam 5 (FIG. 3) described later is provided. The semiconductor wafer 1, the die bond sheet 2, and the adhesive layer 8 of the laser microjet dicing tape 24 are installed in a laser microjet dicing apparatus guided by a water jet 6, and full cut dicing is performed. The tape 24 is placed on the fixed table of the laser microjet dicing device. At this time, the base film 29 of the laser microjet dicing tape 24 is left uncut. In this case, in the state where the semiconductor wafer 1 and the die bond sheet 2 are superposed on each other, both are simultaneously diced into a predetermined chip size, so that the chip 1 '
The small pieces of die bond sheet 2'bonded to the back surface of the chip 1'have exactly the same size, and are bonded to each other without any deviation. As a result, it is possible to sufficiently perform packaging in a size substantially the same as the size of the chip 1 '.

The laser microjet dicing apparatus 20 referred to in the present invention adopts a method of cutting an object to be cut with a laser beam such as a YAG laser or a semiconductor laser, but the laser beam itself is basically straight, Even if the direction of the laser beam 5 is slightly deviated during cutting as shown in the enlarged view of FIG. 3, a columnar water jet 6 is jetted at the same time as the laser beam 5, and the laser beam 5 passes through the water jet 6. The laser beam is guided as it passes. That is, the water jet 6 acts as an optical axis guide for the laser beam 5. Therefore, the laser beam 5 is not scattered, and precise cutting can be performed with the width of the diameter of the water jet 6.
Furthermore, the water jet 6 has a cooling effect on the cut portion, and effective dicing is realized, which also has the characteristic that it is less susceptible to thermal mutation and the like.

As shown in FIG. 1, when a semiconductor wafer is diced by a laser microjet dicing apparatus, a laser beam 5 is guided by a water jet 6 on a scribe line to form a semiconductor wafer into full-cut chips. The diameter of the water jet 6 is 30
Since it can be narrowed down to about 40 μm, a semiconductor wafer can be diced. Further, in the case of the dicing method according to this method, the dicing blade does not directly contact and cut the wafer 1 or the chips 1'as in the dicing method according to the conventional blade cutting method, but the dicing is performed by the laser beam 5. Very few chips are generated. On the other hand, in the conventional blade cutting method as shown in FIG. 4, the external pressure from the dicing blade 13 at the time of cutting causes the wafer 1 or the chip 1 ′ to be shaken, or cutting resistance is applied, resulting in chipping. A crack will occur. On the other hand, in the laser microjet dicing method, no external pressure is applied because the cutting is non-contact, and the chipping is suppressed to a minimum. or,
The water jet 6 has a relatively small water pressure of several tens to several hundreds of bar and passes through the cut scribe line to escape, so that it does not act as an external pressure enough to increase the chip.

In the present invention, the semiconductor wafer 1 to which the die bond sheet 2 is attached on the back surface is mounted on the laser microjet dicing tape 24, and the ring frame 3 is set in the laser microjet dicing apparatus. The wafer 1, the die bond sheet 2, and the adhesive layer 8 of the laser microjet dicing tape 24 are subjected to full cut dicing. In this case, since the jetted water jet 6 having a diameter of several tens of μm is received by the fine holes installed in the fixed table 18 of the device and drained, the water jet 6 is fed from the scribe line to the laser micro jet. It must penetrate to the back side of the dicing tape 24. Therefore, the laser microjet dicing tape 2
4 requires that the water jet 6 jetted at the time of dicing penetrates the back surface. However, the adhesive layer 8 of the semiconductor wafer 1, the die bond sheet 2, and the laser microjet dicing tape 24 is a YAG laser,
Alternatively, since the water jet 6 is fully cut by the heat of the laser beam 5 by the semiconductor laser, the water jet 6 can pass through the adhesive layer 8 as it is, but the laser microjet dicing tape 24 needs to be supported and fixed. 29 must be left without being fully cut, and eventually the water jet 6 cannot be penetrated. In view of this point, in the tape 24 for laser micro jet dicing applied in the present invention, the adhesive layer 8 is fully cut by the heat of the laser beam 5, and the base film 29 is made of laser such as PET, nylon, or PP. And a material that allows
For example, a porous film is used so that the water jet can pass therethrough. By applying such a tape for laser microjet dicing, the semiconductor wafer 1
The adhesive layer 8 of the die bond sheet 2 and the laser microjet dicing tape 24 is fully cut by the laser 5 to provide a space through which the water jet can escape, and the base film 29 of the laser microjet dicing tape 24 transmits the laser. Also, the water jet escapes from the hole. As described above, the laser microjet dicing tape 24 applied in the present invention needs to satisfy these requirements. Specifically, the laser dicing as proposed in Japanese Patent Application No. 2001-124919 is used. There is no problem if you apply the adhesive tape. However, the applicable tape for laser microjet dicing 24 is not limited to this, and can be appropriately used as long as it satisfies the above conditions.

Further, the adhesive layer 8 of the laser microjet dicing tape 24 is proposed in Japanese Patent Application No. 2001-124919 because the die bond sheet 2 has to be peeled from the adhesive layer 8 in a later pick-up step. It is possible to reduce the adhesive strength of the adhesive if it is used in a conventional tape for laser dicing, to which an ordinary radiation-curable adhesive layer is applied.
In some cases, this is preferable, but a normal acrylic pressure-sensitive adhesive may be used. The pressure-sensitive adhesive tape for laser dicing used in the present invention will be described in more detail below. The adhesive tape used in the present invention is an adhesive tape used for laser dicing in which a laser is guided by a water jet. The water micro jet method refers to a method in which the diameter of water jetted as a laser guide is controlled at the μm level. The pressure of the water jet is preferably 30 to 70 MPa and is not limited to this, but if it is too small, chipping of the element occurs on the cutting surface side, and if it is too large, chipping of the element occurs on the cutting back surface side.

The pressure-sensitive adhesive tape of the present invention has a water-permeable film as a base material. Specifically, it is a water-permeable film having a diameter of 30 to 100 μm, preferably a diameter of 50 μm.
It is a water permeable film. By using such a base material, the water of the water jet can flow out from the adhesive tape without accumulating between the adhesive tape and the wafer, and the adhesive tape may flap due to water pressure, resulting in chipping (chip). The possibility of causing it can be eliminated.

In order for such a substrate to permeate water, the structure of the substrate is preferably a mesh or a porous structure. Examples of the substrate include non-woven fabric, hollow fiber, woven fabric, fibrous material such as nylon mesh used for electromagnetic wave shielding of PDP, and rubber-like elastic body, and non-woven fabric is particularly preferable. Even in the case of a non-woven fabric, it is desirable that the non-woven fabric exhibits non-oriented stretchability. The rubber-like elastic body may have a honeycomb structure.

When a fibrous material is used as the substrate, the fiber diameter is preferably 10 μm or more and less than 50 μm. A base material having a fiber diameter of 50 μm or more is not preferable because the flat portion is melted and fused to the chucking table. Further, if the diameter of the folded portion of the fiber is 50 μm or more, that portion will be melted, which is not preferable. The opening diameter for making the base material thus formed water-permeable is preferably 20.
To 200 μm, and more preferably 40 to 200 μm.

Further, the heat resistance of the substrate used is appropriately selected depending on the conditions of laser dicing such as the cutting speed, the output of the laser and the amount of water. What is necessary is to use a material that does not melt due to the heat during laser dicing.

The material of the substrate is polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-
1, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, homopolymer or copolymer of α-olefin such as ionomer, polyethylene terephthalate, polycarbonate, engineering plastics such as polymethylmethacrylate, nylon-6 Polyamides such as nylon-6,6, nylon-12, and aramid, or thermoplastic elastomers such as polyurethane, styrene-ethylene-butene or pentene copolymers. Also, a mixture of two or more selected from these groups may be used, and can be arbitrarily selected depending on the adhesiveness to the pressure-sensitive adhesive layer. Of these, polypropylene, polyethylene terephthalate and nylon-6,6 are particularly preferable.

The thickness of the base material is preferably thin so as to prevent vibration of the material, and the base material is preferably thin as long as extensibility can be maintained because the base material is not cut. Therefore,
The appropriate thickness of the base material is 30 to 300 μm, and 100 μm
m is preferred.

One side of the pressure-sensitive adhesive tape comprises a pressure-sensitive adhesive layer obtained by applying a solution of an acrylic pressure-sensitive adhesive and drying it as in the conventional product. The pressure-sensitive adhesive layer is preferably a radiation-curable pressure-sensitive adhesive layer. The radiation referred to in the present invention means a light ray such as ultraviolet ray or an ionizing radiation such as an electron beam.

As the die bond sheet 2 in the present invention, a general-purpose die bond sheet can be applied. For example, a die bond sheet made of an epoxy resin, a polyamide resin, a polyimide resin, a silicone resin, an acrylic resin and its modified organisms, or a mixture thereof. Is widely known. Further, as shown in FIG. 2, in the present invention, the die bond sheet 2
And laser microjet dicing tape 24 for laser microjet dicing having both functions of supporting and fixing laser microjet dicing tape 24
May be attached and fixed to the ring frame 3, and the semiconductor wafer 1 may be attached and supported and fixed, and dicing may be performed by a laser microjet dicing method. In this case, in the dicing die bond tape 7 for laser microjet dicing, only the adhesive layer 10 is fully cut,
It will be peeled off from the base film 29 in the subsequent pickup step. The pressure-sensitive adhesive layer 10 may have a composition in which the material of the die bond sheet described above is mixed with a normal acrylic pressure-sensitive adhesive or a radiation-curable pressure-sensitive adhesive, or a layer having a die bond sheet composition and an acrylic pressure-sensitive adhesive, Alternatively, a multilayer structure with a radiation-curable pressure-sensitive adhesive layer can be used as appropriate. Further, as the acrylic pressure-sensitive adhesive and the radiation-curable pressure-sensitive adhesive referred to herein, usual ones can be used, and for example, the composition as proposed in the above-mentioned Japanese Patent Application No. 2001-124919 is widely applied. . Further, the base film is made of a material that allows the laser beam 5 to pass therethrough and penetrates the water jet 6 in the same manner as described above.
Can be left as is.

As described above, the semiconductor wafer 1 to which the die bond sheet 2 is attached on the back surface side is attached to and supported by the laser microjet dicing tape 24 attached and fixed to the ring frame 3, or the semiconductor wafer 1 is attached to the ring frame 3. The semiconductor wafer 1 is manufactured by the laser microjet dicing method while the wafer 1 is bonded and supported by the dicing die bond tape 7 for laser microjet dicing which is bonded and fixed to the ring frame 3.
, Die bond sheet 2, adhesive layer 8 of laser microjet dicing tape 24, or semiconductor wafer 1
And laser microjet dicing dicing
By fully cutting the adhesive layer 10 of the die bond tape 7, the occurrence of chipping is suppressed to the utmost limit, and the chip 1 ',
It is possible to create a die bonded sheet small piece 2'or a dicing die bond tape adhesive layer small piece 10 'that is stuck to the back surface with exactly the same size, and without a slight deviation.

[0024]

EXAMPLES The present invention will be described in detail below based on examples.
To do. The present invention is not limited to the following examples.
However, it can be modified in various ways. Examples 1-4, ratio
The following evaluations were performed on Comparative Examples 1 to 4.・ Chips and adhesives (small pieces of die bond sheet, or die
Die bond tape adhesive layer small piece or liquid adhesive
Deviation from the agent) Chip and adhesive after dicing (Small die bond sheet
Piece, or dicing die bond tape adhesive layer small piece,
Or, observe the dimensional deviation with the liquid adhesive) and find the maximum value
Was measured.・ Chip evaluation The chip after dicing was observed and generated on the chip surface.
Measure the size of the chip (including cracks) and use it as the average value.
It was The size of the chip was defined as the size from the edge of the chip.·Workability The workability of 1-wafer processing was observed. Examples 1 to 4 and Comparative Example 1
For details on the tapes and equipment used in
It is summarized in Table 1. In addition, carry out the above evaluation items
The results obtained are shown in Table 2.

[0025]

[Table 1]

Example 1 A die-bonding sheet was attached to a 6-inch silicon wafer having a thickness of 150 μm, and was attached and fixed with a dicing tape A attached and fixed to a 6-inch ring frame. This was installed in a laser micro jet dicing machine and 2 mm x 2 mm under the conditions of a cutting speed of 100 mm / s and a laser beam diameter (water jet diameter) of 40 μm.
It was diced to the chip size. In Examples 1 to 4, the adhesive layer of the dicing tape was cut.

Example 2 A die bond sheet was attached to a 6-inch silicon wafer having a thickness of 150 μm, and the die-bonding tape A attached and fixed to a 6-inch ring frame was attached and supported. This was installed in a laser micro jet dicing machine, and 5 mm x 5 mm under the conditions of a cutting speed of 100 mm / s and a laser beam diameter (water jet diameter) of 40 μm.
It was diced to the chip size.

Example 3 A die-bonding sheet was attached to a 6-inch silicon wafer having a thickness of 150 μm, and attached and fixed with a dicing tape B attached and fixed to a 6-inch ring frame. This was installed in a laser micro jet dicing machine and 2 mm x 2 mm under the conditions of a cutting speed of 100 mm / s and a laser beam diameter (water jet diameter) of 40 μm.
It was diced to the chip size.

Example 4 A 6-inch silicon wafer having a thickness of 150 μm was bonded and supported and fixed by a dicing die bond tape A which was fixed and fixed to a 6-inch ring frame, and was irradiated with ultraviolet rays. This was installed in a laser micro jet dicing machine and 2 mm x 2 m under the conditions of a cutting speed of 100 mm / s and a laser beam diameter (water jet diameter) of 40 μm.
It was diced to a chip size of m.

Comparative Example 1 A 6-inch silicon wafer having a thickness of 150 μm was bonded and supported and fixed by a dicing tape C which was fixed and fixed to a 6-inch ring frame. This was installed in a blade cut dicing device, and dicing into a chip size of 2 mm × 2 mm under conditions of a cutting speed of 100 mm / s and a blade thickness of 40 μm. Further, a chip was picked up by a pick-up die bonder, a required amount of liquid adhesive was applied on a continuously flowing lead frame, and the picked-up chip was die-bonded at that position.

Comparative Example 2 A die-bonding sheet was attached to a 6-inch silicon wafer having a thickness of 150 μm, and attached and fixed with a dicing tape C attached and fixed to a 6-inch ring frame. This was installed in a blade cut dicing machine, and 2 m under the conditions of a cutting speed of 100 mm / s and a blade thickness of 40 μm.
It was diced into a chip size of m × 2 mm.

Comparative Example 3 A 6-inch silicon wafer having a thickness of 700 μm was bonded, supported and fixed with a dicing tape C. This is installed in a blade cut dicing machine and the cutting speed is 100 mm /
Under conditions of s and blade thickness of 40 μm, a groove having a depth of 70 μm was formed so as to have a chip size of 5 mm × 5 mm.
Next, a protective tape was attached to the surface on which the groove was formed, and the surface was ground by a grinding machine until it was divided into a chip size of 5 mm × 5 mm. After bonding the dicing die bond tape B to the ground surface, the protective tape was irradiated with ultraviolet rays and peeled off. Further, the dicing / die bond tape is irradiated with ultraviolet rays and installed in a blade cut dicing device, and the cutting speed is 10
The pressure-sensitive adhesive layer of the dicing die-bonding tape was fully cut under the conditions of 0 mm / s and blade thickness of 35 μm.

Comparative Example 4 A 6-inch silicon wafer having a thickness of 700 μm was bonded and supported by a dicing tape C. This is installed in a blade cut dicing machine and the cutting speed is 100 mm /
Under conditions of s and a blade thickness of 40 μm, a groove having a depth of 70 μm was formed so as to have a chip size of 2 mm × 2 mm.
Next, a protective tape was attached to the surface on which the groove was formed, and the surface was ground by a grinding machine until it was divided into a chip size of 2 mm × 2 mm. After bonding the dicing die bond tape B to the ground surface, the protective tape was irradiated with ultraviolet rays and peeled off. Further, the dicing / die bond tape is irradiated with ultraviolet rays and installed in a blade cut dicing device, and the cutting speed is 10
The pressure-sensitive adhesive layer of the dicing die bond tape was fully cut under the conditions of 0 mm / s and blade thickness of 20 μm.

[0034]

[Table 2]

The following can be seen from the above test results. Examples 1 to 4: It was confirmed that there was no deviation between the chip and the small piece of the die bond sheet or the small piece of the dicing / die bond tape adhesive layer, the chipping was extremely small, and the workability was no problem compared with the conventional case. Comparative Example 1: The gap between the chip and the liquid adhesive is large, and the chipping is large. Comparative Example 2: Very large chipping Comparative Example 3: There is no deviation between the chip and the small piece of the die bond sheet, and the chipping is very small, but the workability is very poor. Comparative Example 4: There is a slight deviation between the chip and the small piece of the die bond sheet, and the workability is also very poor.

[0036]

According to the present invention, in the process of dicing a semiconductor wafer, the semiconductor wafer having the die bond sheet bonded on the back side is bonded, supported and fixed by a tape for laser microjet dicing, which is fixed on a ring frame. In this state, the semiconductor wafer, the die bond sheet, and the adhesive layer of the laser microjet dicing tape are subjected to full cut dicing by laser microjet dicing to prevent chipping during dicing, and the dimensions of the semiconductor chip. It was possible to simply attach and integrate a small piece of die bond sheet of the same size as the back surface of the chip.

[Brief description of drawings]

FIG. 1 is a front view showing an example of a typical embodiment of the present invention.

FIG. 2 is a front view showing another example of a typical embodiment of the present invention.

FIG. 3 is an enlarged view showing a laser beam passing through a water jet.

FIG. 4 is a diagram showing a conventional blade cut dicing method.

FIG. 5 is a diagram showing a state in which a chip is die-bonded on a die pad of a lead frame by a liquid adhesive.

FIG. 6 is a view showing blade-cut dicing of a semiconductor wafer having a sheet-like adhesive stuck to the back surface thereof.

FIG. 7 is a diagram showing the bonding of a die bond sheet to the back surface of a semiconductor wafer.

FIG. 8 is a diagram showing a die bond sheet bonding in a state where a pattern surface of a semiconductor wafer is protected by a protective tape.

FIG. 9 is a front view showing a state in which a semiconductor wafer having a back surface on which a die bond sheet is bonded is bonded and supported by a laser microjet dicing tape.

[Explanation of symbols]

1 Semiconductor Wafer 1'Chip 2 Die Bond Sheet 2'Die Bond Sheet Small Piece 3 Ring Frame 4 Dicing Tape 24 Laser Micro Jet Dicing Tape 5 Laser Beam 6 Water Jet 7 Laser Micro Jet Dicing Dicing Die Bond Tape 8 Laser Micro Jet Dicing Adhesive layer 9 of tape Base film 29 Base film of tape for laser microjet dicing 10 Adhesive layer of dicing die bond tape for laser microjet dicing 10 'Adhesive layer of dicing die bond tape for laser microjet dicing 12 Dicing Tape 13 Dicing Blade 14 Inner Lead 15 Die Pad 16 Lead Frame 17 Liquid Adhesive 18 Ray The fixed table of the MicroJet dicing machine

Claims (3)

[Claims] 1. A pressure-sensitive adhesive for a semiconductor wafer, a die bond sheet, and a laser microjet dicing tape in a state in which a semiconductor wafer having a die bond sheet bonded to the back surface side is bonded and supported and fixed by a laser microjet dicing tape. A method for dicing a semiconductor wafer, wherein the layer and the layer are subjected to full-cut dicing by laser microjet dicing in which a laser beam is guided by a water jet. 2. The semiconductor wafer and the adhesive layer of the laser dicing die-bonding tape for laser microjet dicing are bonded to the semiconductor wafer by a die-bonding dicing tape for laser microjet dicing. A method for dicing a semiconductor wafer, which comprises performing full-cut dicing by laser microjet dicing guided by a jet. 3. The method for dicing a semiconductor wafer according to claim 1, wherein the laser microjet dicing tape or the laser microjet dicing die-bonding dicing tape is fixed by a ring frame.