JP3296334B2 - Method and apparatus for manufacturing BGA semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a BGA semiconductor device and an apparatus for manufacturing the same, and more particularly, to an outer shape cutting method for cutting and separating a BGA semiconductor device into individual pieces and an apparatus therefor.

[0002]

2. Description of the Related Art Rather than forming a group of solder balls serving as bump electrodes on a semiconductor chip in a wafer state, a plurality of groups of solder balls are formed at predetermined intervals on the upper surface of an insulating tape, and each solder ball is formed. It is more efficient to apply a pelletized semiconductor chip to the lower surface of the insulating tape under the ball group, and to electrically connect the solder balls to predetermined portions of the semiconductor chip through through holes in the insulating tape or through bonding wires. Solder balls can be formed on the substrate.

In this case, however, it is necessary to cut the insulating tape between the semiconductor chips and the sealing resin thereunder in order to obtain individual BGA semiconductor devices.

For this purpose, A: dicer cutting, B: die cutting, and C: laser cutting in the atmosphere (in an oxygen atmosphere).

[0005]

However, in the case of A: dicer cutting, it is necessary to attach a UV sheet, which increases the number of steps. Further, when the silicone resin is used as the sealing resin, the cutting accuracy is deteriorated because the resin is a soft resin.

[0006] B: In the case of die cutting, a different die is required for each package size (BGA semiconductor device size), and thus there is a problem in terms of operation of manufacturing equipment and cost.
Further, when the epoxy resin is used as the sealing resin, the cutting accuracy is deteriorated because this resin is a hard resin.

C: In the case of laser cutting in the air (in an oxygen atmosphere), due to the adhesion (oxidation) of carbon due to thermal stress at the time of cutting, the vicinity of the cut portion, that is, between the solder ball electrodes near the periphery or from there to the periphery. The probability that a short circuit accident will occur between the drawn wires increases.

Accordingly, an object of the present invention is to provide an effective method for manufacturing a BGA semiconductor device and an apparatus for manufacturing the same, which do not have such disadvantages.

[0009]

A feature of the present invention is that a plurality of semiconductor chips are arranged and fixed at a predetermined interval from each other on a first main surface of an insulating material, and the insulating material on each semiconductor chip is fixed. A group of solder balls is provided on the second main surface of
Each solder ball is electrically connected to a predetermined portion of the semiconductor chip through a through hole formed in the insulating material or through a bonding wire, and a sealing resin is applied to the first main surface of the insulating material at an interval between the semiconductor chips. When the formed structure is prepared and the BGA semiconductor device including the semiconductor chip, the insulating material, and the group of solder balls is separated by cutting the insulating material and the sealing resin at intervals, the structure is placed in a vacuum chamber. The method is for manufacturing a BGA semiconductor device, which is placed and cut by a laser beam in a vacuum.

Here, the gas pressure of the vacuum chamber at the time of cutting is 100 torr or less, that is, 100 torr.
A high degree of vacuum as described above is preferable in order to reliably suppress the generation of carbon due to oxidation.

When a laser beam is irradiated from outside the vacuum chamber through, for example, an acrylic window having a thickness of 10 mm, the laser power is lost, and the focal length of the laser beam is reduced due to the difference in the refractive index between the atmosphere, acrylic, and vacuum. It shifts. Therefore, it is preferable that the laser oscillator that emits the laser beam is mounted in the vacuum chamber.

Further, it is preferable that the laser beam in vacuum is an excimer laser beam which predominantly performs cutting by a chemical reaction. However, it is a double oxide of yttrium oxide and aluminum oxide and has a wavelength of 250 nm to 350 n.
m YAG laser beam can also be used because it is predominantly cut by a chemical reaction.

Another feature of the present invention is that a plurality of semiconductor chips are arranged and fixed on the first main surface of the insulating material at a predetermined interval from each other, and the second main surface of the insulating material on each semiconductor chip is provided. A group of solder balls is provided, and each solder ball is electrically connected to a predetermined portion of the semiconductor chip through a through hole formed in the insulating material or through a bonding wire. When a structure in which a sealing resin is formed on the main surface of the semiconductor device 1 is prepared, and the insulating material and the sealing resin are cut at intervals, a BGA semiconductor device including a semiconductor chip, an insulating material, and a group of solder balls is separated. And a method of manufacturing a BGA semiconductor device in which a structure is placed in an inert gas chamber and cut by a laser beam in an inert gas atmosphere.

Here, the inert gas chamber contains at least 90% by volume of an inert gas (nitrogen gas or argon gas) at the time of cutting.
It is preferable to surely suppress generation of carbon due to oxidation.

When a laser beam is irradiated from outside the inert gas chamber through, for example, a 10 mm thick acrylic, the laser power is lost, and the refractive index of the atmosphere-acryl-inert gas is different. The distance shifts. Therefore, it is preferable that the laser oscillator that emits a laser beam is mounted in the inert gas chamber.

Further, it is preferable that the laser beam in the inert gas is an excimer laser beam which predominantly performs cutting by a chemical reaction. However, it is a double oxide of yttrium oxide and aluminum oxide and has a wavelength of 250 nm to 3 nm.
A 50 nm YAG laser beam can also be used because it predominantly cuts by a chemical reaction.

In any of the above BGA semiconductor device manufacturing methods, the insulating material may be an insulating tape, preferably a polyimide tape. Alternatively, the insulating material is an insulating plate, preferably glass epoxy (Galaeppo)
Can be a board.

In any of the above BGA semiconductor device manufacturing methods, the sealing resin can be provided at intervals to seal the side surfaces of the semiconductor chip. Alternatively, the sealing resin may cover the side surface of the semiconductor chip within the interval and cover the bottom surface of the semiconductor chip outside the interval.

In any of the above BGA semiconductor device manufacturing methods, the sealing resin may be an epoxy resin. Alternatively, the sealing resin can be a silicone resin.

Another feature of the present invention resides in a BGA semiconductor device manufacturing apparatus for performing the above-described BGA semiconductor device manufacturing method.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a view showing a first embodiment of the present invention, wherein FIG. 1A is a view showing a cutting step, and FIG.
FIG. 3 is a cross-sectional view showing a cut and separated BGA semiconductor device. FIG. 2 is an enlarged plan view of FIG. 1B as viewed from above.

A plurality of semiconductor chips 1 are fixedly arranged on the lower surface of the polyimide tape 2 with a predetermined interval 5 therebetween.
A group of solder balls 3 serving as bump electrodes is provided on the upper surface of the polyimide tape 2 on each semiconductor chip 1.
Each of the solder balls 3 is connected to a predetermined portion of the semiconductor chip 1 through a through hole 6 formed in the polyimide tape 2, and further, a gap 5 between the semiconductor chip 1 and the lower surface of the polyimide tape 2. A structure on which an epoxy resin 4 as a sealing resin is formed is prepared.

The cutting device 20 includes a vacuum chamber 26,
An excimer laser oscillator 21 in the vacuum chamber, a stage 23 in the vacuum chamber, a valve 24 connected through a port on the outer wall of the vacuum chamber, and a valve 24.
And a vacuum pump 25 connected to the

After transferring the above-mentioned structure onto the stage 23 in the vacuum chamber 26, the valve 24 is opened,
The inside of the vacuum chamber is set to a gas pressure of 100 torr or less, for example, 10 torr.

Then, the excimer laser beam 22 is irradiated from the excimer laser oscillator 21 to the polyimide tape 2 and the epoxy resin 4 at the interval 5 and cut, so that the individual BGA semiconductor devices 10 as shown in FIG. Is obtained.

Referring to FIG. 2, in each BGA semiconductor device 10, solder balls 3 are arranged in a matrix on a polyimide tape 2 on a semiconductor chip 1. For example, the cut polyimide tape 2 is 10 mm
The size is from 10 mm to 40 mm x 40 mm. There, the solder ball 3 having a diameter of 0.3 mm to 0.76 mm,
They are arranged in both directions at a pitch of 0.5 mm to 1.27 mm. The distance from the peripheral edge to the center of the solder ball in the outermost arrangement is, for example, 0.7 mm to 1.5 mm.

In a BGA semiconductor device having such a structure, when laser cutting is performed in the air (in an oxygen atmosphere), the carbon is attached (oxidized) due to thermal stress at the time of cutting.
A short circuit accident occurs at some places near the cut portion, that is, between the solder ball electrodes near the periphery or between the wirings drawn out from there around.

However, if laser cutting is performed in a vacuum as in the first embodiment, such a short circuit accident will not occur.

In the first embodiment, a solder ball is provided on the upper surface of a polyimide tape, an epoxy resin is used as a sealing resin, and the sealing resin is present only within the interval. The case where an excimer laser beam is used has been exemplified.

However, in the first embodiment in which laser cutting is performed in a vacuum in a vacuum chamber, solder balls may be provided on the upper surface of the glass epoxy substrate, and silicon resin may be used as the sealing resin. The sealing resin may be present from within the gap to the bottom surface of the semiconductor chip.
It is also possible to use a YAG-based laser beam of nm to 350 nm.

FIGS. 3A and 3B are views showing a second embodiment of the present invention, wherein FIG. 3A is a view showing a cutting step, and FIG.
FIG. 3 is a cross-sectional view showing a cut and separated BGA semiconductor device.

A plurality of semiconductor chips 31 are fixedly arranged on the lower surface of the glass epoxy (glass epoxy) plate 32 with a predetermined interval 35 therebetween, and a group of bump electrodes is formed on the upper surface of the glass epoxy 32 on each semiconductor chip 31. Solder balls 33 are provided, and each of the solder balls 33 is connected to a predetermined portion of the semiconductor chip 31 through a through hole 36 formed in the glass epoxy plate 32.
A structure in which a silicon resin 34 as a sealing resin is formed in a space 35 between the semiconductor chip 31 and the semiconductor chip 31 is prepared.

The cutting device 40 includes an inert gas chamber 4
6, an excimer laser oscillator 41 in the inert gas chamber, a stage 43 in the inert gas chamber, a valve 44 connected through a port on the outer wall of the inert gas chamber, and nitrogen connected to the valve 44. Gas source 45
And

The above structure is connected to the inert gas chamber 4.
After being conveyed onto the stage 43 in 6, after evacuation by a vacuum system (not shown), the valve 44 is opened,
90% or more by volume in the inert gas chamber 46,
For example, by exposing an excimer laser beam 42 from an excimer laser oscillator 41 to the glass epoxy plate 32 and the silicon resin 34 at intervals 35 in the presence of 95% nitrogen gas and cutting the same, as shown in FIG. Individual BGA semiconductor devices 30 are obtained.

The solder balls 33 on the glass epoxy plate 32 of the BGA semiconductor device 30 according to the second embodiment.
The arrangement of is the same as that of the first embodiment shown in FIG. 2, for example. Also in this second embodiment, since the cutting is performed in an inert gas, the carbon deposition due to the thermal stress at the time of cutting is performed. (Oxidation) can prevent a short circuit accident between the solder ball electrodes near the cut portion, that is, near the periphery or between the wirings drawn out from there around.

In the second embodiment, nitrogen gas is exemplified as the inert gas, but argon gas can be used. Further, in the second embodiment, a solder ball is provided on the upper surface of a glass epoxy plate, a silicon resin is used as a sealing resin, and the sealing resin is present from within the gap to the bottom surface of the semiconductor chip. The case where an excimer laser beam is used is exemplified.

However, in the second embodiment in which laser cutting is performed in an inert gas atmosphere in an inert gas chamber, solder balls are provided on the upper surface of the polyimide tape in the same manner as in the first embodiment. Alternatively, an epoxy resin can be used as a sealing resin, the sealing resin can be present only within the interval, and a YAG laser beam having a wavelength of 250 nm to 350 nm is used as a laser beam for cutting. Is also possible.

In the first and second embodiments, the D ² BGA (Die Dim) is used to electrically connect the solder balls to the respective portions of the semiconductor chip through the through holes of the insulating material, that is, through hole bonding.
The description has been made by using a BGA semiconductor device of an enhancement ball grid array (enhance ball grid array) type.

However, in the first and second embodiments, another type using a solder ball, for example, an FPBGA (Finepitch Plastic) for electrically connecting a solder ball to each portion of a semiconductor chip by a bonding wire, that is, wire bonding.
It goes without saying that a BGA semiconductor device of the Ball Grid Array type can also be used.

[0041]

As described above, according to the present invention, since cutting is performed by a laser beam, cutting can be performed even when the package size (BGA semiconductor device size is different) by simply moving the laser oscillator or the stage. This provides a versatile cutting method.

Further, since the cutting is performed in a non-contact manner, a cutting displacement due to stress at the time of positioning or cutting does not occur. Therefore, high-precision cutting can be performed.

Since the cutting is performed in a non-contact manner, there is no external physical damage during positioning or cutting.

Furthermore, since the cutting is performed in a vacuum or an inert gas atmosphere, the cut surface is not oxidized by heat during laser cutting, so that a short circuit accident due to undesired adhesion of carbon near the cut surface can be prevented. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a plan view showing an arrangement of solder balls of the BGA semiconductor device according to the embodiment of the present invention.

FIG. 3 is a diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor chip 2 Polyimide tape 3 Solder ball 4 Epoxy resin 5 Interval 6 Through hole 10 BGA semiconductor device 20 Cutting device 21 Excimer laser oscillator 22 Excimer laser beam 23 Stage 24 Valve 25 Vacuum pump 30 BGA semiconductor device 31 Semiconductor chip 32 Glass epoxy plate 34 Silicon resin 35 Interval 36 Through hole 40 Cutting device 41 Excimer laser oscillator 42 Excimer laser beam 43 Stage 44 Valve 45 Nitrogen gas source 46 Inert gas chamber

Claims (18)

(57) [Claims] A plurality of semiconductor chips are arranged and fixed on a first main surface of an insulating material at a predetermined interval from each other, and a group of semiconductor chips is provided on a second main surface of the insulating material on each of the semiconductor chips. A structure in which solder balls are provided, each of the solder balls is electrically connected to a predetermined portion of the semiconductor chip, and a sealing resin is formed on a first main surface of the insulating material at an interval between the semiconductor chips. When a body is prepared and the BGA semiconductor device including the semiconductor chip, the insulating material and the group of solder balls is separated by cutting the insulating material and the sealing resin at the intervals, the structure is evacuated. A method for manufacturing a BGA semiconductor device, comprising placing the substrate in a chamber and performing the cutting with a laser beam in a vacuum. 2. The method for manufacturing a BGA semiconductor device according to claim 1, wherein a gas pressure of the vacuum chamber at the time of performing the cutting is 100 torr or less. 3. The method for manufacturing a BGA semiconductor device according to claim 1, wherein said laser oscillator for emitting said laser beam is mounted in said vacuum chamber. 4. The method for manufacturing a BGA semiconductor device according to claim 1, wherein said laser beam is an excimer laser beam. 5. A plurality of semiconductor chips are arranged and fixed on a first main surface of an insulating material at a predetermined interval from each other, and a group of semiconductor chips is provided on a second main surface of the insulating material on each of the semiconductor chips. A structure in which solder balls are provided, each of the solder balls is electrically connected to a predetermined portion of the semiconductor chip, and a sealing resin is formed on a first main surface of the insulating material at an interval between the semiconductor chips. When a body is prepared and the BGA semiconductor device including the semiconductor chip, the insulating material and the group of solder balls is separated by cutting the insulating material and the sealing resin at the intervals, the structure is improper. A method for manufacturing a BGA semiconductor device, comprising placing the semiconductor device in an active gas chamber and performing the cutting by a laser beam in an inert gas atmosphere. 6. The method for manufacturing a BGA semiconductor device according to claim 5, wherein an inert gas having a volume ratio of 90% or more is present in the inert gas chamber when the cutting is performed. . 7. The BGA according to claim 5, wherein said inert gas is nitrogen gas or argon gas.
A method for manufacturing a semiconductor device. 8. The method of manufacturing a BGA semiconductor device according to claim 5, wherein said laser oscillator for emitting said laser beam is mounted in said inert gas chamber. 9. The method for manufacturing a BGA semiconductor device according to claim 5, wherein said laser beam is an excimer laser beam. 10. The method of manufacturing a BGA semiconductor device according to claim 1, wherein said insulating material is an insulating tape. 11. The method of manufacturing a BGA semiconductor device according to claim 10, wherein said insulating tape is a polyimide tape. 12. The method of manufacturing a BGA semiconductor device according to claim 1, wherein said insulating material is an insulating plate. 13. The method according to claim 12, wherein the insulating plate is a glass epoxy plate. 14. The method of manufacturing a BGA semiconductor device according to claim 1, wherein the sealing resin is provided at the interval and covers a side surface of the semiconductor chip. Of manufacturing a BGA semiconductor device. 15. The method of manufacturing a BGA semiconductor device according to claim 1, wherein said sealing resin covers a side surface of said semiconductor chip within said space and said semiconductor outside said space. A method of manufacturing a BGA semiconductor device, wherein the method covers a bottom surface of a chip. 16. The method of manufacturing a BGA semiconductor device according to claim 1, wherein said sealing resin is an epoxy resin. 17. The method of manufacturing a BGA semiconductor device according to claim 1, wherein said sealing resin is a silicon resin. 18. A BGA semiconductor device manufacturing apparatus for performing the BGA semiconductor device manufacturing method according to claim 1.