JP3189799B2 - Method for manufacturing 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 of manufacturing a semiconductor device in which a protruding electrode tip formed on a pad electrode film of a semiconductor chip is used as an external connection terminal.

[0002]

2. Description of the Related Art Generally, a semiconductor wafer on which a pattern has been formed is ground to a predetermined thickness using a back surface grinding method. In this backside grinding method, a soft film made of a base material such as vinyl chloride as a protective film is attached to the pattern surface of a semiconductor wafer, and while the semiconductor wafer is uniformly pressed and rotated from above the soft film, diamond grains are removed. This is to grind and remove the back surface of the semiconductor wafer with the granules mixed in the resin.

The scribe line of the ground semiconductor wafer is cut and divided into individual semiconductor chips, and the semiconductor chips and external terminal leads are electrically connected to each other via bonding wires or TAB leads. It is a general technique to process and form external terminal leads after sealing.

In order to form a bump electrode such as an Au bump on a semiconductor wafer, the back surface of the semiconductor wafer is ground by the above-described back surface grinding method, and before or after the removal, the Cr is removed.
Such a barrier metal film is formed, and an Au bump is selectively formed by an Au electrolytic plating method.

[0005]

A large number of semiconductor devices are mounted on various devices such as computers, workstations, personal computers, word processors, mobile phones, and small portable camcorders. In recent years, the progress of miniaturization and weight reduction of these devices has been remarkable, and since the miniaturization, weight reduction, high performance and high function of these devices will further advance in the future, semiconductors mounted on these devices will be The demand for smaller, thinner, and more reliable equipment is
It is expected that the number of semiconductor elements will increase at an accelerating rate in accordance with the demand for higher integration and higher functionality. However, as the diameter of semiconductor wafers increases, the processing of semiconductor wafer thickness by the conventional backside grinding method has a limitation in reducing the thickness due to the restriction of preventing damage to the semiconductor wafer during handling or grinding. As a result,
A semiconductor chip accommodated in a semiconductor device becomes thicker, which is a factor that hinders the thinning of the semiconductor device and the thinning of equipment. Further, in order to avoid damage to the semiconductor wafer due to concentration of a load on the Au bump during grinding of the back surface of the semiconductor wafer, the formation of the Au bump is generally performed after the back surface grinding. Performing the back surface grinding may be very difficult in consideration of avoiding damage to the semiconductor wafer due to local concentration of load.

On the other hand, the mounting area occupied by a semiconductor device in a device tends to increase with the increase in the degree of integration and function of a semiconductor element. In particular, the inside of a conventional semiconductor device includes bonding wires and inner leads. Requires an electrical conduction path, and requires an outer lead on the outside of the semiconductor device to obtain a junction, which essentially increases the mounting area, and further comprises a resin thickness and a semiconductor chip thickness. The mounting height has also been increased, and these factors have hindered miniaturization and weight reduction of the semiconductor device, and thus hindered miniaturization and weight reduction of equipment.

Further, the element surface of the semiconductor chip which is divided after grinding is easily damaged by a small external force, and care must be taken in handling the semiconductor chip and setting device conditions in the assembling process and the mounting process. Was needed.

It is an object of the present invention to prevent the semiconductor wafer from being damaged even when the semiconductor wafer is thinned by grinding the back surface, and at the same time, to prevent the element surface of the semiconductor chip from being damaged. It is an object of the present invention to reduce a mounting area by minimizing an electrical conduction path and to reduce a mounting height by minimizing a resin thickness and a semiconductor chip thickness.

[0009]

In order to solve the above-mentioned problems, a method of manufacturing a semiconductor device according to the present invention includes a step of forming a plurality of semiconductor elements on a semiconductor substrate and a step of forming a plurality of semiconductor elements on the semiconductor element. Forming a protruding electrode group, exposing the tip of the protruding electrode group, forming a resin film on the semiconductor substrate, and removing the resin film on a scribe line of the semiconductor substrate; A step of selectively forming an insulation protection reinforcing film on the surface of the resin film and the side surface of the resin film on the scribe line, and then dividing the semiconductor element to obtain individual semiconductor devices. It is assumed that. In the step of dividing the semiconductor substrate into semiconductor element units to obtain individual semiconductor devices,
After or before the removal of the resin film on the scribe line of the semiconductor substrate, it is desirable to divide the surface of the resin film or the surface and side surfaces of the resin film after forming an insulation protection reinforcing film.

According to the above-described means, even if the semiconductor substrate before being divided into the semiconductor chips is thinned by grinding the back surface,
Since the resin film formed on the semiconductor substrate acts as a protective reinforcing plate, damage to the semiconductor substrate during back surface grinding and handling can be avoided. At the same time, handling of the semiconductor chip in a bare state in the assembling process and the mounting process is eliminated, and damage to the element surface of the semiconductor chip can be avoided. Also, a protruding electrode group serving as an external connection terminal is formed on the electrode of the semiconductor chip, and the tip is exposed and the surface of the semiconductor chip is sealed with a resin film, so that two-dimensional electrical conduction can be easily performed. It is possible to provide a method for manufacturing a small and thin semiconductor device in which the number of paths is minimized and the thickness of the resin and the thickness of the semiconductor chip are reduced.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view illustrating a semiconductor device according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a method of manufacturing the semiconductor device according to the first embodiment. FIG. 1 shows a state in which a semiconductor wafer 1 on which a resin film 3 and a bump electrode 5 are formed on the surface is cut to the size of individual semiconductor chips 2. The back surface of the wafer 1 is mirror-polished using a back surface grinding method so that the thickness of the semiconductor wafer 1 is reduced, and then the scribe lines 4 are cut using a dicing blade. The grinding of the back surface of the semiconductor wafer 1 is performed by forming the resin film 3 on the surface of the semiconductor wafer 1 before grinding the back surface so that the resin film 3 functions as a protective reinforcing plate. A wafer having a thickness of about 0.6 mm at the time of wafer processing can be thinned to about 0.35 mm to about 0.4 mm by a back surface grinding method. 0.7 when processed
In the same manner, the thickness of the semiconductor wafer 1 can be reduced to about 0.4 mm to about 0.5 mm. Thus, the thickness of the semiconductor wafer 1, that is, the thickness of the semiconductor wafer 1 can be reduced regardless of the size of the semiconductor wafer 1. Here, as a resin material for forming the resin film 3, for example, a polyimide resin having low stress and high heat resistance is used, and a polyimide resin generally used in a method of forming a resin portion is spin-coated. A method of heat curing later is used. Further, in order to obtain a predetermined resin film thickness, it can be easily obtained by repeating spin coating. In addition, as the resin material of the resin film 3 formed on the surface of the semiconductor wafer 1, an epoxy resin having low stress and low shrinkage can be used instead of the above-described polyimide resin. The predetermined thickness of the resin film 3 can be easily obtained by using the squeegee printing method. As a result, the function of the resin film 3 as a protective reinforcing plate is further improved.

A method for manufacturing a semiconductor device according to a first embodiment of the present invention will be described with reference to FIG. First, in the first step, as shown in FIG.
m selectively on the electrode pads of the semiconductor wafer 1 having a thickness of about m by electrolytic plating via a chromium thin film.
U-plating is applied to form columnar projecting electrodes 5 at a height of about 100 μm. Next, in the second step, as shown in FIG. 2B, a resin film 3 is formed on the semiconductor wafer 1 so as to cover the upper end of the bump electrode 5. In the third step, as shown in FIG. 2C, the resin film 3 is used as a protective reinforcing plate, and the back surface of the semiconductor wafer 1 is ground by a back surface grinding method so that the thickness of the semiconductor wafer 1 is reduced to about 0.4 mm. Process. In the fourth step, as shown in FIG. 2D, the upper surface of the resin film 3 provided on the upper part of the semiconductor wafer 1 is lightly etched to expose the upper end of the bump electrode 5. In the fifth step, as shown in FIG. 2E, the resin film 3 of the scribe line 4 is scraped off with a dicing blade, dried at a high temperature,
A silicon nitride film 6 is selectively formed by a plasma CVD method except for the upper end of the bump electrode 5. Finally, in a sixth step, as shown in FIG. 2F, the semiconductor wafer 1 is pasted on an adhesive tape for dicing (not shown), and the semiconductor wafer 1 is completely scraped off with a dicing blade along a scribe line 4, Each semiconductor chip 2 is separated. In addition, in order to remove the resin film 3 of the scribe line 4, not only the physical method described in the fifth step, but also a method by chemical etching is possible. On the other hand, the formation of the silicon nitride film 6
Although the function as insulation protection is slightly reduced, the resin film 3
Can be performed immediately after light etching.

Further, as shown in FIG. 1, the semiconductor device cut out to the size of each semiconductor chip 2 as described above,
As described above, the resin film 3 is formed on the upper surface of the semiconductor chip 2 which has been thinned by the back surface grinding, and is formed perpendicularly to the pad electrode of the semiconductor chip 2 from the upper surface of the resin film 3. The tip of the cylindrical protruding electrode 5 protrudes, and the protruding electrode 5 is an Au electrode formed by using an electrolytic plating method, and has a height of 80 μm to 100 μm.
It is. However, the shape of the projecting electrode 5 may be cylindrical or prismatic. On the other hand, the amount of protrusion of the protruding electrode 5 is determined by the height of the protruding electrode 5, the thickness of the resin film 3, and the bonding stability. In the first embodiment, the amount of protrusion is about 20 μm. In the first embodiment, the side surface of the semiconductor chip 2 is exposed in a diced state, and similarly, the back surface is exposed in a ground state. Further, although not specifically shown in FIG. 1,
A silicon nitride film 6 for improving the reliability as a semiconductor device is formed on the outermost surface of the resin film 3 excluding the side and back surfaces of the semiconductor chip 2 and the surface of the bump electrode 5 by a plasma CVD method at a temperature of 200 ° C. to 250 ° C. 1μ at low temperature
m, and serves as an insulation protection reinforced film for preventing a decrease in the reliability of the semiconductor device due to moisture absorption into the resin film 3.

A method of joining the semiconductor device of the first embodiment of the present invention to a printed wiring board showing that it can be adapted to various mounting forms will be described with reference to FIG. FIG. 3 is a sectional view showing a method of joining the semiconductor device of the first embodiment of the present invention shown in FIG. 1 to a printed wiring board. As shown in FIG. 3A, the semiconductor device is directly face-down bonded to the printed wiring board 7 on which the foot pattern 8 is formed, and the Au bump 9 previously provided on the foot pattern 8 and the projection electrode 5 of the semiconductor chip 2 Are joined by thermocompression bonding. Further, in order to enhance the reliability of the semiconductor device including the alloy joint, the peripheral portion of the semiconductor device is sealed with an epoxy-based sealing resin 10 by a potting method. As shown in FIG. 3B, a silicon adhesive 11 having high thermal conductivity is applied to the back surface of the semiconductor device shown in FIG. 3A,
An Al alloy plate serving as the heat radiating plate 12 is adhered, and heat radiation from the semiconductor device is positively improved. FIG. 3C shows an example in which the pitch of the protruding electrodes 5 formed on the semiconductor device is fine.
The semiconductor device of the first embodiment and the TAB tape 13 are joined via the protruding electrodes 5 in exactly the same manner as the method of joining the B tape and the semiconductor chip 2, and the ends of the leads of the TAB tape 13 are terminated. The portion and the foot pattern 8 on the printed wiring board 7 are joined using a solder joining method, and the peripheral portion of the semiconductor device including the solder joint is covered with an epoxy-based sealing resin 10 as in FIGS. 3A and 3B. This is an example of sealing by a potting method. In FIG. 3D, a silicon-based adhesive 11 having high thermal conductivity is applied to the back surface of the semiconductor device described with reference to FIG. 3C, and an Al alloy plate serving as a heat radiating plate 12 is adhered to improve heat radiation from the semiconductor device.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4A is a perspective view showing a semiconductor device according to a second embodiment of the present invention, and FIG. 4B is a side view of FIG. 4A. As shown in FIG. 4A and FIG. 4B, projecting electrodes 5 having two different heights are formed around the semiconductor chip 2 in a staggered manner on the semiconductor chip 2 which is thinly processed by the back surface grinding. A high protruding electrode 5 is formed in the array of the protruding electrodes 5 formed inside the semiconductor chip 2, and a low protruding electrode 5 is formed in the array of the protruding electrodes 5 formed outside the semiconductor chip 2. The protruding amount is about 20 μm. The resin film 3 is formed in a step shape so that By configuring the semiconductor device in this way, even if the protruding electrodes 5 on the semiconductor chip 2 have a fine pitch, it is possible to easily perform TAB bonding in which a short circuit between adjacent leads hardly occurs.

Next, a third embodiment and a fourth embodiment of the present invention will be described with reference to FIGS. FIG.
And FIG. 6 are perspective views showing the semiconductor devices of the third embodiment and the fourth embodiment, respectively. In the third embodiment shown in FIG. 5, a recess 14 is formed in the resin film 3 around the protruding electrode 5 protruding from the semiconductor device.
3A, when solder is used instead of the Au bump 9 as a bonding material between the bump electrode 5 and the foot pattern 8 shown in FIG. 3A, a solder pool for preventing a short circuit due to a solder bridge between the adjacent bump electrodes 5 Has the role of. On the other hand, the fourth embodiment shown in FIG. 6 is an example in which the upper end portion of the protruding electrode 5 protruding from the semiconductor device and the outer side portion among the cylindrical side portions are exposed. The semiconductor device accommodating portion (not shown), the vertical conductor pattern (not shown) on the side surface of the semiconductor device accommodating portion, and the conductor pattern on the bottom surface are continuously provided. It is housed in the semiconductor device housing portion of the printed wiring board 7, and the upper end of the protruding electrode 5 of the semiconductor device and the cylindrical side are soldered to the conductor pattern so as to improve the reliability at the time of soldering. The height at the time of mounting on the printed wiring board 7 is reduced.

As described above, according to the method for manufacturing a semiconductor device of the present invention, the resin film 3 is formed on the surface of the semiconductor chip 2, thereby damaging the semiconductor wafer 1 and reducing the element surface of the semiconductor chip 2. Damage can be prevented. In addition, it is possible to minimize the two-dimensional electric conduction path at the time of mounting on the printed wiring board 7 and at the same time, to reduce the mounting height.

[0018]

According to the method of manufacturing a semiconductor device of the present invention, the resin film formed on the semiconductor substrate functions as a protective enhancement film even if the semiconductor substrate before being divided into semiconductor chips is thinned by back grinding. Therefore, damage to the semiconductor substrate during back surface grinding and handling can be reliably avoided. At the same time, handling of semiconductor chips in a bare state in the assembly process and the mounting process is eliminated,
Damage to the semiconductor chip element surface can also be reliably avoided. Further, a protruding electrode group serving as an external connection terminal is formed on the electrode of the semiconductor chip, and at least the tip is exposed to seal the surface of the semiconductor chip with a resin film. The electrical conduction path is minimized, and
It is possible to manufacture a small and thin semiconductor device having high reliability by reducing the thickness of the resin and the thickness of the semiconductor chip.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a sectional view illustrating a method for manufacturing the semiconductor device according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a method of joining the semiconductor device to the printed wiring board according to the first embodiment of the present invention.

FIG. 4 is a perspective view and a sectional view showing a semiconductor device according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a semiconductor device according to a third embodiment of the present invention.

FIG. 6 is a perspective view showing a semiconductor device according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 2 Semiconductor chip 3 Resin film 4 Scribe line 5 Projection electrode 6 Silicon nitride film 7 Printed wiring board 8 Foot pattern 9 Au bump 10 Sealing resin 11 Silicon adhesive 12 Heat sink 13 TAB tape

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-136049 (JP, A) JP-A-3-101128 (JP, A) JP-A-54-45570 (JP, A) JP-A-3- 73534 (JP, A) JP-A-2-189925 (JP, A) JP-A-2-125633 (JP, A) JP-A 64-12553 (JP, A) JP-A-4-266038 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/301 H01L 21/56 H01L 21/60

Claims (1)

(57) [Claims] A step of forming a plurality of semiconductor elements on a semiconductor substrate; a step of forming a protruding electrode group connected to electrodes of the semiconductor element; Forming a resin film on the substrate; removing the resin film on a scribe line of the semiconductor substrate; and selectively strengthening insulation protection on a surface of the resin film and a side surface of the resin film on the scribe line. Forming a film and then dividing the semiconductor element to obtain individual semiconductor devices. A method for manufacturing a semiconductor device, comprising: