JP3194045B2 - 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 for manufacturing a semiconductor device having a columnar electrode.

[0002]

2. Description of the Related Art For example, when a semiconductor device called a CSP (Chip Size Package) is manufactured, as shown in FIG. 6, a plurality of columnar electrodes 2 are first formed on a silicon substrate (semiconductor substrate) 1 in a wafer state. The formed product is positioned and placed on the upper surface of the printing table 3. Next, the print mask 4 is positioned and placed on the upper surface of the silicon substrate 1. The printing mask 4 is formed by forming a circular opening 4b slightly smaller than the plane size of the silicon substrate 1 in a mask main body 4a having a thickness slightly larger than the height of the columnar electrode 2.

[0003] Next, as shown in FIG. 7, a liquid sealing resin is applied to the opening 4 b
The inside is printed to form the sealing film 6. In this state, the upper surface of the columnar electrode 2 is covered with the sealing film 6. next,
By appropriately polishing or etching the upper surface side of the sealing film 6, the upper surface of the columnar electrode 2 is exposed as shown in FIG. Next, as shown in FIG. 9, a solder ball 7 is formed on the upper surface of the columnar electrode 2. Next, through a dicing step, individual semiconductor devices are obtained.

FIG. 10 is a partial cross-sectional view showing a state where the semiconductor device 10 obtained as described above is mounted on a circuit board 11. In this case, the semiconductor device 1
No. 0 is mounted on the circuit board 11 because the solder ball 7 is joined to the connection terminal 12 formed at a predetermined position on the upper surface of the circuit board 11.

Incidentally, such a conventional semiconductor device 1
At 0, since the thickness of the sealing film 6 is the same as the height of the columnar electrode 2, the columnar electrode 2 is unlikely to swing and move. As a result, in the temperature cycle test after being mounted on the circuit board 11, A problem that stress generated due to a difference in thermal expansion coefficient between the circuit board 11 and the circuit board 11 cannot be absorbed by the columnar electrode 2 and a crack may be generated at an interface between the columnar electrode 2 and the solder ball 7. was there.

Therefore, as a solution to the above problem,
For example, a semiconductor device as shown in FIG. 3 can be considered. In this semiconductor device, a plurality of columnar electrodes 12 are formed on a silicon substrate 11, and the silicon substrate 11 between the columnar electrodes 12 is formed.
A sealing film 16 is formed so as to be depressed between the columnar electrodes 12, and a solder ball 17 is formed on the upper surface of the columnar electrode 12. In this semiconductor device, since the sealing film 16 is formed so as to be depressed between the columnar electrodes 12, the columnar electrode 12 can be easily swung,
Eventually, the columnar electrode 12 can absorb the stress.

[0007]

By the way, in the semiconductor device as shown in FIG. 3, the thickness of the sealing film 16 (the columnar electrode 1
It is important to control the thickness (the thickness of the most depressed portion between the two). However, immediately after forming the sealing film 16 by screen printing, the thickness of the sealing film 16 cannot be measured by a micrometer because the sealing film 16 is in a liquid state and has not been cured. Therefore, the thickness is measured after the sealing film 16 is cured. As a result of this measurement, if the thickness is not as expected, even if the screen printing conditions are adjusted, There is a problem that a large number of defective products are generated. An object of the present invention is to make it possible to adjust the thickness of a sealing film at an early stage.

[0008]

According to the present invention, a liquid sealing resin is screen-printed on a semiconductor substrate between a plurality of columnar electrodes formed on the semiconductor substrate to form a sealing film having a predetermined thickness. In the method of manufacturing a semiconductor device to be formed, the thickness of the sealing film printed on the semiconductor substrate is adjusted based on the weight of the liquid sealing resin formed on the semiconductor substrate. is there. According to the present invention, the thickness of the sealing film printed on the semiconductor substrate is adjusted based on the weight of the liquid sealing resin formed on the semiconductor substrate. Also, by measuring the weight of the liquid sealing resin, the thickness of the sealing film can be indirectly measured, and therefore, the thickness of the sealing film can be adjusted early.

[0009]

1 to 3 show respective manufacturing steps of a semiconductor device according to an embodiment of the present invention. Therefore, a method of manufacturing the semiconductor device according to this embodiment will be described with reference to these drawings in order. First, as shown in FIG. 1, a silicon substrate (semiconductor substrate) 11 in a wafer state on which a plurality of columnar electrodes 12 are formed is positioned and placed on the upper surface of a printing table 13. Next, the print mask 14 is formed on the upper surface of the silicon substrate 11.
Position and place. The print mask 14 is formed by forming a circular opening 14 b slightly smaller than the plane size of the silicon substrate 11 in a mask body 14 a having a thickness smaller than the height of the columnar electrode 12.

Next, as shown in FIG. 2, a liquid sealing resin is applied to the printing mask 1 with a squeegee 15 having a substantially V-shaped tip.
4 is printed in the opening 14b to form the sealing film 16.
In this case, the squeegee 15 is formed of minourethane (urethane-based rubber), and the angle of the tip is preferably about 60 °, but there is no problem even if it is about 55 ° to 80 °. The hardness of the squeegee 15 is 55 ° in JIS standard.
When printing, the squeegee 15 is reciprocated in a substantially vertical state, and its tip is pushed between the columnar electrodes 12. It is formed to be thinner than the height and to be recessed between the columnar electrodes 12. When the sealing film 16 is formed on the upper surface of the columnar electrode 12, the sealing film 16 on and near the columnar electrode 12 is appropriately polished or etched to expose the upper surface of the columnar electrode 12. Next, FIG.
As shown in (1), a solder ball 17 is formed on the upper surface of the columnar electrode 12. Next, through a dicing step, individual semiconductor devices are obtained.

The weight (g) of the liquid sealing resin printed on the silicon substrate 11 and the thickness (m) of the sealing film 16
4), the result shown in FIG. 4 was obtained in the case of the 5-inch silicon substrate 11, and the result shown in FIG. 5 was obtained in the case of the 6-inch silicon substrate 11. In this case, the weight of the liquid sealing resin printed on the silicon substrate 11 was measured immediately after the screen printing by measuring the entire weight with a balance, and the silicon substrate 11 measured in advance from the measurement result was used.
Were determined by subtracting the weights. In addition, the thickness of the sealing film 16 is the thickness at the most depressed portion between the columnar electrodes 12, and was measured with a micrometer after the liquid sealing resin was dried and cured. In addition, the weight of the liquid sealing resin hardly changed even after curing.

Now, as apparent from FIGS. 4 and 5,
The thickness of the sealing film 16 is directly proportional to the weight of the liquid sealing resin printed on the silicon substrate 11. Therefore, the thickness of the sealing film 16 can be controlled by adjusting the weight of the liquid sealing resin printed on the silicon substrate 11.

The printing amount (weight) of the liquid sealing resin printed on the silicon substrate 11 is determined by the amount of pushing of the squeegee 15 (the tip of the squeegee 15 is Amount). Therefore, the weight of the liquid sealing resin printed on the silicon substrate 11 can be controlled by adjusting the pushing amount of the squeegee 15.

As a result, in mass production, immediately after screen printing, when the weight of the liquid sealing resin printed on the silicon substrate 11 is measured, the thickness of the sealing film 16 after curing can be determined. This means that the thickness of 16 was measured indirectly. When the measured value of the weight of the liquid sealing resin (thickness of the sealing film 16 after curing) is not an expected value, the amount of the liquid sealing resin printed on the silicon substrate 11 is adjusted by adjusting the amount of pushing of the squeegee 15. The weight of the resin is controlled, and thus the thickness of the cured sealing film 16 is controlled. Therefore, the thickness of the sealing film 16 can be adjusted at an early stage, and the occurrence of a large number of defective products can be prevented.

[0015]

As described above, according to the present invention, the thickness of the sealing film printed on the semiconductor substrate is adjusted based on the weight of the liquid sealing resin formed on the semiconductor substrate. Therefore, even immediately after screen printing, the thickness of the sealing film can be measured indirectly by measuring the weight of the liquid sealing resin. And it is possible to prevent the occurrence of a large number of defective products.

[Brief description of the drawings]

FIG. 1 is a sectional view of an initial manufacturing process for manufacturing a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a sectional view of the manufacturing process following FIG. 1;

FIG. 3 is a sectional view of the manufacturing process following FIG. 2;

FIG. 4 is a diagram illustrating an example of a relationship between the weight of a liquid sealing resin and the thickness of a sealing film.

FIG. 5 is a view for explaining another example of the relationship between the weight of the liquid sealing resin and the thickness of the sealing film.

FIG. 6 is a cross-sectional view of an initial manufacturing process for manufacturing a conventional semiconductor device.

FIG. 7 is a sectional view of the manufacturing process following FIG. 6;

FIG. 8 is a sectional view of the manufacturing process following FIG. 7;

FIG. 9 is a sectional view of the manufacturing process following FIG. 8;

FIG. 10 is a sectional view showing a state where the semiconductor device as shown in FIG. 9 is mounted on a circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Silicon substrate 12 Columnar electrode 13 Printing table 14 Printing mask 15 Squeegee 16 Sealing film 17 Solder ball

Claims (4)

(57) [Claims] 1. A method of manufacturing a semiconductor device, comprising forming a sealing film having a predetermined thickness by screen-printing a liquid sealing resin on the semiconductor substrate between a plurality of columnar electrodes formed on the semiconductor substrate. And adjusting the thickness of the sealing film printed on the semiconductor substrate based on the weight of the liquid sealing resin formed on the semiconductor substrate. 2. The method according to claim 1, wherein the sealing film is formed so as to be depressed between the columnar electrodes. 3. The method of manufacturing a semiconductor device according to claim 2, wherein the thickness of the sealing film is adjusted by a squeegee pushing amount. 4. The invention according to claim 1, wherein the weight of the liquid sealing resin formed on the semiconductor substrate is measured before the liquid sealing resin is cured. Manufacturing method of a semiconductor device.