KR100299304B1 - Method for manufacturing semiconductor memory module - Google Patents

Abstract

PURPOSE: A method for manufacturing a semiconductor memory module is provided to obtain a minimized and thin film module by manufacturing the semiconductor memory module using a bonding, a molding and sealing processes after directly mounting a chip on a printed circuit substrate. CONSTITUTION: A printed circuit substrate(41) having a bonding position(44) is provided. A chip bonding pad(32) is formed on an individual chip(31). The bonding position(44) and the chip bonding pad(32) of the individual chip(31) are connected electrically using a wire bonding process. A protect layer is formed on the printed circuit substrate including the individual chip by using a molding and sealing processes, thereby forming a semiconductor memory module of a thin film and a small type.

Description

Semiconductor memory module manufacturing method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor memory module, and more particularly, to a method of manufacturing a semiconductor memory module capable of reducing costs, improving productivity, miniaturization, and thickness through improvement of a manufacturing process.

A semiconductor memory module is composed of several parts and elements with regularity and separation, and is an assembly circuit regarded as a single part unit performing a predetermined function. Such semiconductor memory modules are applied to most electronic devices. With the recent miniaturization and thinning of electronic devices, semiconductor memory modules are also required to be miniaturized and thinned. In addition, productivity improvement and cost reduction are essential to enhance competitiveness among manufacturers.

1 is a cross-sectional view of a typical package, and FIG. 2 is a perspective view of a conventional semiconductor memory module in which the package of FIG. 1 is installed on a printed circuit board.

Referring to FIG. 1, the package 10 is separated into individual chips 11 through a wafer mounting process and a wafer dicing saw process after a wafer probe test. Each individual chip 11 is attached to a lead frame 13 using an adhesive material to a chip support paddle 12 through a chip attaching process. A chip bonding pad 14 formed on the chip 11 and the lead frame 13 are connected to each other by a wire 15 through a wire bonding process. In order to protect the chip 11 and the wire 15 which have been wire-bonded from various damage factors, the sealing and molding of the chip surroundings with a protective material is performed through a molding and sealing process. Through the protective film 16 is formed. After this process, the shape of the lead frame 13 is formed according to the prescribed shape and separated so as to serve as a complete integrated circuit (IC), a mechanical / chemical deflash process. , Tin plating process, trim process, form / singulation process, pretest process, burn-in test process and post test The test 10 process is completed to manufacture the package 10.

Using the package 10 manufactured as described above, as shown in FIG. 2, the semiconductor memory module 20 is manufactured. The fabrication of the semiconductor memory module 20 is first provided with a multilayer printed circuit board 21 printed with a circuit pattern, and a selected portion of the multilayer printed circuit board 21 by screen printing solder flux. The packages 10 are individually mounted and solder reflow is performed at 200 to 270 ° C. Reference numeral 22 is an out lead.

As described above, the conventional semiconductor memory module 20 is manufactured by forming the package 10 according to the package process sequence, and installing the package 10 individually on the multilayer printed circuit board 20. In general, an integrated circuit package (ICPKC) may be divided into a surface mount package, an insert package, and other types of packages, and the package 10 applied to the conventional semiconductor memory module 20 is one of these types.

Since the semiconductor memory module 20 has to go through several to several tens of steps to separately manufacture the package 10, the manufacturing process is long and the production cost increases, and the package 10 directly prints the printed circuit board 21. Because it must be installed in the module 20, it is difficult to miniaturize and thin, which leads to a decrease in competitiveness among manufacturers. In addition, the use of solder flux to install the individual package 10 on the printed circuit board 21 causes problems such as deterioration in reliability of solder joints.

Therefore, the present invention does not install the package on a printed circuit board after the package is completed with individual chips, and the semiconductor memory can be manufactured by a simple process such as a wire bonding process or a molding / sealing process after the chip is directly installed on a printed circuit board. It is an object of the present invention to provide a method for manufacturing a semiconductor memory module that can reduce costs and improve productivity, as well as miniaturization and thickness of modules.

The semiconductor memory module manufacturing method of the present invention for achieving the above object comprises the steps of fabricating a printed circuit board having a bonding position; Forming chip bonding pads on individual chips; Electrically connecting a bonding position of the printed circuit board and a chip bonding pad of the individual chip through a wire bonding process; And forming a protective film on the printed circuit board including the individual chips through a molding / sealing process.

1 is a cross-sectional view of a typical package.

2 is a perspective view of a conventional semiconductor memory module in which the package of FIG. 1 is installed on a printed circuit board.

3A to 3C are perspective views illustrating a method of manufacturing a semiconductor memory module according to a first embodiment of the present invention.

4 is an enlarged cross-sectional view taken along line 4-4 of FIG. 3A.

FIG. 5 is a cross-sectional view of a semiconductor memory module according to a first embodiment of the present invention, taken along line 5-5 of FIG. 3C.

6 is a cross-sectional view of a semiconductor memory module according to a second embodiment of the present invention.

7A to 7C are cross-sectional views illustrating a method of manufacturing a semiconductor memory module in accordance with a third embodiment of the present invention.

8 is an enlarged view of a portion “A” of FIG. 7A.

<Description of the symbols for the main parts of the drawings>

10: package 11, 31, 71: chip

12 chip support paddle 13 lead frame

14, 32, 72: chip bonding pads 15, 51, 91: wire

16, 53, 93: protective film 20, 345, 600, 780: semiconductor memory module

21, 41, 61, 81: printed circuit board 22, 42: out lead

Circuit pattern: 43a, 43b, 43c, 43d, 83a, 83b, 83c, 83d

44, 84: bonding position

45a, 45b, 45c, 45d, 85a, 85b, 85c, 85d: substrate

46, 86: solder resist 47: groove

52, 92: adhesive layer 87: through hole

94: sealing layer

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

3 (a) to 3 (c) are perspective views illustrating a method of manufacturing a semiconductor memory module according to a first embodiment of the present invention, and FIG. 4 is cut along line 4-4 of FIG. 3 (a). 5 is an enlarged cross-sectional view, and FIG. 5 is a cross-sectional view of the semiconductor memory module according to the first embodiment of the present invention taken along the line 5-5 of FIG.

Referring to FIG. 3A, a multilayer printed circuit board 41 having a plurality of grooves 47 and a plurality of chips 31 are provided, respectively. An adhesive layer 52 is formed on the bottom of the groove 47. The chip 31 is attached to the groove 47 of the multilayer printed circuit board 41 through a chip attaching process.

In the above, the chip 31 is separated into individual chips 31 through a wafer mounting process and a wafer dicing saw process after a wafer probe test, and an upper end of the chip 31. A plurality of chip bonding pads 32 are formed at the surface edges. As shown in FIG. 4, the multilayered printed circuit board 41 is stacked by forming circuit patterns 43a, 43b, 43c, and 43d on top of each of the plurality of substrates 45a, 45b, 45c, and 45d. A plurality of out leads 42 are formed, and a plurality of grooves 47 are formed so that the chips 31 may be embedded at the positions where the chips 31 are to be installed. A solder resist 46 is applied on the multilayer printed circuit board 41 so that a portion of the first circuit pattern 43a around the groove 47 is exposed to form a bonding position 44. The bonding position 44 of the first circuit pattern 43a is plated with gold or silver. The groove 47 is formed by partially removing only the first layer made of the first circuit pattern 43a and the first substrate 45a, or the second layer made of the second circuit pattern 43b and the second substrate 45b. It can be removed and formed, and its depth can be changed according to design rules. The adhesive layer 52 is formed in a manner by dotting, printing or tape.

Referring to FIG. 3B, the wire 51 is interposed between the chip bonding pad 32 of the chip 31 and the bonding position 44 of the first circuit pattern 43a through a wire bonding process. To form.

Referring to FIG. 3 (c), the chip 31 and the wire 51 having finished the wire bonding process are protected around the chip through a molding and sealing process to protect the chip 31 and the wire 51 from external damage factors. Is formed by encapsulating and forming a protective film 53 to form a protective film 53, thereby completing the semiconductor memory module 345 according to the first embodiment of the present invention, the cross section of which is shown in FIG.

In the semiconductor memory module 345 according to the first embodiment manufactured by the above process, the grooves 47 are formed in the multilayered printed circuit board 41 to directly embed the chips 31 in the grooves 47. The molding of the multilayered printed circuit board 41 itself, in which the 31 is embedded, can be made smaller than that of installing the package 10 directly on the multilayer printed circuit board 21 as in the conventional semiconductor memory module 20 shown in FIG. 2. And thinning, and in particular, since all the chips 31 applied to the semiconductor memory module 345 of the present invention do not need to install the lead frame 13 shown in FIG. 1, further miniaturization and thinning can be achieved. (A conventional package does not require a lead frame depending on the package type, but many require a lead frame as shown in FIG. 1).

In addition, since the semiconductor memory module 345 according to the first embodiment of the present invention is molded after the chip 31 is directly installed on the multilayer printed circuit board 41, the package 10 as shown in FIG. 2. After fabrication, the package 10 can be simplified in terms of process rather than installing the package 10 on the printed circuit board 21, thereby improving productivity and reducing costs.

FIG. 6 is a cross-sectional view of a semiconductor memory module 600 according to a second embodiment of the present invention. The semiconductor memory module 600 according to the second embodiment may include a semiconductor memory module 345 according to the first embodiment described above. The manufacturing process is the same, but is manufactured by directly installing the chip 31 on the multilayered printed circuit board 61 in which the groove 47 capable of embedding the chip 31 is not formed. The semiconductor memory module 600 of the second embodiment to which the multilayered printed circuit board 61 without the grooves 47 is applied cannot be made thinner than the semiconductor memory module 345 of the first embodiment. Since is the same as the semiconductor memory module 345 of the first embodiment, it is possible to achieve miniaturization and thickness as compared with the conventional semiconductor memory module 20, as well as to improve productivity and cost. The same reference numerals as those in FIG. 5 among the reference numerals in FIG. 6 mean the same names and parts.

7A to 7C are cross-sectional views illustrating a method of manufacturing a semiconductor memory module in accordance with a third embodiment of the present invention, and FIG. 8 is an enlarged view of portion “A” of FIG. 7A. to be.

Referring to FIG. 7A, a multilayer printed circuit board 81 having a plurality of through holes 87 and a plurality of chips 71 are provided, respectively. An adhesive layer 92 is formed at the rear inlet of the through hole 87. The chip 71 is directly attached to the multilayer printed circuit board 81 by the adhesive layer 92 at the rear inlet of the through hole 87.

In the above, the chip 71 is separated into individual chips 71 through a wafer mounting process and a wafer cutting process after the wafer probe test, and a plurality of chip bonding pads 72 are formed at the center of the upper surface of the chip 71. do. 8, the multilayer printed circuit board 81 is stacked by forming circuit patterns 83a, 83b, 83c, and 83d on top of each of the plurality of substrates 85a, 85b, 85c, and 85d. The chip 71 is manufactured by forming a plurality of through holes 87 in the position where the chip 71 is to be installed. The solder resist 86 is coated on the multilayer printed circuit board 81 so that a portion of the first circuit pattern 83a around the front surface of the through hole 87 is exposed to form a bonding position 84. The bonding position 84 of the first circuit pattern 83a is plated with gold or silver. The adhesive layer 92 is formed at the back opening of the through hole 87 in a manner by dotting, printing or tape.

Referring to FIG. 7B, a wire 91 is formed between the chip bonding pad 72 of the chip 71 and the bonding position 84 of the first circuit pattern 83a through a wire bonding process. The wire 91 passes through the through hole 87.

Referring to FIG. 7C, in order to protect the chip 71 and the wire 91 which have been finished with the wire bonding process from various damage factors from the outside, the operation of encapsulating and forming a chip around the chip with a protective material through a molding and sealing process is performed. The passivation layer 93 and the sealing layer 94 are formed through the semiconductor memory module 780 according to the third embodiment of the present invention. The semiconductor memory module 780 according to the third embodiment is a read on chip type (LOC type).

The semiconductor memory module 780 according to the third embodiment manufactured by the above process is a multilayer printed circuit provided when compared with the semiconductor memory modules 345 and 600 according to the first and second embodiments described above in terms of manufacturing process. It is the same as the basic principle of the present invention for directly installing a chip on a substrate. Accordingly, the semiconductor memory module 780 according to the third embodiment can also be made smaller and thinner than the conventional lead-on-chip type semiconductor memory module in which a package is installed on a multi-layer printed circuit board. Savings can be achieved.

The semiconductor memory modules 345 and 600 according to the first and second embodiments of the present invention described above are integrally formed with a protective film through a molding and sealing process, but each of the chips is the same as the semiconductor memory module 780 according to the third embodiment. It can also be formed in a divided form in which a protective film is formed. In addition, the protective film of the semiconductor memory module 780 according to the third embodiment may also be integrally formed.

Meanwhile, although the semiconductor memory modules 345, 600, and 780 according to the first, second, and third embodiments of the present invention have been described with some types of various semiconductor memory modules applied to electronic devices as embodiments, conventional semiconductor memory modules Unlike the package mount method of the present invention, all types of semiconductor memory modules can be manufactured using the manufacturing principle of the present invention, which is a chip mount method.

As described above, the present invention does not install the package on the printed circuit board after the package is completed with the individual chips, and the semiconductor memory module is used in the wire bonding process and the molding / sealing process after the chip is directly installed on the printed circuit board. By reducing the cost, productivity can be reduced by simplifying the process, and productivity can be improved. Since the chip is directly installed on the printed circuit board, the module can be miniaturized and thinned, thereby increasing the competitiveness among manufacturers.

Claims (1)

Fabricating a printed circuit board having a bonding position; Forming chip bonding pads on individual chips; Electrically connecting a bonding position of the printed circuit board and a chip bonding pad of the individual chip through a wire bonding process; And forming a protective film on the printed circuit board including the individual chips through a molding / sealing process.