JP2004356147A - Mounting structure for semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure for semiconductor device that does not make a semiconductor element mounting method complicated and can prevent the increase of the costs of thin metallic wires. <P>SOLUTION: A damping resistance can be formed easily and inexpensively in a semiconductor device by disposing noise preventing resistive metallic balls at proper places instead of some of mother board joining metallic balls. Since the damping resistance on the printed board of a mother board can be reduced, the mounting density of the mounting structure for semiconductor device can be increased. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor device such as an LSI or a mounting structure of a module which is a unit in which the semiconductor device is mounted on a printed circuit board.
[0002]
[Prior art]
2. Description of the Related Art In recent years, the mobility of electric devices has been rapidly increasing, and miniaturization of semiconductor devices used in the devices has been progressing in order to make the devices smaller. In addition, miniaturization of the module that integrates functions is also progressing. On the other hand, higher performance is demanded by users, and the processing speed of microcomputers and the like may be improved year by year, and the operating frequency of semiconductor devices is also increasing. Higher operating frequencies cause EMI degradation in equipment and increase noise for other components. In order to cope with such a problem, a damping resistor, an EMI filter, and the like are inserted in a high-speed signal among signals input and output by the semiconductor device. With the increase in speed, the addition of these noise suppression components tends to increase, but their mounting area does not become stupid. Since the miniaturization is also required as shown at the beginning, the reduction of the noise countermeasure parts is an issue. As a conventional technique for reducing the number of components for noise suppression, for example, there is a method described in Patent Document 1. Patent Literature 1 discloses a method in which components such as a chip resistor are arranged on a conductive pattern of a semiconductor device, and the chip components are not arranged on a motherboard to improve a mounting density.
[0003]
[Patent Document 1]
JP, 2003-37239, A (paragraph 0023-0028)
[0004]
[Problems to be solved by the invention]
However, in the above configuration, since it is necessary to newly fix the chip component on the conductive pattern of the semiconductor device, there is a problem that the mounting method of the semiconductor device becomes complicated, and a thin metal wire having a length exceeding the chip component. Is required, so that there has been a problem that the cost of the thin metal wire increases.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a semiconductor device mounting structure in which a method of mounting a semiconductor element is not complicated and a cost of a thin metal wire is not increased.
[0006]
[Means for Solving the Problems]
A first aspect of the present invention (corresponding to claim 1) provides a semiconductor device fixed on a conductive pattern and a semiconductor device having one end connected to an electrode of the semiconductor element and the other end connected to a metal ball. A metal ball having the metal ball having a resistance value for damping is used as an electrode of the semiconductor element which requires the following.
[0007]
According to a second invention (corresponding to claim 2), in the first invention, the metal ball is selected from a conductive metal ball having a small resistance value and a resistance metal ball having a large resistance value. It is characterized by.
[0008]
A third invention (corresponding to claim 3) is characterized in that, in the first invention, the semiconductor element is sealed with an insulating resin.
[0009]
According to a fourth aspect of the present invention (corresponding to claim 4), in the first aspect of the invention, the resistive metal ball is formed by forming a conductive metal thin film on the surface of an insulating ball.
[0010]
According to a fifth aspect of the present invention (corresponding to claim 5), in the fourth aspect of the present invention, the resistance value of the resistive metal ball is adjusted by adjusting the material or thickness of the conductive metal thin film. It is characterized by.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
[0012]
(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 shows a connection mode of a motherboard to a printed circuit board according to the first embodiment of the present invention.
[0014]
In FIG. 1, reference numeral 6 denotes a semiconductor module, which is a unit for integrating components such as an LSI, a resistor, and a capacitor described later on a printed circuit board. 1 and 2 are electronic components used for the module 6, for example, 1 is a component such as a resistor or a capacitor, and 2 is a semiconductor element such as an LSI. 4 and 7 are components for joining the module 6, where 4 is a conductive metal ball and 7 is a resistive metal ball. Reference numeral 8 denotes a printed circuit board for forming a module. Reference numeral 5 denotes a printed circuit board of a motherboard on which modules are mounted. A solder paste 3 electrically and physically connects the metal balls 4 and 7 to the printed boards 8 and 5. The input / output signals of the semiconductor element 2 include signals that are switched at a high frequency, and these signals reduce EMI and noise by interposing a damping resistor as a measure against EMI and noise. A metal ball, which is a component for joining the printed circuit board 5 of the motherboard, having a resistance value is prepared, and is mounted using a solder paste 3 at an appropriate place where damping is to be performed.
[0015]
FIG. 2 shows a state after mounting the metal balls. FIG. 2 is a view of the module as viewed from the bottom. 23 is a printed circuit board of the module, 21 is a conductive metal ball, 22 is a resistive metal ball, and 24 is a semiconductor element mounted on the component surface. As shown in FIG. 2, it can be seen that resistive balls are mounted in a mixed manner. The choice of this mounting is to use a conventional mounting equipment to mount resistive metal balls in advance for the locations of signals that need damping, and to mount conductive metal balls for signals that do not need damping. It can be implemented by letting it be programmed.
[0016]
FIG. 3 shows the structure of the resistive metal ball. 31 is a metal thin film and 32 is an insulator. It is general that the resistance value is obtained by resistivity × length / cross-sectional area. In FIG. 3, a conductive metal thin film is formed on the surface of an insulating ball such as an inexpensive ceramic and the material or thickness of the metal thin film is adjusted to change the resistivity or the cross-sectional area in the above-described formula. By doing so, the resistance value of the metal ball can be adjusted. Here, in order to obtain a metal ball having a high resistance value, it can be realized by using a metal having a high resistivity and reducing the thickness of the thin film.
[0017]
As described above, in the embodiment of the present invention, it is not necessary to newly fix a chip component on the conductive pattern of the semiconductor element, and therefore, there is no problem that the mounting method of the semiconductor element becomes complicated. Further, since a metal thin wire having a length exceeding the chip component is not required, there is no problem that the cost of the metal thin wire increases. Then, even after the semiconductor block is sealed with resin, the arrangement of the resistive balls can be changed, so that more flexible noise countermeasures can be taken.
[0018]
【The invention's effect】
As described above, the mounting structure of the semiconductor device according to the present invention is different from the conventional structure using uniformly conductive metal balls for bonding with the motherboard, in which resistive metal balls for noise suppression are substituted in place. In this case, the damping resistor can be easily formed on the semiconductor device at low cost. This makes it possible to reduce the damping resistance on the printed circuit board of the motherboard, thereby increasing the mounting density. Since the location of the noise countermeasure can be easily changed by changing the arrangement of the resistive balls, a highly flexible noise countermeasure is possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing a connection configuration between a mother board and a printed circuit board according to the first embodiment of the present invention; FIG. 2 is a mounting diagram of metal balls according to the first embodiment of the present invention; FIG. Structural diagram of resistive metal ball [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electronic component 2 Semiconductor element 3 Solder paste 4 Conductive metal ball 5 Printed circuit board of motherboard 6 Module 7 Resistive metal ball 8 Module printed circuit board 21 Conductive metal ball 22 Resistive metal ball 23 Module printed circuit board 24 Semiconductor element 31 Metal thin film 32 Insulator

Claims (5)

In a semiconductor device fixed on a conductive pattern and a semiconductor device in which one end is connected to an electrode of the semiconductor element and the other end is connected to a metal ball, the electrode of the semiconductor element for which noise countermeasures are required is connected to the metal ball. A mounting structure of a semiconductor device, wherein a metal ball having a resistance value for damping is used. 2. The semiconductor device mounting structure according to claim 1, wherein said metal ball is selected from a conductive metal ball having a small resistance value and a resistance metal ball having a large resistance value. 2. The semiconductor device mounting structure according to claim 1, wherein said semiconductor element is sealed with an insulating resin. 2. The semiconductor device mounting structure according to claim 1, wherein the resistive metal ball is formed by forming a conductive metal thin film on a surface of an insulating ball. 5. The semiconductor device mounting structure according to claim 4, wherein the resistance value of said resistive metal ball is adjusted by adjusting the material or thickness of said conductive metal thin film.

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