JP2997379B2 - 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 semiconductor device mounted on an information processing device such as a computer.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 3, a resin-coated semiconductor device mounted on an information processing device such as a computer has a semiconductor element 11 and a Kovar metal (iron-nickel-cobalt alloy) or a 42 alloy (iron Base 12 made of a metal material such as a nickel alloy) and a plurality of external lead terminals (
(Power supply lead terminal, ground lead terminal and signal lead terminal) 1
3 and a coating material 14 made of a thermosetting resin such as an epoxy resin.The semiconductor element 11 is mounted and fixed on a base 12 via a brazing material such as a gold-silicon eutectic alloy. The power supply electrode, the ground electrode, and the signal electrode are electrically connected to each of the external lead terminals (power supply lead terminal, ground lead terminal, and signal lead terminal) 13 via a bonding wire 15.
It is manufactured by covering a part of the external lead terminals 13 with the covering material 14.

However, in this conventional package for housing a semiconductor element, the base 12 to which the semiconductor element 11 is fixed is made of Kovar metal or 42 alloy, and has a thermal conductivity of about 18 W /
m · K, and the coating material 14 covering the semiconductor element 11 is made of a thermosetting resin such as epoxy resin, and its thermal conductivity is as low as about 18 W / m · K. When a large amount of heat is generated, the heat generated by the semiconductor element 11 is accumulated around the semiconductor element 11, and as a result, the temperature of the semiconductor element 11 becomes high due to the heat generated by the semiconductor element 11 itself. Cause destruction,
It has the disadvantage that the characteristics change and malfunctions occur.

In recent years, the density and integration of the semiconductor element 11 have been rapidly increased, and the number of electrodes has been greatly increased. Each electrode of the semiconductor element 11 (power supply electrode, ground electrode, signal electrode ), The number of external lead terminals 13 to be connected also increases rapidly, and the line width of each external lead terminal 13 is extremely thin.
Inductance is getting higher, about 15nH. Therefore, the semiconductor element is connected via this external lead terminal 13.
When power and an electric signal for driving are supplied to the semiconductor device 11, a large noise is generated when a fluctuation occurs in a power supply voltage supplied to the semiconductor element 11 due to a high inductance of the external lead terminal 13. With semiconductor element 11
To cause a malfunction in the semiconductor device.

Further, the external lead terminal 13 is made of Kovar metal, 42 alloy, or the like, and the impedance of the external lead terminal 13 viewed from the semiconductor element 11 is
Since the impedance is lower than the characteristic impedance of the semiconductor element 11 connected to the external lead terminal 13,
When an electric signal is input / output to / from the semiconductor element 11 via the external lead terminal 13, the characteristic impedance of the semiconductor element 11 is not matched with the impedance of the external lead terminal 13 as viewed from the semiconductor element 11 side. As a result, the electric signal transmitted through the external lead terminal 13 has a disadvantage that noise or attenuation occurs due to reflection, and the semiconductor element 11 cannot be normally operated.

[0006]

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned drawbacks, and has as its object to effectively prevent the temperature of the semiconductor element itself from being raised to a high temperature by the heat generated by the semiconductor element, and to supply power to the semiconductor element. Provided is a semiconductor device that can effectively absorb noise caused by voltage fluctuations, effectively avoid noise and attenuation due to impedance mismatch, and operate a semiconductor element normally and stably for a long period of time. is there.

[0007]

According to the present invention, a base made of an aluminum nitride sintered body, a semiconductor element mounted and fixed on the base, and a power electrode, a ground electrode and a signal electrode of the semiconductor element are connected. A semiconductor lead comprising a power supply lead terminal, a ground lead terminal, and a signal lead terminal, and a resin coating material that covers the base, the semiconductor element, and a part of each lead terminal, wherein the ground electrode and the ground lead terminal are The power supply electrode and the power supply lead terminal are provided on the metallization layer for ground attached on the upper surface of the base, and the signal electrode and the power supply metallization layer are provided on the metallization layer for power supply attached on the upper surface of the metallization layer for sandwiching a dielectric layer therebetween. The signal lead terminal is electrically connected to a resistor connected to a part of the ground metallization layer.

[0008]

According to the semiconductor device of the present invention, since the base on which the semiconductor element is mounted is formed of an aluminum nitride sintered body having a thermal conductivity of 50 W / m.K or more, which is easy to conduct heat, the semiconductor element is Even if a large amount of heat is generated during operation, the heat is well absorbed and diffused into the substrate, and as a result, the semiconductor device always has a low temperature, and can operate normally and stably for a long period of time.

Further, according to the semiconductor device of the present invention, a dielectric layer is interposed between the power supply lead terminal and the ground lead terminal to which the power supply electrode and the ground electrode of the semiconductor element are connected, and the power supply electrode of the semiconductor element is connected to the ground. Since a large capacitance of 3 nF or more is connected to the electrodes, even if noise occurs due to fluctuations in the power supply voltage to the semiconductor element, the noise is effectively absorbed by the large capacitance. As a result, no noise enters the semiconductor element, and the semiconductor element can be operated normally and stably for a long period of time.

Further, according to the semiconductor device of the present invention, since the resistor is connected between the ground lead terminal and the signal lead terminal, the characteristic impedance of the semiconductor element and the impedance of the external lead terminal as viewed from the semiconductor element are accurate. As a result, it is possible to effectively prevent noise, attenuation, and the like from occurring in the electric signal that is put into and out of the semiconductor element through the signal lead terminal.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and 2 show one embodiment of the semiconductor device of the present invention, wherein 1 is a base and 2 is a semiconductor element.

The substrate 1 is made of an aluminum nitride sintered body, and has a mounting portion 1a for mounting the semiconductor element 2 at a substantially central portion of the upper surface thereof, and the semiconductor element 2 is bonded to the mounting portion 1a with an adhesive. It is fixed by bonding through.

The base 1 functions as a support member for supporting the semiconductor element 2 and also functions to absorb and remove heat generated when the semiconductor element 2 operates.

The substrate 1 made of the aluminum nitride-based sintered body has a high thermal conductivity of 50 W / m · K or more of the aluminum nitride-based sintered body constituting the base body 1 and easily conducts heat. Even if a large amount of heat is sometimes generated, the heat is well transmitted and absorbed by the base 1, and as a result, the semiconductor element
The temperature of the semiconductor element 2 does not become high due to the heat generated by the element 2 itself, and the semiconductor element 2 does not undergo thermal destruction or change in characteristics, and does not cause malfunction.

The substrate 1 made of the aluminum nitride sintered body is, for example, made of aluminum nitride (A
lN) Yttria (Y ₂ O ₃ ), calcia (CaO), magnesia (MgO) and a suitable organic solvent
A raw material powder is prepared by adding and mixing a solvent, and then the raw material powder is filled in a predetermined mold and pressed at a constant pressure to be molded, and thereafter, the molded body is heated to about 1800 ° C. It is manufactured by firing at a temperature.

The base 1 made of the aluminum nitride sintered body has a ground metallization layer 3a attached to the outer peripheral portion of the upper surface thereof.
The second ground electrode and the ground lead terminal 4a are connected via a bonding wire 5a.

The metallized layer 3a for grounding is made of tungsten, molybdenum, or the like. A metal paste is obtained by adding aluminum nitride powder, glass powder, a suitable organic solvent and a solvent to tungsten or molybdenum powder and mixing them. The upper surface of the base 1 is printed and applied in a predetermined pattern by a conventionally known screen printing method, and thereafter, is baked at a high temperature to be adhered to the upper surface of the base 1.

A power lead terminal 4b is attached to the ground metallization layer 3a via a dielectric layer 6 having a power metallization layer 6a on the upper surface thereof.
A power supply electrode of the semiconductor element 2 and a power supply lead terminal 4b are electrically connected to 6a via bonding wires 5b.

The dielectric layer 6 having the power supply metallized layer 6a has a thickness of 3 nF between the power supply electrode and the ground electrode of the semiconductor element 2.
When the above-mentioned large capacitance is connected and power and an electric signal for driving are supplied to the semiconductor element 2, even if a large noise occurs due to a fluctuation in the power supply voltage supplied to the semiconductor element 2, the noise is reduced. An effect of effectively preventing the semiconductor element 2 from entering the semiconductor element 2 is achieved, whereby the semiconductor element 2 operates stably and normally.

The dielectric layer 6 is made of, for example, a barium titanate porcelain having a high dielectric constant. A raw material powder such as barium carbonate, titanium oxide, magnesium titanate or the like is fired and reacted to obtain barium titanate. The barium titanate powder is formed by pulverizing the powder into fine powder, and then a suitable solvent and a solvent are added to the barium titanate powder to form a slurry, which is then formed into a sheet by using a doctor blade method or the like. Thus, a green sheet is obtained and finally manufactured by firing the green sheet at a temperature of about 1300 ° C.

The power supply metallization layer 6a formed on the surface of the dielectric layer 6 is made of silver-palladium,
A metal paste obtained by adding an organic solvent and a solvent to silver and palladium powders is mixed and printed on the surface of the dielectric layer 6 and baked at a temperature of about 900 ° C. to be adhered to the dielectric layer 6. .

A resistor 7 is connected to a part of the ground metallization layer 3a, and a signal electrode of the semiconductor element 2 and a signal lead terminal 4c are respectively connected to the resistor 7 via a bonding wire 5c. It is electrically connected.

The resistor 7 is connected between the ground lead terminal 4a and the signal lead terminal 4c, and serves to match the impedance of the signal lead terminal 4c viewed from the semiconductor element 2 side to the characteristic impedance of the semiconductor element 2. Thus, when the signal lead terminal 4c is connected to the signal electrode of the semiconductor element 2 and an electric signal is input / output to / from the semiconductor element 2 via the signal lead terminal 4c, the characteristic impedance of the semiconductor element 2 and the semiconductor element 2 Signal lead terminal 4c viewed from the side
Since the impedance of the semiconductor device 2 matches the impedance of the semiconductor device 2, the electric signal transmitted through the signal lead terminal 4c does not generate any noise or attenuation due to reflection, and as a result, the semiconductor element 2 can always be normally operated.

The resistor 7 is made of a resistor material such as ruthenium oxide (RuO) or lanthanum boride (LaB ₆ ), and is formed by a conventionally known thick film forming technique such as a screen printing method or a thin film forming method such as a vapor deposition or sputtering method. It is applied on the substrate 1 by a technique such that one end thereof comes into contact with the ground metallization layer 3a.

The electric resistance value of the resistor 7 is determined as appropriate in accordance with the magnitude of the impedance of the signal lead terminal 4c as viewed from the semiconductor element 2 side and the magnitude of the characteristic impedance of the semiconductor element 2. The impedance always matches.

A ground lead terminal 4a connected to the ground metallization layer 3a, a power lead terminal 4b connected to the power metallization layer 6a, and a signal lead terminal 4c connected to the resistor 7 are each made of Kovar metal ( The ground lead terminal 4a, the power lead terminal 4b, and the signal lead terminal 4c are made of a metal material such as iron-nickel-cobalt alloy) or 42 alloy (iron-nickel alloy), respectively. It functions to connect the signal electrode to an external electric circuit.

The ground lead terminal 4a and the power lead terminal 4b
The signal lead terminal 4c is formed in a predetermined plate shape by subjecting an ingot (a lump) of Kovar metal or the like to a conventionally known metal working method such as a rolling method or a punching method.

The ground lead terminal 4a, power supply lead terminal 4b, and signal lead terminal 4c are plated with a metal having excellent corrosion resistance, such as nickel or gold, and a good wettability with a brazing material by plating to a thickness of 1.0 to 20.0 μm. The thickness of each layer can effectively prevent oxidative corrosion of each lead terminal 4a, 4b, 4c and make the connection between each lead terminal 4a, 4b, 4c and an external electric circuit firm. Can be. Therefore,
The ground lead terminal 4a, the power supply lead terminal 4b and the signal lead terminal 4c have excellent corrosion resistance of nickel, gold, etc.
Further, it is preferable that a brazing material and a metal having good wettability are layered to a thickness of 1.0 to 20.0 μm by plating.

Further, the base 1, the semiconductor element 2, the dielectric layer
6, resistor 7, ground lead 4a, power lead 4
(b) A part of the signal lead terminal 4c is covered with the resin coating material 8, and the semiconductor element 2 is hermetically sealed to obtain a semiconductor device as a final product.

The resin coating material 8 is made of a resin such as epoxy, and has a base on which the semiconductor element 2 is mounted and fixed in a predetermined jig.
Set 1 and each lead terminal 4a, 4b, 4c, etc.
The jig is filled with an epoxy resin, and the filled resin is thermoset at a temperature of 150 to 180 ° C. to cover the base 1 on which the semiconductor element 2 is mounted.

Thus, in the semiconductor device of the present invention, each lead terminal is connected to an external electric circuit, and each electrode (ground electrode, power supply electrode, signal electrode) of the semiconductor element is electrically connected to the external electric circuit. Of the information processing device.

The package for accommodating a semiconductor element of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

[0033]

According to the semiconductor device of the present invention, the base on which the semiconductor element is mounted is made of an aluminum nitride sintered body that has a thermal conductivity of 50 W / m · K or more and is easy to conduct heat. Even if the device generates a large amount of heat during operation, the heat is well absorbed and diffused into the substrate, and as a result, the semiconductor device always has a low temperature, and can operate normally and stably for a long period of time.

According to the semiconductor device of the present invention, the ground electrode and the ground lead terminal are electrically connected to the ground metallization layer attached to the upper surface of the base, respectively, and the power electrode and the power lead terminal are grounded. A power supply lead terminal and a ground lead terminal, which are electrically connected to a power supply metallization layer attached to the upper surface of the metallization layer with a dielectric layer interposed therebetween, and to which a power supply electrode and a ground electrode of a semiconductor element are connected. Since a large electrostatic capacitance of 3 nF or more is connected between the power supply electrode and the ground electrode of the semiconductor element with a dielectric layer interposed between them, noise accompanying fluctuations in the power supply voltage supplied to the semiconductor element Even if the noise occurs, the noise is effectively absorbed by the large capacitance, and as a result, the noise does not enter the semiconductor element at all, and the semiconductor element operates normally for a long time, and It can be operated stably.

Further, according to the semiconductor device of the present invention, the signal electrode and the signal lead terminal are electrically connected to the resistor connected to a part of the ground metallization layer, respectively. The characteristic impedance of the semiconductor element and the impedance of the external lead terminal as seen from the semiconductor element are accurately matched because a resistor is connected between the semiconductor element and the semiconductor element through the signal lead terminal. Generation of noise, attenuation, and the like in the electric signal is effectively prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a semiconductor device of the present invention.

FIG. 2 is a plan view of a base of the semiconductor device shown in FIG.

FIG. 3 is a cross-sectional view of a conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base 2 ... Semiconductor element 4a ... Ground lead terminal 4b ... Power supply lead terminal 4c ... Signal lead terminal 6 ... Dielectric layer 7 ... Resistor 8 .... Resin coating materials

Claims (1)

(57) [Claims] And 1. A substrate made of aluminum nitride sintered body, a semiconductor element mounted fixed on the substrate, a power supply electrode of the semiconductor element, the ground electrode, the power supply lead terminals are signal electrodes are connected, a ground lead a semiconductor device composed of the terminal and the signal lead terminal, the base, the resin coating material covering a portion of the semiconductor element and the lead terminals, the ground electrostatic
The pole and the ground lead terminal are connected to the contact
The power electrode and the power lead terminal are provided on the ground metallization layer.
Is covered with a dielectric layer on the top surface of the ground metallization layer.
The signal electrode and the signal are applied to the
The lead terminal is connected to a part of the ground metallization layer.
A semiconductor device which is electrically connected to the resistors .