JP2000299403A - Semiconductor package and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve effects for preventing the generation of noises due to crosstalks in a semiconductor package during high-speed operation of LSIs. SOLUTION: A first conductive layer 1 is at a ground potential, second conductive layers 3a and 3b are at a power supply potential or at a signal potential, and an insulation material 2 is pinched vertically by the first conductive layer 1 are the second conductive layers 3a and 3b, forming a capacitive structure between the first conductive layer 1 and the second conductive layers 3a and 3b. Electromagnetic waves (crosstalks) generated in the second conductive layers 3a and 3b being at a power supply potential or at a signal potential is induced forcedly on the side of the first conductive layer 1 which is at a ground potential through the capacity structure. Therefore, the crosstalk is not conveyed between the second conductive layers 3a and 3b but is induced to the side of the first conductive layer 1 being at a ground potential and is absorbed thereby, so that noises can be prevented as much as possible from being generated in the second conductive layers 3a and 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor package and a method for manufacturing the same.

[0002]

2. Description of the Related Art As the density and speed of semiconductor LSIs increase, higher technology is also required for semiconductor packages.

A power supply potential or signal potential wiring layer is provided adjacent to the semiconductor package. Electromagnetic waves are generated from the power supply potential or signal potential wiring layer during LSI operation, and the wiring is generated by magnetic mutual interference. A crosstalk phenomenon that noise is mixed in the layer may occur.

When the operation of the LSI is slow, noise generated in the semiconductor package does not affect the operation of the semiconductor device and can be ignored.

However, in the case of high-speed LSI operation, noise generated in the semiconductor package may affect the operation of the semiconductor device, and it is necessary to suppress the crosstalk phenomenon. Has been adopted.

FIG. 8 is a perspective view showing a conventional semiconductor package in which the crosstalk phenomenon is suppressed, and FIGS.
FIG. 9B is a sectional view illustrating the manufacturing process of the semiconductor package illustrated in FIG. 8;

As shown in FIG. 9A, the semiconductor package according to the conventional example shown in FIG. 8 has an insulating material 52 formed on a metal substrate (usually using copper or the like) 51, on which wiring and wiring are formed. A metal film (mainly using a copper foil) 57 is formed, and then a photoresist 55 is selectively formed in a region where a wiring is to be formed by using a photolithography technique.
The metal film 57 is patterned using the photoresist 55 as a mask, and as shown in FIG.
53b and 53c are formed.

The semiconductor package according to the conventional example shown in FIG. 10 has a metal substrate 51 as shown in FIG.
Is formed in the insulating film 52 on the substrate 51, and the via hole 59 is formed as shown in FIG.
The inside is filled with a metal by a printing technique or the like to form a via 58, and as shown in FIG.
Then, as shown in FIG. 11C, the metal film 57 is patterned using the resist 55 as a mask to form wirings 53a, 53b and 53c.

[0009]

However, in the conventional example shown in FIG. 8 described above, since an insulating material exists between adjacent wirings, the insulating material is sandwiched between the adjacent wirings using the wiring as an electrode. Electromagnetic waves (crosstalk) generated in wiring due to potential changes due to the formation of the capacitance structure
However, there is a problem that the noise acts on adjacent wirings through the capacitor structure to cause noise, and the noise reduction effect is insufficient.

In the conventional example shown in FIG. 10, since the wiring 53c located at the center is joined to the metal substrate 51 by the via 58, as shown in FIG.
Electromagnetic waves (crosstalk) 11 radiated from 3b are captured by the wiring 53c.
1, the magnetic field of the electromagnetic wave (crosstalk) 11 acts on the loop, and a new electromotive force is generated on the substrate 51 at the ground potential, which affects the adjacent wirings 53a and 53b, and generates noise N. is there.

In order to solve these problems, Japanese Patent Application Laid-Open No.
In the conventional example disclosed in Japanese Patent No. 246425, a groove is provided between adjacent wirings to reduce the capacitance between the wirings to suppress crosstalk. When the distance between the two is narrow, there is a problem that the effect of suppressing the crosstalk is not exhibited.

An object of the present invention is to provide a semiconductor package which reduces noise due to crosstalk in the package during high-speed operation, and a method for manufacturing the same.

[0013]

In order to achieve the above object, a semiconductor package according to the present invention has a first conductive layer of a ground potential and a second conductive layer of a power supply potential or a signal potential. A capacitor structure is provided between the first conductive layer and the second conductive layer to suppress crosstalk between the second conductive layers.

An air layer is interposed between the second conductive layers.

Further, a third conductive layer is interposed between the second conductive layers with insulation therebetween, and the third conductive layer is joined to the first conductive layer, and an electromagnetic wave radiated from the second conductive layer is formed. Is captured by the third conductive layer.

Further, in the method of manufacturing a semiconductor package according to the present invention, a step of forming a first conductive layer at a ground potential is provided;
Laminating a second conductive layer on the first conductive layer with an insulating material interposed therebetween to form a capacitance structure between the first conductive layer and the second conductive layer.

Further, the insulating material located between the second conductive layers is removed by an etching method, and an air layer is interposed between the second conductive layers.

Further, a third conductive layer for capturing the electromagnetic wave radiated from the second conductive layer is interposed between the second conductive layers insulated.

Further, the third conductive layer is formed by depositing on the first conductive layer.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment) FIG. 1 shows Embodiment 1 of the present invention.
1 is a perspective view showing a semiconductor package according to the first embodiment.

Referring to FIG. 1, the semiconductor package according to the present invention has a first conductive layer 1 at ground potential and second conductive layers 3a and 3b at power supply potential or signal potential. A capacitor structure is provided between the second conductive layers 3a and 3b to suppress crosstalk between the second conductive layers 3a and 3b. An air layer 4 is interposed between the second conductive layers 3a and 3b.

More specifically, the first conductive layer 1 at ground potential
As the power supply potential or the signal potential
Wirings 3a and 3b are used as the conductive layers 3a and 3b, and an insulating material 2 is sandwiched between the metal substrate 1 and the wirings 3a and 3b to form a capacitance structure between the metal substrate 1 and the wirings 3a and 3b.
Crosstalk between a and 3b is suppressed. Insulating material 2 located between wirings 3a and 3b
A groove is formed at a depth reaching the metal substrate 1 so that the wiring 3a,
An air layer 4 is interposed between 3b.

Next, the operation of the present invention will be described with reference to FIGS. FIG. 3 shows that a pulse is input to one of the wirings 3a,
FIG. 4 is a diagram showing a state of monitoring the state of noise on the other wiring 3b, and FIG. 4 is a diagram showing a state of propagation of electromagnetic waves.

In FIG. 3, when a pulse is input to one wiring 3a, a change in the potential of the wiring 3a causes the wiring 3a to change.
An electromagnetic wave (crosstalk) 11 is generated from a.

Here, when the insulating material 2 is sandwiched between the wirings 3a and 3b and the wiring 3a and 3b have a capacitance structure as in the prior art, the electromagnetic wave from the wiring 3a passes through the capacitance structure to the other wiring 3b. Propagation occurs, and a new electromotive force is generated in the other wiring 3b due to the electromagnetic wave, and the new electromotive force is transmitted as noise to the wiring 3b.

However, as shown in FIGS. 3 and 4, in the case of the present invention, the metal substrate 1 is at the ground potential, the wirings 3a and 3b are at the power supply potential or the signal potential, and the metal substrate 1 is connected to the wirings 3a and 3b. The insulating material 2 is vertically sandwiched between the metal substrate 1 and the wirings 3a and 3b to form a capacitance structure.
Electromagnetic wave (crosstalk) 11 generated in wiring 3a or 3b
Is forcibly guided to the metal substrate 1 at the ground potential through the capacitor structure.

Therefore, the electromagnetic wave generated on one side of the wiring 3a is not propagated to the other side of the wiring 3b, but is guided to and absorbed by the metal substrate 1 at the ground potential, so that noise is generated on the other side of the wiring 3b. Can be suppressed.

When the air layer 4 is interposed between the wirings 3a and 3b, the dielectric constant of air is 1.0.
The capacitance value between them can be extremely minimized, and together with the capacitance structure, it can contribute to the reduction of crosstalk.

Next, a specific example of the present invention will be described as a first embodiment with reference to FIGS.

In the semiconductor package according to the first embodiment of the present invention shown in FIG. 1, an insulating material 2 made of, for example, polyimide is formed on a metal substrate 1 made of, for example, a copper plate, and wirings 3a, 3b are formed on the insulating material 2. A groove 4 is formed in the insulating material 2 located between the adjacent wirings 3a and 3b to a depth reaching the metal substrate 1, and the insulating material 2 located below the wirings 3a and 3b is separated into the left and right by the groove 4. The insulating material 2 is vertically sandwiched between the metal substrate 1 and the wirings 3a and 3b, and the metal substrate 1 and the wirings 3a and 3b
b, a capacitive structure is formed, and electromagnetic waves (crosstalk) generated in the wiring 3a or 3b are forcibly guided to the metal substrate 1 at the ground potential through the capacitive structure.

The metal substrate 1 is not limited to a copper plate, but may be any other conductive substrate. The insulating material 2 may be made of an organic or inorganic insulating material other than polyimide. And wiring 3a, 3
As b, copper foil coated with gold / nickel foil may be used.

As shown in FIGS. 3 and 4, according to the first embodiment of the present invention, the metal substrate 1 is at the ground potential, the wirings 3a and 3b are at the power supply potential or the signal potential. 3a and 3b sandwich the insulating material 2 up and down to form a capacitance structure between the metal substrate 1 and the wirings 3a and 3b;
Since the electromagnetic wave (crosstalk) generated in the wiring 3a or 3b is forcibly guided to the ground potential metal substrate 1 through the capacitor structure, the electromagnetic wave generated in one wiring 3a is not propagated to the other wiring 3b. The other wiring 3 is guided by the ground potential to the metal substrate 1 side and absorbed.
Generation of noise in b can be suppressed as much as possible.

Further, since the air layer 4 is interposed between the wires 3a and 3b, the dielectric constant of air is 1.0.
The capacitance value between the wirings 3a and 3b can be extremely minimized, and it can contribute to the reduction of crosstalk in conjunction with the capacitance structure.

Next, a method for manufacturing a semiconductor package according to the first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 2A, first, an insulating material 2 is formed on a metal substrate 1, and a metal film 7 is formed on the insulating material 2 by plating or the like.

Next, as shown in FIG. 2B, a photoresist 5 is selectively formed in a portion other than the groove forming region by using a photolithography method. Further, the metal film 7 and the insulating material 2 are formed by etching using the resist 5 as a mask.
Is selectively etched to form a groove 4 in the insulating material 2 and the metal substrate 1.
And the metal film 7 is left only on the remaining insulating material 2.

Subsequently, as shown in FIG. 2C, the photoresist 5 is removed, and a resist 6 is selectively formed in the wiring formation region again by using photolithography.

Next, as shown in FIG.
Is used as a mask to etch the metal film 7 to form wirings 3a and 3b made of the metal film 7 on the insulating material 2 respectively.

Through the above steps, the metal substrate 1
Wirings 3 a and 3 b are formed on the upper insulating material 2, and a groove 4 is engraved in the insulating material 2 located between the adjacent wirings 3 a and 3 b to a depth reaching the metal substrate 1. 3b
The insulating material 2 located in the lower layer is separated left and right, and the insulating material 2 is vertically sandwiched between the metal substrate 1 and the wirings 3a and 3b to form a capacitance structure between the metal substrate 1 and the wirings 3a and 3b. Alternatively, the semiconductor package according to the first embodiment of the present invention, in which electromagnetic waves (crosstalk) generated in 3b are forcibly guided to the metal substrate 1 at the ground potential through the capacitor structure, is completed.

(Embodiment 2) FIG. 5 is a perspective view showing a semiconductor package according to Embodiment 2 of the present invention, and FIG. 6 and FIG.
3A to 3C are cross-sectional views illustrating a method of manufacturing a semiconductor package according to a second embodiment of the present invention in the order of steps.

In the semiconductor package according to the second embodiment of the present invention shown in FIG. 5, an insulating material 2 made of, for example, polyimide is formed on a metal substrate 1 made of, for example, a copper plate, and wirings 3a, 3b are formed on the insulating material 2. Then, a groove 4 is formed in the insulating material 2 located between the adjacent wirings 3a and 3b to a depth reaching the metal substrate 1, and the insulating material 2 located below the wirings 3a and 3b is separated to the left and right by the groove 4. Then, the insulating material 2 is vertically sandwiched between the metal substrate 1 and the wirings 3a and 3b, and the metal substrate 1 and the wirings 3a and 3b are sandwiched.
3b is formed as a capacitor structure, and furthermore, the wiring 3c is insulated and interposed between the wirings 3a and 3b, and the wiring 3c is joined to the metal substrate 1, so that an electromagnetic wave (crosstalk) generated in the wiring 3a or 3b is generated. Forcibly induced to the metal substrate 1 side of the ground potential through the capacitor structure, and the wires 3a, 3b
The electromagnetic wave radiated from the ground is captured by the wiring 3c of the ground potential.

According to the second embodiment of the present invention, in addition to forcibly guiding the electromagnetic wave (crosstalk) generated in the wiring 3a or 3b to the ground potential metal substrate 1 through the capacitor structure, the wiring 3a, 3b Since the electromagnetic wave radiated from 3b is captured by the wiring 3c of the ground potential, there is an advantage that the crosstalk can be further suppressed.

Next, a method for manufacturing a semiconductor package according to the second embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 6A, first, an insulating material 2 is formed on a metal substrate 1, and a metal film 7 is formed on the insulating material 2 by plating or the like.

Next, as shown in FIG. 6B, a photoresist 5 is selectively formed in a portion other than the groove forming region by using a photolithography method. Further, as shown in FIG. 6C, the metal film 7 and the insulating material 2 are selectively etched by using an etching method with the resist 5 as a mask, and a groove 4 is formed in the insulating material 2 so as to reach the metal substrate 1. And the metal film 7 is left only on the remaining insulating material 2.

Next, as shown in FIG. 7D, after the photoresist 5 is removed, a second metal film 7a is deposited and formed on the region including the groove 4 of the substrate 1 by plating or the like. As shown in FIG. 7E, a photoresist 6 is selectively formed in a wiring formation region by using a photolithography method.

Next, as shown in FIG.
The metal films 7, 7a are etched using the mask as a mask, and the wirings 3a, 3 made of the metal films 7, 7a are respectively formed on the insulating material 2.
b, 3c are formed.

Through the above steps, the metal substrate 1
Wirings 3 a and 3 b are formed on the upper insulating material 2, and a groove 4 is engraved in the insulating material 2 located between the adjacent wirings 3 a and 3 b to a depth reaching the metal substrate 1. 3b
The insulating material 2 located in the lower layer is separated left and right, the insulating material 2 located in the lower layer of the wirings 3a and 3b is separated left and right by the groove 4, and the insulating material 2 is vertically separated by the metal substrate 1 and the wirings 3a and 3b. Between the metal substrate 1 and the wirings 3a and 3b to form a capacitance structure, and furthermore, a wiring 3c between the wirings 3a and 3b.
Are insulated and interposed, and the wiring 3c is joined to the metal substrate 1, and an electromagnetic wave (crosstalk) generated in the wiring 3a or 3b
The semiconductor package according to the second embodiment of the present invention forcibly guiding through the capacitance structure to the side of the metal substrate 1 at the ground potential and capturing electromagnetic waves radiated from the wirings 3a and 3b by the wiring 3c at the ground potential. Complete.

[0050]

As described above, according to the present invention, the first conductive layer has the ground potential, the second conductive layer has the power supply potential or the signal potential, and the first conductive layer and the second conductive layer have the same potential. The insulating material is vertically sandwiched between the first and second conductive layers to form a capacitor structure, and an electromagnetic wave (crosstalk) generated in the second conductive layer of a power supply or a signal potential is transmitted through the capacitor structure to a ground potential of a second potential. 1 Forcibly guiding to the conductive layer side,
Crosstalk is not propagated between the second conductive layers, and the ground potential is guided to the first conductive layer side and absorbed, thereby suppressing generation of noise in the second conductive layer as much as possible.

Further, in addition to forcibly guiding electromagnetic waves (crosstalk) generated between the second conductive layers to the first conductive layer at the ground potential through the capacitor structure,
Since the electromagnetic waves radiated from the conductive layer are captured by the third conductive layer at the ground potential, crosstalk can be further suppressed.

Further, by arranging the air layer between the second conductive layers, the dielectric constant between the second conductive layers is reduced, so that the crosstalk is hardly propagated, and is effective on the first conductive layer side of the ground potential. In addition, it is possible to easily induce electromagnetic waves, and noise generation due to crosstalk can be suppressed as much as possible, and the influence on the semiconductor device due to crosstalk can be eliminated.

Further, in the present invention, the configuration in which the air layer is disposed between the second conductive layers is such that electromagnetic waves (crosstalk) are transmitted to the ground potential through a capacitor structure formed between the first conductive layer and the second conductive layer. Is an auxiliary component added to the structure for guiding to the first conductive layer, so that even if the space between the second conductive layers of high density becomes narrower and the air layer becomes narrower, the effect of suppressing crosstalk is conventionally achieved. Thus, it is possible to cope with high-density mounting without drastically decreasing as in FIG.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view illustrating a method of manufacturing the semiconductor package according to the first embodiment of the present invention in the order of steps.

FIG. 3 is a diagram showing a state in which a pulse is input to one wiring and the state of noise in the other wiring is monitored.

FIG. 4 is a diagram illustrating a propagation state of an electromagnetic wave according to the embodiment of the present invention.

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

FIG. 6 is a cross-sectional view illustrating a method of manufacturing a semiconductor package according to Embodiment 2 of the present invention in the order of steps.

FIG. 7 is a sectional view illustrating a method of manufacturing a semiconductor package according to Embodiment 2 of the present invention in the order of steps.

FIG. 8 is a perspective view showing a semiconductor package according to a conventional example.

FIG. 9 is a sectional view illustrating a method for manufacturing a semiconductor package according to a conventional example in the order of steps.

FIG. 10 is a perspective view showing a semiconductor package according to a conventional example.

FIG. 11 is a sectional view illustrating a method of manufacturing a semiconductor package according to a conventional example in the order of steps.

FIG. 12 is a diagram showing a propagation state of an electromagnetic wave in a conventional example.

[Explanation of symbols]

 Reference Signs List 1 metal substrate 2 insulating material 3a, 3b wiring (second conductive layer) 3c wiring (third conductive layer) 4 groove (air layer) 5, 6 photoresist 7, 7a metal film 11 crosstalk

Claims (7)

[Claims] A first conductive layer having a ground potential and a second conductive layer having a power supply potential or a signal potential, wherein a capacitance structure is provided between the first conductive layer and the second conductive layer; A semiconductor package characterized in that crosstalk between two conductive layers is suppressed. 2. The semiconductor package according to claim 1, wherein an air layer is interposed between the second conductive layers. 3. A third conductive layer is insulated and interposed between the second conductive layers, and the third conductive layer is bonded to the first conductive layer, and is radiated from the second conductive layer. The semiconductor package according to claim 1, wherein an electromagnetic wave is captured by the third conductive layer. 4. A step of forming a first conductive layer at a ground potential, and laminating a second conductive layer on the first conductive layer with an insulating material interposed therebetween, wherein the first conductive layer and the second conductive layer are stacked. And a step of forming a capacitor structure between the semiconductor package and the semiconductor package. 5. The method according to claim 4, wherein the insulating material located between the second conductive layers is removed by an etching method, and an air layer is interposed between the second conductive layers. The manufacturing method of the semiconductor package described in the above. 6. The method according to claim 4, wherein a third conductive layer for capturing an electromagnetic wave radiated from the second conductive layer is insulated and interposed between the second conductive layers. The manufacturing method of the semiconductor package described in the above. 7. The method according to claim 6, wherein the third conductive layer is deposited on the first conductive layer.