JP2988599B2 - Wiring board and high-speed IC package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a wiring board and a high-speed IC package to which the present structure is applied so that a desired characteristic impedance can be ensured even if a wiring width of a microstrip line or a strip line is changed.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 5, a wiring board is composed of a dielectric substrate 101, a grounding conductive film 102 provided on one surface of the dielectric substrate 101, and a grounding conductive film. In many cases, the microstrip line is formed of a strip-shaped conductor film 103 provided on a surface facing the semiconductor device 102. In this configuration, the characteristic impedance of the microstrip line is
Of the dielectric substrate 10
1 and the width w of the strip-shaped conductor film 103. That is, the dielectric substrate 10
When the thickness h of 1 is determined, the width w of the strip-shaped conductor film 103 corresponding to a predetermined characteristic impedance automatically becomes a predetermined width.

Further, another wiring board may be constituted by a strip line as shown in FIG. this is,
A second dielectric substrate 106 is provided on the first dielectric substrate 104 on which a grounding conductive film 105 is provided on one surface,
On the upper surface of the second dielectric substrate 106, the conductive film 1 for grounding is provided.
07 is formed. Further, the first dielectric substrate 1
A strip-shaped conductor film 108 is provided between the layers 04 and the second dielectric substrate 106. In the wiring board having such a configuration, if the relative permittivity εr of the first dielectric substrate 104 and the second dielectric substrate 106 is clear, the characteristic impedance of the strip line becomes equal to that of the first dielectric substrate 104. The sum B of the thickness of the second dielectric substrate 106 and the thickness of the second dielectric substrate 106 and the width W of the strip-shaped conductive film 108
Is almost determined by That is, when the thickness B of the dielectric material sandwiched between the grounding conductive films 105 and 107 is determined, the width W of the strip-shaped conductive film 108 corresponding to a predetermined characteristic impedance is automatically set to a predetermined value. Of width.

[0004] Furthermore, high-speed I
Conventionally, the configuration shown in FIG. 7 is adopted for the C package 200. That is, a conductive substrate, a first dielectric substrate 110 provided with an opening 109 for mounting a semiconductor element on the conductive substrate, and a first dielectric substrate 11
The second dielectric substrate 1 on the periphery of the first substrate and having an opening larger than the opening 109 and a partially cutout 118
11, a strip-shaped conductor film 112 and a similar strip-shaped conductor film 113 formed on an extension thereof are provided on the upper surface of the first dielectric substrate 110,
Metallic leads are provided on the conductor film 113. 8 shows an enlarged plan view and an enlarged cross-sectional view of a portion G in FIG. 7 in FIG. In the configuration shown in these figures, a grounding conductive film 116 provided on the conductive substrate 117 side of the first dielectric substrate 110 and a surface opposed to the grounding conductive film 116 are provided. A microstrip line is constituted by the strip-shaped conductor film 112, and the conductor film 115 for grounding, the conductor film 115 provided on the upper surface of the second dielectric substrate 111, and the first
A strip line is constituted by the strip-shaped conductive film 114 provided between the dielectric substrate 110 and the second dielectric substrate 111, and further extends on the strip-shaped conductive films 112, 114. Conductor film 113, first dielectric substrate 110, and conductor film 116 for grounding
Constitute a microstrip line. A metal lead 114a is provided on the conductor film 113. In such a high-speed IC package, in a state where the semiconductor element is mounted on the conductive substrate 117 in the opening 109 and the terminal of the semiconductor element and the end of the conductive film 113 are electrically connected by wire bonding or the like,
The high-speed signal is applied to the metallic lead 114a and the conductive film 11
When the signal is input to an input terminal composed of 3 or the like, it is transmitted to the semiconductor element via other conductive films 111 and 112 and wire bonding or the like. Thereafter, the output signal processed in the semiconductor device is taken out from another output terminal in the reverse procedure.

[0005]

However, in a conventional wiring board composed of microstrip lines,
If the relative permittivity εr is clear, it is substantially determined by the thickness of the dielectric substrate and the width of the strip-shaped conductive film. That is, when the thickness of the dielectric substrate is determined, the width of the strip-shaped conductor film corresponding to the predetermined characteristic impedance is automatically determined to the predetermined width. There was a drawback that could not be set. Also, in a conventional wiring board composed of strip lines, when the thickness of the dielectric substrate sandwiched between the two grounding conductive films is determined, the dielectric substrate corresponds to a predetermined characteristic impedance. Since the width of the strip-shaped conductor film provided between the layers is automatically set to a predetermined width, the width of the strip-shaped conductor film is limited as described above. Also, the first microstrip line
In a conventional high-speed IC package in which a main wiring is a dielectric substrate and a strip line formed between a second dielectric substrate on which one surface of a conductive film is formed and a first dielectric substrate, Similarly to the above-described wiring board, the width of the strip-shaped conductive film is determined by the thickness of the first dielectric substrate and the thickness of the second dielectric substrate in accordance with a predetermined characteristic impedance of each line, There is a disadvantage that the wiring cannot be routed by freely changing the width of the conductor film. On the other hand, the width of the strip-shaped conductor film is small in the expanded portion of the wiring in order to increase the number of wirings, and in the portion serving as the terminal of the package, due to the mechanical strength in joining the metallic leads and the like. Often taken large. For this reason, if the characteristic impedance of the microstrip line in the expanded portion of the wiring is set to a predetermined value, the characteristic impedance of a portion serving as a terminal of the package cannot be set to the same value. There were drawbacks that occurred. The present invention has the following problems that the wiring width of the line of the wiring board or the wiring width of the line used for the high-speed IC package is limited, and that the electrical characteristics at the terminals of the high-speed IC package are deteriorated. New wiring board or high-speed I
It is intended to provide a C package.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a strip-shaped conductor film provided between a first dielectric substrate and a second dielectric substrate. In a wiring board in which a strip line is formed by a grounding conductive film provided on one surface of each of the first dielectric substrate and the second dielectric substrate so as to sandwich a strip-shaped conductive film, The first dielectric substrate and the second dielectric substrate were each composed of at least two dielectric sheets. Further, a conductor layer is provided in a part of the interlayer of each dielectric sheet, and the conductor layer and the grounding conductor film are electrically connected so as to have substantially the same potential. Thus, the wiring board is formed of a conductive layer between the first dielectric substrate and a conductive layer between the second dielectric substrate, a dielectric region therebetween, and a strip line composed of a strip-shaped conductive film. A first dielectric substrate and a second dielectric substrate having no conductive layer between them, a grounding conductive film of the first dielectric substrate, and a grounding conductor of the second dielectric substrate A strip line is formed on the film and the extension of the strip-shaped conductor film, and is made of a strip-shaped conductor film having different widths.

Further, a conductive substrate, a first dielectric substrate provided with an opening for mounting a semiconductor element on the conductive substrate, and a first dielectric substrate surrounding the first dielectric substrate, A second dielectric substrate provided with an opening larger than the opening and a partially cutout portion, a grounding conductive film provided on the conductive substrate side of the first dielectric substrate, A microstrip line is constituted by a strip-shaped conductor film provided on a surface facing the grounding conductor film, and the conductor provided on the upper surface of the grounding conductor film and the second dielectric substrate A strip line is constituted by a film and a strip-shaped conductor film provided between the first dielectric substrate and the second dielectric substrate, and a conductor is provided on an extension of the microstrip line and the strip line. Metallic lead provided on film In Ranaru fast IC package, the first dielectric substrate is composed of a dielectric sheet of at least two layers. Further, a conductive layer is provided in a part of the interlayer of the dielectric sheet, and the conductive layer and the grounding conductive film are electrically connected to have substantially the same potential. Thus, the wiring portion and the terminal portion of the high-speed IC package are formed by a microstrip line composed of the conductor layer, the dielectric sheet and the strip-shaped conductor film, and the grounding conductor provided on the first dielectric substrate. A conductive film for grounding provided on the upper surface of the film and the second dielectric substrate; and a strip-shaped conductive film which is on an extension of the strip-shaped conductive film and has a width different from that of the conductive film. A strip line, a first dielectric substrate provided with a grounded conductive film provided on the first dielectric substrate and an interlayer conductive layer, and an extension of the strip-shaped conductive film for the strip line. And the microstrip line is formed of a strip-shaped conductor film having a width different from that of the conductor film.

[0008]

According to the present invention, as described above, the dielectric substrate has a structure in which at least two dielectric sheets and a conductive film having substantially the same potential as the grounding conductive film are provided between the dielectric sheets. In addition, the wiring width of the microstrip line or the strip line can be changed in the middle. Therefore, the characteristic impedance of the line can be made substantially the same while changing the width of the line. Therefore, the above problem can be eliminated.

[0009]

Next, an embodiment of the present invention will be described. The embodiment is merely an example, and it goes without saying that various changes or improvements can be made without departing from the spirit of the present invention.

(Embodiment 1) FIG. 1 is a perspective view showing a first embodiment of the present invention, and FIG. 2 is a view showing a sectional structure of FIG.
8 is a dielectric sheet, 10 and 19 are grounding conductive films, 1
Reference numerals 1 and 17 denote conductive layers formed between the layers, and reference numerals 12a and 20 denote conductive vias. In this embodiment, a substantially uniform conductor layer 11 is formed on the upper surface of a dielectric sheet 9 having a grounding conductor film 10 formed on one surface, and reaches a surface 12 of DD'-E'-E. A conductive via (12) for electrically connecting the conductive layer (11) and the grounding conductive film (10).
a is provided in plurality. Another dielectric sheet 13 is laminated on the conductor layer 11 and the dielectric sheet 9,
Further, on the dielectric sheet 13, the strip-shaped conductor film 1 having a different width from the surface 12 of DD′-E′-E is used as a boundary.
4 and 15 are provided. A substrate made of the grounding conductive film 10, the dielectric sheets 9, 13 and the conductive layer 11 and the conductive via 12a is mirror-projected from the surface on which the strip-shaped conductive films 14 and 15 are formed. Substrates, ie, the dielectric sheets 16 and 18, the conductive layer 17 and the grounding conductive film 19, and the conductive via 2 for electrically connecting the conductive layer 17 and the grounding conductive film 19 to each other.
0 is provided on the dielectric sheet 13 and the strip-shaped conductor films 14 and 15.
In such a configuration, one strip line is composed of a dielectric substrate 62 having strip-shaped conductor films 14 and conductor layers 11 and 17 arranged so as to sandwich the conductor films 14. Another strip line is composed of a dielectric substrate 63 having strip-shaped conductor films 14 and conductor films 10 and 19 for grounding disposed so as to sandwich the conductor films 14.

With this structure, the thickness of the dielectric can be equivalently changed within the same wiring board.
Therefore, the width of the strip-shaped conductor film of the strip line can be easily changed. That is, the line width can be freely selected while the characteristic impedance of the microstrip line is set to a predetermined value. That is, there is an advantage that the wiring design of the wiring board becomes easy.

(Embodiment 2) FIGS. 3 and 4 show a high-speed I / O circuit according to a second embodiment.
2A and 2B are a plan view and a cross-sectional view showing the periphery of a terminal of the C package, wherein 21 and 25 are dielectric sheets, 22 and 30 are conductor films for grounding, and 23 is a conductor provided between dielectric sheets 21 and 25. And 24, a ground conductor film 22 and a conductor layer 2
Conductive vias 26, 2 for electrically connecting 3;
7, 28 are strip-shaped conductor films, 29 is a metal lead, 31 is a second dielectric substrate, 32 is a conductive substrate, 6
Reference numeral 4 denotes a first dielectric substrate. The basic configuration is similar to the first embodiment. In such a configuration, the wiring board includes two microstrip lines and one strip line. The first microstrip line has a conductor layer 23 formed substantially uniformly up to a plane cut by pq so as to have substantially the same potential as the grounding conductor film 22 bonded to the conductive substrate 32 and a dielectric layer. It is composed of a body sheet 25 and a strip-shaped conductor film 26 formed thereon. The strip line includes a strip-shaped conductor film 27 having a different width on the extension of the strip-shaped conductor film 26, and a first dielectric substrate 64 and a second dielectric substrate provided so as to sandwich the conductor. 31 and a grounding conductive film 22 and 30 formed on one surface of each of the dielectric substrates. The second microstrip line is provided on the extension of the strip-shaped conductor film 27 of the strip line, and has a width different from the width of the conductor film.
8, a first dielectric substrate 64 and a grounding conductive film 22.

With such a configuration, the width of the strip-shaped conductor film of the microstrip line can be freely changed. This makes it possible to make the predetermined characteristic impedance constant regardless of the location in the vicinity of the wiring and the terminals of the high-speed IC package, and to eliminate unnecessary reflection which has been a problem in the conventional package.

In the above embodiment, the description has been made on the assumption that the conductive layer provided between the two dielectric sheets is formed substantially uniformly. It goes without saying that even the mesh structure from which the body layer has been removed does not impair the effects of the present invention. Also, a case has been described where the dielectric substrate is composed of two layers of dielectric sheets,
When it is desired to provide three or more types of strip-shaped conductor films having different widths, the dielectric substrate is composed of three or more layers, and the conductor layers provided between the layers are formed of the respective strip-shaped conductor films. What is necessary is just to set to the position corresponding to width. That is, the characteristic impedances of the lines corresponding to three or more types of strip-shaped conductor film widths may be made substantially the same, and needless to say fall within the scope of the present invention. Further, in the embodiment of the present invention, a plurality of conductive vias have been used to electrically connect the conductive layer provided between the layers and the grounding conductive film. Means for forming a body film may be used.

[0015]

As described above, according to the present invention,
A strip-shaped conductive film provided between the first dielectric substrate and the second dielectric substrate, and the first dielectric substrate and the second conductive film sandwiching the strip-shaped conductive film. In a wiring board in which a strip line is formed by a grounding conductive film provided on one surface of each of the dielectric substrates, the first dielectric substrate and the second dielectric substrate may have at least two dielectric layers.
A conductive layer is provided in a part of each dielectric sheet between layers, and the conductive layer and each of the grounding conductive films are electrically connected to have substantially the same potential. And a conductive layer provided on the first dielectric substrate, a conductive layer provided on the second dielectric substrate, and a layer between the first dielectric substrate and the second dielectric substrate. The characteristic impedance of the strip line composed of the provided strip-shaped conductive film has a characteristic impedance of a grounded conductive film provided on the first dielectric substrate and a grounded conductive film provided on the second dielectric substrate. Since the configuration is such that the characteristic impedance of a strip line formed of a strip-shaped conductive film having a width different from the width of the conductive film on the extension of the strip-shaped conductive film is substantially the same as that of the conductive film, Of microstrip line or strip line The width of the trip-like conductive film can be easily changed, there is an advantage that can significantly improve the flexibility of the wiring board design. Further, in the high-speed IC package, since substantially the same configuration as that described above is provided in the wiring and the terminal portion, there is an advantage that not only the flexibility of the wiring design is improved but also unnecessary reflection at the terminal portion can be eliminated. Further, by changing the number of layers of the dielectric sheet, the characteristic impedance of the microstrip line at the terminal portion is made approximately the same as the characteristic impedance of the microstrip line at the wiring and the like, while the lead connection at the terminal portion having a metal lead is provided. There is an advantage that a wiring width with sufficiently high strength can be realized. As described above, a high-speed operation semiconductor element is mounted on a package, such as a higher degree of freedom in designing a wiring board and a drastic improvement in electrical characteristics of a high-speed IC package as compared with the conventional technology, and 10 Gb / s or more. In realizing a module excellent in the above, there is a great effect of the present invention.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the first embodiment of the present invention.

FIG. 3 shows a high-speed I for explaining a second embodiment of the present invention;
It is the top view which expanded the periphery of C package terminal.

FIG. 4 is a diagram showing a high-speed I for explaining a second embodiment of the present invention;
It is sectional drawing to which the periphery of C package terminal was expanded.

FIG. 5 is a perspective view illustrating a conventional wiring board including a microstrip line.

FIG. 6 is a perspective view illustrating a conventional wiring board composed of a strip line.

FIG. 7 is a plan view illustrating a conventional general high-speed IC package.

8 is an enlarged plan view of the periphery of a terminal of the conventional package shown in FIG. 7;

FIG. 9 is an enlarged cross-sectional view of the periphery of a terminal of the conventional package shown in FIG. 7;

[Explanation of symbols]

 Reference Signs List 9 dielectric sheet 10 grounding conductive film 11 conductive layer 12 plane showing line boundary 12a conductive via 13 dielectric sheet 14 strip-shaped conductive film 15 strip-shaped conductive film 16 dielectric sheet 17 conductive Layer 18 Dielectric Sheet 19 Grounding Conductive Film 20 Conductive Via 21 Dielectric Sheet 22 Grounding Conductive Film 23 Conductive Layer 24 Conductive Via 25 Dielectric Sheet 26 Strip Conductor Film 27 Strip Conductor Film 28 strip-shaped conductor film 29 lead 30 grounding conductor film 31 dielectric substrate 32 dielectric substrate 62 dielectric substrate 63 dielectric substrate 64 dielectric substrate 101 dielectric substrate 102 grounding conductor film 103 strip-like Conductor film 104 Dielectric substrate 105 Grounding conductor film 106 Dielectric substrate 107 Grounding conductor 108 strip-shaped conductive film 110 dielectric substrate 111 the dielectric substrate 112 strip-shaped conductive film 113 strip-shaped conductive film 114 strip-shaped conductive film 114a lead 116 for grounding conductor film 117 dielectric substrate

Claims (2)

(57) [Claims] 1. A strip-shaped conductor film provided between layers of a first dielectric substrate and a second dielectric substrate, and the first dielectric substrate sandwiching the strip-shaped conductor film. And a wiring board in which a stripline is formed by a grounding conductive film provided on one surface of each of the second dielectric substrates, wherein the first dielectric substrate and the second dielectric substrate are at least It is composed of two layers of dielectric sheets, and a conductor layer is provided in a part between the layers of each dielectric sheet, and the conductor layer and each of the grounding conductor films are electrically connected to have substantially the same potential. And a conductive layer provided on the first dielectric substrate, a conductive layer provided on the second dielectric substrate, and an interlayer between the first dielectric substrate and the second dielectric substrate. Characteristic of a strip line composed of a strip-shaped conductor film provided on a substrate The grounding conductive film provided on the first dielectric substrate, the grounding conductive film provided on the second dielectric substrate, and the strip-shaped conductive film. A wiring board, wherein the characteristic impedance of a strip line made of a strip-shaped conductive film having a width different from the width of the body film is substantially the same. 2. A conductive substrate, a first dielectric substrate provided with an opening for mounting a semiconductor element on the conductive substrate, and a first dielectric substrate surrounding the first dielectric substrate, A second dielectric substrate provided with an opening larger than the opening and a partially cutout portion, a grounding conductive film provided on the conductive substrate side of the first dielectric substrate, A microstrip line is constituted by a strip-shaped conductor film provided on a surface facing the grounding conductor film, and the conductor provided on the upper surface of the grounding conductor film and the second dielectric substrate A strip line is constituted by a film and a strip-shaped conductor film provided between the first dielectric substrate and the second dielectric substrate, and a conductor is provided on an extension of the microstrip line and the strip line. From the metallic leads provided on the membrane The first dielectric substrate comprises at least two layers of dielectric sheets, a conductor layer is provided in a part of the dielectric sheet between layers, and the first dielectric substrate and the first dielectric substrate are provided. A microstrip line comprising a grounded conductive film provided on a substrate and electrically connected so as to have substantially the same potential, and comprising the conductive layer, a dielectric sheet, and a strip-shaped conductive film. The characteristic impedance of the conductive film for grounding provided on the first dielectric substrate, the conductive film for grounding provided on the upper surface of the second dielectric substrate, and the extension of the strip-shaped conductive film Wherein a characteristic impedance of a strip line formed of a strip-shaped conductor film having a width different from the width of the conductor film and a conductor layer between the grounding conductor film provided on the first dielectric substrate and the interlayer are provided. Not the first The characteristic impedance of the dielectric substrate is substantially the same as the characteristic impedance of a microstrip line formed of a strip-shaped conductor film having a width different from the width of the conductor film on the extension of the strip-shaped conductor film for the strip line. A high-speed IC package characterized by the above.