JP2003282782A - Wiring auxiliary package and printed wiring board structure equipped with the package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring auxiliary package which can transmit a signal at a high speed while making impedance match internal circuit wiring and is improved in wiring density. <P>SOLUTION: The wiring of the wiring auxiliary package 111 is connected to a printed wiring board 112 through through-holes 120 of the printed wiring board 112 via pads of an IC 100. A microstrip line structure 114 or a microstrip line structure 115 is composed of grounding layers 113 of the wiring auxiliary package 111 electrically connected to grounding signals 116 of the IC 100 and either an upper or a lower wiring layer to obtain an impedance-matched wiring structure, so that the reflection of a signal occurring on a transmission line due to impedance mismatching can be prevented, and the signal can be transmitted at a high speed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring auxiliary package and a printed wiring board structure using the same,
In particular, the present invention relates to a wiring auxiliary package capable of preventing deterioration of a transmission signal waveform due to reflection when transmitting a high-speed signal by controlling the impedance of a wiring pattern in the wiring auxiliary package, and a printed wiring board structure including the package. .

[0002]

2. Description of the Related Art Conventionally, in a semiconductor integrated circuit, in response to a demand for a large number of pins and downsizing, BGA,
Development of thin, small, and multi-pin packages such as CSP is progressing. However, the development of the printed wiring board corresponding to the evolution of the semiconductor integrated circuit has not progressed so much, and the pin count is restricted as the downsizing of the semiconductor integrated circuit package progresses. In the case of a package that has an external terminal row on the bottom surface of a conventional general printed wiring board,
In order to form a multi-pin array, it is necessary to dispose pins on the outer circumference of the package lower surface and to draw out the signal lines from the outer circumference. Therefore, it is necessary not to arrange the external terminal row in the central portion of the lower surface of the package.

As a method for solving the problem of pulling out a signal line from a semiconductor package having a multi-pin array as described above, a technique disclosed in Japanese Patent Application Laid-Open No. 11-68026, "Auxiliary Package for Wiring and Printed Wiring Using the Package" is disclosed. Board structure "
There is. This technique is configured so that the external terminals at the center of the package, which cannot be processed by the printed wiring board, can be easily taken out.

FIG. 5 is a sectional view showing a printed wiring board structure using a conventional wiring auxiliary package. A wiring auxiliary package 511 including only the internal circuit wiring 501 and external terminals is provided inside the semiconductor integrated circuit, and the wiring auxiliary package 511 is arranged relatively to the existing IC 500 via the printed wiring board 510. In addition, a wiring bypass package including only circuit wiring and external terminals is provided, and the bypass package is arranged between a plurality of existing semiconductor packages.

In the wiring auxiliary package 511 including only the internal circuit wiring 501 not including the semiconductor integrated circuit and the external terminals as described above, the semiconductor integrated circuit is not included therein, and the through wiring of the printed wiring board 510 is omitted. It connects through the hole 512. According to the wiring auxiliary package 511, the external terminals in the central portion of the package that cannot be processed by the printed wiring board 510 can be easily taken out. The internal structure is the printed wiring board 510.
As a material of the above, a terminal formed by using a glass / epoxy resin or a silicon material and connected to the printed wiring board 510 can be easily connected by using a solder bump and a conductive adhesive.

[0006]

However, in the conventional technique disclosed in Japanese Patent Laid-Open No. 11-68026, the electrical characteristics of the internal circuit wiring 501 in the wiring auxiliary package 511 are not taken into consideration. In the structure of the circuit wiring and the layer structure in the wiring auxiliary package 511, the printed wiring board 510 is used.
When the signal output from the above IC 500 has a high-speed transmission that requires impedance matching, there is a drawback that reflection occurs in the circuit wiring pattern in the wiring auxiliary package 511 and the waveform deteriorates.

The conductive member for connecting the external terminal and the printed wiring board 510 has an existing zero-ohm square chip and is sandwiched between the external terminal and the pad of the printed wiring board 510. It is designed to connect. IC 500 connected to printed wiring board 510
The output resistance of the wiring has a value of several tens Ω, whereas when the wiring pattern on the wiring auxiliary package 511 is impedance-matched, a wiring having an impedance value of several tens Ω formed on the wiring auxiliary package 511. The pattern width becomes extremely thick as compared with other fine circuit wiring patterns for connection, which causes a physical obstacle when realizing high-density wiring on the wiring auxiliary package 511.

In order to solve the above-described problems of the prior art, the present invention provides an auxiliary package for wiring which enables impedance matching with internal circuit wiring, high-speed signal transmission, and high-density wiring, and the package. An object of the present invention is to provide a printed wiring board structure provided with.

[0009]

[Means for Solving the Problems]
In order to achieve the object, an auxiliary wiring package according to the invention of claim 1 is attached to a lower surface of the package in a vertical direction, and an external terminal row connected to an external terminal row or an external lead line of an existing semiconductor integrated circuit, In an auxiliary wiring package including an internal circuit wiring for connecting the external terminal rows to each other, the internal circuit wiring has an impedance-controlled wiring structure, and is capable of supporting high-speed signal transmission. .

According to the first aspect of the present invention, by controlling the impedance of the transmission line in the wiring auxiliary package, reflection on the transmission line caused by impedance mismatch can be prevented, and high-speed signal transmission can be supported. Can be planned.

In the wiring auxiliary package according to the invention of claim 2, in the invention of claim 1, the impedance controlled wiring structure is formed by a ground layer and one of upper and lower wiring layers. It is characterized by a microstrip line structure or a strip line structure.

According to the invention of claim 2, impedance matching can be achieved with a simple structure, reflection on the transmission line caused by impedance mismatch can be prevented, and high-speed signal transmission can be achieved.

The wiring auxiliary package according to a third aspect of the present invention is the wiring auxiliary package according to any one of the first and second aspects of the invention, wherein an output terminal of the semiconductor integrated circuit is provided on an upper surface of the wiring auxiliary package. By arranging a resistance element having a predetermined resistance value for impedance matching within a very short line distance from, a wiring pattern width is obtained by obtaining a combined resistance value of the output resistance of the semiconductor integrated circuit and the resistance element. The feature is that it can be made thin.

According to the invention of claim 3, a resistance element for impedance matching is arranged on the auxiliary wiring package to form a combined resistance with the output resistance from the semiconductor integrated circuit, and the resistance value is matched. It is possible to form a wiring structure having an impedance value that is on the auxiliary wiring package. Since this combined resistance value is larger than the output resistance from the semiconductor integrated circuit package, the wiring pattern width can be made relatively narrow, and the circuit wiring in the wiring auxiliary package can be made denser and the auxiliary wiring can be used. Space saving of the package can be achieved.

Further, in the wiring auxiliary package according to the invention of claim 4, in the invention of claim 3, as the resistance element for impedance matching, an angular resistance chip other than the existing zero ohm resistance value is used. Characterize.

According to the fourth aspect of the present invention, impedance matching can be easily achieved by using the existing angular resistance chip, and manufacturing can be facilitated and cost can be reduced.

Further, a printed wiring board structure provided with the auxiliary wiring package according to the invention of claim 5 is defined by claims 1 to 4.
In any one of the inventions described above, the wiring auxiliary package is arranged relatively to the semiconductor integrated circuit via a printed wiring board, and the printed wiring board has the semiconductor integrated circuit package and wiring. A through-hole for connecting the external terminals of the auxiliary package is provided.

According to the invention of claim 5, the semiconductor integrated circuit, the wiring auxiliary package, and the printed wiring board can be efficiently arranged and the entire space can be efficiently arranged, and high-density wiring and high-speed signal transmission can be achieved. Either way, a possible structure can be obtained.

A printed wiring board structure provided with an auxiliary wiring package according to a sixth aspect of the present invention is the printed wiring board according to the fifth aspect, wherein the wiring pattern of the printed wiring board is one of a ground layer and a ground layer. It is characterized by being a microstrip line structure or a strip line structure formed by these wiring layers.

According to the sixth aspect of the present invention, impedance matching can be achieved even on the printed wiring board, and high-density wiring and high-speed signals in the entire structure including the semiconductor integrated circuit, the wiring auxiliary package, and the printed wiring board can be obtained. Enables transmission.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a wiring auxiliary package and a printed wiring board structure including the package according to the present invention will be described in detail below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a sectional view showing a structure of a first embodiment of a wiring auxiliary package of the present invention. The wiring of the wiring auxiliary package 111 in this figure is connected from the pad of the semiconductor integrated circuit (IC) 100 through the through hole 120 of the printed wiring board 112. Wiring auxiliary package 111 for high-speed signal transmission
The inner wiring is required to have impedance matching equivalent to the output resistance of the IC 100.

Therefore, the illustrated microstrip line structure 114 and the ground layer 113 electrically connected to the ground signal 116 of the IC 100 and the upper or lower wiring layer are used.
A stripline structure 115 and a combination of microstrip and stripline are performed to form an impedance-matched wiring structure.

Such an impedance-matched wiring structure is reconnected to the printed wiring board 112 through the through hole 120 while maintaining the same impedance value in the wiring auxiliary package 111. The wiring structure on the printed wiring board 112 maintains the wiring structure impedance-matched by the microstrip line structure 114 and the strip line structure 115.
2 is connected to another IC.

With the above structure, the impedance of the transmission line in the auxiliary wiring package 111 can be matched, and reflection on the transmission line caused by impedance mismatch can be prevented.

(Second Embodiment) FIG. 2 is a chart for explaining the wiring pattern width in the structure shown in FIG.
When the output resistance of the IC 100 is several tens of Ω in the structure shown in FIG. 1, the wiring auxiliary package 111 is equivalent to this resistance value.
Such a wiring pattern width is formed by forming an impedance matching wiring structure inside.

As described in the prior art, when the wiring auxiliary package 111 is required, the wiring inside the wiring auxiliary package 111 can be formed at a fine pitch, so that the wiring auxiliary package 111 is formed inside the wiring auxiliary package 111. With such a wiring structure, the pattern width becomes thick and it is difficult to realize high-density wiring.

It is known that high speed signals are handled by distributed constant lines. However, when the line distance from the output end of the IC100 is very small, it can be treated as a lumped constant circuit, and by connecting the resistance elements in series within this range, the output resistance of the IC100 and the combined resistance of the resistance elements can be impedance. It can be regarded as a value. IC10
The output resistance of the IC 100 and the combined resistance of the resistance elements are larger than the output resistance of 0. Therefore, it means that the wiring pattern width in the microstrip line and the strip line structure on the printed circuit board can be reduced.

FIG. 3 is a sectional view showing the structure of the second embodiment of the wiring auxiliary package of the present invention. As shown in this figure, the IC 10 is placed on the wiring auxiliary package 111.
The resistance element 221 is connected in series within the range in which the line distance drawn from 0 is very small.

As a result, the output resistance of the IC 100 and the resistance element 221 are combined to create a combined resistance, which is changed to increase the impedance value, and the wiring pattern width in the auxiliary wiring package 111 for wiring is matched with the impedance value of the combined resistance. To form.

FIG. 4 is a perspective view showing the configuration of the second embodiment of the wiring auxiliary package of the present invention. When the output resistance of the IC 100 is several tens of Ω, the wiring auxiliary package 111
Pattern 331 formed by impedance matching inside
The width becomes thicker as shown, which hinders high-density wiring.

However, according to the configuration of the second embodiment,
Regarding the wiring drawn from the IC 100 on the wiring auxiliary package 111, the resistance element 221 is connected in series within a range where the line distance from the output end is very short. Thereby, the wiring pattern 332 whose impedance is matched with the output resistance of the IC 100 and the combined resistance value of the resistance element 221.
Can be made thinner than the width of the wiring pattern 331 as shown in the drawing, high-density wiring in the wiring auxiliary package 111 can be easily formed, and space saving of the wiring auxiliary package 111 can be achieved. be able to.

[0033]

As described above, according to the first aspect of the present invention, the external terminals mounted on the lower surface of the package in the vertical direction and connected to the external terminal row or the external lead line of the existing semiconductor integrated circuit. In the wiring auxiliary package including the columns and the internal circuit wirings that connect the external terminal rows to each other, the internal circuit wirings are configured to have an impedance-controlled wiring structure. By controlling the impedance of the transmission line, it is possible to prevent reflection on the transmission line caused by impedance mismatch, and it is possible to cope with high-speed signal transmission.

According to a second aspect of the invention, in the first aspect of the invention, the impedance controlled wiring structure is a microstrip formed by a ground layer and one of upper and lower wiring layers. Since it is a line structure or a strip line structure, impedance matching can be achieved with a simple structure, reflection on the transmission line caused by impedance mismatch can be prevented, and high-speed signal transmission can be supported. Play.

According to a third aspect of the present invention, in the invention according to any one of the first and second aspects, the wiring auxiliary package upper surface is provided with an output terminal of the semiconductor integrated circuit. By arranging a resistance element having a predetermined resistance value within a very short line distance for impedance matching, the output resistance of the semiconductor integrated circuit and the combined resistance value of the resistance element are obtained. A resistance element for impedance matching is arranged on the auxiliary package to form a combined resistance with the output resistance from the semiconductor integrated circuit, and a wiring structure having an impedance value matching this resistance value is formed on the auxiliary wiring package. it can. Since this combined resistance value is larger than the output resistance from the semiconductor integrated circuit package, the wiring pattern width can be made relatively narrow, and the circuit wiring in the wiring auxiliary package can be made denser and the auxiliary wiring can be used. This has the effect of saving space in the package.

Further, according to the invention described in claim 4, in the invention described in claim 3, as the resistance element for impedance matching, an angular resistance chip other than the existing zero ohm resistance value is used. In addition, it is possible to easily achieve impedance matching by using the existing angular resistance chip, and it is possible to facilitate manufacturing and reduce cost.

According to the invention described in claim 5, in the invention described in any one of claims 1 to 4, the wiring is relatively provided to the semiconductor integrated circuit via a printed wiring board. Since the auxiliary package for the semiconductor integrated circuit is arranged, and the printed wiring board is provided with through holes for connecting the respective external terminals of the semiconductor integrated circuit package and the auxiliary package for wiring, the semiconductor integrated circuit and the auxiliary wiring for wiring are provided. The package and the printed wiring board can be efficiently arranged, the entire space can be efficiently arranged, and a structure capable of both high-density wiring and high-speed signal transmission can be obtained.

Further, according to the invention of claim 6, in the invention of claim 5, the printed wiring board is
Since the wiring pattern is the ground layer and the microstrip line structure or the strip line structure formed by one of the upper and lower wiring layers, impedance matching can be taken even when placed on a printed wiring board,
It is possible to achieve high-density wiring and high-speed signal transmission in the entire structure including a semiconductor integrated circuit, a wiring auxiliary package, and a printed wiring board.

[Brief description of drawings]

FIG. 1 is a first embodiment of a wiring auxiliary package of the present invention.
3 is a cross-sectional view showing the configuration of FIG.

FIG. 2 is a chart for explaining a wiring pattern width in the structure shown in FIG.

FIG. 3 is a second embodiment of the wiring auxiliary package of the present invention.
3 is a cross-sectional view showing the configuration of FIG.

FIG. 4 is a second embodiment of the wiring auxiliary package of the present invention.
It is a perspective view which shows the structure of.

FIG. 5 is a cross-sectional view showing a printed wiring board structure using a conventional wiring auxiliary package.

[Explanation of symbols]

100 Semiconductor integrated circuit (IC) 111 Wiring auxiliary package 112 printed wiring board 113 Ground layer 114 Microstrip line structure 115 Stripline structure 116 Ground signal 120 through holes 221 resistance element 331,332 pattern

Claims (6)

[Claims] 1. An external terminal row which is attached to a lower surface of a package in a vertical direction and is connected to an external terminal row or an external lead line of an existing semiconductor integrated circuit, and an internal circuit wiring which connects the external terminal rows to each other. In the wiring auxiliary package provided, the internal circuit wiring has a wiring structure in which the impedance is controlled, and is compatible with high-speed signal transmission. 2. The wiring according to claim 1, wherein the impedance controlled wiring structure is a microstrip line structure or a strip line structure formed by a ground layer and one of upper and lower wiring layers. Auxiliary package for. 3. A resistance element having a predetermined resistance value is arranged on the upper surface of the auxiliary wiring package for impedance matching within a range in which the line distance from the output end of the semiconductor integrated circuit is very short. The wiring auxiliary package according to claim 1, wherein the wiring pattern width can be reduced by obtaining an output resistance of a semiconductor integrated circuit and a combined resistance value of the resistance elements. 4. The auxiliary wiring package according to claim 3, wherein an angular resistance chip other than the existing zero ohm resistance value is used as the resistance element for impedance matching. 5. The wiring auxiliary package is arranged relatively to a semiconductor integrated circuit via a printed wiring board, and the printed wiring board has external portions of the semiconductor integrated circuit package and the wiring auxiliary package. 5. A through hole for connecting the terminals is provided.
A printed wiring board structure comprising the wiring auxiliary package described in any one of 1. 6. The printed wiring board according to claim 5, wherein the wiring pattern has a microstrip line structure or a strip line structure formed by a ground layer and one of upper and lower wiring layers. Printed wiring board structure with auxiliary package for wiring.