WO2001082664A1 - Printed wiring board and method of mounting circuit element on this wiring board - Google Patents

Abstract

A printed wiring board on which a plurality of circuit elements having a plurality of terminals is to be mounted. This wiring board has a plurality of conductive lands for selectively connecting a plural kinds of circuit elements and a plurality of wirings for connecting a part of the conductive lands to the ground. The wirings are adapted to the circuit elements so that one of the wirings is disconnected and at least one of the terminals of the circuit can be connected to the ground when at least one of the terminals of the circuit in the circuit element to be connected is connected to the ground. By using this wiring board, an electronic circuit embodied thereon can be easily changed and an electronic apparatus such as a computer terminal can be easily modified.

Description

 Description Printed circuit board and method for mounting circuit elements using the printed circuit board

 The present invention relates to a printed wiring board and a method for mounting a circuit element using the printed wiring board. Background technology

In the field of electronic device manufacturing, electronic circuits are realized by mounting electronic components on printed wiring boards. For example, when mounting an Ic (integrated circuit) chip on a printed wiring board, the leads of the IC chip are soldered to the land formed on the surface of the printed wiring board, Another electronic component is soldered to another land that is conductive by the conductor pattern, thereby making an electrical connection between the IC chip and the other electronic component. When a multilayer printed wiring board is employed, an insulating layer is interposed between the conductor pattern on one surface and the conductor pattern on the other surface, and the insulating layer is interposed between the conductor patterns. ₍ Once an electronic component is mounted on a printed wiring board, it is not easy to change the electronic circuit embodied in connection with the electronic component. The development period of electronic devices such as personal computers is becoming shorter and shorter, and the development process is required to be accelerated Since one product is provided to the factory after many modifications, Shorter remodeling time is directly linked to faster product development, so there is a need for printed wiring boards that allow easy modification of electronic circuits when remodeling electronic equipment.

Japanese Unexamined Patent Publication No. Sho 60-222396 (U.S. Pat. No. 4,894,708) discloses a specific terminal of an IC chip mounted on the front surface after manufacturing a wiring board and an input / output on the back surface of the board. For repairs on the surface of the board with the aim of relieving faulty wiring without changing the wiring board even if the wiring connection between the terminal pins and the through-hole wiring is broken. It discloses a circuit board including a pad, a spare terminal on the back surface, and a spare wiring portion for connecting these. Using this circuit board, high-density mounting of many IC chips Degree LSI package can be provided.

 However, this circuit board can relieve a wiring failure when a break occurs in a wiring connection or a through-hole wiring, but cannot change an electronic circuit when remodeling an electronic device.

 Japanese Unexamined Patent Publication No. 5-243553 / 1993 discloses that each element is formed by performing wiring of two layers mutually insulated by an insulating film on a master slice that has been formed up to a transistor on a semiconductor substrate. It discloses a master slice type semiconductor integrated circuit in which connections are made. In this semiconductor integrated circuit, a spare wiring that is not connected to any element is provided in a vacant area where the basic wiring is not wired, so that a desired circuit can be modified and changed with only one wiring layer. I have. However, it is difficult to apply this technology to printed wiring boards as it is necessary to make a new mask to change the wiring layer.

 Japanese Utility Model No. 419/97974 is an auxiliary circuit board that is additionally provided on a remodeled board as a pre-designed circuit board, and the electronic circuit is changed using strap wires. A circuit board is disclosed. However, this technique has a problem in that the number of components increases because an auxiliary circuit board needs to be additionally provided to remodel the electronic circuit.

 Actually, No. 58-1 4 4 8 7 1 provided a plurality of spare through holes interconnected by a spare pattern formed on the outer layer, and directly connected the circuit pattern formed on the inner layer to the spare through hole. It discloses a repair pattern for a multi-layer printed wiring board that is connected. However, when changing the electronic circuit using this repair pattern, it is necessary to additionally provide other electronic circuit components or to perform connection work with an external circuit using strap wires. There is a problem that the work for remodeling becomes complicated.

 Therefore, an object of the present invention is to provide a printed wiring board in which an electronic circuit can be easily changed when remodeling an electronic device.

 Another object of the present invention is to provide a method for mounting a circuit element (electronic component) using the printed wiring board.

Disclosure of the invention According to the present invention, there is provided a printed wiring board on which a circuit element having a plurality of terminals is to be mounted. The printed wiring board includes a plurality of conductor lands that can selectively connect a plurality of types of circuit elements, and a plurality of wirings that connect a part of the plurality of conductor lands to the ground. And Wiring should be cut when at least one of the circuit's terminals in the connected circuit element is connected to dulland, and at least one of the circuit's terminals is connected to ground As much as possible, they are provided corresponding to a plurality of types of circuit elements.

 Preferably, the conductor land is provided such that a part of the conductor land is connected to a terminal of the circuit element.

 In this case, the conductor lands are desirably provided so that the conductor lands used for the connection differ depending on the type of the circuit element.

 According to another aspect of the present invention, a plurality of conductor lands that can selectively connect a plurality of types of circuit elements, and a plurality of wirings that connect a part of the plurality of conductor lands to the ground. Mounting a circuit element on a printed wiring board on which a circuit element having a plurality of terminals is to be mounted; and cutting one of the wires to reduce the number of circuit terminals in the circuit element. And a step of connecting one to a ground.

 More specifically, the present invention provides a printed wiring board on which a transistor, a transistor, and a logic element (TTL element) having a plurality of terminals are to be mounted. The printed wiring board includes first to sixteenth conductor lands corresponding to the plurality of terminals and the third, fifth, sixth, eighth, tenth, eleventh, and eleventh, respectively. A plurality of conductor patterns respectively connected to the 13th, 14th and 16th conductor lands; a connection pattern for connecting between the 7th and 8th conductor lands; And a connection pattern for connecting between the sixteenth conductor patterns.

 Preferably, the first to eighth conductor lands are arranged in a line at equal intervals, and the ninth to sixteenth conductor lands are arranged such that the first and ninth conductor lands are diagonally arranged. And the eighth and sixteenth conductor lands are arranged at regular intervals in a row so as to be diagonally aligned.

Also, desirably, the third, fifth, sixth, eighth, tenth, eleventh, thirteenth, and thirteenth above are described. The plurality of conductor patterns respectively connected to the first and fourth conductor lands are connected to the ground, and the conductor patterns connected to the sixteenth conductor lands are connected to the power supply line.

 Further, according to the present invention, there is provided a method for modifying an electronic device. This method includes a step of mounting a circuit element (more specifically, a TTL element) on a printed wiring board according to the present invention, and a step of cutting at least one of the conductor pattern and the connection pattern. Have. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a plan view showing an embodiment of a printed wiring board according to the present invention;

 Figures 2A-2E show TTL elements as circuit elements (electronic components) that can be mounted on the printed wiring board shown in Figure 1;

 Fig. 3 shows an example of the connection state when the "08" type TTL element shown in Fig. 2D is mounted on the printed wiring board shown in Fig. 1;

 Fig. 4 shows another example of the connection state when the "08" type TTL element shown in Fig. 2D is mounted on the printed wiring board shown in Fig. 1;

 Fig. 5 is a diagram showing an example of the connection state when the "04" type TTL element shown in Fig. 2C is mounted on the printed wiring board shown in Fig. 1;

 Fig. 6 shows an example of the connection state when the "02" type TTL element shown in Fig. 2B is mounted on the printed wiring board shown in Fig. 1;

 FIG. 7 is a plan view showing an example of a conventional printed wiring board; and

 FIG. 8 is a diagram showing an example of a connection state when the “08” type TTL element shown in FIG. 2D is mounted on the printed wiring board shown in FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a plan view showing an embodiment of a printed wiring board according to the present invention. This printed wiring board has first to sixteenth conductor lands formed on an outer layer of a single-layer or multi-layer circuit board (not shown; which is to be understood as paper itself). Circle in each figure The number described in the mark is the number of each conductor land. In the illustrated example, the shape of the conductor land is rectangular, but may be circular or any other shape as long as it can be electrically connected to the electronic component (circuit component) to be mounted. .

 The first to eighth conductor lands are arranged in a line at equal intervals. The ninth to sixteenth conductor lands are arranged such that the first and ninth conductor lands are on a diagonal and the eighth and sixteenth conductor lands are on a diagonal. They are arranged in a line at intervals.

 The eighth conductor land is connected to ground (GND) via conductor pattern 8A, and the 16th conductor land is connected to power supply line (Vcc) via conductor pattern 16A. I have. The seventh and eighth conductor lands are connected by a connection pattern 20, and the 15th and 16th conductor lands are connected by a connection pattern 22. Also, in order to cope with the processing of vacant terminals of various TTL elements described later, the third, fifth, sixth, tenth, eleventh, thirteenth, and fourteenth conductor lands are Patterns 3 A, 5 A, 6 A, 10 A, 11 A, 13 A, and 14 A are connected to ground.

 The connection between the seventh and eighth conductor lands by the connection pattern 20 and the connection between the 15th and 16th conductor lands by the connection pattern 22 are caused by various circuit components. This is because it is possible to respond to Specifically, for example, there are many types of TTL elements frequently used for changing an electronic circuit, and the arrangement of the ground and the power supply line differs depending on the TTL element used. While the TTL element has 14 pins (7 × 2 rows), in the present embodiment, as shown in FIG. 1, the printed wiring board has 16 conductor lands (8 × 2 rows). ), The mounting position can be changed according to the type of TTL element, so that differences in the layout of ground and power supply lines can be easily accommodated.

As described above, in the present embodiment, the first to sixteenth conductor lands are a part of them (the first to seventh and tenth to sixteenth conductor lands, or the second to eighth and ninth conductor lands). The ninth to fifteenth conductor lands are provided so as to be connected to the circuit elements (14-pin TTL elements). More specifically, the first to sixteenth conductor lands are provided such that the conductor lands to be connected are different depending on the type of the circuit element. Therefore, by changing the mounting position on the printed wiring board according to the type of circuit element, It is possible to easily cope with the difference in arrangement of the ground and the power supply line.

 Referring to FIGS. 2A-2E, a TTL element is illustrated as a circuit element (electronic component) mountable on the printed wiring board shown in FIG. The package of each element is common, and here, terminals 1 to 14 are provided. The terminals 1 to 7 are arranged in a line at equal intervals. Also, the terminals 8 to 14 are arranged in a line at equal intervals so that the terminals 1 and 8 are on a diagonal and the terminals 7 and 14 are on a diagonal. Terminal 7 is connected to ground (GND), and terminal 14 is connected to the power supply line (Vcc), and each element is used.

 FIG. 2A shows a “00” type TTL device having four NAND gates as circuits in the circuit device, for example, SN 7 4AS 00 (QUAD RUP LE 2—I NP UT POSITI VE— NAND GAT ES) is equivalent to this.

 FIG. 2B shows a “02” type TTL element having four NOR gates as circuits in the circuit element, for example, SN 74 AS 02 (QUAD RU PLE 2—I NP UT POSITI VE—NO R GAT ES) corresponds to this. Figure 2C shows a `` 04 '' type TTL element with six impellers each as a circuit in the circuit element, for example, SN 74A S 04 (HEX I NV ERTERS) I do.

 FIG. 2D shows a “08” type TTL element having four AND gates as circuits in the circuit element, for example, SN 7 4A S 08 (QUAD RUP LE 2—I NP UT POSITI VE — AND GAT ES) is the equivalent. FIG. 2E shows a “32” type TTL device having four OR gates each as a circuit in the circuit device. For example, SN 7 4A S 3 2 (QUAD RUP LE 2—I NP UT POSITIVE) — OR GAT ES) is equivalent to this. Fig. 3 is a diagram showing an example of the connection state when the "08" type TTL element shown in Fig. 2D is mounted on the printed wiring board shown in Fig. 1. An example of a method for mounting a circuit element according to the present invention will be described.

In the TTL element, terminals 1 to 7 are respectively connected to the second to eighth conductor lands, and terminals 8 to 14 are respectively connected to ninth to 15th conductor lands. Mounted on the printed wiring board as shown. In the present embodiment, the pattern of the printed wiring board is configured in consideration of the free terminal processing of the TTL element (at least one input terminal of each AND gate is always connected to ground). Since the connection pattern 20 is simply cut to open the seventh conductor land (terminal 6), preparation for remodeling is completed.

 For example, when an electronic circuit embodied on this printed wiring board is to be modified using one AND gate connected to the second to fourth conductor lands (terminals 1 to 3) After completion of the preparation for the above-described modification, the conductor pattern 3A is cut off, and the second to fourth conductor lands are individually wired as indicated by broken lines in the figure. As described above, in the present embodiment, the electronic circuit can be very easily changed, and thereby the electronic device such as the computer terminal can be easily remodeled.

 FIG. 4 is a diagram showing another example of a connection state when the “08” type TTL element shown in FIG. 2D is mounted on the printed wiring board shown in FIG. As in the example shown in FIG. 3, the circuit is embodied on this printed wiring board using one AND gate connected to the second to fourth conductor lands (terminals 1 to 3). If one of the inputs connected to the third conductor land (terminal 2) of the AND gate is constant at the mouth level, the conductor pattern is The cutting of A and the wiring to the third conductor land become unnecessary. Therefore, the work for the remodeling can be performed by cutting the connection pattern 20 and arranging the second and fourth conductor lands, thereby making it easier to change the electronic circuit.

 In the embodiments of FIGS. 3 and 4, the case of the “08” type TTL element has been described. However, the present invention can be similarly applied to the case of the “08” type or “32” type TTL element. it can.

FIG. 5 is a diagram showing an example of a connection state when the “04” type TTL element shown in FIG. 2C is mounted on the printed wiring board shown in FIG. The TTL element has terminals 1 to 7 connected to the first to seventh conductor lands, respectively, and terminals 8 to 14 connected to the 10th to 16th conductor lands, respectively. Then, it is mounted on the printed wiring board. In the present embodiment, the processing of the empty terminals of the TTL element (each inverter) The input and output terminals at least one of them should always be connected to the ground), and the conductor pattern 6 A, 1 OA and Just cut the 14 A and you're ready to convert. Thus, the electronic circuit embodied on the printed wiring board can be extremely easily changed by simply performing wiring for an arbitrary inverter using the inverter. As a result, electronic devices such as computer terminals can be easily remodeled.

 FIG. 6 is a diagram showing an example of a connection state when the “02” type TTL element shown in FIG. 2B is mounted on the printed wiring board shown in FIG. The TTL element has terminals 1 to 7 connected to the first to seventh conductor lands, respectively, and terminals 8 to 14 connected to the 10th to 16th conductor lands, respectively. Mounted on the printed wiring board as shown. In the present embodiment, the pattern of the printed wiring board is configured in consideration of the TTL element free terminal processing (at least one input terminal of each NOR gate must be connected to the ground). Since the connection pattern 22 is cut to open the 15th conductor land (terminal 13), the preparation for remodeling is completed. As a result, wiring can be performed only on an arbitrary N〇R gate (not shown, but the conductor pattern is cut off as necessary), and the NOR gate is used on this printed wiring board. The embodied electronic circuit can be changed very easily. As a result, electronic devices such as computer terminals can be easily remodeled.

 Referring to FIGS. 7 and 8, one example of a conventional printed wiring board and an example of a method for mounting circuit components using the printed wiring board are shown. The technical advantages of the present invention will be described more specifically.

This printed wiring board has first to sixteenth conductor lands formed on the outer layer of the circuit board, as shown in FIG. The first to eighth conductor lands are arranged in a line at equal intervals, and the ninth to sixteenth conductor lands are arranged such that the first and ninth conductor lands are on a diagonal and the eighth to eighth conductor lands. And the 16th conductor lands are arranged in a line at equal intervals so that they are diagonally arranged. The eighth conductor land is connected to the ground (GND) via the conductor pattern 8A, and the 16th conductor land is connected to the conductor pattern. It is connected to the power line (V cc) via pin 16A.

 FIG. 8 is a diagram showing an example of a connection state when, for example, the TTL element shown in FIG. 2D is mounted on the printed wiring board shown in FIG. 7 as a circuit component. The TTL element has terminals 1 to 7 connected to the second to eighth conductor lands, respectively, and terminals 8 to 14 connected to the ninth to 15th conductor lands, respectively. , Mounted on the printed wiring board.

 For example, try to change the electronic circuit embodied on this printed circuit board using one AND gate connected to the second to fourth conductor lands (terminals 1 to 3) In such a case, first, wiring between the 15th conductor land and the 16th conductor land is required to secure the power supply of the circuit (the AND gate). In addition, wiring to the second to fourth conductor lands is required as wiring for the circuit itself, and the fifth, sixth, tenth, Wiring to the 11th, 13th and 14th conductor lands is required. Therefore, as shown by the broken line in FIG. 8, a total of 10 wirings are required.

 On the other hand, in the present invention, for example, in the embodiment of FIG. 3, only the three wirings and the cuts of the patterns 3A and 20 for the second to fourth conductor lands are sufficient, which is extremely easy. The electronic circuit can be changed. Further, in the embodiment of FIG. 4, the wiring to the third conductor land and the cutting of the pattern 3A are not required, and two wirings and one pattern cut are sufficient, and furthermore, the electronic circuit is changed. Becomes easier. Industrial applicability

 As described above, according to the present invention, it is possible to provide a printed wiring board in which an electronic circuit can be easily changed when remodeling an electronic device, and a method for mounting a circuit element using the printed wiring board. become. Further, according to the present invention, an electronic device such as a computer terminal can be easily remodeled using the printed wiring board, which greatly contributes to an improvement in the speed of product development.

Claims

The scope of the claims 1. In a printed wiring board on which a circuit element having a plurality of terminals is to be mounted, the printed wiring board includes a plurality of conductor lands capable of selectively connecting a plurality of types of circuit elements; A plurality of wires connecting a part of the plurality of conductor lands and the ground,  When at least one of the terminals of the circuit in the circuit element to be connected is connected to the ground, at least one of the wirings is cut to disconnect at least one of the terminals of the circuit. A printed wiring board, which is provided corresponding to the plurality of types of circuit elements so that one can be connected to a ground. 2. The printed wiring board according to claim 1, wherein the conductor land is provided such that a part of the conductor land is connected to a terminal of the circuit element. 3. The printed wiring board according to claim 2, wherein the conductor land is provided so that a conductor land used for connection differs according to a type of a circuit element. . 4. A plurality of terminals having a plurality of conductor lands capable of selectively connecting a plurality of types of circuit elements, and a plurality of wirings connecting a part of the plurality of conductor lands and the ground. Mounting the circuit element on a printed wiring board on which the circuit element having the chip is to be mounted;  Cutting at least one of the wirings and connecting at least one of the circuit terminals in the circuit element to ground.