JPH06209169A - Multilayer circuit wiring board having circuit correction function, its circuit correction method and electronic circuit device - Google Patents

Abstract

PURPOSE:To obtain a multilayer circuit board or a circuit correction board having circuit pattirn correction function wherein circuit correction is easily enabled at the time of circuit correction work of an electronic circuit device, and high density mounting of electronic components can be realized, its correction method, and an electronic circuit device wherein electronic components are mounted on the board. CONSTITUTION:Correction pads 6 are arranged on the peripheral part of LSI chips 2 mounted on a board 1. A plurality of wiring patterns 5 are arranged in the vicinity of the pads 6. A correction pattern and connection pads 7 are arranged between the LSI chips 2 Thereby structure wherein correction of wiring (cut and connection is enabled on the board surface layer is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer circuit wiring board having a circuit correcting function, a circuit correction method for the board, and an electronic circuit device in which electronic parts are mounted and mounted on the circuit wiring board.

[0002]

2. Description of the Related Art With the high speed and high integration of LSIs, a high-density mounting technique on a circuit wiring board is very important in electronic circuit devices having a large number of LSIs mounted thereon. That is, by increasing the density, the wiring path between the LSIs is shortened, the wiring delay time in the board of the electric signal is shortened, and high-speed operation as an electronic circuit device is enabled.

Therefore, as a high-density mounting technique, for example, a flip chip in which bumps made of metal such as solder are formed on electrodes on the surface of an LSI chip and the chips are face-down bonded onto a circuit wiring board via the bumps. There is a mounting method.

Further, since the number of input / output terminals of the LSI chip increases and the number of signal wirings in the circuit wiring board increases due to the high integration of the LSI, the circuit wiring board on which the LSI is mounted needs to be multilayered. . Therefore, the circuit wiring board is required to have a fine and multi-point electrode terminal forming technique and a multilayer circuit wiring technique.

By the way, in such a multilayer circuit wiring board, it is necessary to repair the defect in the manufacturing process of the fine wiring pattern and to correct the circuit such as changing the logic between the LSIs after mounting the LSI on the board. Come on. Specifically, the following problems, for example, (1) circuit wiring design failure, (2) manufacturing failure, (3) signal propagation delay time occurring on the wiring route, wiring pattern defect, etc. Circuit changes are necessary due to problems such as defects and (4) design changes for improving the performance of electronic circuit devices.

Therefore, the multilayer circuit wiring board requires a repair pattern structure for circuit modification which does not reduce the packaging density and the operating performance of the LSI, and various structures have been proposed so far. There is.

For example, as one of the methods, a pad for repair wiring connection or an EC (Engineering Change) pad is provided around the projection surface of an electronic circuit component mounted on a multilayer circuit board, and this pad is provided on this pad. A method of performing wire bonding to change a circuit is known. But,
In this method, since the repair pad is provided on the surface of the circuit board, the mounting density of electronic circuit components on the circuit board (total area of mounted electronic circuit components / circuit board area) is significantly reduced. In addition, as related to this kind of technology,
For example, Japanese Patent Application Laid-Open No. 62-25437 and Microelectronics Packaging Handbook (page 39,
(Figs. 1-28, published by Nikkei BP, March 27, 1991)
Is mentioned.

Therefore, as another method for improving the mounting density, the pad structure provided on the circuit board is improved,
A method has been proposed in which a repair pad is also formed on a part of the element connection terminal pad on the projection surface of the electronic component to reduce the area occupied by the repair pad. According to this method, (1) a pad for connecting terminals of an electronic component provided on a surface layer of a substrate is provided with a cutting pad for modification and a pattern connection pad for modification, and the pad for cutting on modification is inserted through the pad for cutting. The structure is such that the wiring pattern in the board that is connected and the modification pattern that is connected to the modification pattern connection pad at the time of modification are respectively provided in the inner layer of the board. The cutting pad for remodeling connected to the terminal is cut from the terminal connection pad, and on the other hand, between the remodeling pattern connection pad connected to the terminal connection pad on the surface layer and the remodeling pattern provided on the inner layer. A dedicated via is provided to connect the two, and (2) the modification pattern is provided as a two-layer structure in the substrate, and the modification pattern is connected to the surface layer. As a pad, in which are provided these conductive vias formed pad channel riding replacement showing the two layers in the via connection is positionable conduction forming position for channel riding replacement. In addition,
As a technique related to this kind of technology, for example, Japanese Patent Laid-Open No.
3-213399 gazette is mentioned.

[0009]

The latter repair method is superior to the former in that the area occupied by the repair pad provided on the circuit board can be reduced. However, after flip-chip mounting an LSI chip on a multilayer circuit wiring board, if a design change or LSI malfunction occurs and circuit correction is performed, it is necessary to remove the already mounted LSI chip, which causes the following problems. Exists.

That is, as work steps for modifying the circuit, (1) removal of the LSI chip (2) leveling (excessive solder remains on the terminal connection pads on the multilayer circuit wiring board side after the removal of the LSI chip, Work to remove this solder) (3) Work to correct the circuit on the multilayer circuit wiring board (4) Work to supply solder to the terminal connection pads of the LSI chip in order to remount the LSI chip on the multilayer circuit wiring board (5) It is necessary to align the mounting position of the LSI chip on the multilayer circuit wiring board after the circuit modification, and to join it by soldering. In order to perform each of the above-mentioned operations (1) to (5), it is necessary to introduce equipment for each operation, secure workers, etc., and
There is a problem that it takes a considerable amount of time to correct the circuit.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and the first object is the LS.
A multi-layer circuit wiring board capable of circuit modification without removing the I-chip, a second purpose is a circuit modification method of the circuit wiring board, and a third purpose is an electronic circuit device in which electronic parts are mounted and mounted on the board. To provide each.

[0012]

In order to achieve the above object, according to the present invention, a repair pad is provided on the outer periphery of the projection surface of an electronic circuit component mounted on a multilayer circuit wiring board, and a repair pad is provided near the repair pad. Multiple wiring patterns of
A repair pattern was provided between the I chips. Further, the circuit repair board having the repair pad and the wiring pattern for repair work is provided between the multilayer circuit wiring board and the electronic circuit component mounted thereon.

The specific means for achieving the object of the present invention will be described below. First, the first object is to provide a repair pad serving as a circuit repair relay path and an inner layer wiring at one end in the peripheral area of the electronic circuit component mounted on the multilayer circuit wiring board (outer peripheral area of the projected surface of the electronic circuit component). A plurality of wiring patterns, which are connected to each other and closely face the repair pad and extend on the surface layer, are provided to form a circuit correction area of the wiring pattern, and an electronic circuit component is provided in the projection plane area of the electronic circuit component. Is achieved by a multilayer circuit wiring board or a circuit modification board which is formed by connecting the terminals of (1) and forming terminal connection pads connected to the inner layer wiring pattern. The circuit correction board is a wiring board having a circuit correction function, and has substantially the same function and structure as the multilayer circuit wiring board.
When it is used alone, it becomes a multilayer circuit wiring board, and when it is mounted on another circuit wiring board, it becomes a circuit correction board. Therefore, in the following description, the case of a single-use multilayer circuit wiring board is taken as an example.

Further, the multi-layer circuit wiring board is formed with a mounting area adjacent to which a plurality of electronic circuit components are mounted in a matrix form, and preferably the circuit modification provided between the mounting areas. A circuit modification area structure may be provided in which a plurality of repair patterns are arranged adjacent to the repair pad in the area and connection pads for circuit wiring connection are provided at both ends of the repair pattern to facilitate connection. desirable. The repair pad forms a first circuit repair relay path, and when the wiring pattern is modified, one of the floating pads is connected to the wiring pattern while the other is connected to the repair pattern to be the second circuit repair relay path. Becomes

A second object is a circuit repairing method using the above-mentioned multilayer circuit wiring board, wherein a step of cutting wires in predetermined circuit cut repair areas of a wiring pattern and a repair pattern, respectively. A step of conducting a conductor connection between the wiring pattern, the repair pad, the repair pattern, and the correction area on the connection pad, and mounting the electronic circuit component adjacent to the repair pad and the connection pad or the repair pattern. This is achieved by a method of modifying a circuit of a multilayer circuit wiring board which enables modification of a circuit between regions. Further, (1) as the step of cutting the wiring, laser beam irradiation and other steps such as mechanically cutting with a micro cutter, an ultrasonic cutter, etc., and (2) as the step of connecting the wiring and the pad , A process of fusion connection using a brazing material such as solder, or a process of connecting using wire bonding, ribbon bonding, or a conductor foil, or using a brazing material at both ends using a brazing material for each wiring or between pads It is desirable to configure with the process of connecting.

A third object of the present invention is to mount electronic circuit components on a multilayer circuit wiring board which achieves the first object, and to provide terminal connecting pads provided in a mounting area on the board. This is achieved by an electronic circuit device that is electrically connected to terminals of electronic circuit components. Usually, a large number of electronic circuit components such as LSI are connected in a matrix on a substrate to achieve high-density mounting. Further, this type of circuit board is configured by integrally connecting and forming a second thin film multilayer circuit wiring board on a first thick film board to which input / output terminals are connected. This first thick-film substrate is generally provided with pins as input / output terminals on its back surface, and a connection terminal group forming a second thin-film multilayer circuit wiring board is provided on its front surface. It is composed of a rigid multilayer circuit wiring board such as a substrate.

A third object is to connect a circuit modification board, which achieves the first object, onto the multilayer circuit wiring board, and mount electronic circuit parts on the circuit modification board.
This is achieved by an electronic circuit device in which a terminal connection pad provided in a mounting area on the multilayer circuit wiring board, a terminal connection pad on a circuit correction board, and a terminal of an electronic circuit component are electrically connected to each other. It

[0018]

According to the multilayer circuit wiring board or the circuit modification board having the circuit modifying function of the present invention, the repair work can be performed around the electronic circuit component mounted on the multilayer circuit wiring board, and it can be mounted once as in the past. There is no need to remove the electronic circuit parts that have been removed, and the work time required for repair work and equipment investment can be greatly reduced. Also, for one repair pad,
By sharing a plurality of wiring patterns, it is possible to reduce the number of repair pads required at the time of repair, prevent the multilayer circuit wiring board area from increasing, and improve the mounting density of electronic circuit components. .

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. <Embodiment 1> FIG. 1 is a cross-sectional view of essential parts of a multilayer circuit wiring board having a circuit correcting function according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a multilayer circuit wiring board of the present invention, and 2 is an LS.
I chip, 3 solder bumps, 4 terminal connection pads,
Reference numeral 5 is a wiring pattern provided on the surface layer, 5'is a wiring pattern provided on the inner layer of the multilayer circuit wiring board, 6 is a repair pad, and 7 is a connection pad.

Further, FIG. 2 shows each pattern of the surface layer when four LSI chips are mounted on the multilayer circuit wiring board of FIG. 1, 9 is an LSI mounting area shown by a broken line, and 10 is both ends connected. It is a repair pattern having a pad 7. Figure 1,
As shown in FIG. 2, the repair pad 6 is arranged around the LSI chip mounting area 9, and the wiring pattern 5 is placed close to the repair pad 6.
Is provided. In this embodiment, the two wiring patterns 5 are arranged close to one repair pad 6, but as many wiring patterns as possible can be provided. Further, a plurality of repair patterns 10 are arranged between the adjacent LSI mounting areas 9 and on the outer periphery thereof in the vicinity of the repair pad 6, and the connection pads 7 are arranged at both ends thereof.

Next, the structure after the circuit modification when the multilayer circuit wiring board shown in FIGS. 1 and 2 is used will be described with reference to FIGS. 3 and 4, 8 is a bonding wire, 11 is a cut area of the wiring pattern 5, 12 is a connection area of the wiring pattern 5 / repair pad 6, and 14 is a cut area of the repair pattern 10. Hereinafter, in the plan view of FIG. 4, A of the terminal connecting pad 4 in one LSI mounting area is shown.
To B in the other adjacent LSI mounting area will be described.

[Procedure 1] In the wiring pattern 5 that is conductor-connected to the terminal connecting pads A and B, both wirings are cut in the cut area 11 of the wiring pattern 5. The cutting means may be any method such as a laser beam, a micro cutter, or an ultrasonic cutter. [Procedure 2] The cut wiring pattern 5 and the repair pad 6 provided in the vicinity thereof are connected by the conductor 8. [Procedure 3] Conductor 8 is provided between the repair pad 6 and the connection pad 7.
Connect with. [Procedure 4] The connection pads 7 formed on the other adjacent repair patterns 10 are connected by the conductors 8. As a method of connecting with a conductor in the above steps 2, 3, and 4, a portion where the connecting portions are close to each other, such as the connecting region 12, is a solder connection, and a portion such as the conductor 8 is slightly apart is a wire. A solid phase / solid phase or liquid layer / solid phase connection method such as bonding, ribbon bonding, conductor foil, or connecting both ends of a wire with solder is desirable. Connection of wires, ribbons, conductor foils, etc. can be made not only by solder connection but also by ultrasonic bonding.

As another circuit modification method, (1)
As in the circuit modification method from C to D of the terminal connection pad 4 shown in FIG. 4, as shown by the connection area 12 between the repair pad 6 and the repair pattern 10 connected to C and D of the terminal connection pad 4. The circuit can be corrected by directly connecting the conductors and cutting the portion of the repair pattern 10 near the connection region 12. Cutting of the repair pattern 10 is not always necessary, but by cutting it, the stray capacitance of the pattern is reduced by avoiding a redundant circuit, and the connection pad 7 at the other end is effectively used for other circuit modification. Because you can
In such a case, it is desirable to cut. Also,
(2) Direct wire bonding, ribbon bonding, or both ends of the wires are soldered to the respective repair pads 6 between the respective repair pads 6 connected to A and B of the terminal connecting pads 4 by the above steps 1 and 2. It can also be realized by a connection method such as.

<Embodiment 2> Next, a circuit-correcting board 13 having a circuit-correcting function prepared by the same method is formed on the multilayer circuit wiring board 1 obtained in Embodiment 1 with reference to FIGS. 5 and 6. A circuit correction method when the LSI chip 2 is mounted via the above will be described. FIG. 5 is a plan view of an electronic circuit device in which a circuit correction board 13 in which the circuit of the terminal connection pads 4 from E to F is modified is mounted on the multilayer circuit wiring board 1, and FIG. Reference numeral 13 denotes a circuit correction board. The repair pad 6 provided on the circuit correction substrate 13 is provided with wiring and connection terminals for connecting to the terminal connection pads 4 of the multilayer circuit wiring substrate 1 on the back surface. The circuit modification method can be realized by combining the steps 1 to 4 shown in the first embodiment.

As described above, according to this embodiment, repair pads for circuit correction are provided around electronic circuit components mounted on a multilayer circuit wiring board, and a plurality of wiring patterns are arranged in close proximity to each other. By performing the cutting and connection on the surface layer of the substrate, the circuit can be corrected without removing the electronic circuit components already mounted on the substrate, and the working time and the facility investment can be reduced.

[0026]

As described above in detail, the initial object can be achieved by the present invention. That is, in the multilayer circuit wiring board or the circuit correction board of the present invention having the function of correcting the circuit pattern, a repair pad is provided around the electronic circuit component mounted on the board to arrange a plurality of wiring patterns close to each other. The wiring can be easily modified on the surface layer of the board, the removal process of the electronic circuit parts already mounted can be deleted, the work time for circuit modification and the equipment investment can be reduced, and one repair pad can be used. By sharing a plurality of wiring patterns, the mounting density of electronic circuit components mounted on the substrate can be improved. In addition, the circuit size of the circuit-corrected board can be made significantly smaller than that of the multilayer circuit wiring board, so that the yield at the time of board production can be improved and the board production cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part of a multilayer circuit wiring board and an electronic circuit device before circuit modification showing an embodiment of the present invention.

FIG. 2 is a plan view of the same multilayer circuit wiring board.

FIG. 3 is a sectional view of an essential part after the circuit pattern is similarly corrected.

FIG. 4 is a plan view of the same circuit pattern after correction.

FIG. 5 is a plan view after circuit pattern correction in an electronic circuit device according to another embodiment in which a circuit correction board is mounted on a multilayer circuit wiring board.

FIG. 6 is a sectional view of an essential part after the circuit pattern is similarly corrected.

[Explanation of symbols]

1 ... Multilayer circuit wiring board, 2 ... LSI
Chip, 3 ... Solder bump, 4
… Terminal connection pads, 5… wiring patterns,
6 ... Repair pad, 7 ... Connection pad,
8 ... Bonding wire, 9 ... LSI
Mounting area, 10 ... Repair pattern, 1
1 ... Wiring pattern cut area, 12 ... Wiring pattern /
Repair pad connection area, 13 ... Circuit correction board,
14 ... Cut area of repair pattern.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutomu Imai 1 Horiyamashita, Hadano, Kanagawa Pref. General Computer Division, Nitrate Manufacturing Co., Ltd. (72) Shinji Abe 1 Horiyamashita, Hadano, Kanagawa Pref. (72) Inventor Hiroyuki Hidaka No. 1 Horiyamashita, Hadano City, Kanagawa Prefecture

Claims (13)

[Claims] 1. A repair pad, which serves as a circuit repair relay path, is provided in the peripheral area of an electronic circuit component mounted on a multilayer circuit wiring board, and one end is connected to an inner layer wiring and the other end is closely opposed to the repair pad and is on the surface layer. And a plurality of wiring patterns extending to form a circuit correction area of the wiring pattern,
A multilayer circuit wiring board formed by connecting terminals of an electronic circuit component in a mounting area of the electronic circuit component and forming a terminal connection pad connected to an inner layer wiring pattern. 2. The multi-layer circuit wiring board is provided with mounting areas adjacent to each other for mounting a plurality of electronic circuit components in a matrix, and repairs are made in the circuit correction areas provided between the mounting areas. The multilayer circuit wiring board according to claim 1, wherein a plurality of repair patterns are arranged adjacent to the pads. 3. The multilayer circuit wiring board according to claim 2, wherein connection pads for connecting circuit wiring are provided at both ends of the repair pattern. 4. The circuit correction board having a circuit correction function is provided between the multilayer circuit wiring board and the electronic circuit component mounted thereon, and the surface of the circuit correction board is provided on any one of claims 1 to 3. A multilayer structure in which repair pads and wiring patterns are provided, and the repair pads on the circuit correction board are connected to the terminal connection pads of the multilayer circuit wiring board on the back side via conductor wiring via conductor wiring. Circuit wiring board. 5. An electronic circuit component is mounted and a plurality of circuit-corrected circuit-corrected boards are mounted on a multilayer circuit wiring board, and circuit correction between adjacent circuit-corrected boards is performed on the multilayer circuit-wired board. A multi-layer circuit wiring board that is modified in the circuit modification area. 6. A circuit repairing method using the multilayer circuit wiring board according to claim 1, further comprising a step of cutting wires in predetermined circuit cut repair areas of the wiring pattern and the repair pattern, respectively. A step of conducting a conductor connection between the wiring pattern and the repair pattern, a step of conducting a conductor connection between the repair pad and a connection pad on the repair pattern, and a step of conducting a conductor connection between the repair pad and the repair pattern, A method of repairing a multilayer circuit wiring board and a circuit repairing board, the method comprising: connecting conductors between connection pads on a repair pattern. 7. A circuit repairing method using the circuit repairing substrate according to claim 4 or 5, wherein a step of cutting wires in predetermined circuit cut repair areas of the wiring pattern and the repair pattern, respectively, Conductive connection between the pattern and the repair pattern, conductive connection between the repair pad and the connection pad on the repair pattern, conductive connection between the repair pad and the repair pattern, and And a method of electrically connecting the connection pads between the conductors with each other. 8. A circuit repairing method for a multilayer circuit wiring board, which comprises a step of supplying a brazing material and performing a melt connection as the connecting step according to claim 6. 9. A circuit repairing method for a circuit repairing substrate, which comprises the step of supplying a brazing material and performing melt-bonding as the connecting step according to claim 7. 10. The method for repairing a multilayer circuit wiring board according to claim 6, wherein the method for cutting the wiring pattern and the repair pattern in the circuit repair area is a step of laser beam irradiation or mechanical cutting. 11. The circuit repairing method for a circuit repairing substrate according to claim 7, wherein the method for cutting the wiring pattern and the repair pattern in the circuit repairing area comprises a step of laser beam irradiation or mechanical cutting. 12. An electronic circuit component is mounted on the multilayer circuit wiring board according to claim 1, and the terminal connection pad and the terminal of the electronic circuit component provided in the mounting area on the substrate are electrically connected. Circuit devices that are connected together electrically. 13. A circuit correction board and an electronic circuit component according to claim 4 or 5 are mounted on a multilayer circuit wiring board, and a terminal connecting pad and a circuit correction board provided in a mounting area on the multilayer circuit wiring board. An electronic circuit device in which the upper terminal connection pad and the terminals of the electronic circuit component are electrically connected to each other.