JP2825221B2 - Printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention] (Industrial application field) The present invention relates to a printed wiring board that implements various functions by mounting a plurality of IC packages. (Prior Art) Conventionally, in this type of printed wiring board, for example, a circuit having a plurality of functions is provided by mounting a plurality of IC packages including a plurality of flip-flop circuits and a plurality of IC packages including a plurality of gate circuits. Are formed. At this time, the design of the wiring pattern for connecting the respective IC packages has been performed independently of the respective functions. For example, when a circuit realizing the functions 1 and 2 as shown in FIG. 3 is formed on the printed wiring board shown in FIG. 2, the circuit shown in FIG. 2
Two functions are realized. However, in the drawing, solid lines indicate patterns on the back surface of the printed wiring board, ○ indicates lands, and □ indicates through holes. The function 1 shown in FIG. 3 is constituted by flip-flop circuits 11, 12 and OR gate circuits 21, 22, 23, which are operated by a clock CLK. A pulse processing circuit is formed. Function 2 is that the flip-flop circuits 13 and 14 and the OR gate circuits 24 and 2 are operated by the clock CLK.
5 and 26. In this case also, a pulse processing circuit for extending the pulse width of the pulse 200 and outputting the pulse 400 is formed. Here, the IC package used to realize the above circuit is an IC package (LS74) in which a flip-flop circuit is built twice and an IC package (LS32) in which four OR gate circuits are built. . When such an IC package is used, in the printed wiring board shown in FIG. 3, the flip-flop circuits 11 and 13 use the IC package 10 and the flip-flop circuits 12 and 14 use the IC package.
It is wired so that the package 30 is used. The OR gate circuits 21, 22, and 23 use the IC package 20 and the OR gate circuits 24, 25, and 26 use the IC package 40. Therefore, in order to realize the above functions 1 and 2, four IC packages, two IC packages containing a flip-flop circuit and two IC packages containing an OR gate circuit, are used. Therefore, even when only function 1 is used, two IC packages 10, 30 and one IC package
The C package 20 had to be mounted on the printed wiring board. In the case of failure diagnosis, for example, the OR gate circuit 22
In a case where the IC package 20 including the IC package 20 is defective, the two IC packages 10 and 30 including the flip-flop circuits 11 and 12
Check that the normal operation of the OR gate circuit
Failure of the IC package 20 including 22 could not be diagnosed. In this way, wiring the IC package without considering the functions to be realized has the disadvantage that the number of IC packages to be mounted increases unnecessarily and increases the cost, and it takes time to troubleshoot the failure. There were drawbacks. (Problems to be Solved by the Invention) As in the past, when the wiring patterns of a plurality of IC packages mounted on a printed wiring board are designed without considering the functions to be realized, each circuit included in one IC package is designed. Are used to realize different functions, which has the disadvantage of having to mount an unnecessarily large number of IC packages and increasing costs.
Unless the quality of the package is checked, no failure can be found, and there is a disadvantage that trouble and time are required for failure diagnosis. The present invention eliminates the above disadvantages, and its purpose is to increase the number of IC packages to be mounted without unnecessarily increasing the number of IC packages.
An object of the present invention is to provide a printed wiring board having a wiring pattern that can reduce costs and speed up fault diagnosis. [Constitution of the Invention] (Means for Solving the Problems) The present invention relates to a first IC package having a plurality of first circuits only and a second IC package having only a second circuit press different from the first circuit. In a printed wiring board on which a wiring pattern is formed so that at least one of each of the two IC packages can be mounted, and a predetermined function is realized by electrically connecting the first circuit and the second circuit, The first IC package has a first circuit in which the number of circuits used for a predetermined function is within the number of circuits incorporated in the first IC package,
The IC package has a second circuit in which the number of circuits of the second circuit used for a predetermined function is within the number of circuits incorporated in the second IC package, and only one of the first IC package is used. It is formed so as to electrically connect the built-in first circuit and the second circuit built only in one of the second IC packages. (Operation) The first embodiment having a plurality of first circuits only, as in the present invention.
An IC package and a second IC package having only a plurality of second circuits different from the first circuit can be mounted at least one each, and by electrically connecting the first circuit and the second circuit Regarding a printed wiring board on which a wiring pattern is formed to realize a predetermined function, in particular, the number of first circuits used for the predetermined function is within the number of circuits of the first IC package, and the predetermined If the number of circuits of the second circuit used for the function is within the number of circuits of the second IC package, the number of required IC packages can be reduced, so only a small amount of time and effort is required Thus, these IC packages can be mounted, and thus productivity can be improved. (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings by attaching the same reference numerals to the same parts as those of the conventional example. FIG. 1 is a block diagram showing one embodiment of the printed wiring board of the present invention. In the figure, solid lines indicate patterns on the back surface of the printed wiring board, and broken lines indicate patterns on the front surface. In addition, ○ indicates a land, and □ indicates a through hole. Further, 10, 20, 30, and 40 indicate IC packages in which terminals are inserted and coupled to lands arranged in two rows and mounted on the front surface of the printed wiring board.
An IC package containing two flip-flop circuits is used as 0, and an IC package containing four OR gate circuits is used as the IC packages 20 and 40. Next, the wiring pattern formed on the printed wiring board shown in FIG. 1 and its function will be described. Also in this case, it is assumed that the functions 1 and 2 shown in FIG. 3 are realized. That is,
Flip-flop circuits 11 and 12 for implementing function 1 are I
Wiring is performed so that two flip-flop circuits built in the C package 10 are used, and three OR gate circuits 21, 22, and 23 necessary for realizing the same function 1 are built in the IC package 20. The three OR gate circuits are wired so that three of them are used. Also, flip-flop circuits 13 and 1 for implementing function 2
4 is wired so that the two flip-flop circuits included in the IC package 30 are used. Similarly, OR gate circuits 24, 25, and 26 necessary for realizing the function 2 are connected to the IC package 40.
Are wired so as to use three of the four OR gate circuits built in. Therefore, the function 1 is realized by the IC packages 10 and 20, and the function 2 is realized by the IC packages 30 and 40, respectively. According to the present embodiment, since each of the IC packages 10 to 40 is used only to realize one function, if only the function 1 is required, two IC packages, which conventionally required three, are required. That is, the function 1 can be realized only by mounting the IC packages 10 and 20 on the printed wiring board, and the number of IC packages can be reduced and the cost can be reduced as compared with the related art. Also, at the time of failure diagnosis, for example, includes the OR gate circuit 22
When the IC package 20 is faulty, the malfunction of the IC package 20 can be found only by confirming that the operation of the flip-flop circuits 11 and 12, ie, the operation of the IC package 10, is normal. Time required for diagnosis and repair can be reduced by reducing the number of IC packages to be checked. [Effects of the Invention] As described above, according to the printed wiring board of the present invention, the number of mounted IC packages required to achieve one function can be minimized, so that the printed circuit board requires less time and effort. The effect of being able to improve the productivity by mounting the IC package on the printed wiring board can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing an embodiment of a printed wiring board according to the present invention, and FIG. 2 is a view showing an example of a printed wiring board wired by a conventional method of wiring a printed wiring board. FIG. 3 is a diagram showing an example of a circuit formed on a printed wiring board. 11,12,13,14 …… Flip-flop circuit 21,22,23,24,25,26 …… OR gate circuit

Continuing from the front page (56) References Edited by the Industrial Research Committee, edited by Kenji Ito “Printed Wiring Board Design Examples” Published by the Industrial Research Committee, Inc. Published on January 15, 1986, first edition, pages 170-172 (company) ) Edited by the Japan Electronic Machinery Manufacturers Association, "Latest Electronic Components Handbook" Published by Denpa Shimbun, February 28, 1978 First edition, 3rd printing, page 19 (58) Fields investigated (Int. Cl. ⁶ , DB name) H05K 1/18 H01L 25/00

Claims (1)

(57) [Claims] A first IC package having a plurality of first circuits only, and a second IC package having a plurality of only second circuits different from the first circuit can be mounted at least one each, and the first circuit A printed circuit board on which a wiring pattern is formed so as to realize a predetermined function by electrically connecting the second IC and the second circuit, wherein the first IC package is a circuit used for the predetermined function. The first IC package has the first circuit whose number is within the number of circuits incorporated in the first IC package, and the second IC package has a circuit number of the second circuit used for the predetermined function. The second circuit having the number of circuits included in the second IC package, wherein the first circuit and the second IC package included only in one of the first IC packages are included. Only with the second circuit built in A printed wiring board comprising a wiring pattern formed so as to be connected pneumatically.