JP4660738B2 - Printed wiring board and electronic device - Google Patents

Description

  The present invention relates to a wiring structure, a printed wiring board, an integrated circuit, and an electronic device.

  In a printed wiring board of an electronic device, a delay time may be intentionally ensured for each signal wiring in order to synchronize the timing of signals between a plurality of signal wirings. There is an extension of the signal wiring as a method for securing the intended delay time. However, meander wiring for meandering the signal wiring is used for efficient wiring. The meander wiring is used, for example, in a memory bus wiring of a mother board of a personal computer.

  In recent years, electronic devices have been reduced in size, and components such as printed wiring boards or integrated circuits have also been reduced in size. Therefore, in order to ensure the intended delay time for the signal line in a limited signal wiring region, the need to use meander wiring is increasing. On the other hand, the meander wiring is likely to cause a problem in a high-speed circuit depending on the wiring method because the delay time differs even if the total sum of the signal wiring lengths constituting the meander wiring is constant.

  Patent Document 1 proposes a wiring structure for securing an intended delay time by making the directions of folding parts of meander wirings adjacent to each other orthogonal.

  FIG. 14 shows a wiring structure of signal wiring provided with general meander wiring. The signal wiring 1102 is composed of meandering signal wiring, and includes a meander wiring having a plurality of folding parts 1104 parallel to each other and a folded part 1106 connecting the two adjacent folding parts 1104 described above. Here, the number of folding parts is called the meander number. For example, in FIG. 14, the meander number N = 8.

FIG. 15 is a dimensional diagram of a signal wiring structure in which a general meander wiring is formed. When the signal wiring width is W, the signal wiring interval is S, the signal wiring length of the folding portion is L _m , the signal wiring length by the signal wiring connected to both ends of the meander wiring is L ₁ , L ₂ , and the meander number is N, sum L _S of the signal wiring lengths of the plurality of the folded portion is determined by equation 1.

Therefore, the total signal wiring length L _total of the signal wiring composed of the meander wiring and the signal wiring connected to both ends of the meander wiring is obtained by Expression 2.

In addition, the distance L _total between the input and output of the signal wiring composed of the meander wiring and the signal wiring connected to both ends of the meander wiring is obtained by Equation 3.

JP-A-2005-32737

  There are two possible wiring structures for securing the intended delay time for signals in a limited signal wiring area using meander wiring. The first wiring structure is a wiring structure in which the meander number is increased. The second wiring structure is a wiring structure in which the signal wiring length of the folding portion is increased.

15, the total signal wiring length L _total = 100 mm of the signal wiring composed of the meander wiring and the signal wiring connected to both ends of the meander wiring, and the signal composed of the meander wiring and the signal wiring connected to both ends of the meander wiring. The distance between the input and output points of the wiring is set as L _total = 50 mm. The signal wiring composed of the meander wiring and the signal wiring connected to both ends of the meander wiring described above is formed on a printed wiring board having a microstrip structure, and has a wiring width W = 0.3 mm and a dielectric thickness H = 0.15 mm. , Relative dielectric constant ε _r = 4.6, characteristic impedance Z ₀ ≈50Ω.

In the above case, when the meander number N = 10 as shown in FIG. 16, the signal wiring length L _m of the folding portion 1304 is 5 mm. As shown in FIG. 17, when the meander number N = 4, the signal wiring length L _m of the folding portion 1404 is 12.5 mm. In the above case, the signal wiring length L by the signal wiring connected to both ends of the meander wiring when the signal wiring spacing S is changed to 0.15, 0.3, 0.6, 0.9, 1.2 mm. ₁ and L ₂ are shown in Table 1, and frequency characteristics of delay time are shown in FIGS. 18 and 19, respectively.

Here, the first wiring structure, which is a wiring structure in which the meander number is increased, will be described. FIG. 16 is a wiring structure diagram of the signal wiring 1302 having a meander number N = 10, and the signal wiring length L _m of each of the plurality of folding portions 1304 is shorter than the total signal wiring length L _S of the plurality of folding portions 1306. It has become. The signal wiring 1302 is compared to the signal line 1402, although the total signal line length _{L total} are equal, six large meander number N. Thus, the signal line 1302 and a signal line length _{L m} of the folds as compared to the signal line 1402 is shorter. Therefore, the signal wiring 1302 is suitable for high-density signal wiring because the influence on the wiring flexibility of the adjacent signal wiring is smaller than that of the signal wiring 1402. On the other hand, in FIG. 18, the delay time is relatively reduced in each signal wiring interval S as compared with FIG. This is due to the following causes. The current flowing through the signal wiring 1302 is shortcut in the folded portion 1306 so as to flow as short as possible. The length of the path where the current is shortcut is shorter than the length of the center line of the signal wiring 1302. For this reason, in FIG. 18, the delay time is relatively reduced in each signal wiring interval S compared to FIG. 19. That is, even if the total signal wiring length L _total is the same, the larger the meander number N, the larger the number of folded portions and the more current shortcuts, the shorter the delay time.

Next, a wiring structure in which the signal wiring length of the folding portion is increased as a second wiring structure. FIG. 17 is a wiring structure diagram of the signal wiring 1402 having a meander number N = 4. Each signal wiring length L _{m of} the plurality of folding sections 1404 is longer than the total signal wiring length L _S of the plurality of folding sections 1406. It has become. The signal wiring 1402 is compared to the signal line 1302, although the total signal line length _{L total} is equal, the meandering number N 6 small. Thus, the signal line 1402 and a signal line length _{L m} of the folds as compared to the signal line 1302 is longer. In addition, the number of folded portions of the signal wiring 1402 is smaller than that of the signal wiring 1302. Therefore, a current shortcut can be suppressed by the signal wiring 1302, which is suitable for securing an intended delay time. This is clear when FIG. 19 is compared with FIG. On the other hand, the frequency characteristics of the delay time are relatively deteriorated in each signal wiring interval S. This is because the signal wiring length L _m of the folded portion is long, because the influence of coupling between the parallel wiring of folds increases.

That is, in the wiring structure in which the meander number N of the meander wirings is increased as the first wiring structure, the delay time is longer than that of the straight signal wiring having the same total signal wiring length _Ltotal due to an increase in the current shortcut. There was a problem of becoming smaller. Also, a second wiring structure, the wiring structure with long signal wire length L _m of the folded portion, by the influence of coupling between the parallel wiring of folds increases, the total signal wire length L _{total is} the same There is a problem that the frequency characteristics of the delay time are deteriorated as compared with the straight signal wiring. There also, in the second wiring structure, when the signal line length L _m of the folded portion increases, the influence of the degree of freedom of wiring adjacent signal lines increases, another problem that is not suitable for high density signal wiring It was.

  INDUSTRIAL APPLICABILITY The present invention can suppress the delay time from decreasing and the frequency characteristics of the delay time from deteriorating, and can provide a wiring structure and a print that can ensure the intended delay time for a signal in a limited signal wiring region. An object is to provide a wiring board, an integrated circuit, and an electronic device.

  In order to solve the above-described problems, the present invention provides the following.

  The printed wiring board of the present invention includes meander wiring composed of meandering signal wiring, and the meander wiring includes a plurality of folding portions that are parallel to each other and a folding portion that connects the plurality of adjacent folding portions. A printed wiring board in which a plurality of wiring layers and insulating layers are alternately stacked, and the 2nth (n is a natural number) folding portion of the plurality of folding portions of the meander wiring is a first Formed in the wiring layer, the 2n + 1-th folding portion is formed in the third wiring layer, and a constant potential layer is formed in the second wiring layer between the first wiring layer and the third wiring layer It is characterized by being.

  According to the present invention, the 2n-th folding portion is formed in the first wiring layer, the constant potential layer is formed in the second wiring layer, and the 2n + 1-th folding portion is formed in the third wiring layer. For this reason, it is possible to suppress inter-wiring coupling between the folding portions adjacent to each other with the second wiring layer formed with the constant potential layer interposed therebetween. Therefore, it is possible to suppress the deterioration of the frequency characteristics of the delay time and secure the intended delay time.

  Here, shield wirings are respectively formed between the plurality of folding portions formed in the first wiring layer and between the plurality of folding portions formed in the second wiring layer. Is preferred.

  According to the present invention, since the shield wiring is formed between the plurality of folding portions formed in the same wiring layer, it is possible to suppress inter-wiring coupling between the folding portions adjacent to each other across the shield wiring. . Therefore, it is possible to further suppress the deterioration of the frequency characteristic of the delay time and secure the intended delay time.

  In addition, by providing the above-described printed wiring board or integrated circuit, an electronic device corresponding to further miniaturization can be provided.

  According to the present invention, it is possible to suppress the coupling between the parallel wirings of the meander wiring folding part. Therefore, it is possible to suppress the deterioration of the frequency characteristics of the delay time and secure the intended delay time.

<First Embodiment>
First, the delay characteristic of the meander wiring formed with the shield wiring according to the first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram of a signal wiring 102 having the wiring structure of the first embodiment. The signal wiring 102 is formed on a printed wiring board, and a meander wiring 103 having a plurality of folding portions 104 parallel to each other and a folding portion 106 connecting a plurality of adjacent folding portions 104 is formed. The signal wiring length L _m of the plurality of folding portions 104 is longer than the total signal length L _S of the plurality of folding portions 106. Further, the plurality of folding portions 104 are in parallel with the signal wiring 108 connected to both ends of the meander wiring 103. Further, a shield wiring 112 is formed between the plurality of folding portions 104.

For example, for the meander wiring of FIG. 1, the total signal wiring length L _{total of the} signal wiring 102 composed of the meander wiring 103 and the signal wiring 108 connected to both ends of the meander wiring 103 is connected to both ends of the meander wiring 103 and the meander wiring 103. The distance between the input and output of the signal wiring 102 consisting of the signal wiring 108 to be _{processed is} L _total = 50 mm. The signal wiring 102 having the above-described meander wiring 103 is formed on a printed wiring board having a microstrip structure, and has a wiring width W = 0.3 mm, a dielectric thickness H = 0.15 mm, and a relative dielectric constant ε _r = 4. 6. Characteristic impedance Z ₀ ≈50Ω. A fixed potential such as a ground potential or a power supply potential is supplied to the above-described shield wiring 112 through vias (VIA) formed at a predetermined interval such as 1 mm.

FIG. 2 shows the frequency characteristics of the delay time of the signal wiring 102 in which the meander wiring with the signal wiring spacing S = 0.9 mm is formed in the above case. In addition, as a comparative example, FIG. 2 also shows the frequency characteristics of the delay time of the straight signal wiring 162 having the total signal wiring length L _total = 100 mm and the signal wiring 172 in which the shield wiring 112 of the signal wiring 102 is not formed.

  As shown in FIG. 2, although the delay time of the signal wiring 102 is smaller than that of the signal wiring 172, the deterioration of the frequency characteristics is suppressed. Further, the delay time is not reduced as much as the signal wiring with the signal wiring interval S = 0.9 mm in FIG.

The reduction of the delay time is suppressed, the respective signal line length L _m of the plurality of folds 104 is longer than the sum L _s of the signal wiring lengths of the plurality of the folded portion 106, namely a small number of the folded portion 106, This is because current shortcuts can be suppressed. Therefore, it is possible to suppress a decrease in delay time while keeping the total signal wiring length L _total constant. Conventionally, a decrease in delay time cannot be suppressed, and in order to secure an insufficient delay time, a further meander wiring 103 has to be formed, which has an influence on the wiring flexibility of the adjacent signal wiring. It was getting bigger. As a result, the printed wiring board has become larger, leading to an increase in manufacturing cost. According to the wiring structure of this embodiment, it is possible to secure a delay time intended for a signal in a limited signal wiring region.

  In the present embodiment, since the plurality of folding portions 104 are in parallel with the signal wiring 108 connected to both ends of the meander wiring 103, the influence on the wiring freedom of the adjacent signal wiring is reduced, and the printed wiring board The manufacturing cost can be reduced.

  Furthermore, since the shield wiring 112 is formed between the plurality of folding portions 104, the coupling between the parallel wirings by the plurality of folding portions 104 can be suppressed, and deterioration of the frequency characteristics of the delay time can be suppressed. That is, the variation in delay time due to frequency can be reduced. In particular, since a rectangular wave signal for transmitting digital information has various frequency components, the deterioration of frequency characteristics causes distortion of the signal waveform. Since the signal wiring 102 has the shield wiring 112 formed between the plurality of folding portions, it is possible to suppress the deterioration of the frequency characteristics. Therefore, accurate and high-speed information transmission can be performed.

<Second Embodiment>
FIG. 3 is a cross-sectional view of a printed wiring board 300 according to the second embodiment. In the printed wiring board 300, wiring layers and insulating layers 308 are alternately laminated. The wiring layer includes a signal wiring layer 302 and constant potential layers 304 and 306 which are wiring layers facing each other up and down across the signal wiring layer 302. A power supply potential is supplied to the constant potential layer 304, and a ground potential is supplied to the constant potential layer 306. In the signal wiring layer 302, meander wiring is formed, and folding portions 312 and 314 of the meander wiring are provided. A shield wiring 342 is formed between the folding portions 312 and 314 of the meander wiring described above. The above-described shield wiring 342 is supplied with a ground potential through vias (VIA) formed at a predetermined interval of, for example, 1 mm, and is coupled to the ground potential constant potential layer 306 and vias (VIA) 324. The power supply potential constant layer 304 is coupled through a via (VIA) 322 through a capacitor 332. Note that a fixed potential such as a ground potential or a power supply potential may be supplied to the constant potential layers 304 and 306 and the shield wiring 342. In particular, the fixed potential layers 304 and 306 may be supplied with a fixed potential having the same potential such as a ground potential or a power supply potential. Further, when the potential of the shield wiring 342 and the potential of the constant potential layers 304 and 306 are different, a capacitor 332 is required for coupling. Note that the above-described coupling includes AC coupling via a capacitor.

  In the present embodiment, constant potential layers 304 and 306 are provided as wiring layers that face up and down across the signal wiring layer 302 in which the meander wiring is formed. For this reason, the coupling between the parallel wirings can be suppressed with respect to the signal wirings of the wiring layers different from the signal wiring layer 302 and the outside of the printed wiring board 300. Further, the shield wiring 342 can suppress the coupling between the parallel wirings of the folding portions 312 and 314 of the meander wiring, which occurs through the insulating layer 308. Further, vias (VIA) 322 and 324 arranged at predetermined intervals can suppress the coupling between the parallel wirings of the folding portions 312 and 314 of the meander wiring, which occurs through the insulating layer 308. In the printed wiring board 300 according to the present embodiment, deterioration of the frequency characteristics can be largely suppressed by largely suppressing the coupling between the parallel wirings of the meander wiring folding portions 312 and 314 using the insulating layer 308 as a dielectric. Therefore, the intended delay time can be secured for the signal, and signal transmission can be performed accurately.

<Third Embodiment>
FIG. 4 is a plan view of a signal wiring 102A according to the third embodiment.
The signal wiring 102A is formed on a printed wiring board in which a plurality of wiring layers and insulating layers are alternately stacked, and the first folding portion 104A, the second folding portion 104B, and the third folding portion 104C that are parallel to each other The first folding part 106A connecting the first folding part 104A and the second folding part 104B, and the second folding part 106B connecting the second folding part 104B and the third folding part 104C, A meander wiring 103A is formed. The first folding portion 104A, the second folding section 104B, respectively the signal line length _{L m} of the third folding portion 104C has a first folded portion 106A and the second sum signal wiring lengths of the folded portion 106B _{L s} Longer. The first folding part 104A, the second folding part 104B, and the third folding part 104C are parallel to the signal wiring 108A connected to both ends of the meander wiring 103A.

The signal wiring 102A is a signal connected to both ends of the meander wiring 103A and the meander wiring 103A. The total signal wiring length L _{total of the} signal wiring 102A including the meander wiring 103A and the signal wiring 108A connected to both ends of the meander wiring 103A is 100 mm. The distance L _mtotal = 50 mm between the input and output of the signal wiring 102A composed of the wiring 108A. The signal wiring 102A has a wiring width W = 0.3 mm, a dielectric thickness H = 0.15 mm, a relative dielectric constant εr = 4.6, and a characteristic impedance Z0≈50Ω.
The signal wiring 102A has a signal wiring interval S = 0.15 mm.

FIG. 5 is a cross-sectional view taken along line AA of the signal wiring 102A. The signal wiring 102A includes a first wiring layer 501, an insulating layer 502, a second wiring layer 503, an insulating layer 504, a third wiring layer 505, an insulating layer 506, a fourth wiring layer 507, an insulating layer 508, The printed wiring board is formed by stacking five wiring layers 509 in this order.
In the first wiring layer 501, the first folding portion 104A is formed. A constant potential such as a ground potential or a power supply potential is supplied to the second wiring layer 503 and the fourth wiring layer 507 over the entire surface. In the third wiring layer 505, the second folding portion 104B is formed. In the fifth wiring layer 509, a third folding portion 104C is formed.
The first folding part 104A and the second folding part 104B, and the second folding part 104B and the third folding part 104C are formed between the first wiring layer 501 and the third wiring layer 505, respectively. Are electrically connected through vias (VIA) 120.

  In the present embodiment, the first folding part 104A is formed in the first wiring layer 501, the second folding part 104B is formed in the third wiring layer 505, and the third folding part 104C is connected to the fifth wiring. Layer 509 was formed. In addition, a constant potential is supplied across the entire surface between the first wiring layer 501 and the third wiring layer 505 and between the third wiring layer 505 and the fifth wiring layer 509. The wiring layer 503 and the fourth wiring layer 507 were formed. For this reason, the coupling | bonding between the parallel wiring of 104 A of 1st folding parts and the 2nd folding part 104B, and the 2nd folding part 104B and the 3rd folding part 104C can be suppressed, respectively. Therefore, it is possible to suppress the deterioration of the frequency characteristics of the delay time and secure the intended delay time.

<Fourth embodiment>
FIG. 6 is a plan view of a signal wiring 102B according to the fourth embodiment.
The signal wiring 102B is different from the signal wiring 102A in that it is formed on a printed wiring board in which a plurality of wiring layers and insulating layers are alternately stacked.

FIG. 7 is a BB cross-sectional view of the signal wiring 102B. The signal wiring 102B is formed on a printed wiring board in which a first wiring layer 501, an insulating layer 502, a second wiring layer 503, an insulating layer 504, and a third wiring layer 505 are stacked in this order.
In the first wiring layer 501, a first folding part 104A and a third folding part 104C are formed. A constant potential such as a ground potential or a power supply potential is supplied to the second wiring layer 503 over the entire surface. In the third wiring layer 505, the second folding portion 104B is formed.

FIG. 8 shows the frequency characteristics of the delay time of the signal wiring 102B. In addition, as a comparative example, the frequency of delay time between the signal wiring 102C having the signal wiring interval S = 0.15 mm of the signal wiring 102 and the signal wiring 102D in which the shield wiring 112 of the signal wiring 102C is not formed. The characteristics are also shown in FIG.
As shown in FIG. 8, the frequency characteristics of the delay time of the signal wiring 102B are greatly improved as compared with the signal wirings 102C and 102D.

In the present embodiment, the first folding portion 104A and the third folding portion 104C are formed in the first wiring layer 501, the second folding portion 104B is formed in the third wiring layer 505, and the first wiring A second wiring layer 503 in which a constant potential is supplied over the entire surface is formed between the layer 501 and the third wiring layer 505. For this reason, the coupling | bonding between the parallel wiring of the 2nd folding part 104B and the 1st folding part 104A and the 3rd folding part 104C can be suppressed. Therefore, it is possible to suppress the deterioration of the frequency characteristics of the delay time and secure the intended delay time.
The signal wiring 102A requires five wiring layers, while the signal wiring 102B requires three wiring layers. That is, the signal wiring 102B can be formed with fewer wiring layers than the signal wiring 102A.

<Fifth Embodiment>
FIG. 9 is a plan view of a signal wiring 102E according to the fifth embodiment.
The signal wiring 102E is different from the signal wiring 102B in that a shield wiring 112A is formed.

  FIG. 10 is a cross-sectional view taken along the line CC of the signal wiring 102E. The signal wiring 102E is the first wiring layer 501, and the shield wiring 112A is formed between the first folding part 104A and the third folding part 104C.

FIG. 11 shows the frequency characteristics of the delay time of the signal wiring 102E. In addition, as a comparative example, the frequency characteristics of the delay times of the signal wirings 102B, 102C, and 102D are also shown in FIG.
As shown in FIG. 11, the signal wiring 102E has the best delay time frequency characteristics compared to the signal wirings 102B, 102C, and 102D.

  In the present embodiment, the first folding portion 104A and the third folding portion 104C are formed in the first wiring layer 501, the second folding portion 104B is formed in the third wiring layer 505, and the first wiring A second wiring layer 503 in which a constant potential is supplied over the entire surface is formed between the layer 501 and the third wiring layer 505. In addition, the shield wiring 112A is formed in the first wiring layer 501 and between the first folding portion 104A and the third folding portion 104C. For this reason, it is possible to suppress the coupling between the parallel wirings of the second folding part 104B, the first folding part 104A and the third folding part 104C, and the first folding part 104A and the third folding part. Coupling between the parallel wirings of the portion 104C can be suppressed. Therefore, it is possible to further suppress the deterioration of the frequency characteristic of the delay time and to secure the intended delay time.

<Sixth Embodiment>
FIG. 12 is a cross-sectional view of a printed wiring board 300A according to the sixth embodiment.
The printed wiring board 300A is different from the printed wiring board 300 in that signal wiring is formed.

  The wiring layer of the printed wiring board 300 </ b> A includes signal wiring layers 302 and 303 and constant potential layers 304, 306, and 308 that are wiring layers facing each other up and down across the signal wiring layers 302 and 303. In the signal wiring layer 302, a first folding part 312 and a third folding part 316 of meander wiring are formed. In the signal wiring layer 303, a second folding portion 314 of meander wiring is formed. A shield wiring 342 is formed in the signal wiring layer 302 and between the first folding portion 312 and the third folding portion 316 of the above-described meander wiring.

In the present embodiment, the first folding portion 312 and the third folding portion 316 and the second folding portion 314 are formed in different signal wiring layers. For this reason, compared with the case of the printed wiring board 300 which formed the several folding part in the same signal wiring layer, the coupling | bonding between the wiring of the folding parts of meander wiring can further be suppressed. Therefore, it is possible to further suppress the deterioration of the frequency characteristic of the delay time and to secure the intended delay time.
When the printed wiring board 300A is manufactured by adjusting the distance between the first folding portion 312 and the shield wiring 342, the second folding portion 314, and the constant potential layer 308, the intended delay time is further increased. Can be secured.

<Modifications and improvements>
The present invention is not limited to a printed wiring board, and may be formed in an integrated circuit. The via (VIA) connected to the above-described shield wiring may be capable of transmitting a signal such as a through hole. Further, the shield wiring described above is not limited to the wiring, but may be any shape that can exhibit a shielding effect such as a pattern. Furthermore, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention. For example, the present invention may be a combination of the features of the above-described embodiments. In the above-described embodiment, the signal wiring including the meander wiring in which the angle between the folding portion and the folding portion is 90 degrees has been described. However, the present invention is not limited to this. For example, the angle between the folding part and the folded part may be 45 degrees, or the folded part may be arcuate as shown in FIG. In the above-described embodiment, the meander number N = 3. However, the present invention is not limited to this. For example, the meander number N = 5 may be used.

<Electronic equipment>
An electronic device to which the printed wiring board or the integrated circuit according to the above-described embodiment, modification, and improvement is applied will be described. Electronic devices to which the above-described printed wiring board or integrated circuit is applied include personal computers, mobile phones, digital still cameras, televisions, car navigation devices, pagers, electronic notebooks, calculators, word processors, workstations, and the like. And the printed wiring board or integrated circuit mentioned above is applicable as an electronic component of these various electronic devices.

It is a top view of the signal wiring concerning a 1st embodiment. It is a frequency characteristic of the delay time of the signal wiring which concerns on the said embodiment. It is sectional drawing of the printed wiring board 300 which concerns on 2nd Embodiment. It is a top view of the signal wiring concerning a 3rd embodiment. It is AA sectional drawing of the signal wiring which concerns on the said embodiment. It is a top view of the signal wiring concerning a 4th embodiment. It is BB sectional drawing of the signal wiring which concerns on the said embodiment. It is a frequency characteristic of the delay time of the signal wiring which concerns on the said embodiment. It is a top view of the signal wiring concerning a 5th embodiment. It is CC sectional drawing of the signal wiring concerning the said embodiment. It is a frequency characteristic of the delay time of the signal wiring which concerns on the said embodiment. It is sectional drawing of the printed wiring board which concerns on 6th Embodiment. It is a top view of the signal wiring in which the return part of the meander wiring is circular. It is a top view of the signal wiring provided with the general meander wiring. It is a dimension drawing of signal wiring provided with general meander wiring. It is a top view of the signal wiring of meander number N = 10. It is a frequency characteristic of the delay time of the signal wiring of meander number N = 4. It is the frequency characteristic of the delay time of the signal wiring of the meander number N = 10. It is a frequency characteristic of the delay time of the signal wiring of meander number N = 4.

Explanation of symbols

  1, 102, 102A, 102B, 102C, 102D, 102E, 402 ... signal wiring, 103, 103A ... meander wiring, 104, 104A, 104B, 104C, 312, 314, 316, 404 ... folding unit, 106, 106A, 106B , 406... Folded portion, 112, 112A, 342, 412... Shield wiring, 302... Signal wiring layer, 304, 306, 308 .. constant potential layer, 308. insulating layer, 120, 322, 324.

Claims (3)

With meander wiring consisting of meandering signal wiring,
The meander wiring has a plurality of folding parts parallel to each other, and a folded part that connects the plurality of adjacent folding parts,
A printed wiring board obtained by alternately laminating a plurality of wiring layers and insulating layers,
Of the plurality of folding parts of the meander wiring, the 2nth (n is a natural number) folding part is formed in the first wiring layer, and the 2n + 1th folding part is formed in the third wiring layer, A printed wiring board, wherein a constant potential layer is formed in a second wiring layer between the first wiring layer and the third wiring layer. In the printed wiring board of Claim 1,
Shield wiring is formed between the plurality of folding portions formed in the first wiring layer and between the plurality of folding portions formed in the second wiring layer, respectively. Printed wiring board.   The electronic device provided with the printed wiring board of Claim 1 or 2.

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