CN212677438U - Stretchable substrate - Google Patents

Abstract

The utility model provides a flexible base plate. A stretchable substrate (101) is provided with: a base material (1) having stretchability; and a conductor pattern (6) formed on the base material (1), the base material (1) having a specific layer. The specific layer includes: a 1 st region (31) which is a hard region extending in a state of the highest Young's modulus in a specific layer; a 2 nd region (32) extending in a state where the Young's modulus is lowest in the specific layer; and a 3 rd region (33) which is located between the 1 st region (31) and the 2 nd region (32) within the specific layer, and has a Young's modulus lower than that of the 1 st region (31) and higher than that of the 2 nd region (32). The conductor pattern (6) includes a portion arranged so as to extend over both the 1 st region (31) and the 2 nd region (32) via the 3 rd region (33). The conductor pattern includes a land electrode (7a) disposed on the base material, and the land electrode is disposed in the 1 st region and is disposed so as to avoid the 2 nd region.

Description

Stretchable substrate

Technical Field

The utility model relates to a flexible base plate.

Background

There are cases where components such as ICs are mounted on a stretchable substrate using a stretchable insulating base material. When a region of the stretchable substrate where the component is mounted (hereinafter referred to as a "mounting region") is stretched, a fracture may occur between the component and the stretchable substrate. Therefore, in order to prevent expansion and contraction in the mounting region, it is conceivable to bond a non-stretchable insulating substrate in advance in the mounting region, thereby setting the non-stretchable region in this portion. The other portion is a continuous stretchable region (hereinafter referred to as a "stretchable region"). An example of such a structure is described in japanese patent application laid-open No. 2016-.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-178121

SUMMERY OF THE UTILITY MODEL

Problem to be solved by utility model

However, even if a non-stretchable region is formed as a mounting region by bonding non-stretchable insulating substrates, stress tends to be concentrated at the boundary between the non-stretchable region and the stretchable region. Therefore, the planar conductor pattern, the conductor via, and the like are easily broken at the boundary. Further, since a non-stretchable insulating substrate is bonded to an original stretchable substrate, the thickness of the substrate increases in the mounting region, which hinders the overall reduction in thickness.

Therefore, an object of the present invention is to provide a stretchable substrate in which stress concentration at a specific portion can be suppressed as much as possible and cracking due to stretching can be prevented from occurring.

Means for solving the problems

In order to achieve the above object, according to the present invention according to the 1 st aspect of the present invention, there is provided a stretchable substrate comprising:

a base material having stretchability; and

a conductor pattern formed on the base material,

the substrate has a specific layer comprising: a 1 st region which is a hard region extending in a state of highest Young's modulus in the specific layer; a 2 nd region extending in a state where the Young's modulus is lowest within the specific layer; and a 3 rd region located between the 1 st region and the 2 nd region within the specific layer and having a Young's modulus lower than the 1 st region and higher than the 2 nd region,

the conductor pattern includes a portion configured to cross both the 1 st region and the 2 nd region via the 3 rd region,

the conductor pattern includes land electrodes disposed on the substrate,

the land electrode is placed on the 1 st region and is arranged so as to avoid the 2 nd region.

According to the utility model discloses an aspect 2 provides an elasticity base plate, its characterized in that possesses:

a base material having stretchability; and

a conductor pattern formed on the base material,

the substrate has a specific layer comprising: a 1 st region which is a hard region extending in a state of highest Young's modulus in the specific layer; a 2 nd region extending in a state where the Young's modulus is lowest within the specific layer; and a 3 rd region located between the 1 st region and the 2 nd region within the specific layer and having a Young's modulus lower than the 1 st region and higher than the 2 nd region,

the conductor pattern includes a portion configured to cross both the 1 st region and the 2 nd region via the 3 rd region,

the conductor pattern includes a stretchable conductor portion and a non-stretchable conductor portion, and the non-stretchable conductor portion is disposed only in the 1 st region.

According to the utility model discloses an aspect 3 provides an elasticity base plate, its characterized in that possesses:

a base material having stretchability; and

a conductor pattern formed on the base material,

the substrate has a specific layer comprising: a 1 st region which is a hard region extending in a state of highest Young's modulus in the specific layer; a 2 nd region extending in a state where the Young's modulus is lowest within the specific layer; and a 3 rd region located between the 1 st region and the 2 nd region within the specific layer and having a Young's modulus lower than the 1 st region and higher than the 2 nd region,

the conductor pattern includes a portion configured to cross both the 1 st region and the 2 nd region via the 3 rd region,

the substrate comprises a plurality of layers that are stacked,

the conductor pattern includes a plurality of conductor pattern elements arranged at a plurality of heights by being arranged on a surface of any one of the plurality of layers,

the stretchable substrate includes a plurality of interlayer connection conductors connecting the conductor pattern elements arranged at different heights to each other, the plurality of interlayer connection conductors including stretchable vias and non-stretchable vias, and the non-stretchable vias being arranged in the 1 st region.

According to the utility model discloses an aspect 4 provides an elasticity base plate, its characterized in that possesses:

a base material having stretchability; and

a conductor pattern formed on the base material,

the substrate has a specific layer comprising: a 1 st region which is a hard region extending in a state of highest Young's modulus in the specific layer; a 2 nd region extending in a state where the Young's modulus is lowest within the specific layer; and a 3 rd region located between the 1 st region and the 2 nd region within the specific layer and having a Young's modulus lower than the 1 st region and higher than the 2 nd region,

the conductor pattern includes a portion configured to cross both the 1 st region and the 2 nd region via the 3 rd region,

the base material has silicone resin as a main material.

Effect of the utility model

According to the utility model discloses, can alleviate the difference according to the young's modulus at position to can restrain the stress concentration at specific position as far as possible. Since the specific layer of the base material includes the 1 st region as the hard region, it is possible to make it less likely to cause fracture due to expansion and contraction.

Drawings

Fig. 1 is a cross-sectional view of a stretchable substrate according to embodiment 1 of the present invention.

Fig. 2 is a plan view of the stretchable substrate according to embodiment 1 of the present invention.

Fig. 3 is a plan view of a modification of the stretchable substrate according to embodiment 1 of the present invention.

Fig. 4 is a flowchart of a method for manufacturing a stretchable substrate according to embodiment 2 of the present invention.

Fig. 5 is an explanatory view of the first step of the method for manufacturing a stretchable substrate according to embodiments 2 and 3 of the present invention.

Fig. 6 is an explanatory view of the 2 nd step of the method for manufacturing a stretchable substrate according to embodiment 2 of the present invention.

Fig. 7 is an explanatory view of the 3 rd step of the method for manufacturing a stretchable substrate according to embodiment 2 of the present invention.

Fig. 8 is an explanatory view of the 4 th step of the method for manufacturing a stretchable substrate according to embodiment 2 of the present invention.

Fig. 9 is an explanatory view of the 5 th step of the method for manufacturing a stretchable substrate according to embodiment 2 of the present invention.

Fig. 10 is an explanatory view of the 6 th step of the method for manufacturing a stretchable substrate according to embodiment 2 of the present invention.

Fig. 11 is an explanatory view of the 2 nd step of the method for manufacturing a stretchable substrate according to embodiment 3 of the present invention.

Fig. 12 is an explanatory view of the 3 rd step of the method for manufacturing a stretchable substrate according to embodiment 3 of the present invention.

Fig. 13 is an explanatory view of the 4 th step of the method for manufacturing a stretchable substrate according to embodiment 3 of the present invention.

Fig. 14 is an explanatory view of the 5 th step of the method for manufacturing a stretchable substrate according to embodiment 3 of the present invention.

Fig. 15 is an explanatory view of the 6 th step of the method for manufacturing a stretchable substrate according to embodiment 3 of the present invention.

Fig. 16 is an explanatory view of the 7 th step of the method for manufacturing a stretchable substrate according to embodiment 3 of the present invention.

Fig. 17 is an explanatory view of the 8 th step of the method for manufacturing a stretchable substrate according to embodiment 3 of the present invention.

Fig. 18 is a cross-sectional view of the stretchable substrate according to embodiment 4 of the present invention.

Fig. 19 is a cross-sectional view of the stretchable substrate according to embodiment 5 of the present invention.

Fig. 20 is a flowchart of a method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 21 is a flowchart of a modification of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 22 is an explanatory view of the 1 st step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 23 is an explanatory view of the 2 nd step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 24 is an explanatory view of the 3 rd step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 25 is an explanatory view of the 4 th step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 26 is an explanatory view of the 5 th step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 27 is an explanatory view of the 6 th step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 28 is an explanatory view of the 7 th step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 29 is an explanatory view of the 8 th step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 30 is an explanatory view of the 9 th step of the method for manufacturing a stretchable substrate according to embodiment 6 of the present invention.

Fig. 31 is a 1 st explanatory diagram of a method of forming gradation of young's modulus in an insulating material layer.

Fig. 32 is a 2 nd explanatory diagram of a method of forming gradation of young's modulus in an insulating material layer.

Fig. 33 is a 3 rd explanatory diagram of a method of forming gradation of young's modulus in an insulating material layer.

Detailed Description

The size ratio shown in the drawings is not necessarily faithfully expressed in reality, and may be exaggerated for convenience of explanation. In the following description, when a concept of "up" or "down" is referred to, absolute "up" or "down" is not necessarily meant, and relative "up" or "down" in the illustrated posture may be meant.

(embodiment mode 1)

A stretchable substrate according to embodiment 1 of the present invention will be described with reference to fig. 1 to 2. Fig. 1 shows a cross-sectional view of a stretchable substrate 101 in the present embodiment. Fig. 2 shows a top view of the stretchable substrate 101.

The stretchable substrate 101 has a stretchable base material 1 and a planar conductor pattern 6 formed on the base material 1. The substrate 1 is made of, for example, silicone resin. However, the substrate 1 is not particularly limited to silicone resin as long as it has elasticity and insulation properties. Substrate 1 has a major surface 1 u. Conductor pattern 6 is disposed on main surface 1 u. The substrate 1 has a specific layer. In the present embodiment, the substrate 1 is not a multilayer structure but a single-layer structure, and therefore the single resin layer directly corresponds to a specific layer. The specific layer includes: a 1 st region 31, which is a hard region extending in a state of the highest young's modulus in a specific layer; a 2 nd region 32 extending in a state where the Young's modulus is lowest in the specific layer; and a 3 rd region 33 which is located between the 1 st region 31 and the 2 nd region 32 within the specific layer and has a lower Young's modulus than the 1 st region 31 and a higher Young's modulus than the 2 nd region 32. Region 3 is a quasi-hard region. In the example shown in fig. 1, the 3 rd region 33 further includes both the 1 st 3 rd region 33a and the 2 nd 3 rd region 33 b. In fig. 1, the base material 1 is indicated by letters Ea, Eb, Ec, and Ed, and the young's moduli in the respective regions are Ea, Eb, Ec, and Ed. Here, the relationship Ea > Eb > Ec > Ed holds. In fig. 1, for convenience of explanation, the base material 1 is divided into the 1 st region 31, the 3 rd region 33, and the 2 nd region 32, and boundary lines are shown, but in reality, the boundary lines do not necessarily clearly exist as described above. The young's modulus does not necessarily change sharply with a certain line as a boundary, but may change gradually from the 1 st region 31 to the 2 nd region 32 so that the value of the young's modulus changes gradually. The young's modulus may change stepwise from the 1 st region 31 to the 2 nd region 32. The 1 st region 31 may be a region hardened by some treatment. The 1 st region 31 may be a region that is locally hardened by electron beam irradiation or the like, for example. The 1 st region 31 is a region where there is little expansion and contraction or a region where there is a large difference in expansion and contraction compared to the 2 nd region 32.

In the present embodiment, the conductor pattern 6 includes a portion arranged to extend over both the 1 st region 31 and the 2 nd region 32 via the 3 rd region 33. A part of the conductor pattern 6 becomes land electrodes 7a, 7 b. The conductor pattern 6 preferably includes both a linear portion and a widened portion. The linear portion may include a zigzag portion as illustrated in fig. 2. The widened portion may have a substantially rectangular shape as illustrated in fig. 2. The stretchable substrate 101 may or may not include the member 3. The component 3 may be an electronic component. The component 3 may be, for example, an IC chip for RFID. In this case, the stretchable substrate 101 is used as an RFID tag. The member 3 has electrodes 3a and 3b on its surface. The component 3 is mounted on the land electrodes 7a, 7b via the bonding member 4. That is, the electrode 3a is bonded to the land electrode 7a via the bonding member 4, and the electrode 3b is bonded to the land electrode 7b via the bonding member 4. Fig. 1 shows a state after the component 3 is mounted. Fig. 2 shows a state before the component 3 is mounted, and the outer shape of the component 3 is indicated by a two-dot chain line. The land electrodes 7a and 7b are arranged to overlap the 1 st region 31. The component 3 is mounted across the land electrodes 7a, 7 b.

In the present embodiment, since the specific layer of the substrate 1 includes the 3 rd region 33 between the 1 st region 31 and the 2 nd region 32 in addition to the 1 st region 31 and the 2 nd region 32, the difference in young's modulus depending on the portion can be alleviated, and the stress concentration at the specific portion can be suppressed as much as possible.

In the present embodiment, since the conductor pattern 6 includes a portion arranged to extend over both the 1 st region 31 and the 2 nd region 32 via the 3 rd region 33, the 1 st region 31 can be selected as the mounting site.

In the present embodiment, the conductor pattern 6 includes land electrodes 7a, 7b for mounting the component 3, and the land electrodes 7a, 7b overlap with the 1 st region 31, where the 1 st region 31 is a region that hardly expands or contracts or a region that has a large difference in elasticity compared with the 2 nd region 32, and therefore, it becomes difficult for a fracture to occur between the conductor pattern 6 and the electrodes 3a, 3b on the component 3 side (that is, the component 3 physically falls off or the electrical joining state of the component 3 becomes insufficient).

As described above, in the present embodiment, a stretchable substrate can be formed in which stress concentration at a specific portion can be suppressed as much as possible and breakage due to stretching can be made less likely to occur.

Preferably, as shown in the present embodiment, the conductor pattern 6 includes land electrodes 7a and 7b disposed on the substrate 1, and the land electrodes 7a and 7b are placed on the 1 st region 31 and are disposed so as to avoid the 2 nd region 32. With this configuration, the land electrodes 7a and 7b for component mounting are placed on the 1 st region 31 that is not easily expanded and contracted, while avoiding the 2 nd region 32 that is easily expanded and contracted, and therefore, breakage after mounting can be more effectively avoided.

Preferably, as shown in the present embodiment, the component 3 is provided to be attached to the land electrodes 7a and 7 b. With this configuration, a stretchable substrate having a certain function by the member 3 can be realized. The stretchable substrate 101 may not have a member as described above. That is, the present invention can also be used for a stretchable substrate in which a region having partially low stretchability is provided. For example, when a circuit element such as an inductor or a capacitor is formed on a stretchable substrate using a conductor pattern, it is desirable to have a region with low stretchability so that the inductance value of the inductor or the capacitor value of the capacitor does not change.

Preferably, the land electrodes 7a, 7b comprise metal foil. With this configuration, the land electrode having excellent conductivity can be easily formed. Preferably, the metal foil is a copper foil. When the metal foil is a copper foil, the bondability to the solder can be improved. In many cases, the metal foil is hard as compared with the conductor pattern in which the conductor paste is cured. By using a metal foil for forming the land electrodes 7a and 7b, the stretchability of the stretchable substrate 101 in the portion where the land electrodes 7a and 7b are formed can be reduced. Therefore, breakage of the component 3 after mounting can be suppressed.

Although the present embodiment has been described with reference to the stretchable substrate 101 having the structure shown in fig. 2 in a plan view, this is merely an example. For example, the stretchable substrate 101i may have a structure as shown in fig. 3.

When the width of expansion and contraction of the stretchable substrate is large or when the number of times of expansion and contraction of the stretchable substrate is large, it is preferable to use a stretchable conductive material for the conductive pattern 6. The portion formed using the stretchable conductive material can be used as a stretchable conductor portion. The stretchable conductive material may be, for example, a stretchable conductive material in which Ag and a silicone resin are mixed uniformly. The conductor pattern 6 is not necessarily formed of a single material, and may be a combination of portions formed of two or more materials. The portion formed using the non-stretchable conductive material becomes a non-stretchable conductor portion. The non-stretchable conductive material may be, for example, a copper foil. Preferably, the conductor pattern 6 includes a stretchable conductor portion and a non-stretchable conductor portion, and the non-stretchable conductor portion is disposed only in the 1 st region 31. With this configuration, the non-stretchable conductor portion is disposed only in the 1 st region 31, and therefore, when the stretchable substrate is stretched, the possibility that the desired portion will have insufficient stretchability or the non-stretchable conductor portion will break can be reduced.

(embodiment mode 2)

A method for manufacturing a stretchable substrate according to embodiment 2 of the present invention will be described with reference to fig. 4 to 10. Fig. 4 is a flowchart of a method for manufacturing a stretchable substrate according to the present embodiment.

The method for manufacturing a stretchable substrate according to the present embodiment includes: step 1 of preparing a structure including a portion where a conductive layer and a 1 st insulating material layer overlap; and a step S2 of partially hardening the 1 st insulating material layer in the structure. In step S2 of partially hardening the 1 st insulating material layer, a 1 st region, a 2 nd region, and a 3 rd region are formed in the 1 st insulating material layer, the 1 st region extending in the 1 st insulating material layer in a state of highest young ' S modulus, the 2 nd region extending in the 1 st insulating material layer in a state of lowest young ' S modulus, and the 3 rd region being located between the 1 st region and the 2 nd region in the 1 st insulating material layer and having a young ' S modulus lower than that of the 1 st region and higher than that of the 2 nd region. The respective steps included in the production method will be described in detail below.

First, as shown in fig. 5, a copper foil 41 is prepared. The copper foil 41 may be a copper foil having a reference hole 41 e. An insulating paste to be an insulating layer 43 having stretchability is applied to one surface of the copper foil 41. The insulating paste contains, for example, silicone resin. The application of the insulating paste may be performed by printing. Thus, as shown in fig. 6, the insulating paste layer 42 is formed. The insulating paste layer 42 is dried at 170 c for 20 minutes. Thereafter, the mixture was heated at 200 ℃ for 120 minutes. Thus, as shown in fig. 7, the insulating paste layer 42 becomes an insulating layer 43 having elasticity. The copper foil 41 is patterned to form a copper foil pattern 44. This corresponds to step S1.

As step S2, as shown in fig. 8, a predetermined region of the insulating layer 43 is irradiated with the electron beam 5. This partially hardens the insulating layer 43 as the 1 st insulating material layer in the structure, i.e., increases the young's modulus, and becomes as shown in fig. 9. That is, the hard region 43a is formed in the region irradiated with the electron beam 5. Quasi-hard regions 43b are also formed on both sides of the hard region 43a due to the irradiation of the electron beam 5. The hard region 43a and the region outside the quasi-hard region 43b remain as a non-hard region 43 c. The quasi-hard region 43b referred to herein is a region having a value of young's modulus between the hard region 43a and the non-hard region 43 c.

As shown in fig. 10, the substrate is turned upside down and the component 3 is mounted so as to straddle two copper foil patterns 44. This makes it possible to obtain a product similar to the stretchable substrate 101 described in embodiment 1. The component 3 may be, for example, an IC chip for RFID. Further, the member 3 may not be mounted on the insulating layer 43.

In the present embodiment, since the step S2 includes the step S2 of partially hardening the 1 st insulating material layer and the 1 st, 2 nd, and 3 rd regions are formed in this step S2, it is possible to obtain a stretchable substrate in which stress concentration at a specific portion can be suppressed as much as possible and a fracture due to stretching is less likely to occur.

Although the present embodiment shows an example in which the electron beam is irradiated in step S2, the method of hardening in step S2 is not limited thereto. The hard region 43a and the quasi-hard region 43b may be formed by a method other than electron beam irradiation.

Preferably, the step S2 of partially hardening the base material as the 1 st insulating material layer includes at least one step selected from the group consisting of: irradiating the 1 st insulating material layer with an electron beam; irradiating the 1 st insulating material layer with UV light; a step of locally applying heat to the 1 st insulating material layer; and a step of locally applying water to the 1 st insulating material layer. By satisfying this condition, a desired region of the 1 st insulating material layer can be partially hardened. In this embodiment, an embodiment in which a step of irradiating an electron beam is adopted is described as an example.

(embodiment mode 3)

A method for manufacturing a stretchable substrate according to embodiment 3 of the present invention will be described with reference to fig. 4, 5, and 11 to 17. In the method for manufacturing a stretchable substrate according to the present embodiment, the basic flowchart is also the same as the flowchart shown in fig. 4. The respective steps included in the production method will be described in detail below.

First, the copper foil 41 shown in fig. 5 is prepared. A conductive paste is applied to one surface of the copper foil 41. The application of the conductive paste may be performed by printing. The conductive paste used here may be one having stretchability after curing, or one having no stretchability after curing. In the non-hard region, a conductive paste having stretchability after curing is preferably used so that stretchability is not hindered. In the case where the conductive paste is printed, it is dried at 170 ℃ for 20 minutes, for example. As shown in fig. 11, a conductor pattern 46 is formed. An insulating paste which is to be a stretchable insulating film 43 is further applied to the surface on which the conductor pattern 46 is formed. The application of the insulating paste may be performed by printing. Thus, as shown in fig. 12, the insulating paste layer 42 is formed. The insulating paste layer 42 is dried, for example, at 170 ℃ for 20 minutes. Thereafter, heating is carried out, for example, at 200 ℃ for 120 minutes. Thus, as shown in fig. 13, the insulating paste layer 42 becomes an insulating layer 43 having elasticity.

The copper foil 41 is removed by full-face etching. As a result, as shown in fig. 14, a structure in which the conductor pattern 46 is embedded in the insulating layer 43 can be obtained. This corresponds to step S1.

As step S2, as shown in fig. 15, a predetermined region of the insulating layer 43 is irradiated with the electron beam 5. This partially hardens the insulating layer 43, which is the 1 st insulating material layer, in the structure, as shown in fig. 16. That is, the hard region 43a is formed in the region irradiated with the electron beam 5. Quasi-hard regions 43b are also formed on both sides of the hard region 43a due to the irradiation of the electron beam 5.

When it is considered that the stretchable substrate is completed and the component 3 is further required to be mounted, the component 3 is mounted so as to straddle the two conductor patterns 46 as shown in fig. 17. This makes it possible to obtain a product similar to the stretchable substrate 101 described in embodiment 1. The component 3 may be, for example, an IC chip for RFID. Further, the member 3 may not be mounted on the insulating layer 43.

The stretchable substrate obtained in the present embodiment includes a conductor pattern 46 derived from a conductive paste instead of a copper foil. As shown in fig. 17, the surface of the conductor pattern 46 on the member 3 side and the surface of the insulating layer 43 on the member 3 side are flush with each other.

Although the copper foil is completely removed in the middle of the manufacturing process in the present embodiment, a stretchable substrate in which stress concentration at a specific portion can be suppressed as much as possible and a fracture due to stretching is less likely to occur can be obtained even by such a manufacturing process.

(embodiment mode 4)

A stretchable substrate according to embodiment 4 of the present invention will be described with reference to fig. 18. Fig. 18 shows a cross-sectional view of the stretchable substrate 102 in this embodiment.

The stretchable substrate 102 has a stretchable base material 1 and a conductive pattern 6 formed on the base material 1. Substrate 1 has a major surface 1 u. The substrate 1 is a substrate in which a plurality of resin layers are laminated. In the example shown in fig. 18, the substrate 1 includes a resin layer 21 and a resin layer 22. The substrate 1 has a specific layer as one of the plurality of resin layers. In fig. 18, either one of the resin layers 21, 22 may be regarded as a specific layer. The specific layer includes: a 1 st region 31, which is a hard region extending in a state of the highest young's modulus in a specific layer; a 2 nd region 32 extending in a state where the Young's modulus is lowest in the specific layer; and a 3 rd region 33 which is located between the 1 st region 31 and the 2 nd region 32 within the specific layer and has a lower Young's modulus than the 1 st region 31 and a higher Young's modulus than the 2 nd region 32. The conductor pattern 6 includes a portion arranged to cross both the 1 st region 31 and the 2 nd region 32 via the 3 rd region 33. Each of the 1 st region 31, the 2 nd region 32, and the like includes the resin layer 21 in addition to the resin layer 22 across the entire thickness direction.

The substrate 1 comprises a plurality of layers stacked. The conductor pattern 6 includes a plurality of conductor pattern elements 61 and 62 arranged at a plurality of heights by being arranged on the surface of any of the plurality of layers. The conductor pattern element 61 is electrically connected to the conductor pattern element 62. In the example shown in fig. 18, the conductor pattern element 61 is disposed on the main surface 1 u. The conductor pattern element 62 is disposed inside the base material 1. At least a part of the conductive pattern element 61 in the conductive pattern 6 overlaps the 1 st region 31, and at least a part of the conductive pattern element 62 overlaps the 2 nd region 32.

The stretchable substrate 102 includes a plurality of interlayer connection conductors connecting conductor pattern elements arranged at different heights to each other. The plurality of interlayer connection conductors include stretchable via holes and non-stretchable via holes. The plurality of interlayer connection conductors include an interlayer connection conductor 71 as a non-stretchable via. The interlayer connection conductor 71 can be formed by, for example, solidifying a conductive paste containing an alloy of Cu and Sn. The plurality of interlayer connection conductors include an interlayer connection conductor 72 as a stretchable via. The interlayer connection conductor 72 may be formed of, for example, a paste obtained by curing a paste obtained by mixing Ag and silicone resin. The stretchable via may be formed of the same material as at least one of the conductor pattern element 62 and the outer conductor 63. The non-stretchable via hole is disposed in the 1 st region 31. The conductive pattern element 61 may be a conductive pattern element formed of a metal foil such as a copper foil, or may be a conductive pattern element obtained by curing a conductive paste.

In the present embodiment, it is also possible to suppress stress concentration at a specific portion as much as possible, and to make it difficult for fracture due to expansion and contraction to occur. In the present embodiment, since the base material 1 includes a plurality of layers stacked, and the conductor pattern 6 includes a plurality of conductor pattern elements arranged at a plurality of heights, and a plurality of interlayer connection conductors connecting these elements are provided, the conductor pattern 6 can be arranged in a three-dimensional manner, and the degree of freedom in layout of the conductor pattern 6 is increased.

(embodiment 5)

A stretchable substrate according to embodiment 5 of the present invention will be described with reference to fig. 19. Fig. 19 shows a cross-sectional view of the stretchable substrate 103 in this embodiment. The basic configuration of the stretchable substrate 103 is the same as that of the stretchable substrate 102 shown in embodiment 4, but in the stretchable substrate 103, the conductor pattern elements 61 are converged in the 1 st region 31.

In the present embodiment, the conductor pattern 6 includes an elastic conductor portion and a non-elastic conductor portion, and the non-elastic conductor portion is disposed only in the 1 st region 31.

In this embodiment, the effects described in embodiment 4 can also be obtained. Further, in the present embodiment, the non-stretchable conductor portion is disposed only in the 1 st region 31, and therefore, breakage can be avoided more reliably.

(embodiment mode 6)

A method for manufacturing a stretchable substrate according to embodiment 6 of the present invention will be described with reference to fig. 20 to 21. Fig. 20 is a flowchart showing a method for manufacturing a stretchable substrate according to the present embodiment. Fig. 21 shows a modification of the method for manufacturing a stretchable substrate in the present embodiment. Fig. 21 will be described later.

The method for manufacturing a stretchable substrate in the present embodiment is basically the same as the method for manufacturing a stretchable substrate described in embodiment 2, and includes steps S1 and S2. However, as a difference from the method for manufacturing a stretchable substrate described in embodiment 2, as shown in fig. 20, step S3 is included.

That is, the method for manufacturing a stretchable substrate according to the present embodiment includes a step S3 of forming a 2 nd insulating material layer so as to overlap with the 1 st insulating material layer after the step S2 of partially hardening the 1 st insulating material layer.

Hereinafter, each step included in the method for manufacturing a stretchable substrate in the present embodiment will be described in detail.

First, as shown in fig. 22, a copper foil 51 is prepared. The copper foil 51 may be a copper foil having a reference hole 51 e. An insulating paste is applied to one surface of the copper foil 51. The application of the insulating paste may be performed by printing. The insulating paste layer is dried, for example, at 170 ℃ for 10 minutes. Thus, as shown in fig. 23, an insulating material layer 521 is formed. As shown in fig. 24, a through hole 52a is formed. The formation of the through hole 52a in the insulating material layer 521 can be performed by a known technique such as laser processing.

Before or after the formation of the through hole 52a shown in fig. 24, as step S2, an electron beam is irradiated to a desired region of the insulating material layer 521. Thus, a desired region of the insulating material layer 521 becomes a hard region.

As shown in fig. 25, a conductive paste 57 is disposed. The conductive paste 57 is arranged to fill the through-hole 52a and to form a desired pattern on the surface of the insulating material layer 521. The conductive paste 57 may be disposed by printing. The conductive paste 57 is dried at, for example, 170 ℃ for 10 minutes.

In step S3, an insulating paste is applied. The application of the insulating paste may be performed by printing. The insulating paste layer is dried, for example, at 170 ℃ for 10 minutes. Thus, as shown in fig. 26, an insulating material layer 522 is formed. The insulating material layer 522 covers the pattern formed by the conductive paste 57. Although the hard region is not shown in fig. 25 and 26, it is actually preferable that a part of the insulating material layer 521 is formed as the hard region.

A modified example of the method for manufacturing the stretchable substrate in the present embodiment will be described with reference to fig. 21. In this modification, as shown in the flowchart of fig. 21, the method includes a step S4 of partially hardening the 2 nd insulating material layer after the step S3 of forming the 2 nd insulating material layer. In this case, as step S4, the electron beam is irradiated to a desired region of the insulating material layer 522. Thus, a desired region of the insulating material layer 522 becomes a hard region. Thus, the structure shown in fig. 27 is obtained.

The stack of insulating material layers 521, 522 has modified regions 431, 432. The modified regions 431 and 432 are regions in which hard regions and quasi-hard regions are combined. The modified regions 431 and 432 are not uniform and include hard regions and quasi-hard regions, but the details of the modified regions 431 and 432 are not shown in detail.

For example, at the stage shown in fig. 26, a method may be considered in which the structure having the modified regions 431 and 432 as shown in fig. 27 is obtained at one time by irradiating the structure in the state shown in fig. 26 with an electron beam without forming any modified region. However, if it is considered that there is a possibility that the portion to be the shadow of the conductor pattern is not sufficiently modified when the electron beam is irradiated, it is preferable to perform the electron beam irradiation every time one insulating material layer is formed, and form the next insulating material layer after the modified region is formed.

As shown in fig. 28, the mounting film 19 is adhered. Here, the heat treatment is carried out, for example, at 200 ℃ for two hours. Thus, the mounting film 19 is fixed. As shown in fig. 29, the copper foil 51 is patterned to form a copper foil pattern 54. Thus, the stretchable substrate is completed. However, in the case where the component 3 is required to be mounted on the stretchable substrate in this state, the component 3 is mounted after the stretchable substrate is turned upside down as shown in fig. 30 from the state shown in fig. 29. The component 3 is mounted via the joint member 4. The electrodes of the component 3 and the copper foil pattern 54 are electrically connected via the joining member 4. The entire member including the member 3 may be referred to as a stretchable substrate.

Preferably, the step S4 of partially hardening the 2 nd insulating material layer includes at least one step selected from the group consisting of: irradiating the 2 nd insulating material layer with an electron beam; irradiating the 2 nd insulating material layer with UV light; a step of locally applying heat to the 2 nd insulating material layer; and a step of locally applying water to the 2 nd insulating material layer. By satisfying this condition, a desired region of the 2 nd insulating material layer can be partially hardened. In this embodiment, an embodiment in which a step of irradiating an electron beam is adopted is described as an example.

(attachment method of gradation)

The description has been made in embodiment 2 and the like with respect to providing the quasi-hard region between the region in which the insulating material layer having stretchability maintains stretchability as it is and the hard region, and it is preferable that the region having stretchability, the quasi-hard region, and the hard region are formed so that young's modulus gradually increases in this order. Preferably, the young's modulus composition changes gradually. In other words, the young's modulus preferably forms a gradient. The quasi-hard region corresponds to the halfway portion of the gradient. When an electron beam is used for forming the hard region, a gradient of the young's modulus can be formed by scattering of the electron beam 5 as shown in fig. 31. In fig. 31, the object 10 may be irradiated with an electron beam or UV light from the light source 12. In the mask 11, an opening is provided in a region substantially corresponding to the hard region. The irradiation of the object 10 is performed through the opening of the mask 11.

In the case of irradiation with UV light instead of irradiation with electron rays, it is preferable to include a photocrosslinking agent in advance in the insulating material layer. By irradiating UV light, a gradient of young's modulus can be formed in the base material by scattering of the UV light itself. As shown in fig. 32, the photocrosslinking agent is diffused in the insulating material layer in advance, and then UV light is irradiated, whereby a gradient of young's modulus can be formed in the insulating material layer.

There are also cases where the young's modulus of the insulating material layer can be increased by applying water to the insulating material layer. In this case, water droplets are disposed in a desired region of the insulating material layer. In this case, the young's modulus of a partial region of the insulating material layer is increased by the reaction with water, and a gradient of the young's modulus can be formed in the insulating material layer.

In some cases, the young's modulus of the insulating material layer can be increased by applying heat to the base material. Thermal diffusion may be used, as may scattering. In fig. 33, the object 10 is irradiated with UV light or the like through the opening of the mask 11 in a state where the photocrosslinkers are arranged so as to be distributed more toward the center.

These are summarized and shown in table 1. Here, methods 1 to 6 are exemplified.

[ Table 1]

The elastic region, the quasi-hard region, and the hard region may be arranged in parallel in this order, and the young's modulus may be gradually increased in this order.

In addition, the base material 1 preferably contains a silicone resin as a main material. With this configuration, a substrate having stretchability can be easily realized.

Preferably, the stretchable conductor portion contains Ag and silicone resin. With this configuration, a conductor part having stretchability can be realized.

Preferably, the stretchable via comprises Ag and silicone. By adopting this structure, both conductivity and stretchability can be provided.

In addition, a plurality of the above embodiments may be combined as appropriate.

The above embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is defined by the appended claims, and includes all changes that come within the meaning and range of equivalency of the claims.

Description of the reference numerals

1: base material, 1 u: main surface, 3: component, 3a, 3 b: electrode (of the component), 4: joining member, 5: electron beam, 6: conductor pattern, 10: object, 11: mask, 12: light source, 13: photocrosslinker, 19: mounting films, 21, 22: resin layer, 31: region 1, 32: region 2, 33: region 3, 33 a: 1 st region 3, 33 b: 2 nd region 3, 41, 51: copper foil, 41e, 51 e: reference hole, 42: insulating paste layer, 43: insulating layer, 43 a: hard region, 43 b: quasi-hard region, 43 c: non-hard region, 44, 54: copper foil pattern, 46: conductor pattern, 52 a: through hole, 57: conductive paste, 61, 62: conductor pattern element, 71, 72: interlayer connection conductor, 101i, 102, 103: stretchable substrate, 430, 431, 432: modified region, 521, 522: a layer of insulating material.

Claims (22)

1. A stretchable substrate is characterized by comprising:

a base material having stretchability; and

a conductor pattern formed on the base material,

the substrate has a specific layer comprising: a 1 st region which is a hard region extending in a state of highest Young's modulus in the specific layer; a 2 nd region extending in a state where the Young's modulus is lowest within the specific layer; and a 3 rd region located between the 1 st region and the 2 nd region within the specific layer and having a Young's modulus lower than the 1 st region and higher than the 2 nd region,

the conductor pattern includes a portion configured to cross both the 1 st region and the 2 nd region via the 3 rd region,

the conductor pattern includes land electrodes disposed on the substrate,

the land electrode is placed on the 1 st region and is arranged so as to avoid the 2 nd region.

2. The stretchable substrate of claim 1,

the device is provided with a component mounted on the land electrode.

3. The stretchable substrate of claim 1,

the land electrode includes a metal foil.

4. The stretchable substrate of claim 2,

the land electrode includes a metal foil.

5. The stretchable substrate according to any one of claims 1 to 4,

the conductor pattern includes a stretchable conductor portion and a non-stretchable conductor portion, and the non-stretchable conductor portion is disposed only in the 1 st region.

6. The stretchable substrate according to any one of claims 1 to 4,

the substrate comprises a plurality of layers that are stacked,

the conductor pattern includes a plurality of conductor pattern elements arranged at a plurality of heights by being arranged on a surface of any one of the plurality of layers,

the stretchable substrate includes a plurality of interlayer connection conductors connecting the conductor pattern elements arranged at different heights to each other, the plurality of interlayer connection conductors including stretchable vias and non-stretchable vias, and the non-stretchable vias being arranged in the 1 st region.

7. The stretchable substrate of claim 5,

the substrate comprises a plurality of layers that are stacked,

the conductor pattern includes a plurality of conductor pattern elements arranged at a plurality of heights by being arranged on a surface of any one of the plurality of layers,

the stretchable substrate includes a plurality of interlayer connection conductors connecting the conductor pattern elements arranged at different heights to each other, the plurality of interlayer connection conductors including stretchable vias and non-stretchable vias, and the non-stretchable vias being arranged in the 1 st region.

8. The stretchable substrate according to any one of claims 1 to 4,

the base material has silicone resin as a main material.

9. The stretchable substrate of claim 5,

the base material has silicone resin as a main material.

10. The stretchable substrate of claim 6,

the base material has silicone resin as a main material.

11. The stretchable substrate of claim 7,

the base material has silicone resin as a main material.

12. The stretchable substrate of claim 5,

the stretchable conductor portion includes Ag and a silicone resin.

13. The stretchable substrate of claim 6,

the stretchable via includes Ag and silicone.

14. The stretchable substrate of claim 7,

the stretchable via includes Ag and silicone.

15. A stretchable substrate is characterized by comprising:

a base material having stretchability; and

a conductor pattern formed on the base material,

the substrate has a specific layer comprising: a 1 st region which is a hard region extending in a state of highest Young's modulus in the specific layer; a 2 nd region extending in a state where the Young's modulus is lowest within the specific layer; and a 3 rd region located between the 1 st region and the 2 nd region within the specific layer and having a Young's modulus lower than the 1 st region and higher than the 2 nd region,

the conductor pattern includes a portion configured to cross both the 1 st region and the 2 nd region via the 3 rd region,

the conductor pattern includes a stretchable conductor portion and a non-stretchable conductor portion, and the non-stretchable conductor portion is disposed only in the 1 st region.

16. The stretchable substrate of claim 15,

the substrate comprises a plurality of layers that are stacked,

the conductor pattern includes a plurality of conductor pattern elements arranged at a plurality of heights by being arranged on a surface of any one of the plurality of layers,

the stretchable substrate includes a plurality of interlayer connection conductors connecting the conductor pattern elements arranged at different heights to each other, the plurality of interlayer connection conductors including stretchable vias and non-stretchable vias, and the non-stretchable vias being arranged in the 1 st region.

17. The stretchable substrate of claim 15 or 16,

the base material has silicone resin as a main material.

18. The stretchable substrate of claim 15,

the stretchable conductor portion includes Ag and a silicone resin.

19. The stretchable substrate of claim 16,

the stretchable via includes Ag and silicone.

20. A stretchable substrate is characterized by comprising:

a base material having stretchability; and

a conductor pattern formed on the base material,

the substrate has a specific layer comprising: a 1 st region which is a hard region extending in a state of highest Young's modulus in the specific layer; a 2 nd region extending in a state where the Young's modulus is lowest within the specific layer; and a 3 rd region located between the 1 st region and the 2 nd region within the specific layer and having a Young's modulus lower than the 1 st region and higher than the 2 nd region,

the conductor pattern includes a portion configured to cross both the 1 st region and the 2 nd region via the 3 rd region,

the substrate comprises a plurality of layers that are stacked,

the conductor pattern includes a plurality of conductor pattern elements arranged at a plurality of heights by being arranged on a surface of any one of the plurality of layers,

the stretchable substrate includes a plurality of interlayer connection conductors connecting the conductor pattern elements arranged at different heights to each other, the plurality of interlayer connection conductors including stretchable vias and non-stretchable vias, and the non-stretchable vias being arranged in the 1 st region.

21. The stretchable substrate of claim 20,

the base material has silicone resin as a main material.

22. The stretchable substrate of claim 20,

the stretchable via includes Ag and silicone.

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