TWI668606B - Pressure sensing printed circuit board, method for manufacturing same and flexible pressure sensing member - Google Patents

Abstract

The invention relates to a pressure-sensitive circuit board, which includes a flexible insulating substrate, a first conductive circuit layer, a sensitive layer, and a first covering layer formed on one surface of the flexible insulating substrate. The first conductive circuit layer includes Metal electrodes disposed at intervals and conductive lines electrically connected to the metal electrodes, the sensitive layer covers the metal electrodes, the first cover layer covers the sensitive layers and covers the conductive lines, and the sensitive The main raw material components of the layer are an elastic resin and conductive particles doped in the elastic resin.

Description

Pressure-sensitive circuit board, manufacturing method of pressure-sensitive circuit board, and flexible pressure-sensitive element

The invention relates to the technical field of pressure sensors, in particular to a pressure-sensitive circuit board, a method for manufacturing the pressure-sensitive circuit board, and a flexible pressure-sensitive element.

At present, the mainstream pressure sensors are mainly metal, metal alloy and semiconductor. Due to the limitation of the elastic modulus of metals, metal alloys, and semiconductor materials, metal or semiconductor resistance strain sensors have the following disadvantages: poor flexibility, small changes in mechanical quantities, poor sensitivity, complex structure, and high manufacturing costs.

In view of this, it is necessary to provide a pressure-sensitive circuit board capable of solving the above technical problems, a method for manufacturing the pressure-sensitive circuit board, and a flexible pressure-sensitive element.

A pressure-sensitive circuit board includes a flexible insulating substrate, a first conductive line layer, a sensitive layer, and a first cover layer formed on one surface of the flexible insulating substrate. The first conductive line layer includes spaced-apart layers. A metal electrode and a conductive wire electrically connected to the metal electrode, the sensitive layer includes conductive particles, the sensitive layer covers the metal electrode, the first covering layer covers the sensitive layer and covers the conductive layer Wire, the main raw material component of the flexible insulating substrate is an elastic resin and the elongation rate of the elastic resin is from 5% to 50%.

In a preferred embodiment, the material of the flexible insulating substrate is polydimethylsiloxane or thermoplastic polyurethane, and the conductive wire has a curved shape.

In a preferred embodiment, the pressure-sensitive circuit board further includes a second conductive circuit layer located on the other surface of the flexible insulating substrate, a conductive hole penetrating through the flexible insulating substrate, and a second covering layer. The two conductive circuit layers are electrically connected to the first conductive circuit layer through the conductive holes, and the second covering layer covers the second conductive circuit layer.

In a preferred embodiment, the main raw material component of the sensitive layer is an elastic resin and the conductive particles doped in the elastic resin; the conductive particles are conductive ink, graphite, pure silver conductive powder, and pure nickel. One or a mixture of any two or more of conductive powder, nickel-coated graphite conductive powder, silver-coated aluminum conductive powder, silver-coated copper conductive powder, silver-coated nickel conductive powder, and silver-coated glass conductive powder.

In a preferred embodiment, the sensitive layer is formed by doping the conductive particles with the resin, an active agent, an anti-scorch agent, an accelerator, and a crosslinking agent; wherein the resin includes 100 parts of ethylene propylene diene Rubber, 5-20 parts of ethylidene norbornene, 5-20 parts of dicyclopentadiene; parts by weight of the active agent 1 to 4 parts; 0.1 to 1 part by weight of the anti-scorch agent; 0.5 to 3 parts by weight of the cross-linking agent; 5 to 20 parts by weight of the accelerator; The weight of the particles is 150 to 300 parts.

A method for manufacturing a pressure-sensitive circuit board includes the following steps: forming a flexible circuit substrate, the flexible circuit substrate including a flexible insulating substrate and a first conductive circuit layer formed on one surface of the flexible insulating substrate; The main raw material component of the insulating substrate is an elastic resin and the elongation rate of the elastic resin is 5% to 50%; the first conductive circuit layer includes a plurality of metal electrodes spaced apart and a conductive material electrically connected to the plurality of metal electrodes. A wire; forming a sensitive layer on the surface of the flexible insulating substrate and around the sides of each of the electrodes, the sensitive layer including conductive particles, the sensitive layer covering the metal electrode; A first covering layer is formed on the surface and the surrounding side of the sensitive layer, and the first covering layer covers the sensitive layer and covers the conductive lines to obtain the pressure-sensitive circuit board.

In a preferred embodiment, the first conductive circuit layer and the second conductive circuit layer may be formed by depositing a conductive metal layer on a surface of the flexible insulating substrate or formed by etching.

In a preferred embodiment, the material of the flexible insulating substrate is polydimethylsiloxane or thermoplastic polyurethane; and the conductive wire has a curved shape.

In a preferred embodiment, the flexible circuit substrate is a double-sided flexible circuit substrate, and the flexible circuit substrate further includes a second conductive circuit layer on the other surface of the flexible insulating substrate and a conductive layer penetrating the flexible insulating substrate. Holes, the second conductive circuit layer and the first conductive circuit layer are electrically connected through the conductive holes.

In a preferred embodiment, the main raw material component of the sensitive layer is an elastic resin and the conductive particles doped in the elastic resin; the materials of the conductive particles are graphite, pure silver conductive powder, and pure nickel conductive One or a mixture of any two or more of powder, nickel-clad graphite conductive powder, silver-clad aluminum conductive powder, silver-clad copper conductive powder, silver-clad nickel conductive powder, and silver-clad glass conductive powder.

In a preferred embodiment, the sensitive layer is formed by doping the conductive particles with the elastic resin, an active agent, an anti-scorching agent, an accelerator, and a cross-linking agent; wherein the resin includes 100 parts of triethylene glycol. Acrylic rubber, 5-20 parts of ethylidene norbornene, 5-20 parts of dicyclopentadiene; 1 to 4 parts by weight of the active agent; 0.1 to 1 part by weight of the anti-scorch agent The weight part of the crosslinking agent is 0.5 to 3 parts; the weight part of the accelerator is 5 to 20 parts; the weight part of the conductive particles is 150 to 300 parts.

A flexible pressure-sensing element includes a flexible insulating substrate, and two sensitive portions formed at intervals on the surface of the flexible insulating substrate. A space between the sensitive portions is defined as a pressure-sensitive area, and each of the sensitive portions The portion includes a metal electrode disposed on the surface of the flexible insulating substrate, a sensitive layer covering the metal electrode, and a first covering layer covering the sensitive layer. The sensitive layer includes conductive particles. They are electrically connected through conductive wire phases. The main raw material component of the flexible insulating substrate is an elastic resin, and the stretch rate of the elastic resin is 5% to 50%.

In a preferred embodiment, the material of the flexible insulating substrate is polydimethylsiloxane or thermoplastic polyurethane; the main raw material components of the sensitive layer are an elastic resin and the conductive material doped in the elastic resin. Particles.

Compared with the prior art, the method for manufacturing a pressure-sensitive circuit board provided by the present invention produces a pressure-sensitive circuit board formed by using one surface of the pressure-sensitive circuit board as a pressure-sensitive surface on two of the metals. When pressure is applied between the electrodes or when one end of the pressure-sensitive circuit board is fixed, the flexible insulation substrate is stretched, so that the sensitive layer is stretched with the stretching. Deformation, after the sensitive layer is stretched, the spacing between the conductive particles covered by the sensitive layer will correspondingly increase, that is, the arrangement between the conductive particles becomes thin, so that the conductive capacity of the conductive particles will weaken, meaning The resistance value of the sensitive portion formed by the conductive particles and the metal electrode increases correspondingly. In this way, by measuring the change in the resistance of the sensitive part, the magnitude of the pressure applied by the outside can be obtained. The pressure is removed, and the sensitive layer will return to the original state. Therefore, the pressure sensor formed by the pressure-sensitive circuit board provided by the present invention has a simple structure and high sensitivity.

100, 200, 300, 400 ‧‧‧ pressure sensitive circuit boards

10‧‧‧ flexible circuit board

110‧‧‧flexible insulation substrate

140, 140a‧‧‧first conductive circuit layer

141, 1410‧‧‧ metal electrode

145‧‧‧electrode pair

142, 1420‧‧‧ Conductive wire

150‧‧‧ sensitive layer

152‧‧‧Conductive particles

101‧‧‧fix

103‧‧‧Pressure Sensing Area

160, 180‧‧‧ Overlay

172‧‧‧Conductive hole

111‧‧‧ surface

120‧‧‧ patterned photoresist layer

131‧‧‧Growth layer

105‧‧‧Sensitive Department

132‧‧‧ conductive metal layer

170‧‧‧Second conductive circuit layer

FIG. 1 is a cross-sectional view of a flexible insulating substrate provided by the present invention.

FIG. 2 is a cross-sectional view of a patterned photoresist layer formed on the basis of FIG. 1.

3 is a cross-sectional view of a growth layer formed on the surface of a flexible insulating substrate and a patterned photoresist layer.

4 is a cross-sectional view of forming a conductive metal layer on a surface of a growth layer to obtain a first conductive circuit layer.

FIG. 5 is a plan view of a first conductive circuit layer.

FIG. 6 is a sectional view with the patterned photoresist layer removed.

7 is a cross-sectional view of forming a sensitive layer on a surface of a metal electrode included in a first conductive circuit layer.

8 is a cross-sectional view of forming a first cover layer on a surface of a conductive circuit included in a sensitive layer and a first conductive circuit layer to obtain the pressure-sensitive circuit board.

FIG. 9 is a cross-sectional view of a pressure-sensitive circuit board according to a third embodiment.

FIG. 10 is a cross-sectional view of a pressure-sensitive circuit board according to a fourth embodiment.

FIG. 11 is a sectional view of a pressure-sensitive circuit board according to a fifth embodiment.

FIG. 12 is a top view of a pressure-sensitive circuit board according to a fifth embodiment.

First embodiment

The first step S1 is described with reference to FIGS. 1 to 6 to form a flexible circuit board 10. The flexible circuit substrate 10 includes a flexible insulating substrate 110 and a first conductive circuit layer 140 formed on one surface of the flexible insulating substrate 110. Referring to FIGS. 5 and 6, the first conductive circuit layer 140 includes metal electrodes 141 disposed at intervals and conductive circuits 142 formed between the metal electrodes 141.

In this embodiment, the conductive wire 142 has a curved shape, for example, it can be a curved S shape, in order to avoid the situation that the finally formed pressure-sensitive circuit board 100 breaks when the circuit is stretched or subjected to external pressure.

The first conductive circuit layer 140 may be formed by etching (subtraction method) or formed by deposition. The first conductive circuit layer 140 formed by the deposition can meet the requirements of the accuracy of the conductive circuits. In this embodiment, a method for forming the flexible circuit substrate 10 is specifically described in a deposition manner, and specifically includes the following steps:

S11: As shown in FIG. 1, a flexible insulating substrate 110 is provided.

The main raw material component of the flexible insulating substrate 110 is an elastic resin, and the stretch ratio of the elastic resin is 5% to 50%. In this embodiment, a material of the flexible insulating substrate 110 may be polydimethylsiloxane (PDMS) or thermoplastic polyurethane (Thermoplastic Polyurethane). When the elongation of the elastic resin is in the range of 5% to 50%, it can meet the bending and stretching requirements of the finally formed pressure sensitive circuit board 100, and it can also meet the measurement sensitivity requirements of the pressure sensitive circuit board 100.

S12: As shown in FIG. 2, a patterned photoresist layer 120 is formed on at least one surface of the flexible insulating substrate 110.

In this embodiment, a patterned photoresist layer 120 is formed only on one surface 111 of the flexible insulating substrate 110. The method for forming the patterned photoresist layer 120 includes: first, forming a photoresist layer on one surface of the flexible insulating substrate 110, and then exposing and developing the photoresist layer to obtain a desired patterned Photoresist layer 120. Of course, if a double-sided circuit board is required, a photoresist layer may be formed on two opposite surfaces of the flexible insulating substrate 110, and a patterned photoresist layer may be formed on the two opposite surfaces of the insulating substrate 110 after exposure and development. 120.

The photoresist layer may be a dry film photoresist, and is bonded to the surface of the flexible insulating substrate 110 by a lamination method. The photoresist layer may also be a thin film formed by curing a liquid photoresist. The liquid photoresist may be formed on the surface of the flexible insulating substrate 110 by coating or printing. The coating method includes spray coating, spin coating, and the like. The material of the photoresist layer is usually an organic resin. For example, in this embodiment, a dry film-like acrylic resin is laminated on one surface of the flexible insulating substrate 110 by a compression method.

S13: As shown in FIGS. 3 and 4, a conductive metal is deposited on the surface of the flexible insulating substrate 110 to form a first conductive circuit layer 140. Please refer to FIG. 6 together. In this embodiment, the first conductive circuit layer 140 formed includes two metal electrodes 141 spaced apart and a conductive line 142 electrically connecting the two metal electrodes 141. The distance between the two metal electrodes is 8mm-70mm. The conductive wire 142 is a curved S-shape and both ends of the conductive wire 142 are connected to the long side direction or non-opposing sides of the metal electrode, respectively. In this way, when applying pressure to the pressure-sensitive circuit board 100 or When the pressure-sensitive circuit board 100 is bent, the conductive wire 142 is not easily broken or detached from the metal electrode 141.

In this embodiment, in order to enable the first conductive circuit layer 140 to better adhere to the surface of the insulating substrate 110 that is not covered by the patterned photoresist layer 120, that is, the first portion of the surface 111, it is preferable to place the first portion in advance on the first portion. A growth layer 131 is formed on the surface 111 as shown in FIG. 3. The material of the growth layer 131 is a material that can be well combined with the conductive metal layer 132. For example, the material can be copper, nickel, silver, or palladium, which can be formed on the first partial surface 111 by a deposition method. The deposition method is a chemical vapor deposition method or a physical vapor deposition method. Among them, the physical vapor deposition method includes a thermal evaporation method and a sputtering method. In this embodiment, the growth layer 131 is a nickel metal layer deposited by a thermal evaporation method.

Then, a conductive metal layer 132 is deposited on the surface of the growth layer 131 by a deposition method, and the conductive metal layer 132 and the growth layer 131 together form the first conductive circuit layer 140. The deposition method may also be a chemical vapor deposition method or a physical vapor deposition method. Among them, the physical vapor deposition method includes a thermal evaporation method and a sputtering method. The material of the conductive metal layer 132 may be copper, silver, aluminum, an alloy of various metals mentioned above, or other suitable metals or alloys. In this embodiment, the conductive metal layer 132 is a copper layer deposited by a thermal evaporation method.

During the thermal evaporation process, the insulating substrate 110 having the patterned photoresist layer 120 is placed in the evaporation chamber as a whole. Therefore, the first portion of the surface 111 that is not covered by the patterned photoresist layer 120 is removed. In addition to the growth layer 131 being deposited, the surface of the patterned photoresist layer 120 is also inevitably deposited with the growth layer 131. Similarly, during the process of depositing the first conductive circuit layer 140, the first conductive circuit layer 140 is inevitably deposited on the surface of the growth layer 131 formed on the surface of the photoresist layer 120.

Of course, it can be understood that in other embodiments, a conductive metal may be directly deposited on the surface of the insulating substrate 110 not covered by the patterned photoresist layer 120 to form the first conductive circuit layer 140 by a deposition method.

S14: As shown in FIG. 6, the patterned photoresist layer 120 is removed to obtain a fabricated circuit board 100.

An appropriate stripping solution is selected, and the insulating substrate 110 in which the patterned photoresist layer 120 and the first conductive circuit layer 140 are combined is disposed in the stripping solution, and is agitated or shaken to accelerate the patterned photoresist layer. 120 dissolved. After the patterned photoresist layer 120 is completely dissolved, the insulating substrate 110 combined with the first conductive circuit layer 140 is cleaned in a cleaning agent, and dried or dried, so that an insulating substrate 110 formed on the surface of the insulating substrate 110 is obtained. Conductive line. The peeling liquid is an organic solvent or a liquid that can dissolve the patterned photoresist layer 120. In this embodiment, the stripping solution is a NaOH solution.

During the dissolving process of the patterned photoresist layer 120, the growth layer 131 and the first conductive circuit layer 140 formed on the surface of the photoresist layer 120 also fall off in the stripping solution. Thus, in In the final structure of the circuit board 100, the growth layer 131 and the first conductive circuit layer 140 formed on the surface of the photoresist layer 120 will not affect the final conductive circuit structure.

In the second step S2, referring to FIG. 7, a sensitive layer 150 covering the metal electrode 141 is formed on the surface of the flexible insulating substrate 110.

The sensitive layer 150 is formed of an elastic resin, an active agent, an anti-scorching agent, an accelerator, a cross-linking agent, carbon black, and naphthenic oil-doped conductive particles. The above-mentioned proportion of the sensitive layer 150 is to change the gap between the conductive particles 152 to change the resistance of the conductive particles when the pressure-sensitive circuit board is deformed.

The elastic resin includes 100 parts of ethylene propylene diene rubber (EPDM), 5 to 20 parts of ethylidene norbornene (ENB), and 5 to 20 parts of dicyclopentadiene (DCDP). EPDM rubber is the main component of the resin. Ethylene norbornene has a relatively fast vulcanization speed, which can be better co-vulcanized with EPDM rubber. Dicyclopentadiene has anti-scorch properties and makes it Conductive elastomer with low permanent deformation.

The active agent is zinc oxide and its weight part is 1 to 4 parts. Zinc oxide, as an active agent for rubber vulcanization, can fully increase the activity of the compounding accelerator, thereby accelerating the vulcanization reaction and shortening the vulcanization time, and can make vulcanization more fully, while improving the thermal stability of the EPDM rubber.

The anti-scorch agent is stearic acid and its weight part is 0.1 to 1 part. Stearic acid acts as an anti-scorch agent to prevent coking of the above raw materials during mixing.

Accelerators are commonly used in the rubber field, such as: CBS, DM, TMTD, or MBT. In this embodiment, the accelerator is an accelerator M (2-mercaptobenzothiazole, MBT for short), and the weight of the accelerator is 5-20 parts by weight.

The cross-linking agent is sulfur and its weight part is 0.5 to 3 parts, and the cross-linking agent is used to increase the cross-linking density.

The naphthenic oil is a process oil, and the weight of the naphthenic oil is 20 to 100 parts. As a filler improver for conductive elastomers, naphthenic oil can increase the self-adhesion of EPDM rubber.

The carbon black (HAF) is 0 to 100 parts by weight. Carbon black is used as a filling and reinforcing agent, which can adjust the hardness and strength of conductive elastomers within a wide range.

The weight of the conductive particles is 150-300 parts. The conductive particles are graphite, pure silver conductive powder, pure nickel conductive powder, nickel coated graphite conductive powder, silver coated aluminum conductive powder, silver coated copper conductive powder, silver coated nickel conductive powder, silver coated glass conductive One kind of powder or a mixture of any two or more kinds.

In this embodiment, the sensitive layer 150 is formed by printing. The thickness of the sensitive layer 150 is between 15 and 100 microns, and the width is at least 45 microns. The distance between the left surface of each sensitive layer 150 and the left surface of the metal electrode 141 is equal to the distance between the right surface of each sensitive layer 150 and the right surface of the metal electrode 141.

In the fourth step, a cover layer 160 is formed by laminating on the peripheral side of the sensitive layer 30. The cover layer 160 also covers the conductive line 142 between the surface of the flexible insulating substrate 110 and the sensitive layer 150. Thus, the pressure-sensitive circuit board 100 is formed.

Second embodiment

Please refer to FIG. 8 and FIG. 5 together, which is a pressure-sensitive circuit board 100 manufactured by the method for manufacturing a pressure-sensitive circuit board according to the first embodiment.

The pressure-sensitive circuit board 100 includes a flexible insulating substrate 110. A first conductive circuit layer 140, a sensitive layer 150 and a first cover layer 160 are formed on one surface of the flexible insulating substrate 110. The main raw material component of the flexible insulating substrate 110 is an elastic resin, and the stretch ratio of the elastic resin is 5% to 50%. In this embodiment, a material of the flexible insulating substrate 110 may be polydimethylsiloxane (PDMS) or thermoplastic polyurethane (Thermoplastic Polyurethane).

The first conductive circuit layer 140 includes a plurality of metal electrodes 141 disposed at intervals, and a conductive line 142 electrically connected to the plurality of metal electrodes 141. The conductive wire 142 has a curved S shape.

The sensitive layer 150 covers each of the metal electrodes 141. The sensitive layer 150 is formed of resin, active agent, anti-scorching agent, accelerator, cross-linking agent, carbon black and naphthenic oil doped conductive particles.

The resin includes 100 parts of ethylene propylene diene rubber (EPDM), 5 to 20 parts of ethylidene norbornene (ENB), and 5 to 20 parts of dicyclopentadiene (DCDP). EPDM rubber is the main component of the resin. Ethylene norbornene has a relatively fast vulcanization speed, which can be better co-vulcanized with EPDM rubber. Dicyclopentadiene has anti-scorch properties and makes it The sensitive layer has the characteristics of low permanent deformation. The proportion of the resin according to the above parts by weight can realize the requirement that the sensitive layer 150 has high elastic deformation when subjected to external force, and can quickly rebound when the pressure is removed.

The active agent is zinc oxide. The zinc oxide is 1 to 4 parts by weight. Zinc oxide, as an active agent for rubber vulcanization, can fully increase the activity of the compound accelerator, and then accelerate the vulcanization reaction. And shorten the vulcanization time, and can make the vulcanization more fully, while improving the thermal stability of EPDM rubber. In other embodiments, the active agent may also be magnesium oxide or a mixture of zinc oxide and magnesium oxide.

The anti-scorch agent is stearic acid, and the weight part of the stearic acid is 0.1 to 1 part. Stearic acid acts as an anti-scorch agent to prevent coking of the above raw materials during mixing.

The accelerator is a commonly used accelerator in the rubber field, such as: accelerator CBS, accelerator DM, accelerator TMTD, or MBT. In this embodiment, the accelerator is an accelerator M (2-mercaptobenzothiazole, referred to as MBT), and the weight part of the accelerator is 5-20 parts.

The cross-linking agent is sulfur and its weight part is 0.5 to 3 parts, and the cross-linking agent is used to increase the cross-linking density.

The naphthenic oil is a process oil, and the weight of the naphthenic oil is 20 to 100 parts. As a filling improver of the sensitive layer 150, naphthenic oil can improve the self-adhesion of the ethylene-propylene-diene rubber.

The carbon black (HAF) is 0 to 100 parts by weight. Carbon black is used as a filling reinforcement, which can adjust the hardness and strength of the sensitive layer in a wide range.

The weight part of the doped conductive particles 152 is 150-300 parts. The conductive particles 152 are graphite, pure silver conductive powder, pure nickel conductive powder, nickel-coated graphite conductive powder, silver-coated aluminum conductive powder, silver-coated copper conductive powder, silver-coated nickel conductive powder, and silver-coated glass. One of the conductive powders or a mixture of any two or more.

Among the above components, the sensitive layer 150 can be obtained by mixing the aforementioned raw materials in parts by weight at room temperature, and the obtained room temperature viscosity of the sensitive layer 150 is between 10 Pa · s to 35 Pa · s.

The first covering layer 160 covers the sensitive layer 150 and the conductive lines 142 covering the surface of the flexible insulating substrate 110.

The working principle of the pressure-sensitive circuit board 100 is that both opposing surfaces of the pressure-sensitive circuit board 100 can be used as pressure-applying surfaces, and the space between the two metal electrodes 141 is defined as pressure-sensitive. District 103. The outer area of the metal electrode 141 of the pressure-sensitive circuit board 100 is a fixed place 101. The fixing place 101 refers to a position where the pressure-sensitive circuit board 100 is fixed to the electronic product.

Applying pressure to one of the surfaces of the pressure-sensitive circuit board 100 as a pressure-sensitive surface between the two metal electrodes 141 or fixing one end of the pressure-sensitive circuit board 100 At the other end, it is equivalent to that the flexible insulating substrate 110 is stretched, so that the sensitive layer 150 is also stretched and deformed. After the sensitive layer 150 is stretched, the distance between the conductive particles 152 covered by the sensitive layer 150 is increased. Correspondingly becomes larger, that is, the arrangement between the conductive particles 152 becomes thinner, so that the conductive ability of the conductive particles 152 becomes weaker, which means that the sensitive portion 105 formed by the conductive particles 152 and the metal electrode 151 together The resistance value increases correspondingly. In this way, by measuring the change in the resistance value of the sensitive portion 105, the magnitude of the pressure applied by the outside can be obtained. And the sensitive parts 105 are connected in series by the conductive wire 142, so the external pressure value can be calculated by measuring the sum of the resistance values of the multiple sensitive parts 105 to improve the measurement accuracy and sensitivity.

Third embodiment

FIG. 9 is a pressure-sensitive circuit board 200 according to a third embodiment of the present invention. The structure of the pressure-sensitive circuit board 200 provided in the third embodiment is basically the same as that of the pressure-sensitive circuit board 100 provided in the second embodiment, except that the first conductive circuit layer 140a includes a plurality of metal electrodes 1410. , Multiple said gold The metal electrodes 1410 are arranged in two columns and multiple rows, and the distance between the two columns of electrodes is also preferably between 8 mm and 70 mm. The two metal electrodes 1410 included in each row form an electrode pair 145, and each electrode pair 145 is connected by a conductive wire 1420, and finally a wire is pulled out at any position of each conductive wire 1420 to make multiple electrode pairs 145 all Connect them in series to measure the pressure by changing the resistance value of multiple metal electrode pairs 145 to improve the sensitivity of pressure measurement.

Fourth embodiment

Please refer to FIG. 10, which illustrates a pressure-sensitive circuit board 300 according to a fourth embodiment of the present invention. The structure of the pressure-sensitive circuit board 300 provided in the fourth embodiment is basically the same as the structure of the pressure-sensitive circuit board 100 provided in the second embodiment, except that the pressure-sensitive circuit board 300 further includes The second conductive circuit layer 170 on the other surface of the flexible insulating substrate 110, the conductive holes 172 penetrating through the flexible insulating substrate 110, and the second cover layer 180 formed on the surface of the second conductive circuit layer 170. The second conductive circuit layer 170 and the first conductive circuit layer 140 are electrically connected to each other through the conductive hole 172. In this embodiment, the first conductive circuit layer 140 and the second conductive circuit layer 170 may be formed by etching.

Fifth Embodiment

Please refer to FIG. 11 and FIG. 12, which is a flexible pressure-sensing element 400 according to a fifth embodiment of the present invention. The flexible pressure-sensing element 400 includes a flexible insulating substrate 110 and two sensitive portions formed on the surface of the flexible insulating substrate 110 and spaced apart from each other. 105. The area between the sensitive parts is defined as a pressure sensitive area 103. Each of the sensitive parts 105 includes a metal electrode 141 disposed on the surface of the flexible insulating substrate 110, and a sensitive layer 150 covering the metal electrode 141. And a first covering layer 160 covering the sensitive layer 150 and two sensitive portions 105 The metal electrodes 141 are electrically connected to each other through conductive wires 142. The main raw material components of the sensitive layer 150 are an elastic resin and conductive particles doped in the elastic resin.

The distance between the two sensitive portions 105 is also preferably between 8 mm and 70 mm.

When the flexible insulating substrate 110 is stretched or bent due to an external force, the sensitive portion 105 is formed by doping conductive particles 152 with the sensitive layer 150 formed of an elastic resin, so that the sensitive layer 150 also undergoes deformation due to stretching. After the layer 150 is stretched, the distance between the conductive particles 152 covered by the sensitive layer 150 will correspondingly increase, that is, the arrangement between the conductive particles 152 becomes thinner, and the conductive ability of the conductive particles 152 will become weak Therefore, the resistance value of the sensitive portion 105 increases correspondingly. In this way, the pressure can be measured according to the change in the resistance value.

That is, in summary, the resistance value of the pressure-sensitive circuit board 100, 200, 300 or the flexible pressure-sensitive element 400 increases when receiving external pressure, and the pressure-sensitive circuit board 100, 200, The 300 or the flexible pressure sensing element 400 can be used as a pressure sensor or a robot of a wearable display device, and has a simple structure and high sensitivity.

In summary, the present invention has indeed met the requirements for an invention patent, and a patent application was filed in accordance with the law. However, the above are only preferred embodiments of the present invention, and the scope of patent application in this case cannot be limited by this. For example, those who are familiar with the skills of this case and equivalent modifications or changes made in accordance with the spirit of the present invention should be covered by the following patent applications.

Claims (13)

A pressure-sensitive circuit board includes a flexible insulating substrate, a first conductive line layer, a sensitive layer, and a first cover layer formed on one surface of the flexible insulating substrate. The first conductive line layer includes spaced-apart layers. A metal electrode and a conductive wire electrically connected to the metal electrode. The main raw material components of the sensitive layer are an elastic resin and conductive particles doped in the elastic resin. The sensitive layer covers the metal electrode. The first covering layer covers the sensitive layer and covers the conductive wires, wherein the main raw material component of the flexible insulating substrate is an elastic resin and the elongation rate of the elastic resin is from 5% to 50%. The pressure-sensitive circuit board according to claim 1, wherein the material of the flexible insulating substrate is polydimethylsiloxane or thermoplastic polyurethane, and the conductive wire has a curved shape. The pressure-sensitive circuit board according to claim 1, wherein the pressure-sensitive circuit board further includes a second conductive circuit layer on the other surface of the flexible insulating substrate, conductive holes penetrating through the flexible insulating substrate, and A second cover layer, the second conductive circuit layer and the first conductive circuit layer are electrically connected to each other through the conductive holes, and the second cover layer covers the second conductive circuit layer. The pressure-sensitive circuit board according to claim 1, wherein the conductive particles are conductive ink, graphite, pure silver conductive powder, pure nickel conductive powder, nickel-clad graphite conductive powder, silver-clad aluminum conductive powder, One of silver-coated copper conductive powder, silver-coated nickel conductive powder, and silver-coated glass conductive powder, or a mixture of any two or more thereof. The pressure-sensitive circuit board according to claim 4, wherein the sensitive layer is formed by doping the conductive particles with the resin, an active agent, an anti-scorching agent, an accelerator, and a cross-linking agent; wherein the resin Including 100 parts of EPDM, 5 to 20 parts of ethylidene norbornene, and 5 to 20 parts of dicyclopentadiene; 1 to 4 parts by weight of the active agent; and The parts by weight are 0.1 to 1 part; the parts by weight of the crosslinking agent are 0.5 to 3 parts; the parts by weight of the accelerator are 5 to 20 parts; and the parts by weight of the conductive particles are 150 to 300 parts. A method for manufacturing a pressure-sensitive circuit board includes the following steps: forming a flexible circuit substrate, the flexible circuit substrate including a flexible insulating substrate and a first conductive circuit layer formed on one surface of the flexible insulating substrate; The main raw material component of the insulating substrate is an elastic resin and the elongation rate of the elastic resin is 5% to 50%; the first conductive circuit layer includes a plurality of metal electrodes spaced apart and a conductive material electrically connected to the plurality of metal electrodes. Wire; a sensitive layer is formed on the surface of the flexible insulating substrate and on the peripheral side of each of the electrodes, and the main raw material components of the sensitive layer are an elastic resin and conductive particles doped in the elastic resin. A sensitive layer covers the metal electrode; a first covering layer is formed on the surface of the flexible insulating substrate and the surrounding side of the sensitive layer, and the first covering layer covers the sensitive layer and covers the conductive wires to The pressure-sensitive circuit board is obtained. The method for manufacturing a pressure-sensitive circuit board according to claim 6, wherein the first conductive circuit layer can be formed by depositing a conductive metal layer on a surface of the flexible insulating substrate or by etching. The method for manufacturing a pressure-sensitive circuit board according to claim 6, wherein the material of the flexible insulating substrate is polydimethylsiloxane or thermoplastic polyurethane; and the conductive wire has a curved shape. The method for manufacturing a pressure-sensitive circuit board according to claim 6, wherein the flexible circuit board is a double-sided flexible circuit board, and the flexible circuit board further includes a second conductive layer on the other surface of the flexible insulating substrate. A circuit layer and a conductive hole penetrating through the flexible insulating substrate, and the second conductive circuit layer and the first conductive circuit layer are electrically connected to each other through the conductive hole. The method for manufacturing a pressure sensitive circuit board according to claim 6, wherein the material of the conductive particles is graphite, pure silver conductive powder, pure nickel conductive powder, nickel-coated graphite conductive powder, silver-coated aluminum conductive powder One or any two or more of silver, copper-clad conductive powder, silver-clad nickel conductive powder, and silver-clad glass conductive powder. The method for manufacturing a pressure-sensitive circuit board according to claim 6, wherein the sensitive layer is formed by doping the conductive particles with the elastic resin, an active agent, an anti-scorching agent, an accelerator, and a cross-linking agent; The resin includes 100 parts of ethylene propylene diene rubber, 5 to 20 parts of ethylidene norbornene, and 5 to 20 parts of dicyclopentadiene; the weight of the active agent is 1 to 4 parts by weight; the The anti-scorch agent is 0.1 to 1 part by weight; the cross-linking agent is 0.5 to 3 parts by weight; the accelerator is 5 to 20 parts by weight; the conductive particles are 150 to 300 parts by weight Serving. A flexible pressure-sensing element includes a flexible insulating substrate, at least two sensitive portions formed at intervals on the surface of the flexible insulating substrate, and the areas separated by the sensitive portions are defined as pressure-sensing areas, each of which The sensitive part includes a metal electrode disposed on the surface of the flexible insulating substrate, a sensitive layer covering the metal electrode, and a first covering layer covering the sensitive layer. The main raw material component of the sensitive layer is an elastic resin and doped in the The conductive particles in the elastic resin are electrically connected between the metal electrodes of the two sensitive parts through conductive wires. The main raw material component of the flexible insulating substrate is an elastic resin and the elongation rate of the elastic resin is 5%. ~ 50%. The flexible pressure-sensitive element according to claim 12, wherein the material of the flexible insulating substrate is polydimethylsiloxane or thermoplastic polyurethane.