Patent Publication Number: US-2023138696-A1

Title: Circuit apparatus, manufacturing method thereof and circuit system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 110140235, filed on Oct. 29, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a circuit apparatus, a manufacturing method thereof and a circuit system, and also relates to a flexible circuit apparatus, a manufacturing method thereof and a circuit system. 
     Description of Related Art 
     In recent years, the technology of smart fabrics and wearable appliances has been extensively developed in industry, people&#39;s livelihood, leisure and medical care. For general smart fabrics and wearable appliances, the electronic devices are usually disposed on a circuit board by means of rigid molding and rigid packaging. Therefore, when the user performs combined actions such as continuous movement, continuous bending and stretching, it may cause problems such as bending and cracking of the circuit board, failure of the solder joints of the electronic devices, and distortion of the electronic signals. 
     SUMMARY 
     An embodiment of the present disclosure provides a circuit apparatus including a flexible circuit board, a flexible packaging material layer and an electronic device. The flexible circuit board has at least one hollow pattern, wherein the flexible circuit board has an inner region and a peripheral region surrounding the inner region, and has a first surface and a second surface opposite to each other. The flexible packaging material layer is disposed in the at least one hollow pattern. The electronic device is disposed on the first surface of the flexible circuit board and electrically connected with the flexible circuit board. 
     An embodiment of the present disclosure provides a manufacturing method of a circuit apparatus including the following steps. A flexible circuit board is provided. An electronic device is formed on the flexible circuit board. At least one hollow pattern is formed in the flexible circuit board. The hollow pattern is filled with a flexible packaging material. 
     An embodiment of the present disclosure provides a circuit system including a fabric substrate, a circuit apparatus and a conductive line. The circuit apparatus is disposed on the fabric substrate and includes a flexible circuit board, a flexible packaging material layer and an electronic device. The flexible circuit board has at least one hollow pattern, wherein the flexible circuit board has an inner region and a peripheral region surrounding the inner region, and has a first surface and a second surface opposite to each other. The flexible packaging material layer is disposed in the at least one hollow pattern. The electronic device is disposed on the first surface of the flexible circuit board and electrically connected with the flexible circuit board. The conductive line is disposed on the fabric substrate and electrically connected to the electronic device. 
     To make the aforementioned more comprehensible, several embodiments accompanied with drawings are described in detail as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS.  1 A to  1 C  are schematic top views of a manufacturing process of a circuit apparatus of the first embodiment of the present disclosure. 
         FIGS.  2 A to  2 C  are cross-sectional schematic diagrams of the manufacturing process of the circuit apparatus along the line A-A in  FIG.  1 A  to  FIG.  1 C . 
         FIG.  3    is a schematic top view of a circuit apparatus of the second embodiment of the present disclosure. 
         FIG.  4    is a schematic top view of a circuit apparatus of the third embodiment of the present disclosure. 
         FIG.  5    is a schematic top view of a circuit apparatus of the fourth embodiment of the present disclosure. 
         FIG.  6 A  is a schematic top view of a circuit apparatus of the fifth embodiment of the present disclosure. 
         FIG.  6 B  is a schematic top view of a circuit apparatus of the sixth embodiment of the present disclosure. 
         FIG.  7    is a schematic top view of a circuit system of an embodiment of the present disclosure. 
         FIGS.  8 A to  8 C  are schematic cross-sectional views of the circuit apparatuses bonded to the fabric substrate, respectively. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     The embodiments are described in detail below with reference to the accompanying drawings, but the embodiments are not intended to limit the scope of the present disclosure. In addition, the drawings are for illustrative purposes only and are not drawn to the original dimensions. For the sake of easy understanding, the same elements in the following description will be denoted by the same reference numerals. 
     The terms mentioned in the text, such as “comprising”, “including” and “having” are all open-ended terms, i.e., meaning “including but not limited to”. 
     When using terms such as “first” and “second” to describe a device, it is only used to distinguish these devices from each other, and does not limit the order or importance of these devices. Therefore, in some cases, the first device can also be called the second device, and the second device can also be called the first device, and this does not deviate from the scope of the present disclosure. 
     In addition, in the text, the range represented by “a value to another value” is a summary expression way to avoid listing all the values in the range one by one in the specification. Therefore, the record of a specific numerical range covers any numerical value within the numerical range, as well as a smaller numerical range defined by any numerical value within the numerical range. 
       FIGS.  1 A to  1 C  are schematic top views of a manufacturing process of a circuit apparatus of the first embodiment of the present disclosure.  FIGS.  2 A to  2 C  are cross-sectional schematic diagrams of the manufacturing process of the circuit apparatus along the line A-A in  FIG.  1 A  to  FIG.  1 C . 
     Referring to  FIGS.  1 A and  2 A , a flexible circuit board  100 , for example, a flexible printed circuit board (FPCB), is provided. In the present embodiment, the flexible circuit board  100  may have a generally well-known structure. For example, the flexible circuit board  100  may include an insulating layer, a plurality of circuit layers disposed in the insulating layer, a plurality of pads disposed on the surface of the insulating layer and a plurality of conductive vias connecting the circuit layers and the pads, but the present disclosure is not limited thereto. In addition, in the present embodiment, the flexible circuit board  100  has a Young&#39;s modulus between 100 MPa and 10 GPa, for example. In  FIGS.  1 A and  2 A , in order to make the drawings clear and convenient for description, only the pads are drawn, and the detailed structure of the flexible circuit board  100  is not drawn. The flexible circuit board  100  has a first surface  100   a  and a second surface  100   b  opposite to each other. In the present embodiment, the first surface  100   a  is a surface on which various electronic devices are disposed. Therefore, the first surface  100   a  may be referred to as the front side of the flexible circuit board  100 , and the second surface  100   b  may be referred to as the back side of the flexible circuit board  100 . In addition, the flexible circuit board  100  includes an inner region  100   i  and a peripheral region  100   p  surrounding the inner region  100   i.  In the present embodiment, the inner region  100   i  is a region in which main electronic devices are disposed. The pad  101  is disposed at the first surface  100   a  of the flexible circuit board  100  and located in the inner region  100   i,  and is used as a connection region where an external apparatus may be electrically connected to the flexible circuit board  100 . In other embodiments, depending on actual layout requirements, the pad  101  may be located in the peripheral region  100   p.    
     Then, the rigid material layer  102  may be disposed on the second surface  100   b  of the flexible circuit board  100 . In the present embodiment, the rigid material layer  102  may be located at a position corresponding to a specific electronic device to be disposed on the first surface  100   a,  so as to provide the specific electronic device with properties such as stretch resistance and bending resistance. As a result, the specific electronic device may be prevented from being damaged when the flexible circuit board  100  is stretched and bent. In other embodiments, the rigid material layer  102  may be located at positions corresponding to all the electronic devices to be disposed on the first surface  100   a,  or the rigid material layer  102  may be omitted. In addition, in the present embodiment, the rigid material layer  102  has a Young&#39;s modulus greater than 3 GPa, for example. Next, the electronic devices  104  are disposed on the first surface  100   a  of the flexible circuit board  100 . The electronic devices  104  are located in the inner region  100   i.  At this time, the rigid material layer  102  may be located under the specific electronic device  104 , preferably directly under the specific electronic device  104 . The electronic device  104  may be a sensing device, a signal processing device, a signal transmission device, a power source, etc., which is not limited by the present disclosure. A plurality of electronic devices  104  may be disposed on the first surface  100   a,  and the plurality of electronic devices  104  are connected in series or parallel to each other and electrically connected to the flexible circuit board  100 . 
     Referring to  FIGS.  1 B and  2 B , hollow patterns  106  are formed in the peripheral region  100   p  of the flexible circuit board  100 . The hollow patterns  106  are formed by, for example, performing a mechanical drilling process, a laser drilling process, a mechanical cutting process, a laser cutting process or a combination thereof on the flexible circuit board  100 . The hollow patterns  106  penetrates through the flexible circuit board  100 . That is, the hollow patterns  106  extends from the first surface  100   a  to the second surface  100   b.  In the present embodiment, the hollow patterns  106  are formed in the peripheral region  100   p  and located on the sides of the flexible circuit board  100  other than the corners. The hollow patterns  106  may have a desired shape, size and quantity according to actual needs, which is not limited by the present disclosure. 
     In the present embodiment, from the top view of the flexible circuit board  100 , i.e., as shown in  FIG.  1 B , at one side of the flexible circuit board  100 , the total length of the hollow patterns  106  extending along an edge of the flexible circuit board  100  is, for example, between 1% and 90% of the length of the edge. For example, at the right side of the flexible circuit board  100  in  FIG.  1 B , the total length of the hollow patterns  106  extending along the edge of the flexible circuit board  100  (length L 1 +length L 2 ) may be between 1% and 90% of the length L of the right side. In addition, the total area of the hollow patterns  106  is, for example, between 1% and 50% of the area of the flexible circuit board  100 . The following will further explain the above-mentioned total length range and total area range. 
     Referring to  FIGS.  1 C and  2 C , the flexible packaging material layer  108  is formed on the first surface  100   a  of the flexible circuit board  100 . The method for forming the flexible packaging material layer  108  is, for example, a molding process. In the present embodiment, the flexible packaging material layer  108  covers the first surface  100   a  and the sidewalls of the flexible circuit board  100 , and fills the hollow patterns  106 . In one embodiment, the flexible packaging material layer  108  may be conformally formed on the first surface  100   a  of the flexible circuit board  100 . In addition, in the present embodiment, the flexible packaging material layer  108  has a Young&#39;s modulus between 1 MPa and 300 MPa, for example. 
     In  FIG.  1 C , in order to make the drawings clear and easy to explain, only the flexible packaging material layer  108  in the hollow patterns  106  is shown, but those skilled in the art may understand that the flexible packaging material layer  108  covers the first surface  100   a.  In addition, the flexible packaging material layer  108  exposes the pad  101  so that an external apparatus (not shown) may be electrically connected to the flexible circuit board  100  through the pad  101 . In this way, flexible packaging material layer  108  are formed in the peripheral region  100   p  of the flexible circuit board  100 . After that, an encapsulation layer  110  may be formed on the second surface  100   b  of the flexible circuit board  100  to complete the manufacture of the circuit apparatus  10  of the present embodiment. In the present embodiment, the encapsulation layer  110  has a Young&#39;s modulus between 1 MPa and 300 MPa, for example. Therefore, in the circuit apparatus  10 , the Young&#39;s modulus of the rigid material layer  102  is greater than the Young&#39;s modulus of the flexible circuit board  100 , and the Young&#39;s modulus of the flexible circuit board  100  is greater than the Young&#39;s modulus of the flexible packaging material layer  108  and the encapsulation layer  110 . 
     In the present embodiment, after the flexible packaging material layer  108  are formed, the encapsulation layer  110  is formed, but the present disclosure is not limited thereto. In other embodiments, the flexible packaging material layer  108  may be formed after the encapsulation layer  110  is formed. In other embodiments, the encapsulation layer  110  may be omitted. 
     In addition, in the present embodiment, the material of the flexible packaging material layer  108  is different from the material of the encapsulation layer  110 , and therefore there is an interface between the flexible packaging material layer  108  and the encapsulation layer  110 , but the present disclosure is not limited thereto. In other embodiments, the material of the flexible packaging material layer  108  may be the same as the material of the encapsulation layer  110 , and therefore, there is no interface between the flexible packaging material layer  108  and the encapsulation layer  110 . 
     In addition, in the present embodiment, the flexible packaging material layer  108  covers all the electronic devices  104 , but the present disclosure is not limited thereto. In other embodiments, the flexible packaging material layers  108  may expose at least one electronic device  104 . 
     In the present embodiment, the flexible packaging material layer  108  is located in the peripheral region  100   p  of the flexible circuit board  100 . Based on the characteristics of the flexible packaging material layer  108  itself, the stretch resistance of the flexible circuit board  100  may be effectively improved, and thus the circuit apparatus  10  may be prevented from being damaged during the continuous stretching action. As shown in  FIG.  1 C , in the circuit apparatus  10 , hollow patterns  106  are formed at the four sides of the flexible circuit board  100  and the flexible packaging material layer  108  is filled in the hollow patterns  106 . Therefore, when the circuit apparatus  10  is subjected to a tensile force in the X direction or Y direction, the flexible circuit board  100  may have greater tensile resistance. In other embodiments, depending on the actual application of the circuit apparatus  10 , the hollow patterns  106  may be formed only at one side, two sides or three sides of the flexible circuit board  100 . 
     In the present embodiment, at one side of the flexible circuit board  100 , the total length of the hollow patterns  106  extending along the edge of the flexible circuit board  100  is, for example, between 1% and 90% of the length of the side. When the total length is less than 1% of the length of the side, the stretch resistance of the flexible circuit board  100  may not be effectively improved. When the total length is greater than 90% of the length of the side, the mechanical strength of the flexible circuit board  100  may be reduced. In one embodiment, at one side of the flexible circuit board  100 , the total length of the hollow patterns  106  extending along the edge of the flexible circuit board  100  may be between 2.6% and 25.1% of the length of the side. 
     In addition, the total area of the hollow patterns  106  is, for example, between 1% and 50% of the area of the flexible circuit board  100 . When the total area is less than 1% of the area of the flexible circuit board  100 , the stretch resistance of the flexible circuit board  100  may not be effectively improved. When the total area is greater than 50% of the area of the flexible circuit board  100 , the mechanical strength of the flexible circuit board  100  may be reduced, and the layout area of the electronic device  104  may be too small. In an embodiment, the total area of the hollow patterns  106  may be 25.1% of the area of the flexible circuit board  100 . 
     In the present embodiment, the hollow patterns  106  are only formed in the peripheral region  100   p  of the flexible circuit board  100  and located on the sides other than the corners of the flexible circuit board  100 , but the present disclosure is not limited thereto. Depending on the actual application of the circuit apparatus  10 , the hollow patterns  106  may be formed in other regions of the flexible circuit board  100 , which will be described below. 
       FIG.  3    is a schematic top view of a circuit apparatus of the second embodiment of the present disclosure. In the present embodiment, the same component as that in the first embodiment will be represented by the same reference number, and no further description will be made. Referring to  FIG.  3   , the difference between the present embodiment and the first embodiment is: in the circuit apparatus  20 , the hollow patterns  106  are only formed in the peripheral region  100   p  of the flexible circuit board  100 , and located at the four corners of the flexible circuit board  100 . In addition, the shapes and sizes of the hollow patterns  106  may be adjusted arbitrarily, which is not limited by the present disclosure. Depending on the actual application of the circuit apparatus  20 , in other embodiments, the hollow patterns  106  may be formed only at one corner, two corners or three corners of the flexible circuit board  100 . 
     In the present embodiment, at one side of the flexible circuit board  100 , the total length of the hollow patterns  106  extending along the edge of the flexible circuit board  100  is, for example, between 1% and 90% of the length of the side. In addition, the total area of the hollow patterns  106  is, for example, between 1% and 50% of the area of the flexible circuit board  100 . 
       FIG.  4    is a schematic top view of a circuit apparatus of the third embodiment of the present disclosure. In the present embodiment, the same component as that in the first embodiment will be represented by the same reference number, and no further description will be made. Referring to  FIG.  4   , the difference between the present embodiment and the first embodiment is: in the circuit apparatus  30 , the hollow patterns  106  are located at one side other than the corners of the flexible circuit board  100 , and extend from the edge of the flexible circuit board  100  into the inner region  100   i.  In addition, the positions, numbers, shapes and sizes of the hollow patterns  106  may be adjusted arbitrarily, which is not limited by the present disclosure. Depending on the actual application of the circuit apparatus  30 , in other embodiments, the hollow patterns  106  may be formed at two sides, three sides or four sides other than the corners of the flexible circuit board  100 . 
       FIG.  5    is a schematic top view of a circuit apparatus of the fourth embodiment of the present disclosure. In the present embodiment, the same component as that in the first embodiment will be represented by the same reference number, and no further description will be made. Referring to  FIG.  5   , the difference between the present embodiment and the first embodiment is that in the circuit apparatus  40 , the hollow patterns  106  are not formed in the peripheral region  100   p,  but is independently formed in the inner region  100   i.  In addition, the positions, numbers, shapes and sizes of the hollow patterns  106  may be adjusted arbitrarily, which is not limited by the present disclosure. 
     In addition, according to actual requirements, in other embodiments, any or all of the first embodiment, the second embodiment, the third embodiment and the fourth embodiment may be combined arbitrarily to improve the stretch resistance of the flexible circuit board. 
       FIG.  6 A  is a schematic top view of a circuit apparatus of the fifth embodiment of the present disclosure. In the present embodiment, the same component as that in the first embodiment will be represented by the same reference number, and no further description will be made. Referring to  FIG.  6 A , the difference between the present embodiment and the first embodiment is: in the circuit apparatus  50 , the fan-shaped hollow patterns  106   a  are formed at the four corners of the flexible circuit board  100 , and the strip-shaped hollow patterns  106   b  extend from the edge of the flexible circuit board  100  into the inner area  100   i.  In addition, the electronic devices  104  are located in the device region R in the inner region  100   i.    
     In the present embodiment, since the fan-shaped hollow patterns  106   a  are formed at the four corners of the flexible circuit board  100 , when the circuit apparatus  50  is twisted with the torsion axis AX, the flexible circuit board  100  may have a higher bending resistance. In addition, the strip-shaped hollow patterns  106   b  extend from the edge of the flexible circuit board  100  into the inner region  100   i  in a direction perpendicular to the torsion axis AX. Therefore, the flexible circuit board  100  may have higher tensile resistance during the twist. In this way, the flexible circuit board  100  may be effectively prevented from being damaged when the circuit apparatus  50  is twisted. 
     In one embodiment, in the case where the circuit apparatus  50  is designed to be twisted by 30° clockwise or counterclockwise with the torsion axis AX, at one side of the flexible circuit board  100 , the total area of the hollow patterns  106   a  and the hollow patterns  106   b  is between 7.85% and 31.4% of the area of the flexible circuit board  100 . In addition, for the flexible circuit board  100  with a size of 80 mm×50 mm, the radius r of each of the fan-shaped hollow patterns  106   a  may be 5 mm, and the length of each of the strip-shaped hollow patterns  106   b  extending along the edge of the flexible circuit board  100 , i.e., the width W of each of the hollow pattern  106   b,  may be 2 mm. For the device region R, the length L 4  of the long side of the device region R may be between 4/7 and 5/7 of the length L 3  of the long side of the flexible circuit board  100 . For the region used to connect with external appliances, the length L 5  between adjacent strip-shaped hollow patterns  106   b  may be between 1/7 and 3/14 of the length L 3  of the long side of the flexible circuit board  100 . 
       FIG.  6 B  is a schematic top view of a circuit apparatus of the sixth embodiment of the present disclosure. Referring to  FIG.  6 B , the difference between the present embodiment and the fifth embodiment is: in the circuit apparatus  60 , the flexible circuit board  100  does not have fan-shaped hollow patterns  106   a  at the four corners. 
     The circuit apparatus of the present disclosure may be disposed on the fabric and may be connected to the external apparatus through a conductive line to form the circuit system of the present disclosure, and may be applied to smart fabrics or wearable appliances. In the following, the circuit apparatus  10  is taken as an example to describe the circuit system of the present disclosure embodiment, and the circuit apparatus of other embodiments may be disposed on the fabric as the circuit apparatus  10 . 
       FIG.  7    is a schematic top view of a circuit system of an embodiment of the present disclosure. Referring to  FIG.  7   , the circuit system  70  includes a fabric substrate  700 , a plurality of circuit apparatuses  10  and a plurality of conductive lines  702 . The fabric substrate  700  may be various fabrics, which is not limited by the present disclosure. The circuit apparatuses  10  are disposed on the fabric substrate  700 . The conductive lines  702  are disposed on the fabric substrate  700  and connected to the pads  101  of the circuit apparatuses  10  to electrically connect the circuit apparatuses  10  to each other. In addition, according to actual needs, the circuit system  70  may be connected to the required external device  704  through the conductive line  702 . 
     The circuit apparatus  10  may be disposed on the fabric substrate  700  in various ways. As shown in  FIG.  8 A , the adhesion layer  800  is disposed between the second surface  100   b  of the flexible circuit board  100  (see  FIG.  2 C ) and the fabric substrate  700  and between the conductive lines  702  and the fabric substrate  700 . In this way, the circuit apparatuses  10  and the conductive lines  702  may be firmly bonded with the fabric substrate  700 . 
     As shown in  FIG.  8 B , the first fixing apparatuses  802  are disposed on the second surface  100   b  (see  FIG.  2 C ) of the flexible circuit board  100 , the second fixing apparatuses  804  are disposed on the fabric substrate  700 , and the first fixing apparatuses  802  and the second fixing apparatuses  804  are attached together, so that the circuit apparatuses  10  may be firmly bonded with the fabric substrate  700 . The first fixing apparatuses  802  and the second fixing apparatuses  804  may be attached together through fasteners, magnetic attraction, electrostatic attraction or pasting, which is not limited by the present disclosure. In this way, the circuit apparatuses  10  may be firmly bonded with the fabric substrate  700 . 
     As shown in  FIG.  8 C , the fixing pedestals  806  are disposed on the fabric substrate  700 , and the circuit apparatuses  10  are accommodated in the fixing pedestals  806 . In this way, the circuit apparatuses  10  may be firmly bonded with the fabric substrate  700 . 
     It will be apparent to those skilled in the art that various modifications and variations may be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.