Patent Publication Number: US-2022223325-A1

Title: Method for manufacturing resistor

Description:
RELATED APPLICATIONS 
     This application claims priority to China Application Serial Number 202110035245.8, filed Jan. 12, 2021, which is herein incorporated by reference. 
     BACKGROUND 
     Field of Invention 
     The present invention relates to a technique for manufacturing a passive device, and more particularly to a method for manufacturing a resistor. 
     Description of Related Art 
     In the manufacturing of chip resistance elements, aluminum compounds are typically used as substrates. In the prior art, when a substrate is manufactured, predetermined division lines are formed on a substrate material by punching according to a chip size of a product, and then the substrate material is sintered at a high temperature. 
     Then, the manufacturer of the resistance element can form an upper electrode, a lower electrode, and a resistive layer of each resistance element on the substrate. The substrate is divided into bar structures along the predetermined division lines, in which the bar structure includes various semi-finished chip resistance elements arranged in a row. Next, terminal electrodes of the chip resistance elements are formed to conduct the upper electrodes and the lower electrodes. Subsequently, the bar structure is diced into individual semi-finished chip resistance elements along the division lines. Then, bonding layers are plated on the semi-finished chip resistance elements to complete the manufacturing of the chip resistance elements. 
     In the manufacturing of the substrate, the method that forms the predetermined division lines by punching has high production efficiency and low cost, such that the method is widely used by the manufacturers of chip resistance elements. However, in the production method, each substrate has a different shrinkage rate from one another after the substrates are sintered at a high temperature, and thus resulting in slight differences between the sizes of the chip resistance elements. As the size of the chip resistance elements continues to shrink, due to the accumulated tolerance caused by different substrate shrinkage rates, the product sizes of the chip resistance elements are uncontrollable, and even the sizes of some chip resistance elements exceed the specifications. 
     SUMMARY 
     Therefore, one objective of the present disclosure is to provide a method for manufacturing a resistor, which firstly forms division lines in a first surface of a substrate, and cuts the substrate from an opposite second surface of the substrate toward the division lines. The existing of the division line can form a forward stress during cutting, such that a fracture surface of the substrate can be formed to extend toward the division line without chipping off. Accordingly, the size specification of the resistor can be effectively controlled, and the quality and yield of the resistor can be enhanced. 
     According to the aforementioned objectives, the present disclosure provides a method for manufacturing a resistor. In this method, various first division lines and various second division lines are formed in a first surface of a substrate to define various device areas on the substrate. Various first electrodes and various second electrodes are formed on the first surface of the substrate, in which the first electrodes and the second electrodes are respectively disposed on the device areas. Various third electrodes and various fourth electrodes are formed on a second surface of the substrate, in which the third electrodes and the fourth electrodes are respectively disposed on the device areas. The second surface is opposite to the first surface. Various resistive layers are formed on the second surface of the substrate, in which the resistive layers are disposed on the device areas respectively and correspondingly, and each of the resistive layers is connected to the third electrode and the fourth electrode on the corresponding device area. The substrate is diced from the second surface by using a cutting tool to form various bar structures, so as to expose a first side surface and a second side surface, which are opposite to the each other, of each of the device areas. Dicing the substrate includes aligning the cutting tool with the first division lines respectively. Various first terminal electrodes and various second terminal electrodes are formed to respectively and correspondingly cover the first side surfaces and the second side surfaces of the device areas. Each of the first terminal electrodes connects the first electrode and the third electrode on the corresponding device area. Each of the second terminal electrodes connects the second electrode and the fourth electrode on the corresponding device area. The bar structures are diced from the second surface by using the cutting tool to separate the device areas from each other. Dicing the bar structures includes aligning the cutting tool with the second division lines respectively. 
     According to one embodiment of the present disclosure, the first division lines and the second division lines are perpendicular to each other. 
     According to one embodiment of the present disclosure, forming the first division lines and the second division lines includes using laser. 
     According to one embodiment of the present disclosure, forming the first division lines and the second division lines includes forming various grooves on the first surface of the substrate by using a cutter. 
     According to one embodiment of the present disclosure, the grooves are V-shaped grooves or arc grooves. 
     According to one embodiment of the present disclosure, the cutting tool includes a diamond round cutter. 
     According to one embodiment of the present disclosure, the substrate is a ceramic substrate. 
     According to the aforementioned objectives, the present disclosure further provides a method for manufacturing a resistor. In this method, various first division lines and various second division lines are formed in a first surface of a substrate, and various third division lines and various fourth division lines are formed in a second surface of the substrate, to define various device areas on the substrate. The third division lines are respectively aligned with the first division lines, and the fourth division lines are respectively aligned with the second division lines. Various first electrodes and various second electrodes are formed on the first surface of the substrate, in which the first electrodes and the second electrodes are respectively disposed on the device areas. Various third electrodes and various fourth electrodes are formed on the second surface of the substrate, in which the third electrodes and the fourth electrodes are respectively disposed on the device areas Various resistive layers are formed on the second surface of the substrate, in which the resistive layers are disposed on the device areas respectively and correspondingly, and each of the resistive layers is connected to the third electrode and the fourth electrode on the corresponding device area. The substrate is diced along the first division lines or the third division lines by using a cutting tool to form various bar structures, so as to expose a first side surface and a second side surface, which are opposite to the each other, of each of the device areas. Various first terminal electrodes and various second terminal electrodes are formed to respectively and correspondingly cover the first side surfaces and the second side surfaces of the device areas. Each of the first terminal electrodes connects the first electrode and the third electrode on the corresponding device area, and each of the second terminal electrodes connects the second electrode and the fourth electrode on the corresponding device area. The bar structures are diced along the second division lines or the fourth division lines by using the cutting tool to separate the device areas from each other. 
     According to one embodiment of the present disclosure, the first division lines and the second division lines are perpendicular to each other. 
     According to one embodiment of the present disclosure, forming the first division lines, the second division lines, the third division lines, and the fourth division lines includes using laser. 
     According to one embodiment of the present disclosure, each of the first division lines, the second division lines, the third division lines, and the fourth division lines is a groove. 
     According to one embodiment of the present disclosure, the cutting tool includes a diamond round cutter. 
     According to one embodiment of the present disclosure, the substrate is a ceramic substrate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The aforementioned and other objectives, features, advantages, and embodiments of the present disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1A  through  FIG. 4A  and  FIG. 5  are schematic three-dimensional diagrams of various intermediate stages showing a method for manufacturing a resistor in accordance with a first embodiment of the present disclosure; 
         FIG. 1B  through  FIG. 4B  are schematic partial side views of various intermediate stages showing a method for manufacturing a resistor in accordance with a first embodiment of the present disclosure; 
         FIG. 6A  is a schematic three-dimensional diagram of a substrate for manufacturing a resistor in accordance with a second embodiment of the present disclosure; and 
         FIG. 6B  is a schematic partial side view of a substrate for manufacturing a resistor in accordance with a second embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments of the present disclosure are discussed in detail below. However, it will be appreciated that the embodiments provide many applicable concepts that can be implemented in various specific contents. The embodiments discussed and disclosed are for illustrative purposes only and are not intended to limit the scope of the present disclosure. All of the embodiments of the present disclosure disclose various different features, and these features may be implemented separately or in combination as desired. 
     In addition, the terms “first”, “second”, and the like, as used herein, are not intended to mean a sequence or order, and are merely used to distinguish elements or operations described in the same technical terms. 
     The spatial relationship between two elements described in the present disclosure applies not only to the orientation depicted in the drawings, but also to the orientations not represented by the drawings, such as the orientation of the inversion. Furthermore, the terms “connected”, “electrically connected” or the like between two components referred to in the present disclosure are not limited to the direct connection or electrical connection of the two components, and may also include indirect connection or electrical connection as required. 
     Because the method that forms division lines when manufacturing a substrate causes the difference between the sizes of the resistance elements, and it also causes the resistance elements to not meet the specifications, a laser is used to directly position the substrate and draw predetermined division lines on the substrate and then the resistance elements are peeled and separated, or a cutter is used to directly cut and separate the resistance elements to solve the problem of the difference between the sizes of the substrates. The inventors find that although the two methods can form a substrate with a predetermined size, and can solve the alignment problem in the sequent processes. However, when the two processing methods are used to divide the substrate, the fracture line of the substrate is easy to shift in an uncertain direction during the breaking process of the substrate, thus resulting in cracks or incomplete defects on the fracture surface of the substrate. Such defects are not easy to find, and the defects will not fall off during the subsequent formation of terminal electrodes and the plating of the bonding layer, such that a false attachment may be formed. In the application end, after the resistance element passes through a soldering furnace, a tearing defect is formed between the falsely attached bonding layer and the substrate, such that the resistance element cannot conduct completely, which seriously affects the reliability of the resistance element. 
     In view of this, the present disclosure provides a method for manufacturing a resistor, which firstly draws predetermined division lines in a first surface of a substrate, and cuts the substrate from an opposite second surface of the substrate toward the division lines. The existing of the division line can form a forward stress during cutting, such that a fracture surface of the substrate can be formed to extend toward the division line without chipping off, thereby enhancing the quality and yield of the resistor. 
     Refer to  FIG. 1A  through  FIG. 4A ,  FIG. 5 , and  FIG. 1B  through  FIG. 4B .  FIG. 1A  through  FIG. 4A  and  FIG. 5 , and  FIG. 1B  through  FIG. 4B  are respectively schematic three-dimensional diagrams and schematic partial side views of various intermediate stages showing a method for manufacturing a resistor in accordance with a first embodiment of the present disclosure. In manufacturing of a resistor  100  shown in  FIG. 5 , a substrate  110  may be provided firstly. The substrate  110  has a first surface  112  and a second surface  114 , which are respectively located on two opposite sides of the substrate  110 . For example, the first surface  112  of the substrate  110  may be a back surface, and the second surface  114  may be a front surface. The substrate  110  is an insulation substrate, and a material of the substrate  110  may be aluminum oxide (Al 2 O 3 ), for example. In some exemplary examples, the substrate  110  is a ceramic substrate. 
     Then, as shown in  FIG. 1A , various first division lines  120  and various second division lines  122  are formed in the first surface  112  of the substrate  110 . In some examples, the first division lines  120  are parallel to each other, and the second division lines  122  are also parallel to each other. In addition, pitches of the first division lines  120  are substantially the same, and pitches of the second division lines  122  are also substantially the same. According to product specifications, the pitches between the first division lines  120  and the pitches between the second division lines  122  may be difference or may be the same. The first division lines  120  intersect the second division lines  122  to define various device areas  130  on the substrate  110 . In some exemplary examples, the first division lines  120  and the second division lines  122  are perpendicular to each other, so as to define various rectangular or square device areas  130  on the substrate  110 . 
     In some examples, the first division lines  120  and the second division lines  122  may be drawn in the first surface  112  of the substrate  110  by using a laser. In other examples, the first division lines  120  and the second division lines  122  may be formed in the first surface  112  of the substrate  110  by using a cutter, such as a diamond round cutter. Each of the first division lines  120  and the second division lines  122  may be a groove, such as a V-shaped groove shown in  FIG. 1B  or an arc groove, formed in the first surface  112  of the substrate  110 . 
     Next, various first electrodes  140  and various second electrodes  150  may be formed on the first surface  112  of the substrate  110  by using, for example, a printing method. The first electrodes  140  and the second electrodes  150  are respectively disposed on the device areas  130 , i.e. each of the device areas  130  has one of the first electrodes  140  and one of the second electrodes  150 . In each of the device areas  130 , the first electrode  140  and the second electrode  150  are separated from each other. For example, as shown in  FIG. 2A  and  FIG. 2B , the first electrode  140  and the second electrode  150  are respectively adjacent to two opposite edges of the device area  130 . Materials of the first electrodes 140  and the second electrodes  150  may be, for example, copper or silver. 
     Similarly, various third electrodes  160  and various fourth electrodes  170  may be formed on the second surface  114  of the substrate  110  by using, for example, a printing method. The third electrodes  160  and the fourth electrodes  170  are respectively disposed on the device areas  130 , such that each of the device areas  130  has one of the third electrodes  160  and one of the fourth electrodes  170 . In each of the device areas  130 , the third electrode  160  and the fourth electrode  170  are separated from each other. For example, as shown in  FIG. 2A  and  FIG. 2B , the third electrode  160  and the fourth electrode  170  may be respectively adjacent to two opposite edges of the device area  130 , in which a location of the third electrode  160  corresponds to a location of the first electrode  140 , and a location of the fourth electrode  170  corresponds to a location of the second electrode  150 . Materials of the third electrode  160  and the fourth electrode  170  may be, for example, copper or silver. 
     In some exemplary examples, the first electrodes  140  and the second electrodes  150 , as well as the third electrodes  160  and the fourth electrodes  170  may be formed by respectively printing the materials of the first electrodes  140  and the second electrodes  150 , as well as the third electrodes  160  and the fourth electrodes  170  on the first surface  112  and the second surface  114  of the substrate  110 , performing a dividing treatment to define patterns, and plastic burning together. 
     Then, various resistive layers  180  may be formed on the second surface  114  of the substrate  110  by using, for example, a printing method. The resistive layers  180  are disposed on the device areas  130  respectively and correspondingly, such that each of the device areas  130  has one of the resistive layers  180 . As shown in  FIG. 2B , in each of the device areas  130 , the resistive layer  180  may be located between the third electrode  160  and the fourth electrode  170 , and connected to the third electrode  160  and the fourth electrode  170 . 
     In some examples, after the resistive layers  180  are formed, the substrate  110  may be diced from the second surface  114  by using a cutting tool  190  to form various bar structures  200 , as shown in  FIG. 3A . In the dicing of the substrate  110  from the second surface  114 , the cutting tool  190  is aligned with the first division lines  120  in the first surface  112  to separate bar structures  200  from each other along the first division lines  120 . The cutting tool  190  may be a cutter, such as a diamond round cutter. The cutting tool  190  separates the bar structures  200  along the first division lines  120 , such that each of the bar structures  200  includes various device areas  130 . As shown in  FIG. 3B , after dicing, a first side surface  132  and a second side surface  134 , which are opposite to each other, of each device area  130  on the bar structure  200  may be exposed. The first side surface  132  and the second side surface  134  both are connected between the first surface  112  and the second surface  114 . In addition, the first electrode  140  and the third electrode  160  are adjacent to the first side surface  132 , and the second electrode  150  and the fourth electrode  170  are adjacent to the second side surface  134 . 
     The cutting tool  190  is aligned with the first division line  120  for cutting, and the first division line  120  can form a forward stress during cutting, such that a fracture surface of the substrate  110  can be formed to extend toward the first division line  120  without chipping off, thereby enhancing the yield of the cutting process. 
     Then, various first terminal electrodes  210  and various second terminal electrodes  220  may be formed by using, for example, a sputtering method. As shown in  FIG. 4A  and  FIG. 4B , the first terminal electrodes  210  respectively cover the first side surfaces  132  of the device areas  130 , and are connected to the first electrodes  140  and the third electrodes  160  to electrically connect the first electrodes  140  and the third electrodes  160 . The second terminal electrodes  220  respectively cover the second side surfaces  134  of the device areas  130 , and are connected to the second electrodes  150  and the fourth electrodes  170  to electrically connect the second electrodes  150  and the fourth electrodes  170 . Materials of the first terminal electrodes  210  and the second terminal electrodes  220  may be metal, such as copper or silver. 
     Next, the bar structures  200  may be diced from the second surface  114  of the substrate  110  by using the cutting tool  190  again to separate the device areas  130  from each other, so as to substantially complete the manufacturing of the resistor  100 , as shown in  FIG. 5 . In the dicing of the bar structures  200  from the second surface  114  of the substrate  110 , the cutting tool  190  is aligned with the second division lines  122  in the first surface  112  to divide the device areas  130  from each other along the second division lines  122 . The cutting tool  190  is aligned with the second division line  122  for cutting, and the second division line  122  can form a forward stress during cutting similarly, such that a fracture surface of the substrate  110  can be formed to extend toward the second division line  122  without chipping off, thereby enhancing the process yield and quality of the resistor  100 . 
     The present disclosure may form division lines on two opposite surface of a substrate. Refer to  FIG. 6A  and  FIG. 6B .  FIG. 6A  and  FIG. 6B  respectively illustrate a schematic three-dimensional diagram and a schematic partial side view of a substrate for manufacturing a resistor in accordance with a second embodiment of the present disclosure. In this embodiment, a substrate  110 a similarly has a first surface  112  and a second surface  114 , which are opposite to each other. The material properties of the substrate  110 a may be the same as those of the aforementioned substrate  110 . 
     Various first division lines  120  and various second division lines  122  may be disposed in the surface  112  of the substrate  110   a.  For example, the first division lines  120  are parallel to each other, and the second division lines  122  are also parallel to each other. Pitches of the first division lines  120  are substantially the same, and pitches of the second division lines  122  are also substantially the same. The first division lines  120  intersect the second division lines  122  to define various device areas  130  on the substrate  110   a.  For example, the first division lines  120  and the second division lines  122  may be perpendicular to each other. 
     Various third division lines  124  and various fourth division lines  126  may be further formed in the second surface  114  of the substrate  110   a.  The third division lines  124  are respectively aligned with the first division lines  120 , and the fourth division lines  126  are respectively aligned with the second division lines  122 . Thus, the third division lines  124  may be parallel to each other, and the fourth division lines  126  may be parallel to each other. In addition, pitches of the third division lines  124  are substantially the same, and pitches of the fourth division lines  126  are substantially the same. The third division lines  124  intersect the fourth division lines  126 , and the third division lines  124  and the fourth division lines  126  may be perpendicular to each other, for example. 
     A laser or a cutter, such as a diamond round cutter, may be used to form the first division lines  120  and the second division lines  122  in the first surface  112  of the substrate  110   a,  and the third division lines  124  and the fourth division lines  126  in the second surface  114 . The first division lines  120  and the second division lines  122  as well as the third division lines  124  and the fourth division lines  126  may be grooves, such as V-shaped grooves or arc grooves, respectively formed in the first surface  112  and the second surface  114 . 
     The first division lines  120  are respectively aligned with the third division lines  124 , such that when the substrate  110   a  is cut into bar structures, the substrate  110   a  may be cut from the first surface  112  along the first division lines  120  by using the cutting tool, in some examples. In another examples, the substrate  110   a  may be cut to form the bar structures from the second surface  114  along the third division lines  124  by using the cutting tool. The second division lines  122  are respectively aligned with the fourth division lines  126 , such that when the bar structure is divided into individual resistors, the substrate  110   a  may be diced from the first surface  112  of the substrate  110   a  along the second division lines  122 , or the substrate  110   a  may be diced from the second surface  114  along the fourth division lines  126  by using the cutting tool. The cutting tool may be a diamond round cutter, for example. 
     The structures, the arrangements, the material properties, and the manufacturing methods of the first electrodes, the second electrodes, the third electrodes, the fourth electrodes, the resistive layers, the first terminal electrodes, and the second terminal electrodes may be respectively similar to those of the first electrodes  140 , the second electrodes  150 , the third electrodes  160 , the fourth electrodes  170 , the resistive layers  180 , the first terminal electrodes  210 , and the second terminal electrodes  220 , and are not repeated herein. 
     According to the aforementioned embodiments, one advantage of the present disclosure is that the present disclosure firstly forms division lines in a first surface of a substrate, and cuts the substrate from an opposite second surface of the substrate toward the division lines. The existing of the division line can form a forward stress during cutting, such that a fracture surface of the substrate can be formed to extend toward the division line without chipping off. Therefore, the size specification of the resistor can be effectively controlled, and the quality and yield of the resistor can be enhanced. 
     Although the present disclosure has been described in considerable details with reference to certain embodiments, the foregoing embodiments of the present disclosure are illustrative of the present disclosure rather than limiting of the present disclosure. It will be apparent to those having ordinary skill in the art that various variations and modifications can be made to the present disclosure without departing from the scope or spirit of the present disclosure. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.