PATENT DOCUMENT

Publication Number: US-10811192-B2
Application Number: US-201816146042-A
Country: US
Kind Code: B2

Title: Reliable capacitor structures

Abstract:
Multilayer ceramic capacitor structures may include structural arrangements, materials, and/or substrate modifications that can improve the reliability of the capacitor for long-term usage when faced with environmental stress. Embodiments may implement reduced entryways in the termination patterns of the capacitor to decrease damage potential due to exposure of moisture. Embodiments may implement structures that decrease interfaces with different physical characteristics, which may lead to a reduction in the formation of micro-fractures during regular usage. Methods of manufacture for the features that improve reliability are also detailed.

Claims:
What is claimed is: 
     
       1. A multilayer capacitor device, comprising:
 a lid region comprising a first plurality of ceramic layers, wherein each ceramic layer of the first plurality of ceramic layers comprises a first ceramic material; 
 a floor region comprising a second plurality of ceramic layers, wherein each ceramic layer of the second plurality of ceramic layers comprises the first ceramic material; and 
 a middle region disposed between the lid region and the floor region, wherein the middle region comprises:
 a non-metallized region having a first thermal expansion coefficient; and 
 a metallized region having a second thermal expansion coefficient that is substantially similar to the first thermal expansion coefficient, wherein the metallized region comprises a third plurality of ceramic layers that comprise a second ceramic material that is different from the first ceramic material. 
 
 
     
     
       2. The multilayer capacitor device of  claim 1 , wherein the first ceramic material comprises a first modification of the second ceramic material, the non-metallized region of the middle region comprises the first modification, and wherein the first modification comprises a doping of the second ceramic material or an application of a coating to the second ceramic material, or both. 
     
     
       3. The multilayer capacitor device of  claim 1 , wherein each respective electrode region of each respective ceramic layer of the third plurality of ceramic layers comprise copper, nickel, silver, a copper alloy, a nickel alloy, or a silver alloy. 
     
     
       4. The multilayer capacitor device of  claim 1 , wherein the second ceramic material comprises substrate that comprises a magnesium oxide or a zirconium oxide or any combination thereof. 
     
     
       5. The multilayer capacitor device of  claim 4 , wherein the second ceramic material comprises a mixture of the substrate with an aluminum oxide, yttrium oxide, or soda-lime glass, or any combination thereof. 
     
     
       6. The multilayer capacitor device of  claim 1 , wherein the second ceramic material comprises nickel oxide, manganese oxide, or cobalt oxide, or any combination thereof. 
     
     
       7. The multilayer capacitor device of  claim 1 , wherein the middle region comprises a first termination surface configured to receive a first terminal of the multilayer capacitor device, and wherein the first termination surface comprises a termination pattern that comprises a cutaway region. 
     
     
       8. A multilayer capacitor device, comprising:
 a plurality of ceramic layers, each respective layer comprising a respective electrode of a plurality of electrodes; and 
 a first termination surface configured to receive a first terminal of the multilayer capacitor device, wherein the first termination surface comprises a plurality of electrode terminations that form a termination pattern, wherein each respective electrode termination is associated with the respective electrode, and wherein the termination pattern comprises: 
 a first subset of electrode terminations of the plurality of electrode terminations comprising a first size; 
 a second subset of electrode terminations of the plurality of electrode terminations comprising a second size, wherein the first size is smaller than the second size; and 
 a cutaway region on the first termination surface along the first subset of electrode terminations. 
 
     
     
       9. The multilayer capacitor device of  claim 8 , wherein the cutaway region comprises a curved cutaway region. 
     
     
       10. The multilayer capacitor device of  claim 9 , wherein the termination pattern comprises a chalice-shaped termination pattern or a rounded pyramidal-shaped termination pattern. 
     
     
       11. The multilayer capacitor device of  claim 8 , wherein the cutaway region comprises a straight cutaway region. 
     
     
       12. The multilayer capacitor device of  claim 11 , wherein the termination pattern comprises a U-shaped termination pattern, a H-shaped termination pattern, a cross-shaped termination pattern, or a T-shaped termination pattern. 
     
     
       13. The multilayer capacitor device of  claim 8 , wherein each electrode of the plurality of electrodes comprises a respective vertical electrode, each electrode termination comprises a reduced height electrode termination, and the termination pattern comprises a reduced-height termination pattern. 
     
     
       14. The multilayer capacitor device of  claim 8 , wherein the termination pattern comprises a second cutaway region along a bottom of the multilayer capacitor device. 
     
     
       15. A multilayer capacitor device, comprising:
 a first plurality of ceramic layers, wherein each ceramic layer of the first plurality of ceramic layers comprises a first electrode region; and 
 a second plurality of ceramic layers; 
 wherein the multilayer capacitor device comprises a stack of ceramic layers of the first plurality of ceramic layers and ceramic layers of the second plurality of ceramic layers arranged to form a metallization density gradient in the multilayer capacitor device that increases from a top of the multilayer capacitor device towards a middle of the multilayer capacitor device, wherein the middle of the multilayer capacitor device does not include any ceramic layer of the first plurality of ceramic layers. 
 
     
     
       16. The multilayer capacitor device of  claim 15 , wherein the stack of ceramic layers is arranged to form a second metallization density gradient in the multilayer capacitor device that increases from a bottom of the multilayer capacitor device towards the middle of the multilayer capacitor device. 
     
     
       17. A multilayer capacitor device, comprising:
 a first plurality of ceramic layers, wherein each ceramic layer of the first plurality of ceramic layers comprises a first electrode region; 
 a second plurality of ceramic layers; and 
 wherein the multilayer capacitor device comprises a stack of ceramic layers of the first plurality of ceramic layers and ceramic layers of the second plurality of ceramic layers arranged to form a metallization density gradient in the multilayer capacitor device that increases from a top of the multilayer capacitor device towards a middle of the multilayer capacitor device, wherein each ceramic layer of a sub plurality of the second plurality of ceramic layers comprises a plurality of electrode strips. 
 
     
     
       18. The multilayer capacitor device of  claim 17 , wherein the stack of ceramic layers is arranged to form a crenelated pattern of electrodes along a body of the multilayer capacitor device. 
     
     
       19. The multilayer capacitor device of  claim 8 , wherein the first subset of electrode terminations is located above the second subset of electrode terminations. 
     
     
       20. The multilayer capacitor device of  claim 8 , wherein the first subset of electrode terminations are located in an upper region of the first termination surface.

Description:
BACKGROUND 
     The present disclosure relates generally to capacitor structures, and more particularly, to multilayer ceramic capacitor structures that implement structures and/or materials that improve reliability of the capacitor structures by mitigating damage due to environmental exposure. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     Many electronic devices include electronic circuits that employ capacitors for filtering, impedance matching, energy storage, and other applications. Ceramic capacitors have been used in compact electrical devices, as the reduced dimensions allow smaller circuit board footprints. Due to the plasticity of the material and the high permittivity of the dielectric, ceramic capacitors may be produced in very compact and customized dimensions and shapes. For example, multilayer ceramic capacitors, i.e., ceramic capacitors having multiple electrode layers forming a capacitor structure, may be used to obtain high capacitances in a compact package. 
     Ceramic capacitors may be susceptible to environmental damage that may decrease reliability of the capacitor over time. As an example, thermal variations may create micro fractures in the body of the capacitor, which may lead to changes in the nominal capacitance and may, eventually, cause failure of the capacitor. The variations in the nominal capacitance or failures of the capacitor may eventually lead to premature failure of the electronic device. 
     SUMMARY 
     A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below. 
     Under normal usage, capacitors may suffer micro fractures due to stress. The micro fractures may lead to exposure of metallization to environmental moisture, which may lead to premature damage to the capacitor. Embodiments described herein include capacitor structures that may have reduced exposed metallization in the termination surface. These reduced moisture entryways may be implemented by the implementation of cut-away regions, e.g., regions on the termination surface without the presence of exposed metallization. Embodiments described herein also include capacitor structures that implement a metallization density gradient that generates a soft gradient in physical characteristics of the material. Embodiments described herein may also implement different materials in non-metallized regions of the capacitor structure. These materials may present physical characteristics that substantially match the physical characteristics of the metallized region. The soft gradient and/or the matched physical characteristics may reduce the formation of micro fractures due to stress. 
     In an embodiment, a multilayer ceramic capacitor is described. The multilayer ceramic capacitor may have a lid and a floor region that include ceramic layers formed from a first ceramic material, and a middle region that includes ceramic layers formed from a second ceramic material, different from the first ceramic material. The ceramic layers of the middle region may include an electrode region. 
     In another embodiment, a multilayer ceramic capacitor is described. The multilayer ceramic capacitor may have ceramic layers having electrodes. A termination surface of the multilayer capacitors, which may be a surface that receives a terminal of the capacitor, may have a termination pattern formed by the exposed terminations of the electrodes of the ceramic layers. The termination pattern may include a cutaway region along the top of the multilayer capacitor device. 
     In another embodiment, a multilayer ceramic capacitor is described. The multilayer ceramic capacitor may have a first group of ceramic layers, with electrodes, and a second group of ceramic layers. The multilayer ceramic capacitor may be formed by stacking layers of the first group of ceramic layers and layers of the second group of ceramic layers to create a gradient of metallization density from the top towards the middle of the capacitor. 
     Embodiments of methods for production for capacitor structures are also described herein. In some embodiments of the method of production, processes for treating the non-metallized regions of the capacitor to change physical characteristics are described. In some embodiments of the method of production, processes for stacking ceramic layers to produce metallization gradient are described. In some embodiments, processes for stenciling ceramic layers that, when pressed, create a particular termination pattern are described. The processes described herein may be generally combined with methods of production of multilayer ceramic capacitors to introduce one or more of the features that improve reliability that are described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which: 
         FIG. 1  is a schematic block diagram of an electronic device that may benefit from the inclusion of one or more reliable capacitor structures, in accordance with an embodiment; 
         FIG. 2  is a perspective view of a notebook computer representing an embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 3  is a front view of a hand-held device representing another embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 4  is a front view of another hand-held device representing another embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 5  is a front view of a desktop computer representing another embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 6  is a front view and side view of a wearable electronic device representing another embodiment of the electronic device of  FIG. 1 , in accordance with an embodiment; 
         FIG. 7A  is a perspective view of a multilayer ceramic capacitor (MLCC), in accordance with an embodiment; 
         FIG. 7B  is a cross-section view of the multilayer ceramic capacitor of  FIG. 7A ; 
         FIG. 7C  is a detailed view of a region of the cross-section view of  FIG. 7B ; 
         FIG. 8A  is a perspective view of a MLCC with a chalice-shaped termination pattern, in accordance with an embodiment; 
         FIG. 8B  is a cross-section perspective view of the MLCC of  FIG. 8A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 9A  is a perspective view of a MLCC with a rounded cross-shaped termination pattern, in accordance with an embodiment; 
         FIG. 9B  is a cross-section perspective view of the MLCC of  FIG. 9A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 10A  is a perspective view of a MLCC with a cup-shaped termination pattern, in accordance with an embodiment; 
         FIG. 10B  is a cross-section perspective view of the MLCC of  FIG. 10A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 11A  is a perspective view of a MLCC with a rounded pyramidal-shaped termination pattern, in accordance with an embodiment; 
         FIG. 11B  is a cross-section perspective view of the MLCC of  FIG. 11A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 12A  is a perspective view of a MLCC with a H-shaped termination pattern, in accordance with an embodiment; 
         FIG. 12B  is a cross-section perspective view of the MLCC of  FIG. 12A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 13A  is a perspective view of a MLCC with a cross-shaped termination pattern, in accordance with an embodiment; 
         FIG. 13B  is a cross-section perspective view of the MLCC of  FIG. 13A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 14A  is a perspective view of a MLCC with a U-shaped termination pattern, in accordance with an embodiment; 
         FIG. 14B  is a cross-section perspective view of the MLCC of  FIG. 14A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 15A  is a perspective view of a MLCC with a T-shaped termination pattern, in accordance with an embodiment; 
         FIG. 15B  is a cross-section perspective view of the MLCC of  FIG. 15A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 16A  is a perspective view of a MLCC with a staircase-shaped termination pattern, in accordance with an embodiment; 
         FIG. 16B  is a cross-section perspective view of the MLCC of  FIG. 16A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 17A  is a perspective view of a MLCC with a pyramidal-shaped termination pattern, in accordance with an embodiment; 
         FIG. 17B  is a cross-section perspective view of the MLCC of  FIG. 17A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 18A  is a perspective view of a MLCC with a reduced height termination pattern, in accordance with an embodiment; 
         FIG. 18B  is a cross-section perspective view of the MLCC of  FIG. 18A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 19  is a cross section front view of an MLCC illustrating a region that may be used for a lid region or a floor region, in accordance with an embodiment 
         FIG. 20A  is a perspective view of a MLCC with low electrode density in a lid and floor region of the capacitor pattern, in accordance with an embodiment; 
         FIG. 20B  is a cross-section perspective view of the MLCC of  FIG. 20A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 21A  is a perspective view of a MLCC with low electrode density in a lid region of the capacitor pattern, in accordance with an embodiment; 
         FIG. 21B  is a cross-section perspective view of the MLCC of  FIG. 21A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 22A  is a perspective view of a MLCC with crenelated electrodes in a lid and floor region of the capacitor, in accordance with an embodiment; 
         FIG. 22B  is a cross-section perspective view of the MLCC of  FIG. 22A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 23A  is a perspective view of a MLCC with crenelated electrodes in a lid region of the capacitor, in accordance with an embodiment; 
         FIG. 23B  is a cross-section perspective view of the MLCC of  FIG. 23A  that illustrates its electrode disposition, in accordance with an embodiment; 
         FIG. 24A  is a perspective view of a MLCC with matched thermal expansion coefficient material along the body of the capacitor, in accordance with an embodiment; 
         FIG. 24B  is a cross-section perspective view of the MLCC of  FIG. 24A  that illustrates its electrode disposition and its cover material disposition, in accordance with an embodiment; 
         FIG. 25A  is a perspective view of a MLCC with matched thermal expansion material in a lid and a floor region of the capacitor, in accordance with an embodiment; 
         FIG. 25B  is a cross-section perspective view of the MLCC of  FIG. 25A  that illustrates its electrode and cover material disposition, in accordance with an embodiment; 
         FIG. 26A  is a perspective view of a MLCC with a staircase-shaped electrode termination and matched thermal expansion material along the body of the capacitor, in accordance with an embodiment; 
         FIG. 26B  is a cross-section perspective view of the MLCC of  FIG. 26A  that illustrates its electrode and cover material disposition, in accordance with an embodiment; 
         FIG. 27A  is a perspective view of a MLCC with a pyramidal shaped electrode termination and matched thermal expansion material in a lid and a floor region of the capacitor, in accordance with an embodiment; 
         FIG. 27B  is a cross-section perspective view of the MLCC of  FIG. 27A  that illustrates its electrode and cover material disposition, in accordance with an embodiment; 
         FIG. 28A  is a perspective view of a MLCC with reduced height termination pattern and matched thermal expansion material along the body of the capacitor, in accordance with an embodiment; 
         FIG. 28B  is a cross-section perspective view of the MLCC of  FIG. 28A  that illustrates electrode and the cover material disposition, in accordance with an embodiment; 
         FIG. 29A  is a perspective view of an MLCC with crenelated terminations in a lid region of the capacitor, and curved electrodes in a central and floor region of the capacitor, in accordance with an embodiment; 
         FIG. 29B  is a cross-section perspective view of the MLCC of  FIG. 29A  that illustrates its electrode and the cover material disposition, in accordance with an embodiment; 
         FIG. 30A  is a perspective view of an MLCC with pyramidal termination patterns and a mixture of right-angled and curved electrodes in a central and floor region of the capacitor, in accordance with an embodiment; 
         FIG. 30B  is a cross-section perspective view of the MLCC of  FIG. 30A  that illustrates its electrode and the cover material disposition, in accordance with an embodiment; and 
         FIG. 31  is a flow diagram illustrating a method to assemble an MLCC, such as the ones described herein. 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     Many electronic devices may employ capacitors for energy storage, tuning, impedance matching, noise filtering, and other functionalities. One such type of capacitor is the group of ceramic multilayer ceramic capacitor (MLCC) devices, e.g., capacitor devices that may be formed by multiple layers of ceramic sheets with stenciled or bonded electrode layers. Due to the distribution of electrode layers within the MLCC device, the distribution of certain material properties, such as thermal expansion coefficient, thermal capacity, piezoelectric coefficient, or rigidity, may be inhomogeneous through the capacitor body. As an example, regions with a high metal density, such as in the center of the MLCC device, may have a higher thermal coefficient when compared with regions with a lower metal density, such as in the periphery of the MLCC device. 
     Stresses associated with these material properties may lead to stress fractures to the MLCC over the course of its lifetime. For example, an MLCC that undergoes variations of temperature may present fractures (e.g., micro fractures) in the interface between regions with different thermal coefficient or thermal coefficient. An MLCC subject to high frequency signals may be subject to piezoelectric vibrations, which may cause stress fractures in the interface between regions with different piezoelectric coefficients or rigidity constants. 
     To improve the life cycle of electronic devices employing capacitors, the present application discusses capacitor devices that may present improved reliability when faced with potential stress damage. As detailed below, certain embodiments include capacitor structures that may have reduced moisture entryways. Reduced entryways may be implemented by reduction or removal of exposed metallization in regions that may be particularly vulnerable fractures, such as the top and/or the bottom of the capacitor structure. As a result of the reduced exposure of metallization to moisture, potential damage due to oxidative stress may be mitigated. 
     Other structures described herein may improve reliability by decreasing the amount of damage due to physical stress. Embodiments may include structures that create a soft gradient in the physical characteristics of the body of the capacitor, by reducing the opportunity for the presence of fractures. Softer gradients may be implemented by selective use of ceramic layers with increasing electrode metallization. Softer gradients may also be implemented by including ceramic layers with no metallization between electrode layers. Some embodiments may decrease the gradients in physical characteristics by employing different materials or modifications to materials in regions without metallization, such that the non-metallized regions and the metallized regions may have matched physical characteristics. Also included are embodiments that employ a combination of the features described above. Embodiments of methods for production of the capacitor structures including the above-described features, and embodiments of electronic devices that make use of the more reliable capacitor structures are also included herein. 
     With the foregoing in mind, a general description of suitable electronic devices that may benefit from the reliable capacitor structures described herein is provided below. Turning first to  FIG. 1 , an electronic device  10  according to an embodiment of the present disclosure may include, among other things, one or more processor(s)  12 , memory  14 , nonvolatile storage  16 , a display  18 , input structures  22 , an input/output (I/O) interface  24 , a network interface  26 , and a power source  28 . The various functional blocks shown in  FIG. 1  may include hardware elements (including circuitry that may make use of the MLCC embodiments described herein), software elements (including computer code stored on a computer-readable medium) or a combination of both hardware and software elements. It should be noted that  FIG. 1  is merely one example of a particular implementation and is intended to illustrate the types of components that may be present in electronic device  10 . 
     By way of example, the electronic device  10  may represent a block diagram of the notebook computer depicted in  FIG. 2 , the handheld device depicted in  FIG. 3 , the tablet device depicted in  FIG. 4 , the desktop computer depicted in  FIG. 5 , the wearable electronic device depicted in  FIG. 6 , or similar devices. It should be noted that the processor(s)  12  and other related items in  FIG. 1  may be generally referred to herein as “data processing circuitry.” Such data processing circuitry may be embodied wholly or in part as software, firmware, hardware, or any combination thereof. Furthermore, the data processing circuitry may be a single contained processing module or may be incorporated wholly or partially within any of the other elements within the electronic device  10 . 
     In the electronic device  10  of  FIG. 1 , the processor(s)  12  may be operably coupled with the memory  14  and the nonvolatile storage  16  to perform various algorithms. Such programs or instructions executed by the processor(s)  12  may be stored in any suitable article of manufacture that includes one or more tangible, computer-readable media at least collectively storing the instructions or routines, such as the memory  14  and the nonvolatile storage  16 . The memory  14  and the nonvolatile storage  16  may include any suitable articles of manufacture for storing data and executable instructions, such as random-access memory, read-only memory, rewritable flash memory, hard drives, and optical discs. In addition, programs (e.g., an operating system) encoded on such a computer program product may also include instructions that may be executed by the processor(s)  12  to enable the electronic device  10  to provide various functionalities. 
     In certain embodiments, the display  18  may be a liquid crystal display (LCD). The display  18  may allow users to view images generated on the electronic device  10 . In some embodiments, the display  18  may include a touch screen, which may allow users to interact with a user interface of the electronic device  10 . Furthermore, it should be appreciated that, in some embodiments, the display  18  may include one or more organic light emitting diode (OLED) displays, or some combination of LCD panels and OLED panels. Display  18  may employ any of the capacitor structure embodiments described herein for filtering, energy storage, or signal integration. 
     The input structures  22  of the electronic device  10  may enable a user to interact with the electronic device  10  (e.g., pressing a button to increase or decrease a volume level). The I/O interface  24  may enable electronic device  10  to interface with various other electronic devices, as may the network interface  26 . The network interface  26  may include, for example, one or more interfaces for a personal area network (PAN), such as a Bluetooth network, for a local area network (LAN) or wireless local area network (WLAN), such as an 802.11x Wi-Fi network, or for a wide area network (WAN), such as a 3rd generation (3G) cellular network, 4th generation (4G) cellular network, long term evolution (LTE) cellular network, or long term evolution license assisted access (LTE-LAA) cellular network. 
     Network interfaces  26  such as the one described above may benefit from the use of tuning circuitry, impedance matching circuitry, or noise filtering circuits that may include reliable capacitor structures devices such as the ones described herein. As further illustrated, the electronic device  10  may include a power source  28 . The power source  28  may include any suitable source of power, such as a rechargeable lithium polymer (Li-poly) battery or an alternating current (AC) power converter. The power source  28  may benefit from the use of any of the capacitor embodiments described herein to provide filtering or energy storage functionalities. 
     In certain embodiments, the electronic device  10  may take the form of a computer, a portable electronic device, a wearable electronic device, or other type of electronic device. Such computers may include computers that are generally portable (such as laptop, notebook, and tablet computers) as well as computers that are generally used in one place (such as conventional desktop computers, workstations, or servers). In certain embodiments, the electronic device  10  in the form of a computer may be a model of a MacBook®, MacBook® Pro, MacBook Air®, iMac®, Mac® mini, or Mac Pro® available from Apple Inc. By way of example, the electronic device  10 , taking the form of a notebook computer  10 A, is illustrated in  FIG. 2  in accordance with one embodiment of the present disclosure. The depicted computer  10 A may include a housing or enclosure  36 , a display  18 , input structures  22 , and ports of an I/O interface  24 . In one embodiment, the input structures  22  (such as a keyboard or touchpad) may be used to interact with the computer  10 A, such as to start, control, or operate a GUI or applications running on computer  10 A. For example, a keyboard or touchpad may allow a user to navigate a user interface or application interface displayed on display  18 . 
       FIG. 3  depicts a front view of a handheld device  10 B, which represents one embodiment of the electronic device  10 . The handheld device  10 B may represent, for example, a portable phone, a media player, a personal data organizer, a handheld game platform, or any combination of such devices. By way of example, the handheld device  10 B may be a model of an iPod® or iPhone® available from Apple Inc. of Cupertino, Calif. The handheld device  10 B may include an enclosure  36  to protect interior components from physical damage and to shield them from electromagnetic interference. The enclosure  36  may surround the display  18 . The I/O interfaces  24  may open through the enclosure  36  and may include, for example, an I/O port for a hard-wired connection for charging or content manipulation using a standard connector and protocol, such as the Lightning connector provided by Apple Inc., a universal serial bus (USB), or other similar connector and protocol. 
     User input structures  22 , in combination with the display  18 , may allow a user to control the handheld device  10 B. For example, the input structures  22  may activate or deactivate the handheld device  10 B, navigate user interface to a home screen, a user-configurable application screen, or activate a voice-recognition feature of the handheld device  10 B. Other input structures  22  may provide volume control, or may toggle between vibrate and ring modes. The input structures  22  may also include a microphone may obtain a user&#39;s voice for various voice-related features, and a speaker may enable audio playback or certain phone capabilities. The input structures  22  may also include a headphone input may provide a connection to external speakers or headphones. 
       FIG. 4  depicts a front view of another handheld device  10 C, which represents another embodiment of the electronic device  10 . The handheld device  10 C may represent, for example, a tablet computer, or one of various portable computing devices. By way of example, the handheld device  10 C may be a tablet-sized embodiment of the electronic device  10 , which may be, for example, a model of an iPad® available from Apple Inc. of Cupertino, Calif. 
     Turning to  FIG. 5 , a computer  10 D may represent another embodiment of the electronic device  10  of  FIG. 1 . The computer  10 D may be any computer, such as a desktop computer, a server, or a notebook computer, but may also be a standalone media player or video gaming machine. By way of example, the computer  10 D may be an iMac®, a MacBook®, or other similar device by Apple Inc. It should be noted that the computer  10 D may also represent a personal computer (PC) by another manufacturer. A similar enclosure  36  may be provided to protect and enclose internal components of the computer  10 D such as the display  18 . In certain embodiments, a user of the computer  10 D may interact with the computer  10 D using various peripheral input devices, such as the keyboard  22 A or mouse  22 B (e.g., input structures  22 ), which may connect to the computer  10 D. 
     Similarly,  FIG. 6  depicts a wearable electronic device  10 E representing another embodiment of the electronic device  10  of  FIG. 1  that may be configured to operate using the techniques described herein. By way of example, the wearable electronic device  10 E, which may include a wristband  43 , may be an Apple Watch® by Apple, Inc. However, in other embodiments, the wearable electronic device  10 E may include any wearable electronic device such as, for example, a wearable exercise monitoring device (e.g., pedometer, accelerometer, heart rate monitor), or other device by another manufacturer. The display  18  of the wearable electronic device  10 E may include a touch screen display  18  (e.g., LCD, OLED display, active-matrix organic light emitting diode (AMOLED) display, and so forth), as well as input structures  22 , which may allow users to interact with a user interface of the wearable electronic device  10 E. 
     Electronic devices  10 A,  10 B,  10 C,  10 D, and  10 E described above may all employ the reliable capacitor structures in analog and/or digital circuitry such as in tuning circuits, impedance matching circuits, power decoupling circuits, filtering circuits, amplifiers, power controllers, integrating circuitry, memory, data storage, and any other such circuitry that may employ use a capacitor. The use of the capacitors described herein may improve the electronic devices  10  by improving the lifetime, the thermal tolerance, the moisture tolerance, and/or water resistance of the electronic device  10 . 
       FIG. 7A  provides an illustration of an MLCC device  102 . The MLCC device  102  may include a body  104 , which contains the electrodes and the dielectric layers that provides the capacitance of the MLCC device  102 . A first terminal  106  and a second terminal  108 , located at two opposite ends of the capacitor, may be used to create electrical coupling between the MLCC device  102  and other circuitry. The illustrated MLCC device  102  may have a top  110  and a bottom  112 . When coupled to a flat printed circuit board (PCB), the bottom  112  is the surface of the MLCC device  102  that is the closest to the PCB, and the top  110  is the surface of the MLCC device that is opposite to the bottom  112 . 
       FIG. 7B  illustrates a cross-section of the MLCC device  102 . The cross-section view illustrates a series of electrodes  116  that are coupled to the first terminal  106 , and a series of electrodes  118  that are coupled to the second terminal  108 . The electrodes  116  and  118  are coupled, respectively, to terminals  106  and  108  through a termination surface  114 . As detailed below, the termination surface  114  may be a surface at an end of the body  104  of the MLCC device  102  that has exposed electrode terminations (i.e., terminations of the electrodes  116  or  118 ) for coupling with the metallization of the terminals  106  or  108 . Also illustrated in  FIG. 7B  are termination regions  115 A, and a capacitive region  115 B. 
     A region  120  in the top  110  of the MLCC device  102  close to the second terminal  108  is illustrated in detail in  FIG. 7C .  FIG. 7C  illustrates a potential path for moisture  122  to reach and damage electrodes  116  or  118 . As discussed above, the body  104  of the capacitor may be generally impermeable. However, the moisture  122  may be able to travel along the surface of the body  104 , including in the region between the body  104  and the second terminal  108 . The moisture  122  may, thus, reach the termination surface  114  and cause damage to the electrodes  118 , as illustrated. Therefore, capacitors that are exposed to moisture  122  from the top  110  of the MLCC device  102  may have the electrode terminations closest to the top  110  more susceptible to damage. Similarly, capacitors that are exposed to moisture  122  from the bottom  112  may have the electrode terminations closest to the bottom  112  more susceptible to damage. Thus, as detailed below, capacitors with reduced entryways in particular regions of the termination surface  114  may be more resilient against moisture damage. The  FIG. 7C  also illustrates a tab length  124  which may be the length of the termination region  115 A, or “keep out” region. 
     With the foregoing in mind, perspective view  130 A of  FIG. 8A  illustrates an embodiment of a capacitor structure  131  having a chalice-shaped termination pattern in the top  110  and bottom  112  of the termination surface  114 . The chalice regions  132  may be regions having no electrodes. As a result of the presence of the chalice regions  132 , the top  110  and bottom  112  of the capacitor structure  131  may be less susceptible to damage from moisture  122 , as discussed above. The cross-section perspective view  130 B of  FIG. 8B  illustrates the electrode arrangement of the capacitor structure  131 . As illustrated, the chalice regions  132  (i.e., regions without conductive electrodes) extend along the body of the capacitor. 
     The perspective view  140 A of  FIG. 9A  illustrates an embodiment of a capacitor structure  141  having a rounded cross-shaped termination pattern in its termination surface  114 . The round cutaway regions  142  may be regions having no electrode metallization. As a result of the presence of the cutaway regions  142 , the top  110  and bottom  112  of the capacitor structure  141  may be less susceptible to damage from moisture  122 . The cross-section perspective view  140 B of  FIG. 9B  illustrates the electrode arrangement of the capacitor structure  141 . As illustrated, the cutaway regions  142  (i.e., regions without conductive electrodes) extend along the body of the capacitor. 
     The perspective view  150 A of  FIG. 10A  illustrates an embodiment of a capacitor structure  151  having a rounded cup-shaped termination pattern in its termination surface  114 . A chalice region  152 , which may be similar to the above-described chalice region  132 , may be a region with no electrodes. As a result, the top  110  of the capacitor structure  151  may be less susceptible to damage from moisture  122 . This arrangement may improve the reliability of the capacitor without the substantial reduction of electrodes, as in the capacitor structure  131  discussed above. The cross-section perspective view  150 B of  FIG. 10B  illustrates the electrode arrangement of the capacitor structure  151 . As illustrated, the chalice region  152  (i.e., the regions without conductive electrodes) extends along the body of the capacitor. 
     The perspective view  160 A of  FIG. 11A  illustrates an embodiment of a capacitor structure  161  having a rounded pyramidal-shaped termination pattern in its termination surface  114 . Round cutaway regions  162 , which may be similar to the above-described round cutaway regions  142 , may be regions of the body of the capacitor structure  161  with no electrodes. As a result, the top  110  of the capacitor structure  161  may be less susceptible to damage from moisture  122 . This arrangement may improve the reliability of the capacitor without the substantial reduction of electrodes, as in the capacitor structure  141  discussed above. The cross-section perspective view  160 B of  FIG. 11B  illustrates the electrode arrangement of the capacitor structure  161 . As illustrated, the round cutaway regions  162  (i.e., the regions without conductive electrodes) extend along the body of the capacitor. 
     The termination patterns in the termination surface  114  of the MLCC devices described include curved cutaway regions (i.e., regions without terminations). The cutaway regions may also be straight, as in the embodiments described below. The perspective view  170 A of  FIG. 12A  illustrates an embodiment of a capacitor structure  171  having an H-shaped termination pattern in its termination surface  114 . The cutaway regions  172  may be regions having no electrodes. As a result of the presence of the cutaway regions  172 , the top  110  and bottom  112  of the capacitor structure  171  may be less susceptible to damage from moisture  122 . The cross-section perspective view  170 B of  FIG. 12B  illustrates the electrode arrangement of the capacitor structure  171 . As illustrated, the cutaway regions  142  (i.e., regions without conductive electrodes) is formed by removing electrode material in the termination regions  115 A of the capacitor structure  171 . Note that, by employing this design, the capacitance of the capacitor structure  171  may be similar to that of a capacitor structure with a regular termination pattern in its termination surface  114 . 
     The perspective view  180 A of  FIG. 13A  illustrates an embodiment of a capacitor structure  181  having a cross-shaped termination pattern in its termination surface  114 . The cutaway regions  182  in the termination surface  114  (i.e., regions without electrodes) are straight cutaways. As a result of the presence of the cutaway regions  182 , the top  110  and bottom  112  of the capacitor structure  181  may be less susceptible to damage from moisture  122 . The cross-section perspective  180 B of  FIG. 13B  illustrates the electrode arrangement of capacitor structure  181 . As illustrated, the cut away regions  182  (i.e., regions without no conductive electrodes) are the termination regions  115 A of the capacitor structure  181  and do not extend into the capacitive region  115 B. By employing this design, the capacitance characteristics of the capacitor structure  181  may be substantially similar to that of a regular capacitor structure (i.e., without cutaway regions) using the similar materials and similar dimensions. 
     The perspective view  190 A of  FIG. 14A  illustrates an embodiment of a capacitor structure  191  having a U-shaped termination pattern in its termination surface  114 . The cutaway region  192 , which may be similar to the above-described cutaway region  172  of capacitor structure  171 , may be a region of the termination region  115 A of capacitor structure  191  without electrode materials. As a result, the top  110  of the capacitor structure  191  may be less susceptible to damage from moisture  122 . The cross-section perspective view  190 B of  FIG. 14B  illustrates the electrode arrangement of the capacitor structure  191 . As illustrated, the cutaway region  192  is in the termination region  115 A of the capacitor structure  191  and does not necessarily extend into the capacitive region  115 B. By employing this design, the capacitance characteristics of the capacitor structure  181  may be substantially similar to that of a regular capacitor structure (i.e., without cutaway regions) using the similar materials and similar dimensions. 
     Perspective view  200 A of  FIG. 15A  illustrates an embodiment of a capacitor structure  201  having a T-shaped termination pattern in its termination surface  114 . The cutaway regions  202 , which may be similar to the above-described cutaway region  182  of capacitor structure  181 , may be regions of the termination region  115 A of capacitor structure  191  without electrodes. As a result, the top  110  of the capacitor structure  191  may be less susceptible to damage from moisture  122 . The cross-section perspective view  200 B of  FIG. 15B  illustrates the electrode arrangement of the capacitor structure  201 . As illustrated, the cutaway regions  202  are in the termination region  115 A of the capacitor structure  201 , and do not necessarily extend into the capacitive region  115 B. By employing this design, the capacitance characteristics of the capacitor structure  201  may be substantially similar to that of a regular capacitor structure (i.e., without cutaway regions) using the similar materials and similar dimensions. 
     Perspective view  210 A of  FIG. 16A  illustrates an embodiment of a capacitor structure  211  having a staircase-shaped termination pattern in its termination surface  114 . The staircase shape may be defined by the exposed terminations of electrodes in the termination surface  114 . The cutaway region  212 , may be regions of the capacitor structure  211  without electrodes. As a result, the top  110  of the capacitor structure  211  may be less susceptible to damage from moisture  122 . The cross-section perspective view  210 B of  FIG. 16B  illustrates the electrode arrangement of the capacitor structure  211 . As illustrated, the cutaway region  212  is in the termination region  115 A of the capacitor structure  211  and does not necessarily extend into the capacitive region  115 B. By employing this design, the capacitance characteristics of the capacitor structure  211  may be substantially similar to that of a regular capacitor structure (i.e., without cutaway regions) using the similar materials and similar dimensions. 
     Perspective view  220 A of  FIG. 17A  illustrates an embodiment of a capacitor structure  221  having a pyramidal termination pattern in its termination surface  114 . The pyramid shape may be defined by the exposed terminations of electrodes in the termination surface  114 . The cutaway regions  222 , may be regions of the capacitor structure  221  without electrodes. As a result, the top  110  of the capacitor structure  221  may be less susceptible to damage from moisture  122 . The cross-section perspective view  220 B of  FIG. 16B  illustrates the electrode arrangement of the capacitor structure  221 . As illustrated, the cutaway regions  222  are in the termination region  115 A of the capacitor structure  220 , and do not necessarily extend into the capacitive region  115 B. By employing this design, the capacitance characteristics of the capacitor structure  221  may be substantially similar to that of a regular capacitor structure (i.e., without cutaway regions) using the similar materials and similar dimensions. 
     The capacitor structures  131 ,  141 ,  151 ,  161 ,  171 ,  181 ,  191 ,  201 ,  211 , and  221  described above employ horizontal electrodes, electrodes that are parallel to the bottom surface of the capacitor structure. Cutaway regions in a top or bottom of a capacitor structure may also be obtained using vertical electrodes, electrodes that are perpendicular to the bottom surface of the capacitor structure. Perspective view  230 A of  FIG. 18A  illustrates an embodiment of a capacitor structure  231  having a reduced height termination pattern in its termination surfaces  114 . The electrode terminations exposed in the termination surface are vertical (i.e., perpendicular to the bottom surface of the capacitor structure). 
     The reduced height shape in the termination surface is defined by a limited height of the exposed electrode terminations in the termination surface  114 . The cutaway region  232 , may be regions of the capacitor structure  231  without electrodes. As a result, the top  110  of the capacitor structure  231  may be less susceptible to damage from moisture  122 . The cross-section perspective view  230 B of  FIG. 18B  illustrates the electrode arrangement of the capacitor structure  231 . As illustrated, the cutaway region  232  is in the termination may have a length  234 , and the electrodes may be tapered in this region. The cutaway region  232  may be in the termination region  115 A of the capacitor structure  231  and does not necessarily extend into the capacitive region  115 B. By employing this design, the capacitance characteristics of the capacitor structure  211  may be substantially similar to that of a regular capacitor structure (i.e., without cutaway regions) using the similar materials and similar dimensions. 
     In the capacitor structures  131 ,  141 ,  151 ,  161 ,  171 ,  181 ,  191 ,  201 ,  211 ,  221 , and  221  described above, the potential damage caused to the capacitor by potential moisture (e.g., moisture  122 ) is mitigated by limiting the amount of exposed terminations in the termination surface  114 . As discussed above, the environmental exposure of the termination surface  114  may result from stresses in the body of the capacitor due to mismatch of physical characteristics in regions with different metallization density in the capacitor. This type of mismatch is illustrated in the front view  300  of an MLCC device  301 , in  FIG. 19 . The MLCC device  301  may have a body  104  and terminals  106  and  108 . The top  110  of the MLCC device  301  may have a lid region  302  and the bottom  112  of the MLCC device  301  may have a floor region  304 , which are characterized by an absence of electrode metallization. By contrast, the middle region  306  may have dense electrode metallization embedded between the dielectrics. Conventionally, the ceramic material between the electrodes in the middle region  306  may be the same material as the ceramic material in the lid region  302  and the floor region  304 . However, the presence of the electrode metallization may impact aggregate physical characteristics of the material in the region, such as thermal capacity, thermal expansion coefficient, piezoelectric coefficient, and/or rigidity. As a result, these physical characteristics in the lid region  302  and/or the floor region  308  may be distinct from the physical characteristics in the middle region  306 . As discussed above, this mismatch in the physical characteristics of the material may cause micro fractures in the body  104  of the MLCC device  301  during regular usage, which increases vulnerability of the MLCC device  301  to moisture damage. 
     With the foregoing in mind, the perspective view  350 A of  FIG. 20A  illustrates an embodiment of a capacitor structure  351  having variable density of metallization. The variable density of the metallization is generated by a variable electrode density, which may be observed in the termination pattern exposed in the termination surface  114 . The capacitor structure  351  may have low electrode density  352  in the lid region  302  and floor region  304 , and may have a high electrode density  354  in the middle region  306 . As a result of the presence of electrodes in the lid region  302  and floor region  304 , the mismatch in the physical characteristics between materials in these regions and materials in the middle region  306  may be reduced. This may decrease the presence micro fractures over time and may prevent the permeabilization of the capacitor structure  351 , and resulting moisture damage. 
     The cross-section perspective view  350 B of  FIG. 20B  further illustrates the variable density in the electrode arrangement of the capacitor structure  351 . As illustrated, the regions with low electrode density  352  may be present sparse metallization relative to the high electrode density region  354 . It should be noted that, in order to preserve the nominal capacitance of the capacitor structure  351 , the separation between adjacent electrodes  356  that form capacitive coupling in the region with low electrode density  352  may be substantially similar to the separation between adjacent electrodes  358 , in the region of high electrode density  354 . The increased separation in the low electrode density region  352  is obtained by increasing the separation between the pairs of electrodes, as illustrated. By employing this design, the mismatch in the physical characteristics may be reduced, and the capacitor may have an improved lifetime. 
     The perspective view  360 A of  FIG. 21A  illustrates an embodiment of another capacitor structure  361  having variable density of electrodes. The variable density of the electrodes is observed in the termination pattern exposed in the termination surface  114 . The capacitor structure  361  may have low electrode density  352  in the lid region  302 , and may have high electrode density  354  in the middle region  306  and the floor region  304 . As with the capacitor structure  351  described above, the presence of electrodes in the lid region  302  decreases differences in the physical characteristics between the regions with low electrode density  352  and high electrode density  354 . Moreover, the floor region  304  of the capacitor structure  361  has the same electrode density as the middle region  306  and, thus, substantially decreasing any mismatch in the physical characteristics. As a result, capacitor structure  361  may present less micro fractures over time and, further, may prevent moisture damage due to permeabilization. 
     The cross-section perspective view  360 B of  FIG. 21B  further illustrates the variable density in the electrode arrangement of the capacitor structure  361 . As illustrated, the regions with low electrode density  352  may have less metallization relative to the high electrode density region  354 . It should be noted that, in order to preserve the nominal capacitance of the capacitor structure  351  the separation between adjacent electrodes  356  that form capacitive coupling in the region with low electrode density  352  may be substantially similar to the separation between adjacent electrodes  358 , in the region of high electrode density  354 . 
     The capacitor structures  351  and  361  described above may have a variable metallization density that is obtained by changing the space between neighboring pair of plates in the lid region  302  and/or floor region  304 . This variable density region, which reduces mismatch in the physical characteristics, may also be obtained by reducing the area of the electrodes in the lid region  302  and/or floor region  304 . The perspective view  370 A of  FIG. 22A  illustrates an embodiment of a capacitor structure  371  having a variable density of the electrode metallization using a crenelated electrode arrangement. The arrangement of electrodes in capacitor structure  371  is illustrated in the termination pattern exposed in the termination surface  114 . The capacitor structure  371  may have crenelated electrode patterns  372  and  374 , both in the lid region  302  and floor region  304 . The middle region  306  and may present regular electrode arrangement  376  in the middle region  306 . The cross-section perspective view  370 B of  FIG. 22B  further illustrates the variable density in the electrode arrangement along the body of the capacitor structure  371 . As illustrated, the lid region  302  and floor region  304  may present sparse metallization relative to the middle region  306  by having the crenelated pattern along the entire body of the capacitor. The crenelated pattern may be implemented along the border by the use of adequately placed electrode strips. It should be noted that the crenelated pattern allows a decreased metallization density without an increased spacing between parallel electrodes in different layers. 
     In the capacitor structure  371 , the crenelated electrode pattern  372  may present a lower metallization density than the crenelated electrode pattern  374 . Furthermore, the crenelated electrode pattern  374  may present a lower metallization density than the regular electrode arrangement  376 . As a result, the capacitor structure  371  presents a metallization density gradient from the bottom  112  and from the top  110  of the capacitor structure  371  towards the middle region  306 . That is, the metallization gradient in capacitor structure  371  gradually decreases from the middle region  306  towards the bottom  112  and towards the top  110 . The gradual change of metallization density may lead to a more gradual change in the physical characteristics discussed herein. The gradual change in the physical characteristics may prevent micro fractures from forming when the capacitor is under stress. Accordingly, the use of the crenelated pattern to generate a gradient in metallization density may decrease the presence micro fractures over time and may prevent the permeabilization of the capacitor structure  371 . 
     The perspective view  380 A of  FIG. 23A  illustrates another embodiment of a capacitor structure  381  having a crenelated electrode arrangement. The crenelated pattern is illustrated the termination pattern exposed in the termination surface  114 . As illustrated, the lid region  302  may have crenelated patterns  382 ,  384 ,  386 , and  388 , and the middle region  306  and floor region  304  may have a regular electrode arrangement  389 . The cross-section perspective view  380 B of  FIG. 23B  further illustrates the crenelated patterns  382 ,  384 ,  386 , and  388  along the body of the capacitor structure  381 . In the capacitor structure  381 , the lid region  302  presents a more granular gradient in the metallization. 
     The metallization density in the crenelated pattern  382  is smaller than in the crenelated pattern  384 , the metallization density in the crenelated pattern  384  is smaller than in the crenelated pattern  386 , and the metallization density in the crenelated pattern  386  may be smaller than in the crenelated pattern  388 . That is, there is a 5-step gradient in the metallization density from the top  110  of the capacitor structure  381  towards the regular electrode arrangement  389  in the middle region  306 . The increase in the granularity of the metallization density, and the associated increase in the granularity of physical characteristics, may lead to a decrease in micro fractures caused by usage stress in the capacitor structures  371 . 
     The reduction in the mismatch of physical characteristics within an MLCC capacitor may also be obtained by changing the material used the non-metallized regions of the capacitor. The perspective view  390 A of  FIG. 24A  illustrates an embodiment of a capacitor structure  391  that may employ distinct materials. The capacitor structure  391  may have a non-metallized portion  392  and a metallized portion  394 . As illustrated, the non-metalized portion  392  encapsulates the metalized portion  394 . The cross-section perspective view of  390 B of  FIG. 24B  illustrates the disposition of the electrodes in the metallized portion  394 . Note that the geometrical arrangement of the electrodes may be similar to that of a conventional multilayer ceramic capacitor. 
     As discussed above, the metalized portion  394  may be formed from a first substrate material (e.g., a first ceramic material) and a conductive material (e.g., the conductive electrodes). In the capacitor structure, the non-metalized portion  392  may be formed from a second substrate material, which may be a different ceramic material or a modification of the first ceramic material. The second substrate material may be chosen to generate a match between the physical characteristics of the non-metallized portion  392  and the metallized portion  394 . The choice of materials or modifications for the materials that may be used to form the non-metallized portion  392  and the metallized portion  394  is detailed below. 
     MLCCs may be produced by stacking ceramic layer sheets with stenciled electrode regions, as detailed below. Thus, in capacitor structure  391  a ceramic sheet may have an electrode region which may be part of the metallized portion  394  and a region without any electrode region, which may be in the non-metallized portion  392 . Therefore, formation of capacitor structure  391  may include a step for modifying the ceramic substrate in the non-metallized portion  392 , which is detailed below, in the discussion of the method described in  FIG. 31 . 
     In certain applications, the mismatch in physical characteristics on the interface between the top and/or the bottom of the capacitor and the metallized regions may be the particularly vulnerable to the effects from mismatch, discussed above. The perspective view  400 A of  FIG. 25A  illustrates an embodiment of a capacitor structure  401  that may employ distinct materials to mitigate mismatch using a simpler manufacturing process. As with the capacitor structure  391 , capacitor structure  401  may have a non-metallized portion, formed by layers  402  and by portions  406 , as well as a metallized portion  404 . Layers  402  may be disposed in the lid region  302  and the floor region  304  of the capacitor. Portions  406  and the metallized portion  404  may be in the middle region  306  of the capacitor. The cross-section perspective view of  400 B of  FIG. 25B  illustrates the disposition of the electrodes in the metallized portion  404 . Note that the geometrical arrangement of the electrodes may be similar to that of a conventional multilayer ceramic capacitor. 
     In the capacitor structure  391 , the ceramic layers in the middle region  306  of the capacitor may be formed from a first substrate material (e.g., a first ceramic material), and the ceramic layers of layers  402 , in the lid region  302  and the floor region  304 , may be formed from a second substrate material. The second substrate material may be chosen to generate a match between the physical characteristics of the layers  402  and the metallized portion  404  in the middle region  306 . It should be noted that, while the capacitor structure  401  may be produced employing a simpler manufacturing process relative to the manufacturing of capacitor structure  391 , there may be a mismatch of physical characteristics between portions  406  and the metalized portion  404 , along the middle region  306 . 
     Capacitor structures that combine concepts discussed above, such as the use of mixed materials to prevent formation of micro fractures, and reduced termination patterns to decrease potential exposure to moisture are also disclosed herein. For example, the capacitor structure  411  illustrated in the perspective view  410 A of  FIG. 26A  and the cross-section perspective view  410 B of  FIG. 26B  may have a stair-case-shaped termination pattern in the termination surface  114  with a cutaway region  212 , similar to the ones discussed with respect to capacitor structure  211  of  FIGS. 16A and 16B . The capacitor structure  411  may also employ different materials (e.g., different substrates or modification of a common substrate) in the non-metallized portion  392  that encapsulates the metallized portion  394 , as discussed with respect to capacitor structure  391  of  FIGS. 24A and 24B . As such, the combination of the concepts may provide a combination of the characteristics for improved reliability. The capacitor may be less susceptible to the formation of micro fractures and, further, may be less susceptible to damage in the presence of the micro fractures. 
     In another example that employs combination of concepts for improved reliability described above, a capacitor structure  421  illustrated in the perspective view  420 A of  FIG. 27A  and the cross-section perspective view  420 B of  FIG. 27B  may have reduced metallization in the termination pattern and a combination of materials for matching of physical properties. A pyramidal termination pattern in the termination surface  114  with cutaway regions  222 , similar to the one discussed with respect to capacitor structure  221  of  FIGS. 17A and 17B , may provide reduced exposure of the metallization to moisture. Moreover, the capacitor structure  421  may also employ different materials (e.g., different substrates or modifications of a common substrate) in the lid region  302 , floor region  304 , and middle region  306  to decrease mismatch in physical characteristics and reduce the vulnerability of the capacitor structure  421  to formation of micro fractures, as discussed with respect to capacitor structure  401  of  FIGS. 25A and 25B . The combination of the reliability improvement concepts in capacitor structure  421  may make it less susceptible to the formation of micro fractures and less susceptible to damage in the presence of the micro fractures due to moisture  122 . 
     In another example, the capacitor structure  431 , illustrated by the perspective view  430 A of  FIG. 28A  and the cross-section perspective view  430 B of  FIG. 28B , may also have a combination of a reduced metallization in the termination pattern and a combination of materials for matching of physical characteristics. Capacitor structure  431  may employ horizontal electrodes, i.e., electrodes perpendicular to the bottom surface of the capacitor structure. The termination surface  114  may have a reduced height termination pattern, defined by a limited height of the exposed electrode termination along the termination surface  114  and the cutaway region  232  without metallization. The reduced-height termination pattern may decrease the susceptibility of the capacitor to damage from exposure to moisture  122 . The capacitor structure  431  may also employ different materials (e.g., different substrates or modification of a common substrate) in the non-metallized portion  392  that encapsulates the metallized portion  394 , similar to capacitor structure  391  of  FIGS. 24A and 24B . The combination of the reliability improvement concepts in capacitor structure  431  may make it less susceptible to the formation of micro fractures and less susceptible to damage in the presence of the micro fractures. 
     While the above descriptions may refer to certain structures that implement the above-described reliability improvement concepts and features, it should be understood that other electrode shapes, electrode terminations, and materials may be used to implement the above-described concepts. Capacitor structure  441 , illustrated in perspective view  440 A and cross-section perspective view  440 B, and capacitor structure  451 , illustrated in perspective view  450 A and cross-section perspective view  450 B are examples of embodiments that may mix different geometries to implement the concepts. 
     Capacitor structure  441 , in  FIGS. 29A and 29B , may combine reduced exposed metallization with decreased mismatching in physical characteristics of the capacitor. The capacitor structure  441  may have reduced exposed metallization in its termination surface  114  by a mixture of staircase shaped electrode terminations  443  and reduced width electrode terminations  445 . The staircase shaped electrode terminations  443  may be defined by the cutaway regions  442 , which may be staircase-shaped cutaway regions. The cutaway regions  442  may be limited to the “keep out” region  448 . The reduced width electrode terminations  445  may be defined by cutaway regions  444 , which may be perpendicular cutaway regions. It should be noted that the cutaway regions  444  may be implemented by use of curves  446  in the electrode shape. The cutaway regions  442  and  444  may reduce the potential exposure to moisture  122 , as discussed above. The capacitor structure  441  may also employ different materials (e.g., different substrates or modification of a common substrate) in the non-metallized portion  392  that encapsulates the body of the capacitor, to decrease mismatches in the physical characteristics of the capacitor and, thus, reduce the susceptibility to the formation of micro fractures, as discussed above. 
     Capacitor structure  451 , in  FIGS. 30A and 30B , may also combine reduced exposed metallization with decreased mismatching in physical characteristics of the capacitor. The capacitor structure  451  may have reduced exposed metallization in its termination surface  114  by a mixture of pyramid shaped electrode terminations  454  and reduced width electrode terminations  455 . The pyramid shaped electrode terminations  454  may be defined by the cutaway regions  453 . The reduced width electrode terminations  455  may be defined by cutaway regions  452 . Cut away regions  452  may be implemented with curves  456  in the electrode shape in the “keep out” region. The cutaway regions  452  and  453  may reduce the potential exposure to moisture  122 , as discussed above. The capacitor structure  451  may also employ different materials (e.g., different substrates or modification of a common substrate) the capacitor structure  421  may also employ different materials (e.g., different substrates or modifications of a common substrate) in layers  402  in the lid region  302  and floor region  304 , and the layers in the middle region  306 . This arrangement may decrease mismatch in physical characteristics and reduce the formation of micro fractures in the interface between layers  402  and the metallized layers in the middle region  306 . 
     Several of the embodiments illustrated above may be implemented as multilayer ceramic capacitors. The flow diagram in  FIG. 31  illustrates a method  600  that may be used to manufacture capacitors such as the multilayer ceramic capacitors with reduced entryways and/or matched physical characteristics described herein. The method  600  may illustrate the formation of a capacitor with a U-shaped pattern, such as in capacitor structure  191 , and that employs matched physical characteristics between metallized and non-metallized regions, such as in capacitor structure  391 . However, it should be noted that all embodiments described herein may be manufactured with the method  600 , with the appropriate modifications to electrode layout, stacking arrangement, and/or choice of materials. The method  600  may employ a first set of ceramic green sheets  606  that may be used to form a first set of electrodes, to be coupled to a first terminal and a second set of ceramic green sheets  608  that may be used to form a second set of electrodes, to be coupled to a second terminal of the capacitor structure. 
     In a process  610 , electrode layers may be formed in the ceramic green sheets  606  and  608  by applying (e.g., stenciling) a conductive material to specific regions of the surface of the ceramic green sheets to produce layers, such as layers  607 A,  607 B,  607 C,  607 D, and  607 E. The formation of reduced termination patterns, discussed above, may take place in the process  610 , by the appropriate design for the electrode shapes. In the illustrated example, appropriate application of the conductive materials in layers  607 A and  607 B may be used to implement the cutaway regions in the termination surface (e.g., cutaway region  192  in capacitor structure  191 ). To that end, the electrode region  616 A in layer  607 A may outline a portion  650 A along an edge of the layer  607 A. Similarly, the electrode region  618 A may outline a portion  650 B along an edge of the layer  607 B to form a cutaway region. By contrast, electrode regions  616 B and  618 B, in layers  607 C,  607 D, and  607 E do not include any cutaway portion, as these layers may be located in regions of the capacitor structure without a cutaway region. 
     In some embodiments of capacitor structures with electrode density gradient, the electrode layers may have non-contiguous electrodes to implement the different gradients, such as in as capacitor structures  371  and  381 . To produce these types of capacitor structures, the process  610  may be adjusted to produce the correct electrode layout, outlining regions without conductive material. In embodiments of capacitor structures showing curved termination patterns, such as in capacitor structures  131 ,  141 ,  151 , and  161 , each ceramic sheet may have an electrode region with a distinct cutaway portion. As such, the process  610  may adjusted to allow individual application of the conductor material to each ceramic sheet. 
     As discussed above, in certain embodiments, modifications to the non-metallized region, that encapsulates the metallized region, is applied. Embodiments in which this type of modification is applied include capacitor structures  411 ,  431 , and  441 . To assemble these capacitor structures, modification of layers may be used. In a process  612 , the non-electrode portions of a ceramic sheet may be modified (e.g., receive a treatment) to modify physical characteristics of the non-metallized areas. For example, the non-metallized region  617 A in layer  607 A may receive a treatment, which may be an addition of impurities (e.g., doping, application of a coating) to adjust physical characteristics of the non-metallized region  617 A. 
     The process  612  may include the use of masking processes (e.g., photolithography) to target the non-metallized region  617 A specifically, without unintentional modification of the electrode region  616 A. In some embodiments, process  612  may include replacement of the non-metallized region  617 A by cutting the original region and attaching a non-metallized region  617 A formed from a different material. Non-metallized regions  619 A,  617 B, and  619 B illustrated in one of the layers  607 B,  607 C,  607 D, and  607 E, may receive similar treatment. The specific materials and treatments that may be used in process  612  to generate matched physical characteristics are detailed below. 
     The layers produced may be stacked and pressed in a process  620  to form a capacitor structure  622 . The stack of ceramic layers may have one or more layers  616  to form a lid region (e.g., lid region  302 ) and one or more layers  618  to form a floor region (e.g., floor region  304 ) of the capacitor structure  622 . The ceramic sheets that form the layers  616  and  618  may receive modifications similar to the ones received by the non-metallized regions of the body, such as non-metallized regions  617 A,  617 B,  619 A, and  169 B in process  612 . In implementations of the method  600  that include modification of the substrate in the lid regions  302  and/or floor regions  304  without modifications in the non-metallized regions of the middle region  306 , such as capacitor structures  401 ,  421 , and  451 , the layers  616  and/or  618  may receive modifications or may be formed from substrates that provide matching of physical characteristics with the metallized regions, as discussed above. In embodiments that employ plain ceramic sheets to provide a gradient of metallization density, such as capacitor structures  651  and  361 , plain ceramic sheets may be placed between ceramic sheets having electrodes. Following the pressing of the sheets, the capacitor may be cut to the final dimensions, and the termination surface may present the desired termination pattern. 
     In order to produce the capacitor structures above, the body of the dielectric material may include any of the ceramic materials employed in capacitor manufacturing, including, but not limited to X5R and/or X7R ceramic materials, as classified under the Electronic Industries Alliance (EIA) Standard EIA RS-198. The electrode materials may include copper, nickel, silver, a copper alloy, a nickel alloy, or a silver alloy, among other conductors. External electrodes (e.g., electrode coating along the termination surface) may be formed using glass frits coated with nickel, copper coated with nickel or tin coated with tin, among other materials, and may or may not include intermediate conductive layers. 
     The materials and/or modifications in non-metallized regions may be chosen to match specific physical characteristics of the capacitor structure. For example, a thermal coefficient for the mixture of ceramic and electrode materials in a metallized region of a capacitor may be about 10.8×10 −6 /° C. at 350° C. and 17.5×10 −6 /° C. at 1050° C. Ceramic materials that form a substrate, may have a distinct thermal coefficient, as discussed above. Magnesium oxide, for example, may have a thermal coefficient of about 13.5×10 −6 /° C. and zirconium oxide may have a thermal coefficient of about 10.5×10 −6 /° C. The base thermal coefficient may be adjusted by mixture with materials, such as aluminum oxide, with thermal coefficient of about 7.6×10 −6 /° C., yttrium oxide with thermal coefficient of about 7.4×10 −6 /° C., and/or soda-lime glass with a thermal coefficient of about 9.0×10 −6 /° C. Moreover, compounds such as 2MgO SiO 2  with thermal coefficient of about 9.9×10 −6 /° C. or MgO SiO 2  with thermal coefficient of about 7.7×10 −6 /° C. may be used. In some embodiments, application of a nickel coating and oxidation of the nickel surface may be used. Nickel oxide may have a thermal coefficient of about 13.9×10 −6 /° C. Manganese oxide and cobalt oxide may be formed in a similar manner, with a coating application followed by oxidation. 
     The embodiments described herein may have a rated voltage between 2.5V and 25V. The rated capacitance may be substantially in an interval between 5.6 μF and 220 μF. In some of the embodiments, in which knowledge of the location of the top of the capacitor may be useful (e.g., capacitor structure  151 , in which the termination pattern is vertically asymmetric), an external marking in the capacitor structure to indicate the top side may be used. The external marking may employ design structures that facilitate processing by computer vision software, to facilitate use of the marked capacitors in an automated manufacturing facility. 
     The described capacitor structures may have floorplan dimensions that obey standards, such as EIA standard dimensions EIA 0805 (2.0×1.25 mm), EIA 0603 (1.6×0.8 mm), EIA 0402 (1.0×0.5 mm), or EIA 0201 (0.6×0.3 mm), to facilitate the design of printed circuit board design. The height of the capacitor structures may vary. In some embodiments the capacitor may have a height smaller than 0.3 mm, 0.5 mm, 0.8 mm, 1.0 mm, 1.25 mm, 1.26 mm, 1.6 mm, or 2.0 mm to facilitate design of the electrical device. Electrode strips and/or neighboring gaps may be applied (e.g., stenciled) at dimensions as small as 30 μm. The capacitors described above may have a recessed “keep out” region with a minimum dimension in a range between 20 and 50 μm. 
     The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure. 
     The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function] . . . ” or “step for [perform]ing [a function] . . . ” it is intended that such elements are to be interpreted under 35 U.S.C. § 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. § 112(f).

Metadata:
Filing Date: 20180928
Publication Date: 20201020
Grant Date: 20201020
Priority Date: 20180928
Inventors: MARTINEZ, PAUL A.
CHOI, WON SEOP
NING, GANG
Shah, Chirag V.
SCHAUER, MARTIN
MEAD, CURTIS C.
TSAI, MING YUAN
WANG, ALBERT
Assignee: APPLE INC
CPC Classifications: [{"code": "H01G4/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01G4/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/224", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/228", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/232", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/012", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01G4/0085", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/30", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01G4/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01G4/228", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 69946101