PRINTED CIRCUIT BOARD AND DEVICE INCLUDING THE SAME

A printed circuit board (PCB) having a decoupling capacitor includes: a PCB including a power supply layer, ground layer, and first decoupling capacitor; a package mounted at a surface of the PCB, wherein the first decoupling capacitor is embedded in a via hole of the PCB, and a first electrode of the first decoupling capacitor is connected to one of power supply pins of the package, and a second electrode of the first decoupling capacitor is connected to the ground layer.

DETAILED DESCRIPTION

FIGS. 3 through 8, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged electronic device. Hereinafter, exemplary embodiments of the present disclosure are described in detail with reference to the accompanying drawings. The same reference numbers are used throughout the drawings to refer to the same or like parts. The views in the drawings are schematic views only, and are not intended to be to scale or correctly proportioned. Detailed descriptions of well-known functions and structures incorporated herein can be omitted to avoid obscuring the subject matter of the present disclosure.

In the present disclosure, it means a direct connection or an indirect connection that an element (e.g., an IC) is connected to another element (e.g., a decap). Here, a direct connection means that another element is not interposed between two elements, and an indirect connection means that at least one element is interposed between two elements.

FIG. 3is a cross-sectional view illustrating a device according to an exemplary embodiment of the present disclosure. Referring toFIG. 3, a device300according to the present embodiment includes a PCB310including a first decap313and a second decap314, a PMIC320, a bulk capacitor330, a package340, an IC350, a third decap360, a fourth decap370, and bumps380.

The PCB310includes a power supply line311, ground line312, the first decap313, and the second decap314. The first decap313is positioned at the inside of the PCB310. Particularly, the first decap313is embedded in a via hole of the PCB310. The first decap313includes a first electrode313a,second electrode313b,and dielectric substance interposed between the electrodes313aand313b.The first electrode313ais exposed at a surface through a via hole of the PCB310, and the second electrode313bis connected to the ground line312. The first decap313prevents an instantaneous overcurrent A from being injected into the package340. That is, an overcurrent C is not injected into the package340and flows to the ground line312through the first decap313. Further, the first decap313receives supply of a current from the PMIC320, accumulates the current, and supplies an accumulated current D to the package340, thereby constantly maintaining an input voltage of the package340. The second decap314is formed similar to the first decap313. The PCB310is designed in a structure having several conductive layers (e.g., six layers and ten layers). An insulator is interposed between conductive layers. For example, the PCB310can have a six layer structure, and here, a third layer can be a power supply layer including the power supply line311and a four layer can be a ground layer including the ground line312. A sixth layer can be also a ground layer. The remaining layers each can be signal layers including a signal line. A structure of the PCB is not limited thereto. This is, for example, a second layer can be a power supply layer and a third layer can be a signal layer. The decaps313and314are embedded in a via hole that penetrates from a first layer (surface) to a ground layer, for example, a four layer or a sixth layer.

The PMIC320is mounted at a surface of the PCB310. A first electrode, i.e., a power supply electrode of the PMIC320is connected to the power supply line311through first via321, and a second electrode, i.e., a ground electrode is connected to the ground line312through second via322to supply power to the package340. Here, the first via321is an electric conductor (e.g., copper) inserted into a via hole that penetrates from a first layer (surface) to a layer (e.g., a third layer) having the power supply line311. The second via322is an electric conductor inserted into a via hole that penetrates from a first layer (surface) to a layer (e.g., a fourth layer) having a ground line313.

The bulk capacitor330is mounted at a surface of the PCB310and is positioned adjacent to the PMIC320. A first electrode of the bulk capacitor330is connected to the power supply line311through third via323, and a second electrode thereof is connected to the ground line312through fourth via324. The bulk capacitor330receives supply of a current from the PMIC320and accumulates a current. When an output voltage of the PMIC320is not stable, i.e., when a voltage drops, by supplying an accumulated current to the package340, the bulk capacitor330maintains a constant input voltage of the package340.

The package340includes a power supply line341, a ground line342, a plurality of power supply pins343ato343d,and a plurality of ground pins344ato344d.The pins343ato343dand344ato344dare positioned at a rear surface of the package340. The package340is mounted at a surface of the PCB310. The plurality of power supply pins343ato343deach are connected to the power supply line341through vias. The plurality of ground pins344ato344deach are connected to the ground line342through the vias. Particularly, at least one of the plurality of power supply pins343ato343dis connected to a decap positioned at the inside of the PCB310. For example, the first power supply pin343ais directly connected to the first electrode313aof the first decap313. The second power supply pin343dis directly connected to a first electrode314aof the second decap314. A length of a wiring that connects a power supply pin of the package and the decap is remarkably reduced, compared with another case (e.g.,FIG. 1). Therefore, PI is improved, and a decap is embedded at the inside of a PCB, compared with another case, and thus the PCB is free from restriction of mounted space and a wiring. Other power supply pins343band343ceach are connected to the power supply line311of the PCB310through vias.

The IC350is mounted at a surface of the package340. A first electrode, i.e., a power supply electrode of the IC350is connected to the power supply line341of the package340through via, and a second electrode, i.e., a ground electrode is connected to the ground line342of the package340through via.

The third decap360is mounted at a surface of the package340. A first electrode of the third decap360is connected to the power supply line341of the package340through via, and a second electrode thereof is connected to the ground line342of the package340through via. The fourth decap370is formed similar to the third decap360.

The bumps380bond a power supply pin and a ground pin of the package340to a surface of the PCB310. Such bumps380can be formed by ball bonding.

FIG. 4is a cross-sectional view illustrating a device according to certain embodiments.

Referring toFIG. 4, a device400includes a PCB410, a PMIC420, a bulk capacitor430, an IC440, and bumps450.

The PCB410includes a power supply line411, ground line412, and decap413. The decap413is positioned at the inside of the PCB410. A first electrode413aof the decap413is positioned at the surface of the PCB410, and a second electrode413bthereof is connected to the ground line412. An overcurrent E is not injected into the package340and flows to the ground line412through the decap413. The decap413receives supply of a current from the PMIC420and accumulates a current, and supplies an accumulated current F to the IC440, thereby maintaining a constant input voltage of the IC440.

The PMIC420is mounted at a surface of the PCB410, and a first electrode, i.e., a power supply electrode of the PMIC420is connected to the power supply line411through via, and a second electrode, i.e., a ground electrode is connected to the ground line412through another via. The bulk capacitor430is mounted at the surface of the PCB410and is positioned adjacent to the PMIC420.

The IC440includes a plurality of power supply pins441aand441band a plurality of ground pins442aand442b.The pins441a,441b,442a,and442bare positioned at a rear surface of the IC440. The IC440is mounted at the surface of the PCB410. The plurality of power supply pins441aand441beach are connected to the power supply line411through vias. The plurality of ground pins442aand442beach are also connected to the ground line412through vias. Particularly, at least one of the plurality of power supply pins441ato441bis connected to a decap embedded in a via hole of the PCB410. For example, the first power supply pin441ais directly connected to the first electrode413aof the decap413. A length of a wiring that connects a power supply pin of an IC and a decap is remarkably reduced, compared with another case (e.g.,FIG. 1). Therefore, PI is improved and a decap is embedded at the inside of a PCB, compared with another case, and thus the PCB is free from restriction of mounted space and a wiring. The second power supply pin441bis connected to the power supply line411of the PCB410through via.

The bumps450bond a ground pin and a power supply pin of the IC440to a surface of the PCB410.

FIG. 5is a cross-sectional view illustrating a device according to certain embodiments. Referring toFIG. 5, a device500includes a PCB510, a PMIC520, a bulk capacitor530, an IC540, and bumps550.

The PCB510includes a power supply line511, ground line512, first decap513, and second decap514. The decaps513and514are positioned at the inside of the PCB510. First electrodes513aand514aof the first decap513each are connected to the power supply line511, and second electrodes513band514bthereof each are connected to the ground line512. For example, the PCB510can have a ten layer structure, and a third layer can be a power supply layer including the power supply line511, and a sixth layer can be a ground layer including the ground line512. In this case, the decaps513and514each are embedded in a via hole that penetrates from a third layer to a sixth layer. An overcurrent G is not injected into the IC540and gets out to the ground line512through the decaps513and514. The decaps513and514receive supply of a current from the PMIC520, accumulate the current, and supplies an accumulated current H to the IC540, thereby constantly maintaining an input voltage of the IC540.

The IC540includes a plurality of power supply pins541ato541dand a plurality of ground pins542ato542d.The pins541ato541dand542ato542dare positioned at a rear surface of the IC540. The IC540is mounted at a surface of the PCB510. The plurality of power supply pins541ato541deach are connected to the power supply line511through vias. The plurality of ground pins542ato542deach are connected to the ground line512through vias. Particularly, at least one of the plurality of power supply pins541ato541dis connected to a decap positioned at the inside of the PCB510through via. For example, the first power supply pin541ais connected to the first electrode513aof the first decap513through first via515. Further, the second power supply pin541dis connected to the first electrode514aof the second decap514through a second via516. A length of a wiring that connects a power supply pin of the IC and a decap is remarkably reduced, compared with another case (e.g.,FIG. 1). Therefore, PI is improved and a decap is embedded in the inside of a PCB, compared with another case, and thus the PCB is free from restriction of mounted space and a wiring.

FIGS. 6 and 7are cross-sectional views illustrating a PCB according to certain embodiments. Referring toFIG. 6, a PCB600includes conductive layers611to616, and insulating layers621to625interposed between the conductive layers611to616, vias631and632, and at least one decap640embedded in the PCB600.

The decap640is embedded in a via hole that penetrates a surface of the PCB600, i.e., from a first layer611to a ground layer, for example, a fourth layer614. Although not limited to a specific dielectric substance, for example, an electrolyte or ceramic is injected into a via hole and thus the decap640is produced. In other words, a method of manufacturing a PCB according to the present exemplary embodiment includes boring a via hole, injecting paste (e.g., ceramic paste) into the via hole (a silk screen printing method), drying (e.g., drying during 30 minutes at 150° C.-170° C.) a PCB to harden the injected paste, and forming a first electrode and a second electrode at both surfaces, respectively of dried paste.

A first electrode641of the decap640is exposed to the outside through a surface of the PCB600, and a second electrode642thereof is connected to a ground layer, for example, a fourth layer. Although not shown, the first electrode641is connected to a power supply pin of an IC (or a package). Therefore, an overcurrent I is not injected into an IC (or package) and flows to a fourth layer through the decap640. The decap640accumulates a current, and supplies an accumulated current J to an IC (or a package), thereby maintaining a constant input voltage of the IC (or the package).

Referring toFIG. 7, a ground layer can be formed in another layer, for example, a sixth layer instead of a fourth layer. Accordingly, a decap740is embedded in a via hole that penetrates from a surface of a PCB700to a sixth layer.

FIG. 8is a cross-sectional view illustrating a PCB according to certain embodiments. A PCB800includes conductive layers811to820, insulating layers821to829interposed between the conductive layers811to820, via831, and at least one decap840embedded in the PCB800.

The via831connects a first layer811and a third layer813. Here, the third layer813is a power supply layer. The decap840is embedded in a via hole that penetrates from a power supply layer, i.e., the third layer813to a ground layer, for example, a sixth layer816. A first electrode841of the decap840is connected to the third layer813, and a second electrode842thereof is connected to the sixth layer816. Although not shown, the first electrode841is connected to a power supply pin of an IC (or a package) through the via831. Therefore, an overcurrent K is not injected into the IC (or the package) and flows to the sixth layer816through the decap840. The decap840accumulates a current and supplies an accumulated current L to an IC (or a package), thereby maintaining a constant input voltage of the IC (or the package).

InFIGS. 6 to 8, a thickness of a conductive layer can be designed in 12 μm or 17.5 μm. A thickness of an insulating layer can be designed in 60 μm or 100 μm. A PCB includes a surface mounting decap and an embedded decap. When a PCB is designed, decaps are divided into surface mounting decaps and embedded decaps based on a capacitance value. For example, it is assumed that 13 decaps of 100 nF, 6 decaps of 1000 nF, 2 decaps of 2200 nF, 2 decaps of 4700 nF, and 1 decap of 220 nF are necessary for the PCB. 13 decaps of 100 nF having the highest use frequency and 6 decaps of 1000 nF having the second highest use frequency are determined as embedding decaps according to the present disclosure. The remaining decaps are determined as surface mounting decaps. Entire decaps can be determined as an embedding decap regardless of the use frequency.

Further, when a PCB is designed, decaps are divided into surface mounting decaps and embedding decaps based on a length of a via hole. For example, it is assumed that a length of a via hole that penetrates from the first layer611to the fourth layer614is 0.3 millimeters or more. Therefore, a surface mounting decap in which a length L is 0.4 millimeters and a thickness W is 0.2 millimeters can be replaced with an embedded decap.

Further, in the foregoing exemplary embodiments, it is illustrated that aground line is positioned under a power supply line, but can be positioned on a power supply line.

A device according to the present disclosure can be, for example, used in a computer such as a personal computer (PC) and a laptop computer, mobile terminal such as a smart phone, mobile phone, potable media player (PMP), tablet PC, navigation terminal, and game player, and household appliances such as an audio/video (AV) device, television (TV), smart hub device, and file server.

As described above, according to a PCB, device, and mobile terminal of the present disclosure, by reducing impedance of a power supply line, PI is improved and the PCB and the device including the PCB are freed from restrictions in the mounting space and wiring.