KR100964152B1 - Solid state drive - Google Patents

Abstract

PURPOSE: A solid state drive is provided to improve cooling efficiency using BGA or CSP type flash memory devices as a memory device and also using a substrate with low CTE as a PCB. CONSTITUTION: A PCB for SSD(200) comprises a memory mounting unit, a CPU mounting unit and an interface mounting unit. The memory mounting unit can mount the memory of BGA or CSP type. The CPU mounting unit is connected to the memory mounting unit. The interface mounting unit is connected to the CPU mounting unit. A flash memory(220) is the BGA or the CSP type.

Description

Solid State Drive {SOLID STATE DRIVE}

The present invention relates to a solid state drive, and more particularly, by using a printed circuit board for a solid state drive as a material having a low thermal expansion coefficient (Low CTE), and using a memory device as a chip size package (CSP) type, The present invention relates to a technology for allowing excellent electrical properties.

A hard disk driver (HDD) is a device that writes external data to a magnetic disk or outputs data recorded on a magnetic disk to an external device in response to a CPU or a host command.

Such HDDs have dramatically increased storage capacity in accordance with the development of manufacturing technology and consumer demand.

Meanwhile, as mobile devices equipped with HDDs increase in recent years, HDDs having low power, low weight, portability, and durability have recently been demanded.

However, since the HDD needs to drive a magnetic disk, there are limitations in implementing low power and low weight. A storage medium that can complement these characteristics is NAND flash memory. Recently, a technology for implementing a high-end HDD using NAND flash memory has been developed. The NAND flash-based next-generation storage device is called a solid state drive (SSD).

SSD converts mechanical components such as rotating magnetic disks (or platters), actuators, and headers into NAND flash memory to realize mass storage with low power, low noise, durability, and portability.

In addition, SSD is disadvantageous in terms of efficiency of storage space compared to magnetic disk-type HDD having a large storage space, but has an advantage in access speed, miniaturization, and stability from impact.

The limit of storage space is being improved gradually with the progress of process technology and design technology, and cost reduction is expected. Therefore, SSDs are expected to replace magnetic disks in the near future.

1 is a plan view showing a schematic structure of a solid state drive.

Referring to FIG. 1, a printed circuit board 10 on which semiconductor elements necessary to configure an SSD is mounted is provided.

Next, a NAND flash memory device 20 that is responsible for a data storage function is mounted on the printed circuit board 10, and a controller 30 that adjusts a function of inputting and reading data into the NAND flash memory device 20 is provided. It is mounted.

Next, the interface 40 is provided at the edge portion of the printed circuit board 10. The interface 10 is a data exchange relay port that enables the exchange of protocols and data on the host side. In a typical computer system, a disk driver's data transfer protocol uses Serial Advanced Technology Attachment (SATA), a standard for HDD, proposed by IBM in the United States, or a small computer system interface (SCSI) that supports network-based systems.

Next, a case 50 for protecting the printed circuit board 10 and the semiconductor devices is provided.

The case includes a lower case 50 that protects the rear surface of the printed circuit board 10 and an upper case provided on the upper portion of the semiconductor elements. In FIG. 1, only the lower case 50 is shown to represent the semiconductor element.

As mentioned above, SSDs are relatively simple in structure and simple in principle. However, as the number of flash memory devices performing a storage function increases and the performance of the controller is improved, there is a problem that high heat occurs in a semiconductor device such as a memory device or a controller. In particular, the heat generation of the flash memory device may be a problem, and if the flash memory device is damaged by the heat generation, the solid state drive may not be able to operate itself. Therefore, a device for cooling should be installed inside the solid state drive. .

However, since the solid state drive is a product that emphasizes portability, there is a problem that a separate cooling device such as a cooling pen cannot be implemented. Therefore, the printed circuit board may be bent due to heat, and when the printed circuit board is bent, a problem of poor contact between the flash memory elements may occur.

2A and 2B are cross-sectional views illustrating a problem of a solid state drive according to the prior art.

FIG. 2A is a cross-sectional view illustrating a memory device in a state in which heat generation does not occur because the solid state drive does not operate. FIG. 2A illustrates a state in which the flash memory devices 20 are normally mounted on the printed circuit board 10.

FIG. 2B illustrates a state where the printed circuit board 10 is bent due to heat generated when the solid state drive is operated. In this case, contact failure between the printed circuit board 10 and the flash memory device 20 is caused. Able to know.

In this case, a package used for flash memory devices uses a thin SOP (TSOP) structure, and a thin SOP (TSOP) structure will be described with reference to the following drawings.

3A and 3B are cross-sectional views illustrating a memory structure used in a solid state drive according to the prior art.

3A illustrates a single chip 60 package structure, and FIG. 3B illustrates a multichip 60 and 65 package structure. Each chip 60 is connected to the lead 75 by wire bonding 70 and packaged by an epoxy molding compound 80 (EMC).

Here, a flash memory device having a TSOP package structure has a lead at a short side of a small outline package (SOP) EIAJ standard having a height of 50 MIL or less and a lead pitch of 50 MIL or less. The one which has a pitch of 0.55 / 0.5mm is mainly used.

Such a TSOP package structure has a limitation in improving the mounting density by means of leads, and a high probability of solder failure occurs. In addition, when the length of the lead increases, the inductance that causes distortion of the signal increases, which is not suitable for a high speed solid skate drive.

The present invention uses a memory device that is directly connected to the heat generated by the solid state drive as a flash memory device of a ball grid array (BGA) or chip size package (CSP) type, and a printed circuit board having a low CTE. The purpose of the present invention is to provide a solid state drive capable of rapidly dissipating heat generated from a flash memory device to the outside and improving performance by minimizing deformation of a printed circuit board.

The solid state drive (SSD) according to the present invention includes a memory mounting unit, a central processing unit mounting unit connected to the memory mounting unit and an interface mounting unit connected to the central processing unit mounting unit, but the memory mounting unit A printed circuit board for a solid state drive (SSD) provided to mount a ball grid array (BGA) or chip size package (CSP) type memory, and a data storage function connected to the memory mounting unit. A controller configured to perform a flash memory provided in a ball grid array (BGA) or chip size package (CSP) type, a controller connected to the central processor mounting unit and controlling a function of reading or writing data stored in the flash memory; An interface module connected to the interface mounting unit and connecting a signal of the controller to an external device; Sh memory, a controller and an interface module and the printed circuit case is packaged so as to protect the rear of the substrate element are not formed.

Here, the printed circuit board is characterized in that the material having a low coefficient of thermal expansion (Low CTE) of 8 ~ 12 ppm / ℃, the printed circuit board is 1.8 inches, 2.5 inches, 3.5 inches rectangular shape The flash memory is characterized in that 2 to 10 is mounted, the controller is characterized in that the BGA (Ball Grid Array) type chip is mounted, the interface module is SATA or IDE It is characterized in that the type is mounted.

The solid state drive according to the present invention uses a low thermal expansion coefficient (Low CTE) of a flash memory device and a printed circuit board of a ball grid array (BGA) or chip size package (CSP) type to improve cooling efficiency. In addition, by increasing the array density of the flash memory device, it is possible to form a high capacity solid state drive.

In addition, the contact point between the flash memory device and the printed circuit board is shorter when compared to the TSOP package, thereby reducing the inductance causing distortion of unnecessary signals in high-speed electronic circuits, and contacting the printed circuit board at the bottom of the chip. Since the part is formed, the part that can detect a signal is limited, which provides an advantageous security effect.

Based on the above object of the present invention will be described in detail with respect to the solid state drive.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments and drawings described below in detail. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, only the embodiments are to make the disclosure of the present invention complete, it is common in the art It is provided to fully inform those skilled in the art of the scope of the invention, which is to be defined only by the scope of the claims.

4A and 4B are cross-sectional views illustrating a memory structure used in the solid state drive according to the present invention.

FIG. 4A illustrates a flash memory device having a single chip 160 structure corresponding to FIG. 3A, and FIG. 4B illustrates a flash memory device having a multichip 160 and 165 structure corresponding to FIG. 3B. Each chip 160, 165 is connected to the solder ball 175 by wire bonding 170 and is protected by the EMC 180.

Such a ball grid array (BGA) or chip size package (CSP) type flash memory device has better electrical characteristics (frequency characteristics) than the TSOP package structure of FIGS. 3A and 3B, thereby enabling a high speed operation system. Will be.

As the conventional TSOP structure is weak in heat generation as described above, the length of the lead must be formed long to cope with the warpage of the printed circuit board. However, in this case, since the electrical contact point becomes long, the inductance that causes distortion of the unnecessary signal may be increased. Therefore, the solid state drive using the flash memory device of the TSOP package structure is less electrical characteristics than the solid state drive of the present invention.

 Due to the above characteristics, the solid state drive according to the present invention can easily realize miniaturization and high capacity.

On the other hand, a ball grid array (BGA) or chip size package (CSP) type flash memory device is less flexible than a flash memory device of a TSOP package structure having a long lead, and thus may be problematic in that it is vulnerable to the bending property of a substrate. have.

Accordingly, the solid state drive according to the present invention uses a printed circuit board formed of materials having a low coefficient of thermal expansion (Low CTE) together with a flash memory device of a ball grid array (BGA) or chip size package (CSP) type. At this time, it is preferable to use a substrate having a CTE (X / Y, ppm / ° C.) of the printed circuit board according to the present invention within a range of 8 to 12.

Here, the resin (Resin) as the main material for manufacturing a printed circuit board according to the present invention is a liquid crystal polymer (Liquid Cristal Polymer, LCP), a wholly aromatic polyester resin (Wholly Aromatic Polyester Resin), polyamide-imide resin (Polyamide-Imide Resin) and at least one selected from Organic-Inorganic Hybrid Resin are used.

In the case of the glass fabric added to the resin, an S or N type glass fabric is preferably used. In the case of the filler, an inorganic filler is used.

The present invention can minimize the bending problem of the substrate by using a printed circuit board having a low thermal expansion coefficient as described above. Accordingly, the weak flexibility of the flash memory device of a ball grid array (BGA) or chip size package (CSP) type may be compensated for. When the flexibility problem is solved, heat resistance, impact resistance, and vibration resistance can be improved as compared to the flash memory device of the conventional TSOP package structure.

5 is a plan view showing a schematic structure of a solid state drive according to the present invention.

Referring to FIG. 5, a printed circuit board 200 for a solid state drive having a low thermal expansion coefficient (Low CTE) is provided.

Next, a flash memory device 220 of a ball grid array (BGA) or chip size package (CSP) type that is responsible for a data storage function is mounted on the printed circuit board 200. In this case, it is preferable to allow 2 to 10 flash memory devices 220 to be mounted. When only one device is used, the capacity is limited, so the effectiveness is reduced as a solid state drive, and when more than 10 memory devices are mounted, heat generation is increased and the size is also increased.

Next, a controller 230 for inputting data to the flash memory device 220 and reading and reading the input data is mounted. In this case, the controller 230 may also use a ball grid array (BGA) or chip size package (CSP) type device similarly to the flash memory device 220. When using a ball grid array (BGA) or chip size package (CSP) type controller 230, a lower inductance may be implemented to implement high-speed control capability.

In addition, since there is no lead protruding from the outside of the flash memory device 220 and the controller 230 as compared with FIG. 1, it is easy to implement high density.

Next, an interface 240 connected to the controller 230 at the edge of the printed circuit board 200 to exchange data with the protocol of the host is provided. The interface 240 may use a Serial Advanced Technology Attachment (SATA) or a Small Computer System Interface (SCSI) that supports a network-based system as a data exchange relay port.

Next, a case 250 for protecting the printed circuit board 200 and the semiconductor devices is provided.

Here, only the lower case 250 which protects the rear surface of the printed circuit board 200 is illustrated, and an upper case which protects the upper portion of the semiconductor elements may be further provided.

In addition, the printed circuit board or case is preferably formed to be applied to more devices by varying the size, such as 1.8 inches to 3.5 inches.

As described above, the solid state drive according to the present invention has very advantageous characteristics than TSOP in flash memory or controller arrangement or microcircuit design. In addition, it is possible to design a small size of the semiconductor substrate, which serves as an interposer between the semiconductor chip and the semiconductor chip and the printed circuit board for the solid state drive. Create solid state drives. In addition, the production cost of the semiconductor chip and the semiconductor substrate is expected to be improved when the solid state drive is manufactured according to the present invention.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments and can be modified in various forms, and having ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1 is a plan view showing a schematic structure of a solid state drive according to the prior art.

2A and 2B are cross-sectional views illustrating a problem of a solid state drive according to the prior art.

3A and 3B are cross-sectional views illustrating a memory structure used in a solid state drive according to the prior art.

4A and 4B are cross-sectional views illustrating a memory structure used in a solid state drive according to the present invention.

Figure 5 is a plan view showing a schematic structure of a solid state drive according to the present invention.

Claims (6)

A memory mounting unit, a central processing unit mounting unit connected to the memory mounting unit, and an interface mounting unit connected to the central processing unit mounting unit, wherein the memory mounting unit is of a BGA (Ball Grid Array) or CSP (Chip Size Package) type. A printed circuit board for a solid state drive (SSD) provided to mount a memory; A flash memory connected to the memory mounting unit and performing a data storage function and provided in a ball grid array (BGA) or a chip size package (CSP) type; A controller connected to the CPU unit and controlling a function of reading or writing data stored in the flash memory; An interface module connected to the interface mounting unit and connecting a signal of the controller to an external device; And And a case packaged to protect the flash memory, the controller and the interface module, and the back portion of the printed circuit board on which the elements are not formed. The method of claim 1, The printed circuit board is a solid state drive, characterized in that provided with a material having a low coefficient of thermal expansion (Low CTE) of 8 ~ 12 ppm / ℃. The method of claim 1, The printed circuit board is a solid state drive, characterized in that provided in the form of a rectangle of size 1.8 to 3.5 inches. The method of claim 1, The flash memory is a solid state drive, characterized in that 2 to 10 are mounted. The method of claim 1, The controller is a solid state drive, characterized in that the BGA (Ball Grid Array) type of chip is mounted. The method of claim 1, The interface module is a solid state drive, characterized in that the SATA or IDE type is mounted.

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