KR20090022481A - Circuit board built-in test pad for memory chip, and cob-type chip package including the same - Google Patents

Abstract

A circuit board with a built-in test pad for a memory chip and a cob-type chip package including the same are provided to independently control the memory chip through the test pad. A memory chip(210) and a controller chip(230) are mounted on one side of PCB. The memory chip is the non-volatile memory device like the flash memory. A controller chip is mounted on the one side of PCB. The controller chip controls the input-output of data to be suitable for the interface. Passive devices including the resistor/capacitor(250) and an oscillator(270) etc. are sealed up with one molding compound. The memory chip is adhered to the predetermined built-in region defined in PCB. A chip pad(211) equipped in the memory chip and the first bonding pad(111) equipped in the front side(101) of PCB are electrically connected by a bonding wire(213).

Description

CIRCUIT BOARD BUILT-IN TEST PAD FOR MEMORY CHIP, AND COB-TYPE CHIP PACKAGE INCLUDING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory card as a data storage device, and more particularly to a memory device or a memory card having a chip on board structure capable of mounting a high capacity memory device in a limited space.

A memory card is a compact recording medium designed to be used not only for a personal computer (PC) but also for a mobile phone, a digital camera, a personal digital assistant (PDA), and the like. Memory cards are widely used in portable communication devices and digital imaging devices because their capacity has been increased to several gigabytes and high-speed operation (eg, 52 MB / s) can be performed at low voltages (for example, 1.65 to 1.95 V). In addition, a flash memory device is mainly used as a memory device used in a memory card. A flash memory device is capable of maintaining data even when the power is turned off, low power consumption, high speed, and high portability. The application range is expanding to digital home appliances such as appliances.

Flash memory cards include Secure Digital Memory Cards (SD Cards), Mini SD Cards (40% smaller than existing SD Cards), Multi-Media Cards (MMCs). Cards'), RS-MMC cards (Reduced Sized MMC, cards that cut the size of existing MMC cards in half), and USB memory cards employing the Universal Serial Bus (USB) interface standard.

The size of the memory card is gradually decreasing. In order to implement a memory device having a desired capacity in a narrow space, the mounting density of the memory device must be increased. As memory cards become ultra slim, securing the mounting space of circuit elements has become a very important and technically difficult task. In order to solve this problem, memory cards are recently implemented using a chip on board (COB) process. COB technology directly prints a memory chip, a core component of a memory card, in a wafer state. It is one of Surface Mount Technology (SMT) which is formed by connecting gold wire on PCB (Prior Circuit Board).

In the COB process, a multi-chip package (hereinafter referred to as 'MCP') including not only a memory semiconductor chip but also a control chip and passive components for controlling the operation of the memory card is included. Briefly introducing the manufacturing method of such a multi-chip package for a memory card, first, a passive element such as a resistor, a capacitor, an oscillation element is mounted on a printed circuit board, and then the control chip and the memory chip (for example, a flash memory chip) are mounted. The wafer is directly attached to the printed circuit board (Die Attach process), and then the attached control chip and memory chip are attached to a bonding pad formed on the printed circuit board through gold (Au) or aluminum (Al) wire. Bonding (wire bonding process). Thereafter, the package body is formed using a resin composition (e.g., an epoxy molding compound) (molding process), and the printed circuit board is cut and separated into individual package bodies (individualization process). . The individual chip packages thus formed are mounted in a predetermined housing to manufacture a memory card as one finished product.

In a conventional COB type memory card, a memory chip is mounted in one package molding together with other circuit elements in a die state. Therefore, in case of a defect in the product, only the memory chip cannot be separated, and after removing the package molding, the memory chip is separated from the circuit board, and then the defect is inspected or the data is recovered. After removing the defects and restoring the data, the chip attaching process and the molding process may be recycled only after performing the individual chip process. Therefore, in the conventional COB type memory card, the inspection and data recovery of the memory chip itself is very cumbersome and inconvenient after being manufactured in the chip package of the finished product.

In addition, as the capacity of nonvolatile memory chips such as flash memory devices increases, their application ranges are expanding, and they are widely used not only for portable mobile devices but also for bulky digital TVs. As such, as the application range of the flash memory device is expanded, many products are released, and the number of recycling of the flash memory device once commercialized is gradually increasing. Meanwhile, in the case of the conventional COB type chip package, in order to recycle the flash memory device, it is cumbersome to separate only the flash memory device after removing the molding of the chip package.

The present invention has been made to solve the above-described problem, COB type COB type chip package capable of independent failure inspection and data recovery of the memory chip itself without disassembling the chip package in the event of a failure of the memory card consisting of chip package It is an object to provide a chip package.

In addition, another object of the present invention is to independently access to a memory device while deactivating other circuit elements constituting the memory card without disassembling the chip package when it is desired to recycle a nonvolatile memory device such as a flash memory. It is to provide a COB type chip package.

In order to solve the above problems, a COB type chip package for a memory card including a nonvolatile memory device according to the present invention includes a circuit device including a nonvolatile memory chip, a first region in which the circuit device is mounted, and a circuit device. A circuit board including a second region that is not mounted, and a molding portion formed to protect the circuit elements mounted in the first region of the circuit board. Here, the circuit board may include a plurality of first bonding pads formed in the first area and electrically connected to the memory chip, and in a second area not covered by the molding part and electrically connected to at least one of the plurality of bonding pads. And at least one test pad.

In addition, an interface terminal for connecting an external device may be formed in the second region of the circuit board, and the test pad is electrically separated from the interface terminal. Available interface terminals include USB interface terminal, SD interface terminal, MMC interface terminal and SATA interface terminal.

In addition, the circuit device may further include a control chip for controlling data input and output of the memory chip according to an interface standard, in which case a plurality of second bonding pads electrically connected to the control chip are formed in the first region of the circuit board. Can be.

A circuit board for a COB type memory card according to the present invention includes a first region in which a circuit element including a nonvolatile memory chip is mounted, and a second region in which the circuit element is not mounted. Here, a plurality of first bonding pads electrically connected to the memory chip are formed in the first region, and at least one test pad electrically connected to at least one of the plurality of bonding pads is formed in the second region. Furthermore, interface terminals such as a USB interface terminal, an SD interface terminal, an MMC interface terminal, and a SATA interface for connecting the memory card to an external device may be formed in the second area, and the interface terminal may be formed to be electrically separated from the test pad. do.

When a failure occurs due to an error of a passive element during the use of a memory card composed of a circuit board and a COB type chip package using the same, only the memory chip may be independently controlled through a test pad. Therefore, defect inspection and data recovery are possible without disassembling the EMC molding.

In addition, the test pad enables independent access to the memory chip, thereby allowing input and output of data regardless of the interface standard adopted by the memory card. Therefore, when the memory card is to be recycled, since the chip package itself is also made very small, it can be mounted on a separate circuit board as a memory device in an external device having a larger volume (eg, a computer, a digital TV, etc.). have. In other words, the test pad may be used as a connection terminal of the memory chip without releasing the EMC molding of the COB chip package and may be mounted as a component on a separate printed circuit board.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view of a chip package according to the present invention. Here, the memory chip 210, which is a nonvolatile memory device such as a flash memory, and the control chip 230 for controlling the input / output of data to be suitable for the interface to be used are disposed on one surface of the PCB 100 in a wafer state not separately packaged. After mounting, the passive elements such as the resistor / capacitor 250, the oscillation element 270, and the like are mounted together and then sealed by one molding body 300. The chip package thus formed is accommodated in a separately provided housing to be used as a memory card.

2 shows a front surface 101 of a PCB 100 on which circuit elements are mounted. Here, the memory chip 210 is attached to a predetermined mounting area defined in the PCB 100. The chip pad 211 provided on the memory chip 210 and the first bonding pad 111 provided on the front surface 101 of the PCB 100 are electrically connected to each other by the bonding wire 213. In addition, after the control chip 230 for controlling the input and output of data in accordance with the interface standard adopted in the memory card is attached to a predetermined mounting area defined separately, the second bonding provided on the front surface 101 of the PCB 100 The pad 113 is electrically connected by the bonding wire. In addition, passive elements such as the resistor / capacitor 250 and the oscillation element 270 may also be attached to a predetermined region of the PCB 100. Although not shown in the drawing, the front surface 101 on which circuit elements such as the memory chip 210, the control chip 230, the resistor / capacitor 250, and the oscillation element 270 are mounted is molded and protected by EMC. .

Next, FIG. 3 illustrates a rear surface 102 of the PCB 100, and an interface terminal 130 is formed at one side of the rear surface 102 of the PCB 100 on which circuit elements are not mounted. One end of the chip package in which the interface terminal 130 is formed is inserted into a connection portion of an external device so that data is input or output. In particular, although FIG. 3 illustrates the USB interface terminal as the interface terminal 130 as an example, the type of the interface terminal that can be used is not limited. It is also possible to form terminals according to an interface standard such as an SD interface, an MMC interface, or a Serial Advanced Technology Architecture (SATA) interface. However, the overall specification of the package is determined according to the interface standard.

In addition, as shown in FIG. 3, a plurality of test pads 150 are formed on the back surface 102 of the PCB 100. The test pad 150 is disposed in an area electrically separated from the interface terminal 130. The test pad 150 is connected to only the memory chip 210 independently, and thus, the test pad 150 may be inspected or data recovered without disassembling the COB type chip package. That is, each test pad 150 is electrically connected to at least one first bonding pad 111. A printed circuit board (PCB) that can be used is a multilayer printed circuit board comprising at least two insulating layers and at least one metal pattern. The metal pattern connects the memory chip 210 and the control chip 230 mounted on the circuit board, or connects the passive elements (resistor, capacitor, oscillation element, etc.) and the control chip, the interface terminal 130 and control It serves to connect the chip 230. In addition, an independent metal pattern for electrically connecting the first bonding pad 111 and the test pad 150 may be additionally separated from the metal pattern connecting the other circuit elements. The method of manufacturing a printed circuit board that may be employed in the present invention may be implemented through a general technology for manufacturing a printed circuit board, and thus a detailed description thereof will be omitted.

In the PCB 100 of the structure shown in Figs. 2 and 3, in order to minimize the mounting density, the front surface 101 of the PCB 100 is a region in which circuit elements are mounted and protected by the EMC molding, and the rear surface thereof. An interface terminal 130 and a test pad 150 were formed thereon, with 102 being an area exposed outside without being protected by EMC. However, since the interface terminal 130 and the test pad 150 only need to be exposed to the outside, they may be disposed on the same plane as the area where the circuit element is mounted. In addition, in the embodiment according to the present invention, the memory chip, the control chip, and the passive element are separately manufactured and then sealed in a single package, but the memory chip on one wafer using SIP (System in Package) technology. It is also possible to form a control chip and a passive element.

A finished memory card is constructed using the COB type chip package shown in Figs. When using a complete memory card, the test pad is protected with insulating tape to prevent short circuits and contamination of the interface terminals. If a failure occurs due to an error of a passive element while using the memory card, only the memory chip 210 is independently controlled through the test pad 150 after removing the insulating tape. Therefore, defect inspection and data recovery are possible without disassembling the EMC molding.

In addition, since independent access to the memory chip 210 is possible through the test pad 150, data input and output may be performed regardless of the interface standard adopted by the memory card. Therefore, when the memory card is to be recycled, since the chip package itself is manufactured to be very small, it can be mounted on a separate circuit board as a storage element in an external device having a larger volume (eg, a computer, a digital TV, etc.). . That is, the test pad 150 may be used as a component on a separate printed circuit board by using the test pad 150 as a connection terminal of the memory chip without releasing the EMC molding of the COB chip package. In this case, the control chip 230 and the passive elements 250 and 270 included in the COB chip package open the interface terminal 130 to make it inactive. Therefore, even when recycled as a component of an external device, only the memory chip 210 can be used independently while using the COB chip package as it is.

1 is a perspective view of a COB type chip package according to an embodiment of the present invention.

2 is a plan view illustrating a front surface of a printed circuit board on which a plurality of circuit elements are mounted.

3 is a plan view illustrating a rear surface of a printed circuit board on which interface terminals and test pads are formed.

Claims (10)

A COB type chip package for a memory card containing a nonvolatile memory device, Circuitry including a nonvolatile memory chip; A circuit board including a first region in which the circuit element is mounted and a second region in which the circuit element is not mounted; And And a molding part formed on the first region of the circuit board to protect the circuit device mounted thereon. The circuit board may include at least one of a plurality of first bonding pads formed in the first area and electrically connected to the memory chip, and in the second area not covered by the molding part. A COB type chip package comprising at least one test pad electrically connected with the test pad. In claim 1, COB type chip package, characterized in that the interface terminal for connecting external devices is formed in the second region of the circuit board In claim 1, The circuit device further includes a control chip for controlling data input and output of the memory chip according to an interface standard, and a plurality of second bonding pads electrically connected to the control chip are formed in the first region of the circuit board. COB type chip package. In claim 2, The at least one test pad is a COB type chip package, characterized in that formed electrically separated from the interface terminal. In claim 2, The interface terminal is a COB type chip package, characterized in that any one of a USB interface terminal, SD interface terminal, MMC interface terminal and SATA interface terminal. A circuit board for a COB type memory card comprising a first region in which a circuit element including a nonvolatile memory chip is mounted, and a second region in which the circuit element is not mounted. A plurality of first bonding pads formed in the first region and electrically connected to the memory chip; And at least one test pad formed in the second region and electrically connected to at least one of the plurality of bonding pads. In claim 6, And the interface terminal for connecting an external device to the second area. In claim 7, Wherein the at least one test pad is electrically isolated from the interface terminal. In claim 7, And the interface terminal is any one of a USB interface terminal, an SD interface terminal, an MMC interface terminal, and a SATA interface terminal. A memory card comprising a nonvolatile memory device, A memory card comprising a COB type chip package according to any one of claims 1 to 5 and a housing in which the COB type chip package is accommodated.

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