KR20060011610A - Memory card having improved mounting density - Google Patents

Abstract

The multimedia card according to the present invention having improved mounting efficiency includes a base card and a chip package, the base card including a first side wall and a second side wall facing each other, a third side wall and a fourth side wall facing each other, The first sidewall and the third sidewall are shorter in length than the second sidewall and the fourth sidewall facing each other, and a card chamfer is formed between the first sidewall and the third sidewall, indicating the directivity of the memory card. The first to fourth sidewalls and the card chamfer form a receptacle in which the chip package is to be mounted, and the first to fourth sidewalls and the card chamfer extend in a straight line in the vertical direction from the underside of the receptacle, and the chip package is provided with an external electrical connection of the memory card. It comprises a plurality of pins constituting, it is mounted on the receiving portion of the base card, characterized in that the bottom surface opposite to the surface on which the plurality of pins are formed is directly bonded to the bottom surface of the receiving portion of the base card. On the other hand, the chip package includes first to fourth sides corresponding to the first to fourth sidewalls of the base card and package chamfers corresponding to the card chamfers, and the first to fourth sides and the package chamfers of the chip package are formed on the first side of the base card. -4 contacts the side wall and the card chamfer.

Description

Highly efficient memory card {Memory Card Having Improved Mounting Density}

1 is a perspective view showing the structure of a memory card according to the present invention;

2A and 2B are plan views showing the front and back sides of the memory card after the chip package is mounted on the base card;

3A to 3C are plan and cross-sectional views showing the structure of a base card suitable for use in the memory card of the present invention;

4 is a structural diagram of a chip package suitable for use with the memory card of the present invention;

Figure 5a is a PCB structural diagram for explaining the process of manufacturing a chip package of the present invention and Figure 5b is a plan view showing the bottom structure of the PCB substrate of Figure 5a,

6 is a plan view for explaining a process of manufacturing a chip package of the present invention;

7 is a perspective view showing an example in which the present invention is applied to a 13-pin memory card.

<Description of Major Symbols in Drawing>

10: base card 12, 14, 16, 18: side wall

20: card champer 50, 150: chip package

52, 54, 56, 58: face 60: package chamfer

70: memory chip 74: control chip

72, 76: electrode pad 84: bonding pad

86: bonding wire 90: circuit board

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to memory card technology, and more particularly, to a memory card having a greatly improved mounting efficiency and a base card and chip package used therein.

Memory cards In particular, multimedia cards (MMCs) are microminiature recording media designed for use in mobile phones, digital cameras, and personal digital assistants (PDAs). MMC cards are widely used in portable communication devices and digital imaging devices because their capacity has been increased to 1G bytes and high-speed operation (eg 52MB / s) at low voltages (for example, 1.65-1.95V) is possible. MMC cards use flash memory technology to write and erase data, and ROM technology to implement read-only functions.

The plastic resin molding package that forms the MMC card has been standardized with a seven pad (or pin) serial interface to facilitate mating with most hardware platforms used in portable devices. These 7-pin standard MMC cards are 24 by 32 by 1.4 mm in size. Other new specifications include:

(1) 7-pin miniature MMC card (RS-MMC: Reduced Size MultiMedia Card) (24 × 18 × 1.4mm)

(2) 13-pin high speed MMC card (HS-MMC: High-Speed MultiMedia Card)

(3) Dual Voltage MMC Cards (Operate on 1.8V and 3V Hosts)

(4) security MMC card

Such a memory card is composed of a chip package in which an integrated circuit chip is embedded and a base card in which the chip package is accommodated. The memory card is being developed to increase its capacity, while electronic devices using the memory card It is very important to increase the mounting density of the memory card as it becomes more efficient and smaller.

An object of the present invention is to increase the mounting density and the mounting efficiency of a memory card.

The multimedia card according to the present invention comprises a base card and a chip package, the base card including a first side wall and a second side wall facing each other, a third side wall and a fourth side wall facing each other, the first side wall and the third side The sidewalls are shorter in length than the second sidewall, the fourth sidewall, respectively facing this, and a card chamfer is formed between the first sidewall and the third sidewall, indicating the directivity of the memory card. The first to fourth sidewalls and the card chamfer form a receptacle in which the chip package is to be mounted, and the first to fourth sidewalls and the card chamfer extend in a straight line in the vertical direction from the underside of the receptacle, and the chip package is provided with an external electrical connection of the memory card. It comprises a plurality of pins constituting, it is mounted on the receiving portion of the base card, characterized in that the bottom surface opposite to the surface on which the plurality of pins are formed is directly bonded to the bottom surface of the receiving portion of the base card. On the other hand, the chip package includes first to fourth sides corresponding to the first to fourth sidewalls of the base card and package chamfers corresponding to the card chamfers, and the first to fourth sides and the package chamfers of the chip package are formed on the first side of the base card. -4 contacts the side wall and the card chamfer.

Embodiment

1 is a perspective view showing the structure of a memory card according to the present invention, Figures 2a and 2b is a plan view showing the front and back of the memory card after the chip package is mounted on the base card, Figures 3a to 3c is a view of the present invention Top and cross sectional views showing the structure of a base card suitable for use in a memory card.

As shown in FIGS. 1 to 3, the memory card 100 includes a base card 10 and a chip package 50.

The base card 10 includes two pairs of sidewalls 12, 14; 16, and 18 facing each other when viewed based on a surface on which the chip package 50 is mounted (hereinafter, referred to as a “front side”). When a pair of long sidewalls are called the 1st side wall 12 and the 2nd side wall 14, and when a pair of short sidewalls are called the 3rd side wall 16 and the 4th side wall 18, The first side wall 12 and the third side wall 16 are shorter in length than the second side wall 14 and the fourth side wall 18 facing each other, and a card chamfer 20 is formed therebetween. . It is also possible to equalize the length of the first sidewall 12 and the third sidewall 16.

The card chamfer 20 is for showing the direction of the memory card 100, and is connected between both side walls 12 and 16 as if chamfered. The card chamfer 20 is connected between the side walls 12 and 16 so that the internal angle is 45 degrees, for example. Pin 1 of the chip package 10 is disposed near the card chamfer 20. As shown in FIG. 2B, the labeling area 30 is formed on the rear surface 32 of the base card 10.

The chip package 50 includes four sides 52, 54, 56, and 58 corresponding to the sidewalls 12 to 18 of the base card 10, and a package chamfer 60 corresponding to the card chamfer 20, respectively. do. Thus, the first face 52 and the third face 56 of the chip package are shorter than the second face 54 and the fourth face 18 facing each other, with the package chamfer 60 between them. Is arranged. The chip package 50 is mounted on the receiving portion 15 formed by the four sidewalls 12 to 18 and the card chamfer 20 of the base card 10, wherein the bottom surface 22 in front of the base card 10 is provided. The chip package 50 is adhesively fixed to it. Further, the first to fourth surfaces 52 to 58 and the package chamfer 60 of the chip package are in contact with the first to fourth sidewalls 12 to 18 and the card chamfer 20 of the base card 10, respectively. Pins 61 are arranged on the surface of the chip package 50. Seven pins are arranged on the chip package 50 shown in Figs. 1 and 2 which serve as external electrical connections of the memory card. The adhesive surface of the chip package 50 directly bonded to the bottom surface 22 of the base card 10 is the opposite side to the surface on which the pin 62 is disposed.

In the memory card 100 of the present invention, the sidewalls 12 to 18 and the card chamfer 20 of the base card 10 extend in a vertical direction on the bottom surface 22 of the base card 10, and the sidewalls The chip package 50 is fitted in the receiving portion 15 formed by the teeth 12 to 18 and the card chamfer 20. In addition, the memory card 100 of the present invention has a structure in which the chip package 50 includes a package chamfer 60 that is not rectangular, and the surface of the chip package 50 is the bottom surface 22 of the base card 10. It is characterized by its direct contact with. That is, in the memory card 100 of the present invention, the chip package 50 is directly mounted on the base card 10 without passing through another medium (eg, PCB base).

The chip package 50 is, for example, a package of a flash memory chip 70 and a control chip 74 as shown in FIG. The individual chip package 50 of FIG. 4 is formed in one of several chip package regions 92 in the PCB substrate 90 shown in FIG. 5A. Note that the chip package shown in FIG. 4 and the chip package shown in FIG. 5A are not identical in structure. That is, the chip package shown in FIG. 4 is an RS-MMC (P type) 7-COB (Chip on Board) package, and the chip package to be formed on the PCB substrate shown in FIG. 5A is 2GB RS-MMC-COB. In FIG. 4 and FIG. 5A, different types of chip packages are used to show that the present invention can be applied to chip packages having various structures.

4 and 5A, the memory chip 70 and the control chip 74 are bonded with a non-conductive adhesive (die attach) in the corresponding chip mounting area of the individual package area 92 of the PCB substrate 90. attach process), bonding the electrode pad 72 of the memory chip 70 and the electrode pad 76 of the control chip 74 to the corresponding bonding pad 84 of the PCB substrate 90 with a bonding wire 86. (Wire bonding step). Then, the plastic resin in a molten state is injected through the molding gate 96 to form a package body. When the package body is formed, the package body and the circuit board are cut and separated into individual chip packages 50 based on the individual package regions 92 defined by the cover 94 on the substrate 90.

Meanwhile, referring to FIG. 5B, a plurality of pins 62 are disposed in the individual package region 92 on the rear surface 95 of the circuit board 90 (that is, the surface opposite to the surface shown in FIG. 5A) and the package chamfer 60 is disposed. A metal guide line 97 is formed which indicates the region in which is to be generated. The metal guide line 97 may be formed when the circuit board 90 is manufactured, and when the package chamfer 60 of FIG. 6 is processed, the package chamfer 60 may be easily processed based on the line 97. can do. In addition, since the metal guide line 97 can be identified by the naked eye, the circuit board 90 to which the present invention is applied can be easily distinguished from other PCBs, and also convenient for visual product inspection.

On the other hand, it is preferable not to arrange wiring of the circuit board 90 in an area within a predetermined distance, for example, within 0.3 mm from the metal guide line 97. This distance is determined according to the tolerances that may occur when processing the package chamfer 60 of FIG. 6 or the positional tolerances of the PCB and the package.

The separated individual chip packages 50 are arranged to form a matrix in an inclined state at an angle (eg, 45 degrees) as shown in FIG. 6, and then cut lines 110 arranged in parallel in the horizontal direction. Cut a portion of the package body along. This produces a chip package 50 having a package chamfer 60 as shown in FIG. As shown in FIG. 4, the body of the chip package 50 is not formed inside the region of the dotted line 88 as in the prior art, but rather wider than the first to fourth surfaces 52 to 58 and the package chamfer. Since it is formed in the solid line area | region which consists of 60, the area | region for mounting the chip | tips 70 and 74 in the chip package 50 can be ensured widely.

Therefore, when the memory card is configured as in the present invention, a large amount of space for the chip elements included in the chip package 50 can be secured, thereby greatly increasing the mounting efficiency of the memory card.

The fact that the memory card of the present invention can be applied not only to the 7-pin standard memory card described above, but also to the 7-pin small memory card, 13-pin high speed memory card, dual voltage memory card, and secure memory card Those skilled in the art will readily understand. In addition, the memory card of the present invention can be applied not only to a chip package including only one memory chip, but also to a chip package having a structure in which two or four memory chips are stacked.

For example, an application of the present invention to a 13-pin memory card is shown in FIG. The memory card 200 of FIG. 7 has four surfaces 152, 154, 156, and 158 corresponding to the four sidewalls 12 to 18 of the base card 10, similarly to the memory card 100 of FIG. 1. And a chip package 150 having a package chamfer 160 corresponding to the chamfer 20. Pins 162 are disposed on the surface of the chip package 150. Unlike the chip package 50 illustrated in FIGS. 1 and 2, 13 pins are disposed on the chip package 150.

According to the present invention, since the mounting density of the chip package is increased, the mounting efficiency of the memory card is improved accordingly. In addition, the present invention can be freely applied to a chip package having a multi-pin structure and a small memory card.

Claims (9)

A memory card comprising a base card and a chip package, The base card includes a first sidewall and a second sidewall facing each other, a third sidewall and a fourth sidewall facing each other, the first sidewall and the third sidewall each having a second sidewall and a fourth sidewall facing each other. A shorter length, a card chamfer is formed between the first side wall and the third side wall, the card chamfer indicating the directionality of the memory card, the first to fourth side walls and the card chamfer to form a receiving portion for mounting the chip package, the first The side wall and the card chamfer extend in a straight line in the vertical direction from the bottom of the receiving portion, The chip package includes a plurality of pins constituting an external electrical connection portion of a memory card, and is mounted on a receiving portion of the base card, and an underside opposite to a surface on which the plurality of pins are formed is formed on a bottom surface of the receiving portion of the base card. Memory card, characterized in that directly bonded. In claim 1, The chip package may include first to fourth sides corresponding to the first to fourth sidewalls of the base card, and a package chamfer corresponding to the card chamfer, wherein the first to fourth sides and the package chamfer of the chip package are formed of the base card. And the first to fourth sidewalls and the card chamfer. The method of claim 1 or 2, And the pin of the chip package is seven or thirteen. The method of claim 1 or 2, And the memory card is any one selected from the group consisting of a 7-pin standard memory card, a 7-pin small memory card, a 13-pin high speed memory card, a dual voltage memory card, and a secure memory card. The method of claim 1 or 2, The chip package, Attach the memory chip and the control chip to the chip mounting area of the individual package area of the circuit board, wire-bond the electrode pads of the memory chip and the control chip to the bonding pads of the circuit board, form the package body, and then the package body and the circuit board. And cutting the separated into the individual package areas and arranging the separated plurality of individual chip packages to form a matrix in an inclined state at a predetermined angle, and then cutting in a horizontal direction to form a package chamfer. Memory card. The method of claim 1 or 2, And a metal guide line indicating a region where a package chamfer is to be formed on a surface where the plurality of pins of the chip package are formed. In claim 5, And the memory chip comprises two or more stacked memory chips. A base card used for the memory card of claim 1. A chip package for use in the memory card of claim 1.

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