JP2003162702A - Semiconductor device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the loadability/unloadability of a card type semiconductor device for a socket. <P>SOLUTION: This semiconductor device is constituted of a wiring board 2 equipped with a surface 2a on which a semiconductor chip 3 is mounted and a back face 2b, a terminal 2c for bonding formed on the surface 2a of the wiring board 2, whose surface 2f is formed with soft gold plating 2g, a terminal 2d for external connection formed on the back face 2b of the wiring board 2, whose surface 2f is formed with hard gold plating 2h, wires 4 for connecting the terminal 2c for bonding to an electrode pad 3b of the semiconductor chip 3, and a cap 5 for covering a resin sealing part 6 for sealing the semiconductor chip 3 or those wires 4. The metallic plating of the surface 2f of the terminal 2d for external connection of a memory card 1 is made harder than or equivalent to the metallic plating of a surface 7b of a terminal 7a of a socket 7 so that the contact resistance of the terminal 2d for external connection of the memory card 1 to the terminal 7a of the socket 7 can be reduced. Thus, the loadability/unloadability of the memory card 1 for the socket 7 can be improved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a manufacturing technique thereof, and more particularly to a technique effectively applied to a semiconductor memory card (hereinafter simply referred to as a memory card).

[0002]

2. Description of the Related Art Multimedia cards (Sandisk, Inc.) and SD (Security Device) cards (Panasonic,
A memory card such as Toshiba and SanDisk) is one of external storage devices that stores information in a semiconductor memory chip inside. In this memory card, since information is directly and electrically accessed to the nonvolatile memory formed in the semiconductor memory chip, there is no control of the mechanical system, so writing is performed as compared with other external storage devices. The read time is fast and the storage medium can be replaced.

Since it is small and light, it is mainly used as an auxiliary storage device for portable personal computers, mobile phones, digital cameras, and other devices requiring portability.

In the multimedia card, the semiconductor memory chip is mounted on a thin wiring board and electrically connected to the terminals of the wiring board by wire bonding. The semiconductor memory chip and a plurality of wires are made of resin. It is sealed with a mold or cap.

In the memory card having such a structure, a wiring board having double-sided wiring is used. A terminal for wire bonding is provided on one surface of the wiring board, and a terminal on the opposite side is in contact with a terminal of a socket. Terminals are provided.

Therefore, in order to improve the bondability of wire bonding with a gold wire, the terminal for wire bonding provided on one surface of the wiring board has a soft gold plating with a low hardness (hereinafter, referred to as "this"). (Gold plating is called soft plating) is required. When manufacturing wiring boards, both sides are plated at the same time, so soft gold plating is also formed on the surface of the terminals that come into contact with the socket terminals of the wiring boards. To be done.

As for various memory cards, for example, "NE Co. Ltd.," issued on September 21, 1998, "NE
Nikkei Electronics September 21st ", 148-155
The description is on the page.

[0008]

However, in the memory card such as the multimedia card of the above-mentioned technology, the memory card is inserted in the push-push type socket (the socket in which the card pops out when the card is pushed again when the card is taken out). After inserting and using, there is a problem that the memory card is difficult to pull out when taking it out.

It is considered that this is because the surface of the terminal of the memory card which comes into contact with the terminal of the socket is soft and soft, so that the contact resistance is high and it is easily caught.

If the memory card is continuously inserted and removed while the contact resistance is high, there is a problem that the plating on the surface is scraped to cause a contact failure.

Further, in order to improve the attachability / detachability (removability) of the memory card, the steps after the card assembly are
Although the process of applying the sealing material (lubricant) to the terminal part of the memory card is added, it is difficult to confirm that the TAT (Turn Around Time) is long and that the sealing material is applied. Problems such as nasty things occur.

An object of the present invention is to provide a semiconductor device and a method of manufacturing the same for improving the detachability.

Still another object of the present invention is to provide a semiconductor device and a method of manufacturing the semiconductor device that can shorten the assembly process.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0015]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, according to the present invention, the first main surface of the wiring board is provided with the first terminal portion having the first metal plating formed on the surface and the second main surface of the wiring board. The
A second terminal portion having a second metal plating formed on its surface;
A wire for connecting the first metal plating of the first terminal portion and the surface electrode of the semiconductor chip, and the hardness of the second metal plating of the second terminal portion is the second metal plating.
The same or more than the metal plating on the surface of the terminal of the socket that comes into contact with the terminal portion of.

Further, according to the present invention, the first terminal portion having the first metal plating formed on the surface thereof and the second terminal having a hardness equal to or higher than that of the metal plating on the surface of the terminal of the socket to be engaged therewith. A step of preparing a wiring board having a second terminal portion on the surface of which metal plating is formed, and a step of mounting a semiconductor chip on the first main surface of the wiring board on which the first terminal portion is provided. Connecting the front surface electrode of the semiconductor chip and the first terminal portion of the first main surface of the wiring board by wire bonding, and sealing the plurality of wires and the semiconductor chip connected by the wire bonding And a step of performing.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. In all the drawings for explaining the embodiments, members having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted.

FIG. 1 is a plan view showing the structure of a memory card which is an example of a semiconductor device according to an embodiment of the present invention, FIG. 2 is a bottom view showing the structure of the memory card shown in FIG. 1, and FIG.
4 is a plan view showing an example of the structure of the wiring board incorporated in the memory card shown in FIG. 4, FIG. 4 is a bottom view showing an example of the structure of the wiring board shown in FIG. 3, and FIG. 5 is a sectional view taken along line AA of FIG. FIG. 6 is an enlarged partial sectional view showing an example of the structure, FIG. 6 is an enlarged partial sectional view showing an example of the structure of a section taken along line BB in FIG. 4, and FIG. 7 is a view after wire bonding is completed in assembling the memory card shown in FIG. 1 is a plan view showing an example of the structure of FIG.
FIG. 9 is a plan view showing an example of the structure of a socket that engages with the memory card shown in FIG. 9, FIG. 9 is a bottom view showing an example of the structure of the socket shown in FIG. 8, and FIG. 10 is a socket showing the memory card shown in FIG. A plan view showing an example of the structure when it is attached to the
11 is a bottom view showing an example of the structure of the memory card inserted state shown in FIG. 10, and FIG. 12 is an enlarged partial sectional view showing an example of the structure of the section taken along the line CC of FIG.

The semiconductor device of the present embodiment shown in FIGS. 1 and 2 is a multimedia card (Sandisk, Inc.) that can be used as an external storage device of a small electronic device such as a mobile phone or a digital camera. Company) and SD cards (Panasonic, Toshiba, Sandisk) and other memory cards 1.

The memory card 1 is composed of a small flat plate having a rectangular shape in plan view, and its thickness is, for example, about 1.4 mm.

Explaining the structure of the memory card 1, a wiring board 2 having a front surface 2a as a first main surface on which the semiconductor chip 3 is mounted and a back surface 2b as a second main surface on the opposite side, Provided on the surface 2a of the wiring board 2,
And the soft gold plating 2 which is the first gold plating on the surface 2f
Bonding terminal (first terminal portion) 2 on which g is formed
c and the front surface 2f provided on the back surface 2b of the wiring board 2.
The external connection terminal (second terminal portion) 2d on which the hard gold plating 2h which is the second gold plating is formed, the soft gold plating 2g of the bonding terminal 2c, and the electrode pad of the semiconductor chip 3 shown in FIG. It comprises a gold wire (wire) 4 connecting to the (surface electrode) 3b, and a cap 5 covering the semiconductor chip 3 and the resin sealing portion 6 sealing the plurality of gold wires 4.

Further, in the memory card 1 of this embodiment, the hard gold plating 2 of the external connection terminal 2d on the back surface 2b is used.
The hardness of h is equal to or higher than the metal plating of the surface 7b of the terminal 7a of the socket 7 that contacts the external connection terminal 2d shown in FIG.
It is higher than g.

That is, the metal plating on the front surface 2f of the external connection terminal 2d on the back surface 2b of the memory card 1 is made harder than the metal plating on the surface 7b of the terminal 7a of the socket 7 into which the memory card 1 is inserted, or is made equivalent. , The contact resistance between the external connection terminal 2d of the memory card 1 and the terminal 7a of the socket 7 electrically connected to the external connection terminal 2d is reduced, and the detachability of the external connection terminal 2d with respect to the socket 7 of the memory card 1 ( (Removability) is improved.

Therefore, in this embodiment, the case where the surface 7b of the terminal 7a of the socket 7 is the hard gold plating 2h will be described.

The hard gold plating 2h is generally
For example, it is used for a terminal portion such as a module substrate or a main substrate of a personal computer, and has high reliability. The hardness of hard gold plating 2h is
For example, the Vickers hardness is 180 to 200 (Hv), and the purity of gold is 99.8 to 99.9%.

On the other hand, the soft gold plating 2g is much softer than the hard gold plating 2h and can be connected to the gold wire 4 for wire bonding, and its hardness is, for example, about Vickers hardness 100 (Hv). In addition, the purity of gold is 99.99% or more.

The memory card 1 includes the semiconductor chip 3
However, since they are electrically connected by wire bonding using the gold wire 4, the surface 2f of the bonding terminal 2c on the surface 2a side on which the semiconductor chip 3 is mounted is mounted.
Must be 2 g of soft gold plating that can be connected to the gold wire 4.

Here, the bonding terminal 2c provided on the wiring board 2 of the memory card 1 on the surface 2a shown in FIG.
The composition of each of the external connection terminals 2d on the back surface 2b shown in FIG. 4 will be described. As shown in FIG. 5, the bonding terminals 2c have a three-layer structure, and the bottom layer is formed in order from the base material 2k side. Is Cu foil (including Cu plating) 2i, the intermediate layer is Ni plating 2j, and the uppermost layer is soft gold plating 2g.

Since the uppermost layer is 2 g of soft gold plating,
Wire bonding with the gold wire 4 is possible.

As shown in FIG. 6, in the external connection terminal 2d, the lowermost layer is Cu foil (including Cu plating) 2i, the first intermediate layer is Ni plating 2j, and the second intermediate layer is soft gold plating 2g. The uppermost layer is hard gold plating 2h.

Since the uppermost layer is hard gold plating 2h,
Hard gold plating 2h on surface 7b of terminal 7a of socket 7
Therefore, the contact resistance between the external connection terminal 2d of the memory card 1 and the terminal 7a of the socket 7 electrically connected thereto can be reduced.

The thickness of each plating on the front and back surfaces is, for example, about 20 μm for the Cu foil 2i and about 8 μ for the Ni plating 2j.
m, soft gold plating 2g is about 0.1 to 0.8 μm, and hard gold plating 2h is about 0.1 to 0.8 μm, but these numerical values are examples and are not limited to these numerical values. Absent.

Further, the semiconductor chip 3 mounted on the memory card 1 of the present embodiment may include, for example, a flash memory (EEPROM (Electrically Erasable Programmable Program)).
le Read Only Memory)) and is mounted on the chip mounting portion 2e of the front surface 2a of the wiring board 2 with its main surface (element formation surface) 3a facing upward as shown in FIG. There is.

The wiring substrate 2 is, for example, a thin glass-filled epoxy substrate, and the insulating solder resist 2l as shown in FIG. 12 is formed on the base material 2k shown in FIGS. 5 and 6. Has been done.

The socket 7 into which the memory card 1 is inserted (engaged) has an opening 7c for inserting and removing the memory card 1, as shown in FIGS. Further, a terminal 7a that comes into contact with the external connection terminal 2d of the memory card 1 is provided inside, and the surface 7b of the terminal 7a is hard gold plating 2h.

The socket 7 shown in FIG. 8 and FIG.
Is a push-push type socket 7 in which the memory card 1 pops out when the inserted memory card 1 is taken out again when the card is pushed out.

10 to 12 are views showing a state in which the memory card 1 is inserted into the socket 7, and the external connection terminal 2d of the memory card 1 and the terminal 7a of the socket 7 are in contact with each other and electrically connected. Is connected to.

Next, a method of manufacturing the memory card 1 of this embodiment will be described.

First, as shown in FIG. 5, soft gold plating 2
6 has a bonding terminal 2c formed on the surface 2f on the surface on which the semiconductor chip is mounted, and the same hard gold plating 2h as the hard gold plating 2h on the surface 7b of the terminal 7a of the socket 7 to be engaged is shown in FIG. The wiring board 2 shown in FIGS. 3 and 4 having the external connection terminals 2d formed on the surface 2f as shown in FIG.

In the bonding terminals 2c on the front surface 2a of the wiring board 2 and the external connection terminals 2d on the rear surface 2b, the Cu foil 2i and the Ni plating 2 are sequentially arranged from the base material 2k side.
j, the soft gold plating 2g is formed, but the same plating on the front and back surfaces may be formed in the same step or may be formed in different steps.

Thereafter, the semiconductor chip 3 is mounted on the chip mounting portion 2e on the surface 2a of the wiring board 2 on which the bonding terminals 2c are provided.

Further, as shown in FIGS. 7 and 12, the electrode pads 3b of the semiconductor chip 3 and the surface 2 of the wiring board 2 are formed.
The bonding terminal 2c of a is electrically connected by wire bonding using the gold wire 4.

Thereafter, the plurality of gold wires 4 and the semiconductor chip 3 connected by wire bonding are sealed by resin molding to form a resin sealing portion 6, and the resin sealing portion 6 is covered with the cap 5.

The cap 5 is fixed with, for example, an adhesive.

As a result, the memory card 1 which is a card type semiconductor device as shown in FIGS. 1 and 2 can be assembled.

In the memory card 1 and the method of manufacturing the same according to the present embodiment, the hardness of the metal plating on the surface 2f of the external connection terminal 2d engaging with the socket 7 of the memory card 1 is set to the surface 7b of the terminal 7a of the socket 7. By making the hardness equal to that of the metal plating, the contact resistance between the external connection terminal 2d of the memory card 1 and the terminal 7a of the socket 7 can be lowered, and the memory card 1 can be smoothly pulled out from the socket 7. Can be easily pulled out.

As a result, the detachability of the memory card 1 can be improved.

Further, since the contact resistance between the memory card 1 and the socket 7 is low, the scraping of the metal plating can be reduced,
It is possible to prevent contact failure.

Further, the connection reliability with the socket 7 of the memory card 1 can be improved.

Further, since the contact resistance between the memory card 1 and the socket 7 can be reduced, the sealing material (lubricant) applying step in the assembly of the memory card 1 can be omitted.

As a result, the process of assembling the memory card 1 can be shortened to shorten TAT (time required for the product to be completely finished).

Furthermore, since the sealing material is not applied, it is not necessary to perform a visual inspection to see if the sealing material is applied, and therefore the inspection work of the memory card 1 can be simplified. .

Further, instead of the inspection of the presence or absence of the sealing material, the inspection is performed by measuring the plating thickness of the bonding terminals 2c and the external connection terminals 2d of the wiring board 2, so that the wiring board is shipped by the board maker. Since the measurement and inspection of the plating thickness can be performed twice when the wiring board is delivered to the semiconductor manufacturer, it is possible to reduce the flow of defective wiring board 2 into the assembly process.

That is, the defective potential in the process of assembling the memory card 1 can be reduced, and the manufacturing cost can be reduced.

Although the invention made by the present inventor has been specifically described based on the embodiments of the present invention, the present invention is not limited to the embodiments of the present invention, and does not depart from the scope of the invention. It goes without saying that various changes can be made with.

For example, in the above-described embodiment, the case where the front surface 2f of the external connection terminal 2d on the back surface 2b of the memory card 1 is the hard gold plating 2h has been described, but instead of the hard gold plating 2h, gold is used instead. Alternatively, palladium (Pd) plating having high hardness may be used.

That is, the metal plating on the surface 2f of the external connection terminal 2d of the memory card 1 is the same as the terminal 7 of the socket 7.
Other metal plating such as palladium (Pd) plating other than the hard gold plating 2h may be used as long as it has hardness equal to or higher than that of the metal plating on the surface 7b of a.

Further, instead of the hard gold plating 2h, first, palladium (Pd) plating may be formed, and then the soft gold plating 2g having a thickness of 0.05 μm or less may be formed on the upper layer thereof. In this case, external connection is performed. The hardness of the use terminal 2d can be made equal to the hardness of palladium (Pd) plating, and can be gold plated in appearance.

The metal plating on the surface 2f of the bonding terminal 2c of the memory card 1 must be a metal plating that is well connected to the wire by wire bonding, and the wire is gold as in the above-described embodiment. In the case of the wire 4, it is preferable to adopt 2 g of soft gold plating.

Further, in the above-described embodiment, the case where the flash memory (EEPROM) is applied to the built-in memory card 1 has been described. However, the present invention is not limited to this. For example, SRAM (Static Random Access Memory) is used.
ry), FRAM (Ferroelectric Random Access Memory)
Alternatively, the present invention can be applied to the memory card 1 including another memory circuit such as MRAM (Magnetic Random Access Memory).

Further, an IC having no memory circuit
It can also be applied to (Integrated Circuit) cards.

[0063]

The effects obtained by the typical ones of the inventions disclosed in this application will be briefly described as follows.
It is as follows.

In the card-type semiconductor device, the hardness of the metal plating on the surface of the terminal engaging with the socket is set to be equal to or higher than the hardness of the metal plating on the surface of the terminal of the socket, so that the contact resistance between both terminals is increased. Therefore, the semiconductor device can be pulled out smoothly and easily even when the semiconductor device is pulled out from the socket. Thereby, the detachability of the semiconductor device can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing a structure of a memory card which is an example of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a bottom view showing the structure of the memory card shown in FIG.

FIG. 3 is a plan view showing an example of a structure of a wiring board incorporated in the memory card shown in FIG.

FIG. 4 is a bottom view showing an example of the structure of the wiring board shown in FIG.

5 is an enlarged partial cross-sectional view showing an example of the structure of a cross section taken along the line AA of FIG.

6 is an enlarged partial cross-sectional view showing an example of a structure of a cross section taken along the line BB of FIG.

7 is a plan view showing an example of a structure after completion of wire bonding in assembling the memory card shown in FIG. 1. FIG.

8 is a plan view showing an example of the structure of a socket that engages with the memory card shown in FIG. 1. FIG.

9 is a bottom view showing an example of the structure of the socket shown in FIG.

10 is a plan view showing an example of a structure when the memory card shown in FIG. 1 is inserted into the socket shown in FIG.

11 is a bottom view showing an example of the structure of the memory card inserted state shown in FIG.

12 is an enlarged partial cross-sectional view showing an example of the structure of a cross section taken along the line CC of FIG.

[Explanation of symbols]

1 Memory card (semiconductor device) 2 wiring board 2a surface (first main surface) 2b Back surface (second main surface) 2c Bonding terminal (first terminal part) 2d External connection terminal (second terminal part) 2e Chip mounting part 2f surface 2g Soft gold plating (first metal plating) 2h Hard gold plating (second metal plating) 2i Cu foil 2j Ni plating 2k base material 2l solder resist 3 semiconductor chips 3a Main surface 3b Electrode pad (surface electrode) 4 gold wire 5 caps 6 Resin sealing part 7 socket 7a terminal 7b surface 7c opening

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tamaki Wada             5-22-1 Kamimizuhonmachi, Kodaira-shi, Tokyo Stock             Ceremony Company Hitachi Cho-LS System             Within (72) Inventor Masachika Masuda             5-20-1 Kamimizuhonmachi, Kodaira-shi, Tokyo Stock             Ceremony Company within Hitachi Semiconductor Group (72) Inventor Toshihiko Ota             5-20-1 Kamimizuhonmachi, Kodaira-shi, Tokyo Stock             Ceremony Company within Hitachi Semiconductor Group F term (reference) 5B035 AA07 AA08 BA00 BB09 CA02                       CA03

Claims (5)

[Claims] 1. A semiconductor device comprising a wiring board having a first main surface on which a semiconductor chip is mounted and a second main surface opposite to the first main surface, the semiconductor chip being connected by wire bonding. A first terminal portion provided on the first main surface of the wiring board and having a first metal plating formed on the surface, and a second terminal surface provided on the second main surface of the wiring board. Of the second terminal portion, and a wire connecting the first metal plating of the first terminal portion and the surface electrode of the semiconductor chip, A semiconductor device, wherein the hardness of the second metal plating is equal to or higher than that of the metal plating on the surface of the terminal of the socket that comes into contact with the second terminal portion. 2. A semiconductor device having a wiring board having a first main surface on which a semiconductor chip is mounted and a second main surface opposite to the first main surface, the semiconductor chip being connected by wire bonding. A first terminal portion provided on the first main surface of the wiring board and having a first metal plating formed on the surface, and a second terminal surface provided on the second main surface of the wiring board. Of the second terminal portion, and a wire connecting the first metal plating of the first terminal portion and the surface electrode of the semiconductor chip, The hardness of the second metal plating is equal to or higher than the metal plating on the surface of the terminal of the socket that comes into contact with the second terminal portion, and is higher than that of the first metal plating. apparatus. 3. A semiconductor device having a wiring board having a first main surface on which a semiconductor chip is mounted and a second main surface opposite to the first main surface, the semiconductor chip being connected by wire bonding. A first terminal portion provided on the first main surface of the wiring board and having a first gold plating formed on the surface, and a second terminal surface provided on the second main surface of the wiring board. And a gold wire connecting the first gold plating of the first terminal portion and the front surface electrode of the semiconductor chip, the second terminal portion The hardness of the second gold plating of the
The same or higher than the metal plating on the surface of the terminal of the socket contacting the terminal portion of the above, and higher than the first gold plating. 4. A semiconductor device having a wiring board having a first main surface on which a semiconductor chip is mounted and a second main surface opposite to the first main surface, the first main surface of the wiring board. And a socket provided on the second main surface of the wiring board and engaging with a first terminal portion on the surface of which a first gold plating capable of connecting to a gold wire for wire bonding is formed. A second terminal portion on the surface of which a second gold plating having a hardness equal to or higher than that of the gold plating on the surface of the terminal and higher than that of the first gold plating is formed on the surface; A semiconductor device, characterized in that it is formed in a card shape and has the gold wire connecting a terminal portion and a surface electrode of the semiconductor chip. 5. The surface of the first terminal portion having the first metal plating formed on the surface thereof, and the surface of the second metal plating having hardness equal to or higher than that of the metal plating on the surface of the terminal of the socket to be engaged. A step of preparing a wiring board having a second terminal portion formed on the wiring board; a step of mounting a semiconductor chip on a first main surface of the wiring board on which the first terminal portion is provided; Connecting the front surface electrode and the first terminal portion of the first main surface of the wiring board by wire bonding, and sealing a plurality of wires and the semiconductor chip connected by the wire bonding. A method of manufacturing a semiconductor device, characterized by comprising assembling a card-type semiconductor device.