JP3545348B2 - Mounting package - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mounting package for mounting a sensor chip for sensing a surface shape having minute unevenness such as a human fingerprint or an animal nose pattern.
[0002]
[Prior art]
In the progress of the information society and the environment of the modern society, interest in security technology is increasing. For example, in the information-oriented society, personal authentication technology for system construction such as electronic cashing is an important key. Research and development on authentication technologies for theft and credit card and other unauthorized use are also being actively pursued (for example, Yoshimasa Shimizu et al., IC Cards with Personal Authentication Function). Review, Faculty of Engineering, Technical report of IEICE OFS 92-32, P25 30 (1992)).
[0003]
There are various authentication methods such as fingerprints and voices. Among them, many techniques have been developed for the fingerprint authentication technique. Fingerprint authentication methods are broadly classified into an optical reading method and a method using human electrical characteristics and a method of detecting unevenness of a fingerprint and replacing it with an electric signal.
The optical reading method is a method in which fingerprint data is read and collated mainly by using light reflection and an image sensor (CCD) (for example, Seigaku Igaki et al., Personal collation method and apparatus, Japanese Patent Application Laid-Open No. 61-1986). 221883 publication). Further, a method of reading the pressure difference of a fingerprint of a finger using a piezoelectric thin film has also been developed (for example, Masanori Sumihara et al., Fingerprint Sensor, JP-A-5-61965).
[0004]
An authentication method has also been proposed in which a resistance change amount is detected using a pressure-sensitive sheet or a capacitance change amount is detected, thereby replacing a change in electrical characteristics caused by skin contact with a distribution of electric signals to detect a fingerprint. (For example, Kazuhiro Hemi et al., Surface Shape Sensor, Individual Authenticator and Activated System Using It, JP-A-7-168930).
However, in the conventional techniques described above, first, the optical reading method is difficult to miniaturize and general-purpose, and its use is limited. Further, in the method of detecting the unevenness of the finger using a pressure-sensitive sheet or the like, it may be considered that the material is special and the workability is difficult.
[0005]
On the other hand, “Marco Tartagni” and the like have developed a capacitive fingerprint sensor using LSI manufacturing technology (Marco Tartagni and Robert Guererie, A 390 dpi Live Liver ing in the Company's International Partnership of the Electronic Company's Leadership, Electronic Company,,,,,,,,,,,,,,,,,,,,,,,, and). Conference, p200 201 (1997)).
This is a method in which a sensor chip in which small capacitance detection sensors are two-dimensionally arranged on an LSI detects a concave and convex pattern on the skin using a feedback capacitance method. The fingerprint authentication system using this sensor chip is characterized in that a special interface is not required and the size can be reduced as compared with the conventional optical system.
[0006]
Such a sensor chip is generally mounted on a package as shown in FIG. FIG. 3 is a schematic cross-sectional view (a) and a plan view (b) showing the configuration of a conventional sensor chip mounting package. In this mounting package, the sensor chip 301 is mounted on the bottom surface of the concave portion of the container 302 made of plastic. Further, a plurality of pins 303 are fixed to the container 302, and these are connected to the terminal portions 301 a of the sensor chip 301 by wires 304. The pin 303 is pulled out from the bottom surface of the concave portion of the container 302 from the side surface of the container 302 and projects outside.
[0007]
The wire 304 is covered and protected by the potting resin 305 in the container 302. In addition, a frame-shaped cover 306 extending from a bank-shaped frame portion of the container 302 to a peripheral portion including the terminal portion 301a of the sensor chip 301 is fixed to the frame portion of the container 302 with an adhesive, and an inner edge of the cover 306 is provided. Are in contact with the periphery of the sensor chip 301. The detection area 301b of the sensor chip 301 is exposed on the upper surface from the opening area of the cover 306.
[0008]
[Problems to be solved by the invention]
However, in the system using the sensor chip mounted as described above, since a finger directly contacts the detection area 301b of the sensor chip 301, another LSI mounted simultaneously is easily damaged by static electricity. have. In order to solve the problem caused by the static electricity, for example, a method has been proposed in which a wiring is provided for electrically connecting the base on which the mounting package shown in FIG. 3 is mounted and the cover 306, and the static is supplied to ground via the wiring and the base. Further, a method of connecting the periphery of a system incorporating the mounting package to ground has been proposed. However, in any of the methods, since the countermeasure in the state of the mounting package is insufficient, the mounting package is affected by static electricity when mounting. Also, the above method complicates the mounting process.
[0009]
The present invention has been made in order to solve the above problems, and a sensor chip for detecting a fingerprint shape of a finger by detecting a capacitance is packaged so as to be protected from destruction by static electricity. It is intended to be implemented in.
[0010]
[Means for Solving the Problems]
The mounting package of the present invention includes a container including a base portion and a frame portion fixed on the main surface, a container disposed on the main surface of the base portion inside the frame portion, including a detection surface on an upper surface, and an integrated circuit. A mounted sensor chip, a plurality of first pins and second pins drawn out of the frame through the base and the frame from the main surface of the base, and fixed on the frame. a frame-shaped cover made of a material having a conductive which is disposed through the frame portion, and the connecting member upper end lower ends are electrically connected to the cover is electrically connected to the second pin Wherein the inner edge of the cover contacts the upper surface of the sensor chip, the cover contacts the upper end of the connection member, the lower end of the connection member contacts the second pin, and the detection surface is exposed inside the cover. Is what it is.
According to the present invention, the cover and the second pin are electrically connected via the connection member.
[0011]
In the above invention, for example, the connection member and the cover are connected by a conductive adhesive.
In the above invention, the first pin is connected to a terminal of the sensor chip, and the second pin is connected to ground.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic sectional view (a), (b) and a plan view (c) showing the configuration of a mounting package according to an embodiment of the present invention. In the package of the present embodiment, the sensor chip 101 is mounted on a base 102a of a container 102 made of plastic. The container 102 is provided with a frame 102b around the periphery of the base 102a, and a plurality of signal pins (first pins) 103a and a ground pin (second pin) 103b sandwiched between the periphery of the base 102a and the frame 102b. It has. The signal pin 103a and the ground pin 103b are drawn out from between the base portion 102a and the frame portion 102b, and protrude outside from the side surface of the container 102. Further, the signal pins 103 a and the terminal portions 101 a of the sensor chip 101 are connected by wires 104.
[0013]
As shown in FIG. 1C, a groove 102c is formed in the frame 102b. The groove 102c is filled with an adhesive 107 described below to prevent the adhesive 107 from seeping out from the upper portion of the frame portion 102b to another portion. Further, in the frame portion of the region where the ground pins 103b of the container 102 are arranged, the through-hole 102d in which the connecting member 108 described below is disposed reaches the end of the ground pin 103b inside the container 102. Is formed.
[0014]
As shown in FIGS. 1A and 2A, a potting resin 105 is formed on the periphery of the sensor chip 101 so as to cover the wire 104 in the container 102 described above. The potting resin 105 is formed to protect the wires 104, but also has a function of fixing the sensor chip 101 to the base 102 a as a secondary function. FIG. 2A is a plan view showing a schematic configuration of the mounting package provided with the potting resin 105. FIG.
[0015]
Further, a frame-shaped cover 106 made of, for example, stainless steel, which is a conductive material, is bonded and fixed to the peripheral portion including the frame portion of the container 102 with an adhesive 107. The cover 106 is not limited to stainless steel and may be made of a conductive material such as another metal member. As shown in FIG. 2B, the cover 106 extends from the frame portion of the container 102 to the peripheral portion of the sensor chip 101 including the terminal portion 101a, and the inner edge of the cover 106 presses the peripheral portion of the sensor chip 101. I have. The detection surface 101b of the sensor chip 101 is exposed from the opening area of the cover 106 to the upper surface. The cover 106 may be made of, for example, a conductive plastic.
[0016]
In addition, in the present embodiment, the connection member 108 made of a conductive material such as metal for connecting the ground pin 103b and the cover 106 is provided. The connection member 108 extends from the upper portion of the frame area of the container 102 on the side where the ground pins 103b are arranged, to the end of the ground pin 103b inside the container 102. The connection member 108 and the cover 106 are adhered by a conductive adhesive. For example, if the conductive adhesive is applied to the upper surface of the connection member 108, when the cover 106 is fixed to the frame portion 102b, the upper portion of the connection member 108 and the cover 106 come into contact with each other, and the conductive adhesive is applied. Is electrically connected via the.
[0017]
Further, as shown in the cross-sectional view of FIG. 1B, the through-hole 102d is formed such that the opening area becomes smaller as going upward. As a result, when the cover 106 is pressed against the upper surface, the opening area of the upper portion of the through-hole 102d is reduced, so that the connection member 108 is pressed. Therefore, when the cover 106 is fixed to the frame portion 102b, the connection member 108 is pressed down and fixed to the upper portion inside the through hole 102d.
[0018]
As described above, according to the present embodiment, the connection member 108 is provided, so that the cover 106 and the ground pin 103b are electrically connected. For this reason, when the mounting package of FIG. 1 is incorporated in a fingerprint collation system or the like, if the connection destination of the ground pin 103b is connected to the ground, the static electricity of the finger that contacts the detection surface 101b will be covered simultaneously. It flows from 106 to ground via the connecting member 108 and the ground pin 103b. As a result, according to the mounting package of the present embodiment, other integrated circuits simultaneously mounted on the sensor chip 101 are protected from electrostatic damage. Further, according to the present embodiment, it is possible to solve the problem caused by static electricity only by incorporating a mounting package without making other wiring connections.
[0019]
【The invention's effect】
As described above, according to the present invention, since the cover is electrically connected to the ground pin, the sensor chip that detects the fingerprint shape of the finger by detecting the capacitance can be damaged by static electricity in the mounting package. An excellent effect of being able to be protected from is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view and a plan view showing a configuration of a mounting package according to an embodiment of the present invention.
FIG. 2 is a schematic plan view showing a configuration of a mounting package according to the embodiment of the present invention.
FIG. 3 is a schematic cross-sectional view and a plan view showing a configuration of a conventional mounting package.
[Explanation of symbols]
101 sensor chip, 101a terminal part, 101b detection surface, 102 container, 102a base part, 102b frame part, 102c groove, 102d through hole, 103a signal pin, 103b ground pin, 104 Wire, 105: potting resin, 106: cover, 107: adhesive, 108: connecting member.

Claims (3)

A container comprising a base portion and a frame portion fixed on the main surface,
A sensor chip disposed on the main surface of the base portion inside the frame portion, including a detection surface on the upper surface, and having an integrated circuit mounted thereon,
A plurality of first pins and second pins which are drawn out of the frame portion from the main surface of the base portion through the space between the base portion and the frame portion;
A frame-shaped cover made of a material having a fixed conductive on said frame portion,
A connection member disposed through the frame portion, an upper end electrically connected to the cover, and a lower end electrically connected to the second pin;
The inner edge of the cover is in contact with the upper surface of the sensor chip, the cover is in contact with the upper end of the connection member, the lower end of the connection member is in contact with the second pin, and the detection surface is A mounting package, which is exposed inside the cover. The mounting package according to claim 1,
The mounting package, wherein the connection member and the cover are connected by a conductive adhesive. The mounting package according to claim 1 or 2,
The first pin is connected to a terminal of the sensor chip,
The mounting package according to claim 2, wherein the second pin is connected to a ground.

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