Electronic component, coaxial connector, and communication device

Information

  • Patent Grant
  • 6783374
  • Patent Number
    6,783,374
  • Date Filed
    Thursday, December 21, 2000
    23 years ago
  • Date Issued
    Tuesday, August 31, 2004
    20 years ago
Abstract
An electronic component, a coaxial connector, and a communication device each have a structure wherein flux does not intrude into the components thereof during mounting. The coaxial connector includes a synthetic resin case divided into a lower-side insulative case and an upper-side insulative case, and a fixed terminal, a movable terminal, and an external terminal each being made of metal. The lower-side insulative case has two notches provided therein. One of the notches receives the lead potion of the fixed terminal, and the other of the notches receives the lead potion of the movable terminal. These notches are configured such that clearances are provided to prevent capillary effect from occurring between the lead portions of the respective two terminals and the lower-side insulative case.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to an electronic component, a coaxial connector, and a communication device.




2. Description of the Related Art




Mobile communication devices such as portable telephones use surface-mounting type coaxial connectors capable of switching signal paths. This type of coaxial connector is typically obtained by integrally molding a resin case, a fixed terminal, and a movable terminal having spring characteristics, by insert-molding.




In some cases, however, when a conventional surface-mounting type coaxial connector is mounted on a printed circuit board via reflow soldering, flux contained in cream solder intrudes into the resin case through small gaps between the resin case and the terminals. This causes a problem that the flux adheres to a portion where the fixed terminal and the movable terminal are in contact with each other, and this causes a contact failure.




Furthermore, even if this coaxial connector is not formed by integrally molding the resin case, the fixed terminal, and the movable terminal, contact failure occurs when a gap exists which allows for the capillary effect between the resin case and the terminals.




SUMMARY OF THE INVENTION




To overcome the above-described problems with the prior art, preferred embodiments of the present invention provide an electronic component, a coaxial connector, and a communication device having a unique construction arranged such that flux does not intrude into the components thereof during mounting.




Preferred embodiments of the present invention provide an electronic component including an insulative case, a plurality of surface-mounting terminals mounted on the insulative case, and a notch provided in the insulative case to receive the lead portion of at least one of the plurality of terminals. In this electronic component, a notch defines a clearance to prevent the occurrence of the capillary effect, the clearance being provided between the notch and the solder fillet portion of the at least one lead portion.




Another preferred embodiment of the present invention provides a coaxial connector including an insulative case having a hollow portion into which the central contact of a mating coaxial connector is inserted, a fixed terminal and a movable terminal for surface mounting, the fixed terminal and movable terminal being mounted in the hollow portion of the insulative case, a surface-mounting external terminal mounted on the outside of the insulative case, the surface-mounting external terminal being connected with the outer conductor of the mating coaxial connector, and notches provided in the insulative case, to receive lead portions of each of the fixed terminal and movable terminal, each of the notches having a clearance to prevent the occurrence of the capillary effect between each of the notches and the solder fillet portion of the lead portions.




Since a clearance is provided between the solder fillet portion of a terminal such as the fixed terminal or the movable terminal and the insulative case, no capillary effect of flux occurs between the solder fillet portion and the insulative case. When an electronic component such as a coaxial connector is mounted on a printed circuit board, therefore, flux does not intrude into the components through the gap between the terminal and the insulative case. Preferably, the notch in the insulative case has a clearance to prevent the occurrence of capillary effect, between the notch and the soldered portion of the lead portion, as well. This allows the notch to have clearances all around the lead portion, and further reduces the likelihood that the flux more will intrude into the components.




Even if a clearance is provided between the solder fillet portion and the insulative case, the flux will move beyond the solder fillet portion and will intrude into the insulative case through the gaps between the insulative case and the terminal, when an excess amount of solder is applied. Therefore, by providing a groove intersecting at least one terminal, on the divided surfaces of the insulative case, the groove provided on a divided surface secures a gap having which prevents capillary effect between the insulative case and the terminal, and thereby prevents the flux from flowing.




Moreover, by configuring the groove to have a substantially V-shaped cross-section, the removal of the insulative case from a mold is facilitated, and molding failure is greatly reduced. Also, by configuring the groove to extend in a direction that is substantially perpendicular to the flowing direction of the flux, the intrusion of the flux is reliably prevented.




The communication device in accordance with various preferred embodiments of the present invention can achieve a high reliability by being equipped with the electronic component and the coaxial connector having the above-described features.




The features, characteristics, elements and advantages of the present invention will be clear from the following detailed description of preferred embodiments of the invention in conjunction with the accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is an exploded perspective view showing a preferred embodiment of a coaxial connector in accordance with the present invention.





FIG. 2

is a perspective view illustrating the upper-side insulative case of the coaxial connector shown in

FIG. 1

, as seen from the bottom surface side.





FIG. 3

is a front view showing the fixed terminal and the movable terminal of the coaxial connector shown in FIG.


1


.





FIG. 4

is a perspective view showing the appearance of the coaxial connector shown in FIG.


1


.





FIG. 5

is a perspective view showing the coaxial connector shown in

FIG. 4

, as seen from the bottom surface side.





FIG. 6

is a side view showing the coaxial connector shown in

FIG. 4

, as seen from the fixed terminal side.





FIG. 7

is a side view showing the coaxial connector shown in

FIG. 4

, as seen from the movable terminal side.





FIG. 8

is a sectional view showing the coaxial connector shown in FIG.


4


.





FIG. 9

is a sectional view showing a state in which a mating connector has been engaged with the coaxial connector shown in FIG.


4


.





FIG. 10

is a block diagram showing a preferred embodiment of a communication device in accordance with the present invention.











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS





FIG. 1

is an exploded perspective view showing a preferred embodiment of a coaxial connector in accordance with the present invention. This coaxial connector (coaxial receptacle)


1


includes an insulative case which is made of synthetic resin and which is divided into two portions, that is, a lower-side insulative case


2


A and a upper-side insulative case


2


B, a metallic fixed terminal


21


, a metallic movable terminal


31


, and an external terminal (outer conductor)


41


.




The lower-side insulative case


2


A preferably has a substantially rectangular shape, and includes guide protrusions


3


provided at the four corners of the top surface (a divided surface), for positioning of the upper-side insulative case


2


B. In the vicinity of each guide protrusion


3


, foot receiving portions


4


are provided for providing the feet


18


(see

FIG. 2

) of the upper-side insulative case


2


B thereon. At the respective approximate central portions of the opposite two sides of the lower-side insulative case


2


A, substantially rectangular notches


6


and


7


are provided, respectively. The lead portion


24


(described later) of a fixed terminal


21


is received in the notch


6


, while the lead portion


34


(described later) of a movable terminal


31


is received in the notch


7


.




The upper-side insulative case


2


B includes a substantially rectangular cover portion


11


and a substantially cylindrical introduction portion


12


provided at the approximate central portion on the upper surface thereof. The substantially cylindrical introduction portion


12


is preferably configured in the form of cone at the upper portion, and includes a introduction hole


13


of which the cross section is preferably substantially circular. The introduction hole


13


passes through the upper-side insulative case


2


B. The central contact of a mating coaxial connector is exposed in the introduction hole


13


through the substantially conical opening side. At the four corners of the cover portion


11


, notches


14


are provided. The notches


14


are engaged with the guide protrusions


3


of the lower-side insulative case


2


A, and thereby the upper-side insulative case


2


B and the lower-side insulative case


2


A are assembled with greatly improved positioning accuracy.




As shown in

FIG. 2

, the feet


18


are provided on the bottom surface (a divided surface) of the upper-side insulative case


2


B. A groove


15


having a substantially V-shaped cross-section is provided between the introduction hole


13


and the side from which the fixed terminal


21


is led out. The groove


15


extends in a direction that is substantially perpendicular to the direction in which the fixed terminal is led out. Configuring the groove


15


to have the substantially V-shaped cross-section facilitates the removal of the upper-side insulative case


2


B from a mold, when producing the upper-side insulative case


2


B by molding. This greatly reduces molding failure.




The fixed terminal


21


is formed by stamping out a flat metallic plate and then subjecting the stamped-out plate to a bending process. The fixed terminal


21


includes a contact portion


22


defining a contact point with the movable terminal


31


, a fixation portion


23


pinched between the insulative case


2


A and


2


B, and a lead portion


24


bent into a L-shape. The contact portion


22


is formed by folding both sides at a predetermined angle, and has a horizontal surface


22




a


and tilting surfaces


22




b


on both sides of the horizontal surface


22




a.






The fixation portion


23


includes substantially semicircular recesses


26


provided on both sides thereof. Each of the recesses


26


is engaged with the feet


18


of the upper-side insulative case


2


B, and thereby the fixed terminal


21


is built into the upper-side insulative case


2


B with greatly improved positioning accuracy. At this time, the fixed terminal


21


is built into the upper-side insulative case


2


B such that the horizontal surface


22




a


of the contact portion


22


and the fixation portion


23


are closely adhered on the bottom surface of the upper-side insulative case


2


B. However, a gap exists at the portion where the fixed terminal


21


intersects the groove


15


.




As shown in

FIG. 3

, the lead portion


24


includes a solder fillet portion


24




a


extending downward and substantially parallel with the side of the lower-side insulative case


2


A, and a soldering portion


24




b


bent inward at a right angle to be substantially flush with the bottom surface of the lower-side insulative case


2


A.




The movable terminal


31


is preferably formed by stamping out a metallic plate having spring characteristics into a predetermined shape, and then subjecting the stamped-out plate to a bending process. The movable terminal


31


includes a movable contact portion


32


which is configured to have a spring-movable function and which defines a contact point with the fixed terminal


21


, a fixation portion


33


pinched between the insulative case


2


A and


2


B, and a lead portion


34


bent into a L-shape. The movable contact portion


32


is curved to arcuately bulge upward. The movable contact portion


32


includes a spring support portion


37


disposed at both ends thereof, and a spring contact portion


38


disposed at the approximate central portion thereof.




The fixation portion


33


includes substantially semicircular recesses


36


provided at both sides thereof. Each of the recesses


36


is engaged with the feet


18


of the upper-side insulative case


2


B, and thereby the movable terminal


31


is built into the upper-side insulative case


2


B with greatly improved positioning accuracy. At this time, the movable terminal


31


is built into the upper-side insulative case


2


B such that the fixation portion


33


is closely adhered on the bottom surface of the upper-side insulative case


2


B.




As shown in

FIG. 3

, a lead portion


34


includes a solder fillet portion


34




a


extending downward and substantially parallel with the side of the lower-side insulative case


2


A, and a soldering portion


34




b


bent inward at a right angle so as to be substantially flush with the bottom surface of the lower-side insulative case


2


A.




An external terminal


41


contacting the outer conductor of a mating coaxial connector is preferably formed by stamping out a metallic plate such as brass or phosphor bronze to provide spring characteristics, and subjecting the stamped-out plate to a bending or drawing process. A flat portion


42


at the approximate center of a plate-shaped body is provided on the top surface portion of the upper-side insulative case


2


B. The flat portion


42


includes legs


43


provided at the four corners thereof. These legs


43


are folded along the side and the bottom surface of the assembly constituted of the terminals


21


and


31


, and the insulative cases


2


A and


2


B. The assembly is very durable. The tip


43




a


of the leg portion


43


is disposed to be substantially flush with the bottom surface of the insulative case


2


A, and provides a soldered portion.




Furthermore, at the approximate central portion of the flat portion


42


, a through-cylinder portion


45


is arranged to be concentric with the substantially cylindrical introduction portion


12


. The through-cylinder portion


45


is engaged with the outer conductor of the mating coaxial connector. The outer conductor


41


provides a ground, and the outer surface thereof is plated as required.





FIG. 4

is a perspective view showing the assembled coaxial connector


1


, as seen from the top surface side thereof, and

FIG. 5

is a perspective view as seen from the bottom surface side. Also,

FIG. 6

is a side view of the coaxial connector


1


, as seen from the fixed terminal


21


side,

FIG. 7

is a side view showing thereof, as seen from the movable terminal side


31


, and

FIG. 8

is a sectional view thereof. As illustrated in

FIGS. 4 and 5

, this coaxial connector


1


includes the soldered portions


24




b


,


34




b


, and


43




a


of the respective terminals


21


,


31


, and


41


provided to be substantially flush with the lower-side insulative case


2


A, and thus enables surface-mounting. The outer terminal


41


includes the through-cylinder portion


45


provided therein, and thereby a stable and reliable connection with the mating coaxial connector is established. As illustrated in

FIG. 8

, in the inner space of the insulative case defined by the insulative case


2


A and


2


B, the fixed and movable terminals


21


and


31


are disposed with the fixed terminal


21


at the upper side.




As illustrated in

FIG. 1

, the lower-side insulative case


2


A includes notches


6


and


7


provided therein. The notch


6


receives the lead portion


24


of the fixed terminal


21


, and the notch


7


receives the lead portion


34


of the movable terminal


31


. The notches


6


and


7


are configured such that clearances are set such that no capillary effect occurs between the lead portions


24


and


34


of the respective terminals


21


and


31


, and the lower-side insulative case


2


A. More specifically, as shown in

FIGS. 6 through 8

, the notches


6


and


7


are configured such that clearances d


1


and d


2


are set such that no capillary effect occurs between the fillet portions


24




a


and


34




a


of the respective terminals


21


and


31


, and the lower-side insulative case


2


A. Furthermore, the notches


6


and


7


are also configured such that clearances are set such that no capillary effect occurs between the soldered portions


24




b


and


34




b


and the lower-side insulative case


2


A.




Hence, when the coaxial connector


1


is surface-mounted on a printed circuit board


61


by the reflow method, the soldered portions


24




b


,


34




b


, and


43




a


are disposed on the conductor pattern (not shown) on the printed circuit board


61


, and solder fillets


62


are provided on the solder fillet portions


24




a


and


34




a


, no capillary effect of the flux contained in the cream solder occurs. The flux contained in the cream solder, therefore, does not intrude into the coaxial connector through the gaps between the terminals


21


and


31


and the insulative case


2


A and


2


B, respectively. Consequently, the flux does not adhere to the contact portion


22


of the fixed terminal


21


and the movable contact portion


32


of the movable terminal


31


, which results in greatly improved contact reliability at terminal contact points.




Even if clearances d


1


and d


2


are provided between the solder fillet portions


24




a


and


34




a


and the lower-side insulative case


2


A, the flux will intrude into the insulative case through the gaps between the insulative case


2


A and


2


B, and the terminals


21


and


31


, if an excess amount of solder is applied. Therefore, by providing a groove


15


intersecting the fixed terminal


21


on a divided surface of the upper-side insulative case


2


B, the groove


15


ensures a gap having such that no capillary effect occurs between the insulative case


2


A and


2


B and the fixed terminal


21


, and thereby intrusion of the flux is prevented. Also, the flux intrudes along the surface of the fixed terminal


21


, however since the groove


15


extends in the direction that is substantially perpendicular to the flowing direction of the flux, the intrusion of the flux is reliably prevented. The groove


25


is provided on the fixed terminal


21


side in this preferred embodiment because the distance from the lead portion


24


to the contact portion


22


is smaller than the length of the movable terminal


31


, and thereby the effect of providing the groove


15


is significant.




Next, the operation of this coaxial connector


1


will be described with respect to

FIGS. 8 and 9

.




As illustrated in

FIG. 8

, when the mating coaxial connector is not mounted, the movable contact portion


32


bulges upward at the approximate central portion thereof. Hence, the movable terminal


31


makes contact with the fixed terminal


21


by the force due to the spring property of the movable contact portion


32


, and thus the terminals


21


and


31


are electrically connected together.




In contrast, as shown in

FIG. 9

, when the mating coaxial connector is mounted, the approximate central portion of the movable contact portion


32


is pushed downward by the central contact


65


of the mating coaxial connector inserted through the introduction hole


13


provided at upper side. As a result, the approximate central portion of the movable contact portion


32


is reversed and the approximate central portion thereof takes an arcuate shape with the approximate central portion thereof bulged downward. The spring contact portion


38


of the movable terminal


31


is detached from the contact portion


22


of the fixed terminal


21


and the electrical connection between the fixed terminal and the movable terminal is disconnected, while the approximate central contact


65


and the movable terminal


31


are electrically connected together. Simultaneously, the outer conductor (not shown) of the mating coaxial connector is engaged with the external terminal


41


, and thereby the outer conductor is also electrically connected with the external terminal


41


.




When the mating coaxial connector is dismounted from the coaxial connector


1


, the central portion of the movable contact portion


32


returns, utilizing the spring characteristics thereof, to the state of bulging upward. As a result, the fixed terminal


21


and the movable terminal


31


are again electrically connected together, while the approximate central contact


65


and the movable terminal


31


are electrically disconnected.




Next, a communication device in accordance with a second preferred embodiment of the present invention will be described using a portable telephone as an example.





FIG. 10

is a block diagram showing the electric circuit of the RF circuit portion of a portable telephone


120


. In

FIG. 10

, reference numeral


122


is antenna element,


123


is a duplexer,


125


is a change-over switch,


131


is a transmission-side isolator,


132


is a transmission-side amplifier,


133


is a transmission-side interstage band-pass filter,


134


is a transmission-side mixer,


135


is a reception-side amplifier,


136


is a reception-side interstage band-pass filter,


137


is a reception-side mixer,


138


is a voltage control oscillator (VCO), and


139


is a local band-pass filter.




Herein, as a change-over switch


125


, the above-described coaxial connector


1


in accordance with the first preferred embodiment is used. Hence, for example, when a set maker checks the electric characteristics of a RF circuit portion in the production process of the portable telephones


120


, by engaging a measuring probe (a mating coaxial connector)


126


connected to a measuring device with the coaxial connector


1


, the signal path from the RF circuit portion to the antenna element


122


is switched to the signal path from the RF circuit portion to the measuring device. Once the measuring probe


126


is disengaged from the coaxial connector


1


, the signal path returns to the signal path from the RF circuit portion to the antenna element


122


. Mounting this coaxial connector


1


produces a portable telephone


120


with greatly improved reliability.




The electronic component, a coaxial connector, and a communication device are not limited to the above-described preferred embodiments, but can be modified within the spirit and scope of the invention.




In particular, the present invention can be applied to an electronic component including a surface-mounting terminal which is led out from an insulative case. For example, apart from the coaxial connector in accordance with the first preferred embodiment, the present invention can also be applied to a piezoelectric component, isolator, circulator, IC components, etc.




Also, the groove provided to eliminate capillary effect, may be provided only on the fixed terminal side as in the above-described preferred embodiments, or maybe provided only on the movable terminal side. Alternatively, the grooves may be provided on both the fixed terminal side and the movable terminal side. In the above-described preferred embodiments, a description has been provided of a coaxial connector wherein the terminals and the insulative case are separately produced. However, a coaxial connector formed by integral molding, that is, by insert-molding the terminals into the insulative case maybe alternative used. In addition, with regard to the outer shape of the insulative case or the shape of the hollow portion, other shapes, such as a rectangle, a circle, or other suitable shapes can be selected in accordance with specification.




As is evident from the above-described description, in accordance with various preferred embodiments of the present invention, a clearance is provided between the solder fillet portion of the terminal such as the fixed terminal or the movable terminal, or the soldered portion, and the insulative case, and hence no capillarity of flux occurs between the solder fillet portion and the insulative case during mounting.




When an electronic component such as a coaxial connector is mounted on a printed circuit board, therefore, flux does not intrude into the components through the gaps between the terminals and the insulative case.




Even if a clearance is provided between the solder fillet portion and the insulative case, the flux will move beyond the solder fillet portion and will intrude into the insulative case through the gaps between the insulative case and the terminals if an excessive amount of solder is applied. Therefore, by providing a groove intersecting at least one terminal, on the divided surface of the insulative case, the groove provided on the divided surface produces a gap which prevents capillary effect between the insulative case and the terminal, and thereby prevents the intrusion of the flux. This produces an electronic component, such as a coaxial connector or a communication device, having a greatly improved reliability.




Moreover, by configuring the groove with a substantially V-shaped cross-section, removal of the insulative case from a mold is greatly facilitated, and molding failure is greatly reduced. Also, by configuring the groove to extend in the direction that is substantially perpendicular to the intrusion direction of the flux, the intrusion of the flux is reliably inhibited.




While the invention has been described in its preferred embodiments, obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.



Claims
  • 1. An electronic component comprising:an insulative case including a lower case portion and an upper case portion; a plurality of surface-mounting terminals mounted on said insulative case; at least one notch formed by a central substantially rectangular cut through the entire thickness of said lower case portion to accommodate a substantially L-shaped lead portion of at least one of said plurality of surface-mounting terminals; and said at least one notch providing a clearance between said lower case portion and said substantially L-shaped lead portion of said at least one of said plurality of surface-mounting terminals such that said substantially L-shaped lead portion does not contact any part of the lower case portion so as to prevent the occurrence of capillary effect of solder applied to said electronic component.
  • 2. A communication device comprising an electronic component as claimed in claim 1.
  • 3. An electronic component as claimed in claim 1, wherein said substantially L-shaped lead portion of said at least one of said plurality of surface-mounting terminals includes a solder fillet portion.
  • 4. An electronic component as claimed in claim 3, wherein said clearance is provided between the solder fillet portion and said insulative case.
  • 5. An electronic component as claimed in claim 1, further comprising:a plurality of terminals led out from a divided surface of said insulative case to the outside of said insulating case; a groove intersecting at least one of said plurality of terminals, said groove being provided in said divided surface of said insulative case.
  • 6. An electronic component as claimed in claim 5, wherein said groove has a substantially V-shaped cross-section, and said groove extends in the direction that is substantially perpendicular to a flowing direction of flux.
  • 7. An electronic component as claimed in claim 1, further comprising a fixed terminal and a movable terminal each having substantially L-shaped lead portions.
  • 8. An electronic component according to claim 7, wherein said at least one notch includes a first notch and a second notch.
  • 9. An electronic component according to claim 8, wherein said first notch receives said substantially L-shaped lead portion of said fixed terminal.
  • 10. An electronic component according to claim 8, wherein said second notch receives said substantially L-shaped lead portion of said movable terminal.
  • 11. An electronic component according to claim 7, wherein the movable terminal includes a movable contact portion having a spring property which bulges upward at an approximate central portion thereof, said movable terminal contacts said fixed terminal by the force caused by the spring property of the movable contact portion to electrically connect said movable terminal to said fixed terminal.
  • 12. An electronic component according to claim 1, wherein said insulative case is made of resin.
  • 13. A coaxial connector comprising:an insulative case having a hollow portion into which a central contact of a mating coaxial connector is inserted and including a lower case portion and an upper case portion; a fixed terminal and a movable terminal for surface mounting, said fixed terminal and movable terminal being mounted to the hollow portion of said insulative case; a surface-mounting external terminal mounted onto the outside of said insulative case, said surface-mounting external terminal being electrically connected with an outer conductor of said mating coaxial connector; and notches formed by central substantially rectangular cuts through the entire thickness of said lower case portion to accommodate substantially L-shaped lead portions of each of said fixed terminal and movable terminal such that said substantially L-shaped lead portions do not contact any part of the lower case portion so as to prevent the occurrence of capillary effect of solder applied to said coaxial connector.
  • 14. A communication device comprising a coaxial connector as claimed in claim 13.
  • 15. A coaxial connector as claimed in claim 13, wherein each of said notches includes a clearance between said substantially L-shaped lead portions of each of said fixed terminal and said movable terminal and said insulative case to prevent the occurrence of capillary effect.
  • 16. A coaxial connector as claimed in claim 15, wherein each of said clearances being defined between a solder fillet portion of said substantially L-shaped lead portions and said insulative case.
  • 17. A coaxial connector as claimed in claim 13, wherein the substantially L-shaped lead portions of each of said fixed and movable terminals are led out from the divided surfaces of the insulative case to the outside of the insulative case, and further comprising:a groove intersecting at least one of said fixed and movable terminals, said groove being provided in a divided surface of said insulative case.
  • 18. A coaxial connector as claimed in claim 17, wherein said groove has a substantially V-shaped cross-section, and said groove extends in a direction that is substantially perpendicular to a flowing direction of flux.
  • 19. An electronic component according to claim 13, wherein the movable terminal includes a movable contact portion having a spring property which bulges upward at the approximate central portion thereof, said movable terminal contacts said fixed terminal by the force caused by the spring property of the movable contact portion to electrically connect said movable terminal to said fixed terminal.
  • 20. An electronic component according to claim 13, wherein said insulative case is made of resin.
Priority Claims (1)
Number Date Country Kind
11-363505 Dec 1999 JP
US Referenced Citations (2)
Number Name Date Kind
6068499 Kuriyama et al. May 2000 A
6081996 Kruppa et al. Jul 2000 A
Foreign Referenced Citations (12)
Number Date Country
1223489 Jul 1999 CN
0 765 010 Mar 1997 EP
0 929 128 Jul 1999 EP
1-137072 Sep 1989 JP
4-78767 Jul 1992 JP
5-50671 Jul 1993 JP
7-36370 Jul 1995 JP
10-003968 Jan 1998 JP
11-86986 Mar 1999 JP
11-265761 Sep 1999 JP
11-307188 Nov 1999 JP
1999-029171 Apr 1999 KR