JP2005116405A - Electric connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an area array type connector for a high frequency IC element without the leakage of a signal current, an interference between adjacent electrodes, and an influence of noise and the like. <P>SOLUTION: The electric connector 1 suitable for the connection of a high frequency IC has a conductive contact element 4 formed integrally to a large number of pierced holes 3 formed in an insulated resin substrate 2, and an outside enclosure conductor (shield body) 5 is formed on the periphery of the conductive contact element 4. Some of the outside enclosure conductors (shield body)4 are formed into chamfer shapes 6 and 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an IC connector using a high-frequency signal, or an electrical connector suitable for electrical connection of various electronic components and a circuit board.

The IC element is arranged in a grid on one surface of the IC element in accordance with the increase in the density of the IC element from the form such as QFP (Quad Flat Package) in which the input / output electrodes are drawn from the side surface. It is changing to an area array type. In order to electrically connect such an IC element to a substrate, a connector in which metal leaf springs are arranged in a grid shape, or a connector in which conductive rubber contacts filled and mixed with conductive particles such as metal particles are arranged in a grid ( Patent Document 1) is used.
Japanese Patent Application No. 2003-288937

  Recently, the frequency of signal currents used for IC elements has been increasing. When the frequency of the signal current used for IC elements increases, the influence of signal current leakage between closely arranged electrodes, mutual interference between adjacent electrodes, noise, etc. becomes stronger. It has become difficult to accurately convey

  It is an object of the present invention to provide an area array connector for a high frequency IC element that is free from the influence of signal current leakage, mutual interference between adjacent electrodes, noise, and the like.

  The electrical connector of the present invention is characterized in that a conductive contact element is integrally formed in a number of through holes provided in an insulating resin substrate, and an outer conductor (shield body) is formed around the conductive contact element. To do. A part of the surrounding conductor (shield body) may have a cutout shape.

  The electrical connector suitable for high-frequency IC connection according to the present invention has an outer conductor (shield body) around the conductive element, so that there is no influence of leakage of signal current, mutual interference between adjacent electrodes, noise, and the like. It becomes an area array type connector for high-frequency IC elements, and when a notch is provided in a part of the outer conductor (shield body), the IC element corresponding to the central conductor (conductive element) or the electrode of the substrate Since the lead-out wiring can be performed on the surface of the IC element or the substrate, the IC element or the substrate considering the characteristic impedance is simplified, and the cost can be reduced.

The present invention is based on the provision of an outer conductor around a conductive contact element that conducts an electrode through which a high-frequency signal current flows, and shielding it to prevent leakage of the high-frequency signal current and mixing of noise signals from adjacent electrodes. .
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a simplified schematic plan view showing an embodiment of the electrical connector of the present invention. FIG. 2 is a simplified cross-sectional schematic view showing a detailed structure in an embodiment of the electrical connector of the present invention shown in FIG. FIG. 3 is an explanatory view showing notches provided in the outer conductor (shield body).

In FIG. 1, an electrical connector 1 of the present invention is an elastic elastomer that protrudes on both sides of an insulating resin substrate 2 by using the through holes 3 on an insulating resin substrate 2 provided with through holes 3 (FIG. 2) in advance. A plurality of conductive contact elements 4 are arranged in a grid shape, surrounding the periphery of necessary ones of the conductive contact elements 4, and using the through holes 3 as in the case of the conductive contact elements 4, an insulating resin substrate An outer conductor (shield body) 5 made of an elastic elastomer projecting on both surfaces of 2 is integrally formed.
In FIG. 1, the outer conductor 5 is provided on all the conductive contact elements 4. However, as shown in FIG. 2, the outer conductor 5 is provided only on the conductive contact elements 4 that require shielding. You can also.

The number of through-holes provided in the insulating resin substrate is one at the center for conductive contact elements, 90 ° (4) or 60 ° (6) at the circumferential position for the outer conductor, for example. What is necessary is just to arrange | position suitably.
The conductive contact element may be cylindrical or prismatic, or may be a truncated cone or a truncated pyramid. The cross-sectional shape of the surrounding conductor may be rectangular or trapezoidal. The central vertical cross-sectional shape of the conductive contact element and the face shape of the surrounding conductor can be made equal, but the thickness of the surrounding conductor can also be reduced (as shown in FIGS. 1 and 2). Drawn).
By making the conductive contact element and the surrounding conductor elastic conductive elastomers, it is possible to follow even if the height of the electrode of the IC element or the substrate varies. The larger the height of the conductive contact element and the surrounding conductor from the surface of the smoke-saving resin substrate, the easier it is to cope with variations in the electrode height, but if it is higher, there is a possibility of bending and contact with each other when it is compressed And the conduction resistance increases, so design with an appropriate balance. The frustoconical shape, the truncated pyramid shape, and the trapezoidal cross-sectional shape are less in contact with each other at the time of pressing and compressing, but this requires a bottom area and restricts the arrangement density. Also in this aspect, the design is appropriately made in consideration of both.

The conductive contact element and the surrounding conductor are manufactured by arranging and molding the above-described conductive composition on an insulating resin substrate having through holes formed in a mold. When the conductive contact element and the surrounding conductor are made of conductive elastomers having different composition components, they are repeatedly molded.
The hardness of the conductive contact element is 50 to 80, preferably 60 to 80 rubber hardness (JIS K6253 durometer hardness) because the electrodes of the electrical workpieces are electrically joined to each other by being compressed from above and below. Preferably it is type A). If the rubber hardness is less than 50, a sufficient repulsive load cannot be obtained and the electrical connection is not stable. On the other hand, if the rubber hardness is greater than 80, the load required for compression increases, which may damage the electrical workpiece.

If the space between the conductive contact element and the outer conductor is filled with an insulating elastomer, the risk of mutual contact is reduced, but the distance between the conductive contact element and the surrounding conductor is increased due to the dielectric constant of the insulating elastomer. On the contrary, by leaving it as an air layer, it is possible to reduce the distance between the conductor contact element and the outer conductor, thereby increasing the arrangement density.
As shown in FIG. 3A, the outer conductor 5 can be configured to surround the entire circumference of the conductive contact element 4, and in this case, the shielding property of the high-frequency current is the highest. In addition, a notch 6 having a height less than the height of the wall is formed in a part of the wall of the outer conductor so that another lead-out wiring can be provided on the surface of the circuit board from the conductive contact element or the corresponding electrode. B)) or a notch 7 (FIG. 3C) extending over the entire height of the wall.

As the insulating resin substrate 2, it is preferable to use an insulating resin substrate that is very little deformed by heat and pressure stress that acts when forming the conductive contact element, and in particular, the insulating resin substrate 2 is used. The flexible resin preferably has a deflection temperature under load of ISO 75-1 (ASTM D648) 1.82 MPa of 210 ° C. or higher, more preferably 220 ° C. or higher, and a linear expansion coefficient of 4 × 10 ⁻⁵ / K or lower. It is also a preferred embodiment to mix glass fiber with this insulating resin.
Resins having these physical properties include engineer plastics, especially PPS (polyphenylene sulfide), PES (polyethersulfone), PEEK (polyetheretherketone), LCR (liquid crystal polymer), PEI (polyetherimide), PAI ( Polyimide amide), PBT (polybutylene terephthalate), polyimide and the like.

In order to further increase the deflection temperature under load of these materials and reduce the linear expansion coefficient, it is preferable to blend glass fibers, glass beads, and the like at a ratio of 10 to 60%. Among these materials, glass fiber blended PPS and glass fiber blended PEI are preferably used from the viewpoint of easy injection molding, warpage, and dimensional stability. Among these, PPS containing 30 to 50% glass fiber is most preferable. Further, when the insulating resin substrate is thinly formed into a film, polyimide is preferable from the viewpoint of thinness and heat resistance.
The material of the conductive contact element 4 and the surrounding conductor 5 is made of a conductive composition in which conductive particles are blended and dispersed in an insulating elastomer material.

As the insulating elastomer material, various elastomers that are fluid before curing and form a cross-linked structure by curing (generic name for materials having rubber-like elasticity near normal temperature) are used. Specific examples include silicone rubber, fluorine rubber, polyurethane rubber, polybutadiene rubber, polyisopropylene rubber, chloroprene rubber, polyester rubber, styrene / butadiene copolymer rubber, and natural rubber. These independent and open-cell foams are also possible.
In these, the silicone rubber which is excellent in electrical insulation, heat resistance, compression set, workability, etc. is preferable.

The conductive particles may be granular or flaky, and any conductive particles can be used as long as at least the surface is coated with a metal.
For example, a single metal such as gold, silver, copper, platinum, palladium, nickel, and aluminum, or granular or flaky particles made of an alloy thereof, and in addition, phenol resin, epoxy resin, silicone resin, urethane resin, etc. Examples include thermosetting resins, these baked products, inorganic materials such as carbon, ceramics, silica, and the like, whose surfaces are coated with the metal by plating, vapor deposition, sputtering, or the like.

Among these, granular silver powder is preferable from the viewpoint of conduction resistance and cost, and further, the tap density is 2.0 g / cm ³ or less and the specific surface area is from the stability of conduction resistance at the time of heat and pressure molding. It is preferable to mix 300 to 700 parts by weight of a granular silver powder of 0.7 m ² / g or less with respect to 100 parts by weight of the insulating elastomer.
The material of the conductive contact element 4 and the outer conductor 5 can be the same insulating elastomer material and the same amount of the same conductive particles, but the combination of the insulating elastomer material and the conductive particles can be different. It is also possible to vary the blending amount of the conductive particles.

It is preferable to add a curing agent to the conductive composition. As the curing agent, for example, a known organohydrogenpolysiloxane / platinum catalyst (addition reaction curing agent) or an organic peroxide catalyst can be used.
On the other hand, the organohydrogenpolysiloxane is not particularly limited as long as it has at least two hydrogen atoms directly bonded to silicon atoms, and may be linear, branched, or cyclic, What is represented by the following average composition formula (1) is preferable. Particularly preferred are those having a degree of polymerization of 300 or less.
R _a H _b SiO _{(4-ab) / 2} (1)
(In the above average composition formula (1), R is an unsubstituted or substituted monovalent hydrocarbon group, preferably having no aliphatic unsaturated bond. A and b are 0 ≦ a <3, 0 <b <3, 0 <a + b <3.)

Specifically, a diorganopolysiloxane whose end is blocked with a dimethylhydrogensilyl group, a copolymer of a dimethylsiloxane unit with a methylhydrogensiloxane unit and a terminal trimethylsiloxy unit, a dimethylhydrogensiloxane unit (H (CH ₃ ) Low viscosity fluid composed of ₂ SiO _0.6 units) and SiO ₂ units, 1,3,5,7-tetrahydrogen-1,3,5,7-tetramethylcyclotetrasiloxane, 1-propyl-3, 5,7-trihydrogen-1,3,5,7-tetramethylcyclotetrasiloxane, 1,5-hydrogen-3,7-dihexyl-1,3,5,7-tetramethylcyclotetrasiloxane, etc. Illustrated.

600 (20 x 30) through-holes for conductive contact elements with a diameter of 0.3 mm are drilled at 2 mm pitches in the XY direction, and through-holes for surrounding conductors are drilled on the same circumference at four locations. An insulating resin substrate made of PPS containing 50% glass fiber and having a thickness of 0.5 mm has a mean degree of polymerization of about 8000 consisting of 99.85 mol% dimethylsiloxane units and 0.15 mol% methylvinylsiloxane units. 450 parts by weight of granular silver powder (average particle size 7.3 μm, tap density 1.4 g / cm ³ , specific surface area 0.60 m ² / g) in 100 parts by weight of vinyl polysiloxane, and the above methyl vinyl polysiloxane A conductive silicone rubber composition in which 0.5 parts by weight of dicumyl peroxide is blended with 100 parts by weight of a mixture of silver and silver powder is placed, and molding is performed at 160 ° C. for 5 minutes using a mold consisting of upper and lower molds. Heated pressing at matter, an insulating resin substrate and a plurality of conductive contact elements and the outer 囲導 body are integrated, it was prepared as in Example types of electrical connectors shown in FIGS. 1 and 3 (b).

Each conductive contact element has a truncated frustoconical shape, the height of the reduced diameter end of the truncated cone of 1.5 mm is 0.3 mm, and the expanded end of the truncated cone is 0.5 mm. The diameter was set to protrude 0.5 mm from both the front and back surfaces of the substrate. The cross-sectional shape of the outer conductor was a trapezoidal upper side of 0.2 mm and a lower side of 0.3 mm of the cross-sectional shape of the conductive contact element.
The electrical connector manufactured in this way has a small displacement of the conductive contact element as small as 0.05 mm and a small warp of the insulating resin substrate as small as 0.05 mm, and is sandwiched between the mounting substrate and the LGA. When the mounting board and the LGA were made conductive with an electrical connector at a compression amount of%, there was no problem in electrical connection, and no leakage of high-frequency current or mutual interference was observed.
The insulating resin substrate of the example had a deflection temperature under load of 270 ° C. and a linear expansion coefficient of 2.5 × 10 ⁻⁵ / K.

  The present invention is extremely useful as an electrical connector for connecting an IC package whose frequency is increasing.

It is the simplified plane schematic diagram which shows one Embodiment of the electrical connector of this invention. It is a cross-sectional schematic diagram which shows the detailed structure in one Embodiment of the electrical connector of this invention of FIG. It is explanatory drawing which shows the notch provided in the surrounding conductor (shield body).

Explanation of symbols

1: Electrical connector 2: Insulating resin substrate 3: Through hole 4: Conductive contact element 5: Outer conductor (shield body)
6: Notch 7: Notch

Claims (2)

  An electrical connector in which conductive contact elements are integrally formed in a large number of through-holes provided in an insulating resin substrate, wherein an outer conductor (shield body) is formed around the conductive contact elements. connector.   The electrical connector according to claim 1, wherein a part of the outer conductor (shield body) has a cutout shape.

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