JPH0770342B2 - Shielded Right Angle Header - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to the field of headers having a plurality of signal and ground posts for connecting coaxial electrical cables to printed circuit boards (PCBs).

BACKGROUND ART In many industrial and test applications, it is desirable to provide coaxial signal lines to printed circuit board circuit sections.
Stringent electrical signal performance requirements, combined with relatively limited space constraints, have made it difficult to achieve high-quality circuit interconnections from cables to PCBs. These connectors and headers must be small, but
They must meet stringent performance requirements arising from high-speed and high-frequency data communications.

Currently, most coaxial cable connectors and headers designed for connecting small cables to PCBs are assembled from numerous components, and their size and complexity make them difficult to manufacture, complex to assemble, and expensive, especially for right-angle headers. A typical right-angle header for connecting a single coaxial cable to a PCB is disclosed in U.S. Pat. No. 4,360,244. This right-angle header comprises two interlocking right-angle units, one of which is a right-angle metal shell encased in an insulating material. In this case, a right-angle pin is centrally located in the insulating material, and signal contact pins protrude from the surface to be connected to the PCB, with ground contact pins affixed to or in contact with the metal shell. Similar right-angle shielded coaxial contacts interlocking with the right-angle units are then connected to the coaxial electrical cable desired to be connected to the PCB. A somewhat similar triaxial right-angle header for directly connecting a triaxial cable to a PCB is disclosed in U.S. Pat. No. 4,744.
It is described in issue 1,703.

Also, a connector for a shielded flat coaxial cable consisting of multiple coaxial cables is disclosed in U.S. Pat. No. 4,639,
No. 053, which discloses a connector having insulators, grounding sheet metal springs for contacting the shields of the individual cables comprising the flat cable, and a grounding metal layer along the inner wall of the housing disposed within the connector housing to make direct contact with the shield surrounding the flat cable as a whole.

SUMMARY OF THE INVENTION The present invention comprises a shielded right-angle header having a plurality of evenly spaced signal contact posts and a plurality of ground contact posts, each signal post embedded in a thermoplastic insulating material and covered by a shielding metal shell.
Each metal shell is bonded to a ground post. Associated shielded, insulated signal and ground posts are held together by a plastic shroud to form a complete header. That is, in a header formed from as many pairs of signal and ground posts as needed, the individual signal conductors are completely shielded by the metal shield, reducing crosstalk between signals transmitted through extremely small, closely spaced conductors under extremely tight space constraints. This arrangement provides higher signal transmission performance than previously possible, making it suitable for computer, automatic test equipment, and telecommunications machine signals. The manufacturing materials, spacing, and shape of the header components can be modified to provide impedance matching and to adjust gap and mounting characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partial perspective view of a header showing signal contacts molded into insulating material along with metal shielding posts and ground contact posts; Figure 2 is a cross-sectional view of the header along a plane parallel to a set of signal and ground contact pins; and Figure 3 is a cross-sectional view of the header along a plane perpendicular to the signal and ground contact pins.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail and completely with reference to the drawings. Figure 1 is a partial perspective view of a header. Exemplary right angle signal contact pins 1 are molded or embedded in a thermoplastic insulating material with pins 1 protruding from face 2. Each pin 1
Surrounding the insulating pins is insulation 4, with gaps 5 between each insulating pin to allow a metallic shielding shell 7 to fit around each portion 4 of the gap 5. Right angle ground contact pins 6 fit through openings 3 in face 2 and are bonded to shell 7.

FIG. 2 is a cross-sectional view of the header taken along one set of ground contact pins 6 and signal contact pins 1 after a thermoplastic insulating shroud 8 has been molded onto the assembly of the portion shown in FIG.

3 is a partial cross-sectional view of the header perpendicular to the contact pins 1 and 6 through the metal shielding shell 7, molded thermoplastic post 4, and thermoplastic shroud 8. An optional mounting opening 9 through the end of the shroud 8 is also shown.

The header is assembled by molding the signal contact pins 1 into a thermoplastic polyester polymer, which is the preferred material.

Other thermoplastics known in the art that are useful for injection molding or other molding processes may also be used, such as polyphenylene sulfide, polyamide, acetal, acetylene-butadiene-styrene terpolymer, polytetrafluoroethylene, polyvinyl chloride, polypropylene, polyethylene, and rubber. The shielding metal shell 7 is attached to the ground contact pin 6 by welding, brazing, soldering, or a conductive adhesive. The shell 7 is preferably fabricated from a thin, folded sheet of beryllium-copper alloy or phosphor bronze, although copper, copper alloy, or steel shells may also be used. Pins 1 and 6 are also preferably fabricated from beryllium-copper alloy or phosphor bronze. The ground contact pin 6 may be an integral part of the metal sheet from which the shell 7 is fabricated. In this case, a flat tab or protrusion may be rolled into a cylindrical or rectangular shape to serve as the pin 6. The combination of the shell 7 and pin 6, either bonded together or formed as a unit from the metal sheet, is then fitted into the opening 3 and slot 5 to complete the header. The shroud 8 can be preformed and bonded to the pins, shields, and contacts by sonic welding, which bonds plastic to plastic without heating the bulk of the material. The shroud 8 is preferably molded from a glass-filled thermoplastic polyester polymer, and may be molded from the same material as the molded portion 4.

In many industrial and test applications, it is desirable to feed coaxial signal lines to a printed circuit board. The header of the present invention accomplishes this in a simple and straightforward manner without complex parts or attachments. In operation, contact pins 1 and 6 projecting from face 2 of the header are terminated in a female connector which is connected to a coaxial or flat coaxial cable. The opposite ends of pins 1 and 6 of the header are connected to and mate with mating receptacles or openings in the printed circuit board, beneath shroud 8, which are spaced in a standard, predetermined pattern.

Although the foregoing describes preferred embodiments of the present invention, other embodiments that will be apparent to those skilled in the art and that utilize the teachings set forth herein are within the scope of the invention as defined by the claims.

Claims (4)

[Claims] [Claim 1] A thermoplastic insulating molded body (a); one or more conductive metal electrical signal contact pins (b) bent at a right angle and uniformly arranged in the thermoplastic insulating molded body; a conductive metal shell (c) surrounding each of the signal contact pins together with the thermoplastic insulating molded body; and a metallic ground contact pin (d) bent at a right angle and fixed to each of the conductive metal shells corresponding to each of the signal contact pins.
and a thermoplastic molded shroud (e). [Claim 2] A header as described in claim 1, wherein the thermoplastic insulating molding and the thermoplastic shroud surrounding the signal contact pin are made of polyester, polyvinyl chloride, polyphenylene sulfide, polyamide, acetal, acetylene-butadiene-styrene terpolymer, polytetrafluoroethylene, polypropylene, polyethylene or rubber. 3. The header of claim 1, wherein said ground contact pins, said signal contact pins and said conductive metal shell are formed from beryllium-copper, phosphor bronze, steel, copper or a copper alloy. [Claim 4] A header as described in claim 1, wherein the thermoplastic insulating molding and the thermoplastic shroud are made of polyester, and the ground contact pins, the signal contact pins and the conductive metal shell are made of beryllium-copper alloy or phosphor bronze.