Semiconductor device manufacturing: process – Making field effect device having pair of active regions... – On insulating substrate or layer
Reexamination Certificate
2000-10-05
2003-08-26
Whitehead, Jr., Carl (Department: 2813)
Semiconductor device manufacturing: process
Making field effect device having pair of active regions...
On insulating substrate or layer
C438S161000, C438S780000
Reexamination Certificate
active
06610563
ABSTRACT:
The present invention relates to a method for producing a surface mounting optoelectronic component comprising a base body, an optoelectronic transmitter and/or receiver that is arranged in a recess of the base body, and an optical device that occludes the recess, as well as to a surface mounting optoelectronic component.
In recent years, surface mounting technology (SMT) has increasingly supplanted the equipping of conductor carriers with wired components. The crucial advantage of SMT is an increase in packing density, which cannot be achieved by conventional insertion methods.
Due to the high packing density, which is desirable in many optical applications, SMT is particularly important in the field of optoelectronics. There are already known optoelectronic components which are designed to be surface mounted in accordance with the SMT concept.
European patent application No 230 336 therefor describes a surface mounting optoelectronic component that comprises an annular housing, the upper opening of which is sealed by a ball lens, while the lower opening of the ring stands on a printed circuit board. Inside the housing, a light-emitting semiconductor element is arranged between the present circuit board and the bottom vertex of the ball lens. The interior space of the ring housing, which is defined by the surface of the printed board and the ball lens, is filled with a transparent glue.
Another surface mounting optoelectronic component is illustrated in EP 0 400 176. This component has a base body with a central depression in which an optically active semiconductor element is arranged. Above the base body, there is a lens, which is connected to the base body via a fixing mechanism such as a clamping peg.
“Siemens SMT-TOPLED für die Oberflächenmontage” (Frank Möllmer and Günter Waitl,
Siemens Components
29 (1991), Vol. 4:147-149) teaches a light emitting diode (LED) which is provided for surface mounting. To produce this diode, a continuously stamped conductor strip is coated with a thermally stable thermoplast, forming the housing frame. In the inner region of the housing frame, an optically active element is mounted on the conductor strip and electrically contacted to interconnects there. Next, the frame's interior region for guarding the active element against environmental influences is cast using a casting resin. A lens or similar optical device is not provided in this component.
The SMT opto-components described in the documents cited above have the unique attribute that first the whole component housing is produced by coating a conductor strip with a thermoplast material, and the opto-electronic transmitter and/or receiver is inserted into the thermoplast housing only after this is produced. The advantages of this method of production are that a very economical mass production at the belt (conductor strip) is possible, and low structural heights and standardized basic structural forms are easy to realize. Due to their low costs, these prehoused SMT opto-components, as they are called, are used above all in display arrays and the like.
SUMMARY OF THE INVENTION
It is the object of the present invention to set forth a method by which the emission characteristic of opto-electronic SMT components of the above type can be improved without raising the component costs unacceptably. The present invention is also directed to designing this type of optoelectronic SMT component with a well definable emission characteristic and simultaneously low component costs.
This object is achieved in accordance with the present invention in a method for producing a surface mounting optoelectronic component having a base body, an optoelectronic transmitter/receiver that is arranged in a recess of the base body, and an optical device that covers the recess, said method comprising the steps of: preparing the base body with the optoelectronic transmitter/receiver arranged in the recess; filling the recess of the prepared base body with a transparent hardenable casting compound; then placing the optical device onto the as yet uncured casting compound; and then curing the casting compound.
In an embodiment, the step of preparing the base body comprises the steps of: coating a conductor strip with a thermoplast housing while simultaneously forming the recess of the base body into a top surface of the thermoplast housing, a portion of said conductor strip being situated inside the recess; mounting the optoelectronic transmitter/receiver on said portion of the conductor strip situated inside the recess; and filling the recess of the base body with a transparent curable casting compound having thermal characteristics adapted to the thermoplast housing material.
In an embodiment, the recess of the base body is filled with the casting compound to a level such that, during the subsequent placement of the optical device, essentially no casting compound runs over an edge of the recess.
In an embodiment, the recess is filled with casting compound essentially to the edge of the recess such that, after the recess is filled with casting compound, a fillet develops owing to the surface tension of the casting compound; and the optical device has a shape in a region contacting the casting compound that no casting compound runs over the edge of the recess when the optical device is subsequently placed onto the casting compound.
In an embodiment, the optical device is placed from above, without pressure, onto one of the base body or at least one seating element attached to said base body within said recess.
In an embodiment, the casting compound is cured by the influence of heat.
In an embodiment, prior to filling the recess, an optical device is produced by one of casting, pressing, or injection processing; then the optical device is readied and transported as bulk material of optical devices; then a respective optical device is automatically picked from the bulk material; and then the picked optical device is automatically positioned over the base body.
This object is also achieved in accordance with the present invention in a method for producing a surface mounting optoelectronic component having a base body, an optoelectronic transmitter/receiver that is arranged in a recess of the base body, and an optical device that covers the recess, said method comprising the steps of: preparing the base body with the optoelectronic transmitter/receiver arranged in the recess; then filling the recess of the prepared base body with a first transparent hardenable casting compound; then readying a casting mold half and filling the mold half with a second transparent hardenable casting compound; then at least partially curing at least one of the first casting compound in the recess of the base body and the second casting compound in the mold half; then casting the optical device onto the base body by joining the base body and the mold half properly positioned, such that second casting compound in the mold half comes into contact with a surface of the first casting compound in the recess of the base body; then curing at least one of the second and first casting compound; and then removing the mold half from the base body with the cast-on optical device.
In an embodiment, the method further comprises, prior to joining the base body and the mold half, wetting the surface of the first casting compound.
In an embodiment, the step of wetting the surface of the first casting compound comprises the steps of: turning the base body about a horizontal axis such that an opening of the recess is directed downwardly; and at least superficially immersing the base body in liquid casting compound.
In an embodiment, the at least partial curing of the first casting compound is by heat treatment.
In an embodiment, the at least partial curing of the second casting compound is by heat treatment.
In an embodiment, the method further comprises the steps of: leading a number of base bodies on a first strip; and leading a number of mold halves on a second strip, wherein the first strip and the second strip are led in parallel at least during the
Brunner Herbert
Lutz Robert
Waitl Günter
Jr. Carl Whitehead
OSRAM Opto Semiconductors GmbH & Co. OHG
Schiff & Hardin & Waite
Schillinger Laura M
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