Adhesive bonding and miscellaneous chemical manufacture – Delaminating processes adapted for specified product – Delaminating in preparation for post processing recycling step
Patent
1987-06-11
1989-07-11
Powell, William A.
Adhesive bonding and miscellaneous chemical manufacture
Delaminating processes adapted for specified product
Delaminating in preparation for post processing recycling step
156643, 156647, 156648, 156662, 357 74, 372107, H01L 21306, B44C 122, H01S 308
Patent
active
048469300
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a method of mounting a component to a substrate, for example the mounting of an optical component such as a laser chip to a substrate.
Recent developments in optical technology have led to the construction of laser chips and photosensor chips which have relatively small dimensions of the order of 200 microns. It is now proposed that these components should be mounted on substrates and accurately aligned with optical waveguides or other optical components. One of the difficulties with this is that it is difficult to hold the component accurately using a micromanipulator or the like during mounting of the component on a substrate.
A paper by M. Kobayashi et al entitled "Guided-Wave optical gate matrix switch" in the Proc. 11th European Conference on Optical Communication (pages 73-76) describes the mounting of a laser diode to a silicon heat sink. The heat sink is a slab of silicon which is apparently laid on the substrate. The laser diode cannot, however, be accurately positioned on the substrate.
In accordance with one aspect of the present invention, a method of mounting a component on a substrate comprises mounting the component on a support; positioning the support on the substrate, wherein at least one of the support and the substrate includes locator means such that the support is located in at least one direction relatively to the substrate; and securing the component to the substrate.
The location of the support in at least one direction relatively to the substrate automatically locates the component also in that direction. Thus, the locator means can be positioned remotely of the component and will not interfere with the mounting of the component.
In accordance with a second aspect of the present invention we provide in combination a component secured to a substrate, the combination further comprising a support to which the component is mounted, at least one of the support and the substrate including locator means for locating the support in at least one direction relatively to the substrate.
In one simple arrangement, the locator means comprises two or more legs positioned on either the support or the substrate, the support being positioned on the legs spaced from the substrate by a predetermined amount determined by the length of the legs.
Preferably, however, complementary locating portions are formed in the support and the substrate. This has the advantage that the support is located in two directions relative to the substrate.
For example, the locating portions may comprise complementary ridges and recesses. Where the substrate comprises a single crystal such as silicon it is particularly convenient if the complementary ridges and recesses have a V-shaped cross-section since these can be formed using known masking and anisotropic etching techniques.
The component may be directly bonded to the substrate, for example by soldering, or indirectly by bonding the support to the substrate. Preferably, both the support and component are bonded to the substrate.
Some examples of methods and combinations in accordance with the invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a side elevation of a first example with some parts omitted for clarity;
FIG. 2 is a plan of the first example with some parts omitted for clarity; and,
FIGS. 3, 4, and 5 are a side elevation, partial end elevation, and plan respectively of a second example.
FIGS. 1 and 2 illustrate a lithium niobate substrate 1. Titanium is diffused into a narrow rectilinear section 2 of the top surface of the substrate 1 to define an optical waveguide by modifying the refractive index of the substrate. A generally U-shaped recess or slot 3 is then cut in the surface of the substrate 1 orthogonal to the waveguide 2 by using a suitable technique such as ion beam milling or reactive ion etch. As can be seen in FIG. 1, the slot 3 has a rectangular cross-section. It will be seen that the formation of the slot 3 divides the optical waveguide 2 into two subsidiary optical waveguides
REFERENCES:
patent: 4546478 (1985-10-01), Shimizu et al.
Patents Abstracts of Japan, vol. 9, No. 27 (E-294) (1750) 6 Feb. 1985; JP, A, 59-172787, (Sharp K.K.) 29 Sep. 1984.
IBM Technical Disclosure Bulletin, vol. 22, No. 7, Dec. 1979, IBM Corp. New York, U.S., L. D. Comerford: "Etched Silicon Structure for Aligning a Photodiode and Optical Fiber", pp. 2935-2936.
British Telecommunications public limited company
Powell William A.
LandOfFree
Mounting a component to a substrate does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mounting a component to a substrate, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mounting a component to a substrate will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-434947