Adhesively and magnetically holding an article

• US 4,071,944 A
• Filed: 10/20/1975
• Issued: 02/07/1978
• Est. Priority Date: 10/20/1975
• Status: Expired due to Term

• Current Assignee: AT&T, Inc.
• Original Assignee: Western Electric Co., Inc. (Nokia Corporation)
• Inventors: Krechel, Henry H., Purvis, Joseph R., Chuss, John T.
• Primary Examiner(s): Kendall, Ralph S.
• Application Number:
  US05/624,137
• Time in Patent Office: 841 Days
• Field of Search: 427/8, 427/47, 427/128, 427/132, 427/82, 427/130, 156/344, 156/155, 156/64, 29/574, 29/590, 269/321 A, 269/321 W, 269/321 WE, 134/40
• US Class Current: 438/17
• CPC Class Codes: H01L 21/67132 Apparatus for placing on an insulating substrate, e.g. tape
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/8319 Arrangement of the layer connectors prior to mounting
• CPC Class Codes: H01L 2224/8385 using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/95144 Magnetic alignment, i.e. using permanent magnetic parts in the semiconductor or solid-state body
• CPC Class Codes: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 24/83 using a layer connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01027 Cobalt [Co]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01038 Strontium [Sr]
• CPC Class Codes: H01L 2924/01056 Barium [Ba]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/0665 Epoxy resin
• CPC Class Codes: H01L 2924/07802 not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: Y10T 156/1158 : Electromagnetic radiation applied to work for delamination [e.g., microwave, uv, ir, etc.]

Abstract

In fabrication of articles, such as semiconductor devices, the articles are adhered to the surface of a magnetized carrier having grooves with a suitable adhesive. Preferably, the grooves are parallel and in sets which intersect each other. The articles are made susceptible to the attraction of a magnetic field. The adhesive is removed by the flow of solvent vapor and liquid through the grooves while the articles are retained in their original position by magnetic forces.

In an alternate method, the articles may be adhered initially to a nonmagnetic substrate, made susceptible to the attraction of magnetic field and transferred to a grooved, magnetized carrier. Any adhesive which clings to the articles is removed by solvent vapor and liquid as before.

Claims

1. A method of holding a wafer of semiconductor material having an array of semiconductor devices formed therein, which comprises the steps of:

adhering the wafer to a magnetized carrier with an adhesive, the carrier having intersecting sets of parallel grooves and material selected from the group consisting of barrium ferrite, strontium ferrite, alnico, or a mixture of barrium and strontium ferrite;

separating the wafer into individual devices;

screening magnetic ink on the individual devices;

partially curing the ink;

electrically testing the devices;

completing the curing of the ink; and

placing the carrier in trichlorethylene solvent vapor and condensing the vapor to form the liquid solvent thereon, the solvent flowing over the surface and through the grooves in the carrier to rapidly and completely remove the adhesive from beneath the devices while the magnetic forces maintain the location and orientation of the devices on the carrier.

2. The method of claim 1 wherein the partial curing of the ink is done by heating it at a temperature which is sufficiently low to avoid melting the adhesive while still being able to partially cure the ink.

3. A method of handling a wafer of semiconductor material having an array of semiconductor devices formed therein, wherein the wafer has been adhered to a nonmagnetic support with an adhesive, which comprises the steps of:

separating the wafer into individual devices;

screening magnetic ink on the individual devices to make them magnetic;

partially curing the ink;

electrically testing the devices to determine the good ones;

completing the curing of the ink;

dissolving a portion of the adhesive;

melting the remaining adhesive to free the devices from the magnetic support;

transferring the devices to a magnetized carrier, the carrier having intersecting sets of parallel grooves and material selected from the group consisting of barrium ferrite, strontium ferrite, alnico, or a mixture of barrium and strontium ferrite; and

placing the carrier in trichloroethylene solvent vapor and condensing the vapor to form the liquid solvent thereon, the solvent flowing over the surface and through the grooves in the carrier to rapidly and completely remove any adhesive transferred with the devices while the magnetic forces maintain the location and orientation of the devices on the carrier.

4. The method of claim 3, wherein the partial curing of the ink is done by heating it at a temperature which is sufficiently low to avoid melting the adhesive while still being able to partially cure the ink.