METHOD FOR SEPARATING SELECTED ARTICLES FROM AN ARRAY

• US 3,627,124 A
• Filed: 01/29/1970
• Issued: 12/14/1971
• Est. Priority Date: 01/29/1970
• Status: Expired due to Term

• Current Assignee: AT&T, Inc.
• Original Assignee: Peter R. Hance, Ronald I. Strohl, William R. Wanesky
• Inventors: Hance, Peter R., Wanesky, William R., Strohl, Ronald I.
• Primary Examiner(s): Lutter, Frank W.
• Assistant Examiner(s): Hill, Ralph J.
• Application Number:
  US05/006,678
• Time in Patent Office: 684 Days
• Field of Search: 209/1-4,9,45-47,49 156/230,234,239,344 324/158T
• US Class Current: 209/45
• CPC Class Codes: H01L 21/67132 Apparatus for placing on an insulating substrate, e.g. tape
• CPC Class Codes: H01L 21/67271 Sorting devices
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2221/68354 used to support diced chips prior to mounting
• CPC Class Codes: H01L 2924/19041 being a capacitor

Abstract

A method for separating defective beam-lead semiconductor devices from an array of devices cemented by wax to a substrate. The devices are tested, the defective ones marked with epoxy ink, the array covered with a screen, the ink cured to fasten the defective devices to the screen, the wax melted and the screen removed to simultaneously separate all the defective devices from the array.

Claims

1. A method for separating selected articles from an array, which comprises the steps of:

marking selected articles in the array with an adhesive;

applying a sheet of material to the array, the material being one to which the adhesive on the selected articles will adhere; and

removing the sheet of material to remove and separate the selected articles from the nonselected articles whereby the nonselected articles remain in the array.

2. A method of separating articles from an array, which comprises the steps of:

selecting the articles to be separated from the array by means of an identifiable characteristic;

marking the article so selected with an adhesive;

applying a sheet of material, to which the adhesive will adhere, to the entire array; and

removing the sheet of material to remove the selected articles whereby all of the selected articles are separated from the nonselected articles simultaneously.

3. A method, as recited in claim 2, wherein the adhesive is epoxy ink and the sheet material is polyester mesh.

4. A method of separating articles from an array, which comprises the steps of:

testing the articles to select those to be separated from the array;

marking the selected articles with epoxy ink;

placing a polyester mesh screen over the array;

pressing the screen against the array and epoxy ink to engage the ink with the screen;

curing the epoxy ink to secure the selected articles to the screen; and

removing the screen to remove the selected articles, the selected articles being separated simultaneously from the nonselected articles and the nonselected articles remaining in the array.

5. A method, as recited in claim 4, wherein the articles are semiconductor devices.

6. A method of separating semiconductor devices from an oriented array of such devices cemented with wax to a substrate, which comprises the steps of:

testing the individual devices in the array to determine the defective and nondefective devices;

marking the defective devices with an epoxy ink, the ink being hardenable upon curing;

applying a polyester mesh screen to the array of devices;

pressing the screen against the array of devices by mEans of a polytetrafluoroethylene-coated plate to force the screen into engagement with the epoxy ink;

curing the epoxy ink to harden the ink and secure the defective parts to the screen;

dissolving the wax to free the devices; and

removing the screen to remove the defective devices whereby the nondefective devices are left oriented on the substrate.

7. A method of separating defective beam-lead integrated circuit devices from an oriented array of devices secured with wax to a substrate, which comprises the steps of:

testing the individual devices in the array to determine the defective and good devices;

applying a liquid epoxy cement to the top surfaces of the defective devices, the cement being hardenable;

applying a polyester mesh screen over the array of devices while the cement is fluid;

pressing the screen against the devices with a polytetrafluoroethylene-coated plate to force the polyester mesh into engagement with the cement;

curing the epoxy cement to secure the defective devices to the polyester mesh;

melting the wax; and

removing the polyester mesh, while the wax is still molten, thereby removing the defective devices and leaving the good devices still oriented on the substrate.