Method of making a lead frame

• US 4,204,317 A
• Filed: 11/18/1977
• Issued: 05/27/1980
• Est. Priority Date: 11/18/1977
• Status: Expired due to Term

• Current Assignee: Integrated Specialties, Inc. (Newell Brands Inc.)
• Original Assignee: The Arnold Engineering Co. (The Kattegat Trust Co. Ltd.)
• Inventors: Winn, Clarence W.
• Primary Examiner(s): Husar, Francis S.
• Assistant Examiner(s): Arbes, C. J.
• Application Number:
  US05/852,765
• Time in Patent Office: 921 Days
• Field of Search: 29/576 S, 29/589, 29/627, 29/624, 29/630 B, 357/70, 156/630
• US Class Current: 29/827
• CPC Class Codes: H01L 21/4821 Flat leads, e.g. lead frames with or without insulating supports
• CPC Class Codes: H01L 21/4828 Etching etching for cleaning without patterning H01L21/4835
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 23/49558 Insulating layers on lead frames, e.g. bridging members
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 29/49121 Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49224 with coating

Abstract

The method of making a metal lead frame wherein a metal lead frame blank is stamped or etched from a metal strip so as to provide a die attach pad and a plurality of leads attached to the pad. Prior to separating the leads from the pad a retainer is applied to the leads adjacent the pad so that the leads are held in fixed positions during and after their separation from the pad.

Claims

1. The method of making a lead frame comprising the sequential steps of:

providing a metal strip;

providing from said strip a lead frame blank having a die attach pad and a plurality of leads attached to said pad in spaced apart relationship and extending therefrom to other parts of said blank;

plating said lead frame blank;

applying retainer means to said leads adjacent said pad in spaced, noncontiguous relation to the latter for holding the leads in position when they are separated from said attach pad; and

subsequently separating said leads from said attach pad.

2. The method of claim 1 in which the die attach pad is centrally located and leads extend therefrom in two directions to provide two sets of leads, and said retainer means includes two retainers, one applied to each set.

3. The method of claim 1 in which said retainer is a high temperature tape.

4. The method of claim 3 in which the die attach pad is centrally located and leads extend therefrom in two directions to provide two sets of leads, and said retainer means includes two retainers, one applied to each set.

5. The method of claim 1 in which said strip includes a plurality of lead frame blanks each having a die attach pad and a plurality of leads attached to said pad in spaced apart relationship and extending therefrom to other parts of said blank, and said method includes applying retainer means to said leads adjacent each of said attach pads to hold them in position when said leads are separated from said attach pad, and then separating said leads from their associated attach pads.

6. The method of claim 5 in which the die attach pads are centrally located in their associated lead frame, with leads extending from each die attach pad in two directions to provide two sets of leads, and said retainer means includes a retainer applied to each set of leads.

7. the method according to claim 1 wherein said attach pad is removed.