Browse Prior Art Database

LEADS FOR SINGLE-SIDED FLEX CIRCUIT

IP.com Disclosure Number: IPCOM000008272D
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2002-May-31
Document File: 2 page(s) / 83K

Publishing Venue

Motorola

Related People

Suma Sreenivasan: AUTHOR [+2]

Abstract

Single-sided flexible circuits are presently sol- dered directly onto a printed circuit board (PCB) with solder portions that are typically cladded with copper. However, such solder portions may not be sufficiently strong to form reliable connections with the PCB as, conventionally, flexible circuits are thin.

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MOT'OROLA Technical Developments

LEADS FOR SINGLE-SIDED FLEX CIRCUIT

by Suma Sreenivasan and Ab. Shukor Bin Yahaya

  Single-sided flexible circuits are presently sol- dered directly onto a printed circuit board (PCB) with solder portions that are typically cladded with copper. However, such solder portions may not be sufficiently strong to form reliable connections with the PCB as, conventionally, flexible circuits are thin.

  An improvement to a solder portion of a flexi- ble circuit can be made by a fold that strengthens such a solder portion as shown in Figures 1 and 2. In Figure 1, an adhesive is applied on an underside of the solder portion before folding the solder portion.

THERMOSET ADHESIVE -

Fig. 1 Cross section of solder portion before folding.

  After application of the adhesive, the solder of the adhesive, the copper at the fold is cleaned to portion is folded inwards and held in place until the remove impurities such as oxides. After cleaning, adhesive is cured. Pressure may be required to hold the fold is dipped into molten solder to coat the the fold firmly in place to enable proper curing of copper with a layer of solder. Figure 2 shows the the adhesive and formation of the fold. Upon curing solder portion when formed.

Fig. 2 Cross-section of solder portion when formed completely.

A Motorola, Inc. ,997 42

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MO-LA Technical Developments

  Flexible circuits with solder portions folded...