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COST EFFECTIVE INTEGRATED HOUSING AND PRINTED CIRCUIT MODULE FOR BATTERY PACK

IP.com Disclosure Number: IPCOM000028163D
Original Publication Date: 2004-Apr-29
Included in the Prior Art Database: 2004-Apr-29
Document File: 5 page(s) / 340K

Publishing Venue

Motorola

Related People

Bryan Ho: AUTHOR [+3]

Abstract

This article presents a method of assembling a battery pack by means of utilizing low temperature and low pressure over molding onto printed circuit module sub-assembly. Since the method of overmolding is applied onto printed circuit module sub-assembly, which also consists of connecting tabs, this method can construct frame assembly module that can allow flexibility of using cells from different supplier, which have variable dimensional tolerance and shape such as round edges or sharp edges. The design offers the following advantages

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COST EFFECTIVE INTEGRATED HOUSING AND PRINTED CIRCUIT MODULE FOR BATTERY PACK

By Bryan Ho, WH Chew , Fauzi Yahaya


Abstract

This article presents a method of assembling a battery pack by means of utilizing low temperature and low pressure over molding onto printed circuit module sub-assembly. Since the method of overmolding is applied onto printed circuit module sub-assembly, which also consists of connecting tabs, this method can construct frame assembly module that can allow flexibility of using cells from different supplier, which have variable dimensional tolerance and shape such as round edges or sharp edges. The design offers the following advantages. It

a.      Improves energy density of battery

b.      Reduces mechanical part count

c.      Increases manufacturing productivity

d.      Reduces overall product cost

Introduction

Overmolding has been widely used to provide integrated solution that reduces total component or part count such as in connector design. Its application on electronic components have been introduced lately after advancement in molding technologies that have developed capability to successfully employ low temperature and low pressure molding set-up, which do not impair electronic components. Its direct advantages are obvious, thus the method of integrated housing design solution for portable battery pack that is described in this article is innovated.

As shown in the diagram below, the printed circuit module with connection tabs are encapsulated with plastic resin through overmolding process and formed the shape of a frame. The complete isolation of the electronic components and the capability of this design to control the position of interconnecting tabs from making illegal contact to the cell at specific locations eliminated the need for atypical design that requires insulations.

Plastic resin encapsulates the components and tabs and hence omits the use of additional insulators

 
                                               

Figure1:Integrated of housingand circuitry module

Printed circuit board module

 

Tabs

 

Plastic

 

Figure2: Cross sectional view of the assembly

                                                           

Through this innovation, the manufacturing of battery pack has been reduced to only two parts whereby the second part is the cell. This unique approach allows for cells from several other suppliers, which typically have significant dimensional variation and shapes of the edges (round or sharp) to be assembled similar to conventional battery pack of frame design. 

Other advantages of this method are:

1. Energy Density Improvement

The housing and printed circuit module integrated solution reduces battery size by eliminating the usage of insulator and embedding the PCB and tabs into plastic resins. In addition, this integration also eliminates the assembly tolerances required since the manual cell-pack placement pro...