Patent Publication Number: US-7593231-B2

Title: Adhesive sheet for attaching an electronic part and an electronic device having such an electronic part

Description:
This application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2005-039880 filed Feb. 16, 2005, the entire content of which is hereby incorporated by reference. 
   FIELD OF THE INVENTION 
   The present invention relates to techniques for adhesively attaching electronic parts used in the manufacture of electronic devices. 
   BACKGROUND OF THE INVENTION 
   In portable acoustic devices such as a cell phone, a double-sided adhesive sheet is employed to attach an exciter to a vibratory speaker plate so that the vibratory speaker plate is vibrated by the exciter (see Japanese patent application publication Nos. H11-331969 and 2001-62396). 
     FIG. 5  shows one such example wherein an exciter  1  is adhesively attached to a vibratory plate  2  through a double-sided adhesive sheet  3 . 
   The use of such a double-sided adhesive sheet allows ready and economical attachment of electronic parts to their associated elements. 
   It is desirable that the electronic parts can readily be removed if not properly adhered to their associated elements. A solvent or a sharp knife has conventionally been used to remove the electronic parts. However, such conventional means often cause damages to the electronic parts. The electronic parts, if damaged, can not be reused and must be abandoned. 
   It is, therefore, an object of the present invention to provide a double-sided adhesive sheet which allows for ready removal of electronic parts. 
   SUMMARY OF THE INVENTION 
   According to one aspect of the present invention, there is provided an electronic device including an element having a surface, an electronic part having a surface to be adhesively attached to the surface of the element, and an adhesive sheet including a first adhesive layer releasably attached to the surface of the element, a second adhesive layer releasably attached to the surface of the electronic part and a third layer adhered between the first adhesive layer and the second adhesive layer, wherein the third layer has an extension extending outwardly from between the surface of the element and the surface of the electronic device. 
   To remove the electronic part, a force is applied in such a direction as to separate the extension of the third layer from the surface of the element. At this time, the force is concentrated on the proximal end of the extension of the third layer between the surface of the electronic part and the surface of the element. This facilitates removal of the surface of the electronic part from the surface of the element. 
   In one embodiment, the first adhesive layer extends over one side of the extension of the third layer so that the extension of the third layer is attached to the element. 
   In another embodiment, the second adhesive layer extends over the other side of the extension of the third layer so that the extension of the third layer is attached to the electronic part. 
   In either embodiment, the extension of the third layer is free from undesirable vibration. 
   In one embodiment, the element is a vibratory speaker plate, and the electronic part is an exciter which is operable to vibrate the vibratory speaker plate when an electric signal to that effect is received. 
   According to another aspect of the present invention, there is provided an adhesive sheet for attaching an electronic part to an element. 
   ADVANTAGES OF THE INVENTION 
   According to the present invention, the electronic part can readily be removed from the element simply by pulling or lifting the extension of the third layer. The invention avoids damages to the electronic part while it is removed and thus, permits repeated use of the electronic part. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view, partly broken away, of a flat speaker according to one embodiment of the present invention; 
       FIG. 2  is a side view of the flat speaker as seen in the direction of the arrow in  FIG. 1 ; 
       FIG. 3  is an enlarged view of a part of the flat speaker as encircled in  FIG. 1 ; 
       FIG. 4  is a view similar to  FIG. 2 , but showing another embodiment of the flat speaker according to the present invention; and 
       FIG. 5  is a perspective view of a known flat speaker. 
   

   PREFERRED EMBODIMENTS 
   The present invention will now be described with reference to the accompanying drawings. 
     FIGS. 1 to 3  show a flat speaker  10 , as an electronic device, made according to the present invention. 
   The flat speaker  10  includes a vibratory plate  12  and an exciter  11  adapted to vibrate the vibratory plate  12  upon receipt of an electric signal to that effect. 
   The exciter  11  is adhered to the vibratory plate  12  by an adhesive sheet  13 . As shown best in  FIG. 2 , the adhesive sheet  13  includes a first adhesive layer  13   a  releasably adhered to a surface  12   a  of the vibratory plate  12 , a second adhesive layer  13   b  releasably adhered to a surface  11   a  of the exciter  11 , and an intermediate third layer  13   c  disposed between the first adhesive layer  13   a  and the second adhesive layer  13   b  and made, for example, of polyethylene terephthalate. In the illustrated embodiment, the third layer  13   c  has an extension  13   c - 1  projecting outwardly from between the surface  12   a  of the vibratory plate  12  and the surface  11   a  of the exciter  11 . Also, the first adhesive layer  13   a  has an extension  13   a - 1  attached to one side of the extension  13   c - 1  of the third layer  13   c , and the second adhesive layer  13   b  has an extension  13   b - 1  attached to the other side of the extension  13   c - 1  of the third layer  13   c . As shown in  FIG. 1 , the extension  13   c - 1  is attached to a side  11   b  and part of an upper surface  11   c  of the exciter  11  through the extension  13   b - 1  of the second adhesive layer  13   b . This attachment avoids undesirable vibration of the extension  13   c - 1 . As an alternative, the extension  13   c - 1  may be attached to the vibratory plate  12  through the extension  1   3   a - 1  of the first adhesive layer  13   a . The first and second adhesive layers  13   a  and  13   b  may be made of not only a sticky substance, but also a pressure-sensitive adhesive, a temperature-sensitive adhesive and other adhesives. 
     FIG. 4  is a side view showing the principal part of a flat speaker according to another embodiment of the present invention. 
   This speaker differs from the one shown in  FIGS. 1 to 3  only in that an additional layer  14  is adhered to the extension  13   a - 1  of the first adhesive layer  13   a . The additional layer  14  is made, for example, of polyethylene terephthalate. This alternative embodiment has an advantage when the extension  13   a - 1  of the first adhesive layer  13  has a sticky surface. 
   In use, the extensions of the adhesive sheet  13  are first detached from the exciter  11  or the vibratory plate  12 , as shown in  FIGS. 2 and 4 , by hand or by the use of a tool. The adhesive sheet  13  is then moved away from the vibratory plate  12  so that the exciter  11  is gradually removed from the vibratory plate  12 . 
   For ready identification of the exciter  11 , the third layer  13   c  with its extension  13   c - 1  may be pigmented or colored. Alternatively, an identification mark may be printed on the third layer  13  with its extension  13   c - 1 . 
   INDUSTRIAL APPLICABILITY 
   The present invention is applicable to not only a cell phone and a personal digital assistant (electronic handheld information device), but many other electronic devices as well. 
   Although the present invention has been described in terms of specific embodiments, it is anticipated that alternations and modifications thereof will no doubt become apparent to those skilled in the art. It is therefore intended that the following claims be interpreted as covering all such alternations and modifications as fall within the true sprit and scope of the invention.