Abstract:
An electrical connector for interconnecting a first circuit such as an integrated circuit having a plurality of IC terminals with a second circuit having a plurality of contact pads when the terminals and pads are positioned opposite each other. The connector includes an electrically insulating sheet made of a first elastic material formed with a plurality of bores extending therethrough in a direction mutually perpendicular to the first and second circuits, and a plurality of electrical conductors, each made of a second, electrically conductive elastic material and shaped so as to contact the first circuit terminals. The elastic material electrical conductors are each positioned relative to the electrically insulating sheet so as to cover each of the bores and extend into the bore co-axially therewith. The elastic conductors are sized to extend into the bores a distance insufficient to contact the second circuit pads when the insulating elastic sheet is uncompressed, and sufficient to contact the second circuit pads when the elastic insulating sheet is compressed, thereby, upon compression of the sheet to complete an electric connection between the first circuit terminals and the second circuit pads.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a connector structure for electrically connecting electronic parts for testing the electronic parts, and more particularly to a connector structure for connecting an integrated circuit and an electronic circuit for testing the integrated circuit. 
     BACKGROUND OF THE INVENTION 
     The connector structure of this type is utilized to connect an integrated circuit having a plurality of IC terminals with an electronic circuit having a plurality of electronic pads respectively paired with the IC terminals of the integrated circuit to test the electronic performances of the integrated circuit before it is put on the market. The word “an integrated circuit” refers here to a semiconductor chip wafer, a semiconductor integrated circuit chip, and a semiconductor integrated circuit chip package. In order to test the integrated circuit, IC terminals of the integrated circuit are to be electrically connected with the electronic pads of the electronic circuit, respectively. 
     There have been provided various types of integrated circuits such as ball grid array types or fine-pitch ball grid array types. The IC terminals of such integrated circuit are formed with solder bumps and arrayed at one side of the integrated circuit. Because of the fact that the IC terminals of the integrated circuits are formed with solder bumps, the IC terminals of the integrated circuit may have different heights. This may cause some problems that the IC terminals of the integrated circuit partially cannot be electrically connected with the electronic pads of the electronic circuit when the integrated circuit is put on the electronic circuit to have each of the IC terminals face each of the electronic pads. The connector structure such as an IC socket, therefore, is utilized to connect the integrated circuit and the electronic circuit. 
     There is shown in FIGS. 10 and 11 a primary example of a conventional IC socket  1  designed to connect an integrated circuit  6  and an electronic circuit  7 . The integrated circuit  6  has a plurality of IC terminals  6   a  while the electronic circuit  7  has a plurality of electronic pads  7   a  each paired with the IC terminals  6   a  of the integrated circuit  6 . As shown in FIG. 10, the IC socket  1  comprises a support portion  2  and a plurality of probe pins  3  each having first and second electrically conductive terminals  3   a  and  3   b  at its respective longitudinal ends. The support portion  2  of the IC socket  1  is formed with a plurality of through bores  2   a  having each of the probe pins  3  respectively received therein. The IC socket  1  is positioned between the integrated circuit  6  and the electronic circuit  7  to electrically connect the integrated circuit  6  and the electronic circuit  7 . Under these conditions, the integrated circuit  6  is urged toward the electronic circuit  7  by urging means (not shown in the drawings), to ensure the connections between the integrated circuit  6  and the electronic circuit  7  by way of the IC socket  1 . 
     FIG. 11 shows one of the probe pins  3  in detail. The probe pin  3  herein shown comprises a coil spring  4  having first and second contact balls  4   a  and  4   b  at its both ends to be respectively held in contact with the first and second terminals  3   a  and  3   b  of the probe pin  3 . The first and second terminals  3   a  and  3   b  of the probe pins  3  are respectively held in contact with the IC terminals  6   a  of the integrated circuit  6  and the electronic pads  7   a  of the electronic circuit  7 . The coil spring  4  enables to withstand the force generated on the IC socket  1  by the urging means which is urging the integrated circuit  6  toward the electronic circuit  7 . 
     The conventional IC socket  1 , however, cannot meet requirements of recently designed integrated circuits to the effect that each of the integrated circuits should have terminals arranged at an extremely short interval. 
     Moreover, the curved line distance between the integrated circuit  6  and the electronic circuit  7  caused by the coil spring  4  is much longer than the straight line distance between the integrated circuit  6  and the electronic circuit  7 . This difference in distance may bring about errors on the results of the test especially when the electronic performances of the integrated circuit are tested. 
     Furthermore, the coil spring  4  to generate electromagnetic induction is liable to cause an undesirable effect on the results of the test. 
     Another example of a conventional IC socket  11  designed to connect an IC  16  and an electronic circuit  17  is shown in FIGS. 12 and 13. The IC socket  11  comprises a support portion  12  having a predetermined thickness and formed with upper and lower surfaces  12   a  and  12   b  substantially extending in parallel relationship with each other, and a plurality of first and second terminals  13   a  and  13   b.    
     FIG. 13 partly shows the IC socket  11 . The support portion  12  is made of an insulating rubber such as a silicon rubber and has a plurality of electrically conductive wires  15  each embedded in the support portion  12  in inclined relationship to the upper and lower surfaces  12   a  and  12   b  to be spaced apart from each other at a predetermined small pitch. The first and second terminals  13   a  and  13   b  are respectively positioned on upper and lower surfaces  12   a  and  12   b  of the support portion  12  with their center axes dislocated from each other to have received therebetween some of the electrically conductive wires  15 . The electrically conductive wires  15  spaced apart from each other at the predetermined small pitch results in each of the first and second terminals  13   a  and  13   b  of the IC socket  11  being kept insulated from the adjacent first and second terminals  13   a  and  13   b , respectively. 
     The IC socket  11  shown in FIG. 13 is positioned between an integrated circuit  16  and an electronic circuit  17  to electrically connect the integrated circuit  16  and the electronic circuit  17 . Under these conditions, the integrated circuit  16  is urged toward the electronic circuit  17  by urging means (not shown in the drawings), to ensure the connection between the integrated circuit  16  and the electronic circuit  17  by way of the IC socket  11 . The support portion  12  and each of the electrically conductive wires  15  embedded in the support portion  12  in inclined relationship with the upper and lower surfaces  12   a  and  12   b  of the support portion  12  enables the IC socket  11  to withstand the force generated by the urging means which is urging the integrated circuit  16  toward the electronic circuit  17 . 
     The conventional IC socket  11 , however, cannot meet the requirements of recently designed integrated circuits to the effect that each of the integrated circuits should have terminals arranged at an extremely short interval. 
     Moreover, the first and second terminals  13   a  and  13   b  respectively positioned on upper and lower surfaces  12   a  and  12   b  of the support portion  12  with their center axes dislocated from each other to have some of the electrically conductive wires  15  which are in inclined relationship with the upper and lower surfaces  12   a  and  12   b  of the support portion  12  received therebetween. This structure of the IC socket  11  is complex in structure and thus makes it difficult to have a number of terminals in a small space. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a connector structure, such as an IC socket, for connecting electronic parts, particularly an integrated circuit and an electronic circuit, for testing the electronic parts. 
     According to a first aspect of the present invention, there is provided a connector structure for electrically connecting a pair of electric parts each having a plurality of terminals which can be electrically connected when the electric parts are arranged with the terminals facing and spaced apart from each other, comprising: an electrically insulating elastic sheet made of an elastic material, and formed with a plurality of through bores respectively facing and spaced apart from the terminals of the pair of electronic parts, each of the through bores having an center axis; and a plurality of electrically insulating elastic bodies each made of an elastic material and each positioned with respect to the electrically insulating elastic sheet to cover each of the through bores of the electrically insulating elastic sheet, the electrically insulated elastic sheet being deformable to have the electrically conductive elastic bodies displaced with respect to the terminals of the electric parts along the center axis of each of the thorough bores between a first position where the electrically conductive elastic bodies are respectively spaced apart from the terminals of at least one of the electric parts and a second position where the electrically conductive elastic bodies are respectively held in electrical contact with the terminals of the electric parts to complete electrical connection between the electric parts. 
     Each of the electrically conductive elastic bodies of the connector structure may have a portion protruding toward one of the electric parts to facilitate each of the electrically conductive elastic bodies to be brought into contact with each of the terminals of one of the electric parts when the electrically conductive elastic bodies are displaced with respect to the terminals of at least one of the electric parts to assume the second position. 
     Each of the electrically conductive elastic bodies of the connector structure may be formed with a concavity having each of the terminals of the other of the electric parts received therein. 
     Each of the electrically conductive elastic bodies of the connector structure may be formed with a convexity held in contact with each of the terminals of the other of the electric parts. 
     Each of the terminals of the other of the electric parts may be formed with a concavity, and each of the electrically conductive elastic bodies may be formed with a convexity identical in profile to the concavity of each of the terminals so that the protruding portion of each of the electrically conductive elastic bodies is received in and registered with the cavity of each of the terminals of the other of the electric parts. 
     One of the electronic parts may be a semiconductor integrated circuit chip package, a semiconductor chip wafer or a semiconductor integrated circuit chip. 
     According to a second aspect of the present invention there is provided a connector structure for electrically connecting a pair of electric parts each having a plurality of terminals which can be electrically connected when the electric parts are arranged with the terminals facing and spaced apart from each other, comprising: an electrically insulating elastic sheet having a plurality of projecting portions facing and spaced apart from one of the terminals of the pair of electronic parts, each of the projecting portions being formed with a through bore having a center axis; and a plurality of electrically conductive elastic bodies positioned with respect to the electrically insulating elastic sheet to cover each of the through bores of the electrically insulating elastic sheet, the electrically conductive elastic bodies being displaceable with respect to the terminals of the electric parts along the center axis of each of the thorough bores between a first position where the electrically conductive elastic bodies are respectively spaced apart from the terminals of at least one of the electric parts and a second position where the electrically conductive elastic bodies are respectively held in electrical contact with the terminals of the electric parts to complete electrical connection between the electric parts. 
     Each of the electrically conductive elastic bodies of the connector structure may have a portion protruding toward one of the electric parts to facilitate each of the electrically conductive elastic bodies to be brought into contact with each of the terminals of one of the electric parts when the electrically conductive elastic bodies are displaced with respect to the terminals of at least one of the electric parts to assume the second position. 
     Each of the electrically conductive elastic bodies of the connector structure may be formed with a concavity having each of the terminals of the other of the electric parts received therein. 
     Each of the electrically conductive elastic bodies of the connector structure may be formed with a convexity held in contact with each of the terminals of the other of the electric parts. 
     Each of the terminals of the other of the electric parts may be formed with a concavity, and each of the electrically conductive elastic bodies may be formed with a convexity identical in profile to the concavity of each of the terminals so that the protruding portion of each of the electrically conductive elastic bodies is received in and registered with the cavity of each of the terminals of the other of the electric parts. 
     One of the electronic parts may be a semiconductor integrated circuit chip package, a semiconductor chip wafer or a semiconductor integrated circuit chip. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features and advantages of the connector structure according to the present invention will be more clearly understood from the following description taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a top view of the connector structure according to the present invention; 
     FIG. 2 is a cross-sectional view of a first preferred embodiment of the connector structure taken on line A—A of FIG. 1 according to the present invention; 
     FIG. 3 illustrates the connector structure shown in FIG. 2 with an integrated circuit and an electronic circuit having the connector structure intervene therebetween; 
     FIG. 4 illustrates the connector structure shown in FIG. 2 with the integrated circuit and the electronic circuit having the connector structure intervene therebetween and being urged toward each other; 
     FIG. 5 is a cross-sectional view of a second preferred embodiment of the connector structure according to the present invention; 
     FIG. 6 illustrates the connector structure shown in FIG. 5 with a integrated circuit and an electronic circuit having the connector structure intervene therebetween; 
     FIG. 7 illustrates the connector structure shown in FIG. 5 with the integrated circuit and the electronic circuit having the connector structure intervene therebetween and being urged toward each other; 
     FIG. 8 is a cross-sectional view of a third preferred embodiment of the connector structure having an electrically insulating flat elastic sheet; 
     FIG. 9 is a cross-sectional view of a fourth preferred embodiment of the connector structure having an electrically insulating flat elastic sheet; 
     FIG. 10 is a plan view of a conventional IC socket; 
     FIG. 11 is an enlarged fragmentary cross-sectional view of the conventional IC socket shown in FIG. 10; 
     FIG. 12 is a plan view of another conventional IC socket; and 
     FIG. 13 is an enlarged fragmentary cross-sectional view of the conventional IC socket shown in FIG.  12 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The first preferred embodiment of the connector structure according to the present invention will be described hereinafter with reference to the drawings, particularly to FIGS. 1,  2 ,  3  and  4 . 
     FIGS. 1 to  4  partly show a connector structure  20  which is designed to electrically connect an integrated circuit  30  including a semiconductor integrated circuit chip having a plurality of spherical solder bumps or chip pads, and a semiconductor integrated circuit chip package of ball grid array having a plurality of IC terminals, with an electronic circuit  40  having a plurality of electronic pads  41 . The connector structure  20  may be applied to a semiconductor chip wafer in which each of the semiconductor chip mounted on the wafer has a plurality of spherical solder bumps or chip pads. The integrated circuit  30  and the electronic circuit  40  constitute a pair of electronic parts according to the present invention. 
     The connector structure  20  comprises an electrically insulating elastic sheet  21  and a plurality of electrically conductive elastic bodies  22 . The electrically elastic sheet  21  and each of the electrically conductive elastic bodies  22  are made of elastic materials each having a predetermined thickness. 
     As shown in FIG. 2, the electrically insulated elastic sheet  21  has upper and lower surfaces  21   a  and  21   b , and formed with a plurality of projected portions  23  projected upwardly so as to respectively face the IC terminals  31  of the integrated circuit  30  shown in FIGS. 3 and 4. Each of the projecting portions  23  is formed with a through bore  23   a  having an axis  23   b  extending in substantially parallel relationship with the thickness of the electrically insulating elastic sheet  21 . Each of the electrically conductive elastic bodies  22  has upper and lower surfaces  22   a  and  22   b , and is formed with a concavity  24  open at the upper surface  22   a  and a protruding portion  25  protruded downwardly in FIG.  2  and away from the concavity  24 . 
     The electrically conductive elastic bodies  22  are substantially identical in structure to each other, and the projected portions  23  of the electrically elastic sheet  21  are similarly substantially identical in shape to each other. This means that only one of the electrically conductive elastic bodies  22  and only one of the projected portions  23  of the electrically insulating elastic sheet  21  will be described hereinafter. 
     The electrically conductive elastic body  22  is positioned with respect to the electrically insulating elastic sheet  21  to cover the through bore  23   a  of the electrically insulating elastic sheet  21 . The electrically conductive elastic body  22  is thus supported by the projected portion  23  of the electrically insulating elastic sheet  21  with the lower surface  22   b  of the electrically conductive elastic body  22  and the lower surface  21   b  of the electrically insulating elastic sheet  21  forming a lower cavity  20   b.    
     The electrically conductive elastic bodies  22  are bonded with the electrically insulating elastic sheet  21  by molding, cementing, welding, fusion welding, depositing processes and the like. 
     Referring now to FIGS. 3 and 4, the connector structure  20  is arranged between the integrated circuit  30  and the electronic circuit  40 . The electrically conductive elastic bodies  22  of the connector structure  20  formed as above described are respectively displaceable with respect to the electronic pads  41  of the electronic circuit  40  along the center axes  23   b  of the thorough bores  23   a  between a first position where the electrically conductive elastic bodies  22  are respectively held in contact with the IC terminals  31  of the integrated circuit  30  and spaced apart from the electronic pads  41  of the electric circuit  40 , and a second position where the electrically conductive elastic bodies  22  are respectively held in electrical contact with the IC terminals  31  of the integrated circuit  30  and the electronic pads  41  of the electronic circuit  40  to complete electrical connection between the integrated circuit  30  and the electronic circuit  40 . 
     FIG. 3 shows the first position of the connector structure  20  in which the IC terminals  31  of the integrated circuit  30  are respectively received in the concavities  24  of the electrically conductive elastic bodies  22  of the connector structure  20 . Under this state, the electrically conductive elastic bodies  22  are supported by the electrically insulating elastic sheet  21  to have their protruding portions  25  respectively face and spaced apart from the electronic pads  41  of the electronic circuit  40 . This means that the IC terminals  31  of the integrated circuit  30  and the electronic pads  41  of the electronic circuit  40  are not electrically connected with each other. 
     When the integrated circuit  30  is urged toward the electronic circuit  40  from the above state, the connector structure  20  assumes the second position as shown in FIG.  4 . While the integrated circuit  30  is moved toward the electronic circuit  40 , the electrically insulating elastic sheet  21  is deformed to have the electrically conductive elastic bodies  22  displaced with respect to and brought into contact with the electronic pads  41  of the electronic circuit  40 , respectively. It is thus to be noted that the IC terminals  31  of the integrated circuit  30  and the electronic pads  41  of the electronic circuit  40  can electrically be connected with each other by the deformable electrically conductive elastic bodies  22 . 
     The second preferred embodiment of the connector structure according to the present invention will be described hereinafter with reference to the drawings,  5  particularly to FIGS. 5,  6  and  7 . 
     FIGS. 5 to  7  partly show a connector structure  50  which is designed to electrically connect an integrated circuit  60  including a semiconductor integrated circuit chip having a plurality of solder bumps or chip pads, and a semiconductor integrated circuit chip package of long grid array having a plurality of IC terminals, with an electronic circuit  40  having a plurality of electronic pads  41 . The connector structure  50  may be applied to a semiconductor chip wafer in which each of the semiconductor chip mounted on the wafer has a plurality of solder bumps or chip pads. The integrated circuit  60  and the electronic circuit  70  constitute a pair of electronic parts according to the present invention. 
     The connector structure  50  comprises an electrically insulating elastic sheet  51  and a plurality of electrically conductive elastic bodies  22 . The electrically insulating elastic sheet  51  and the plurality of electrically conductive elastic bodies  52  are made of elastic materials each having a predetermined thickness. 
     As shown in FIG. 5, the electrically insulating elastic sheet  51  has upper and lower surfaces  51   a  and  51   b , and formed with a plurality of projected portions  53  projected upwardly so as to respectively face the IC terminals  61  of the integrated circuit  60  shown in FIGS. 6 and 7. Each of the projected portions  53  is formed with a through bore  53   a  having an axis  53   b  extending in substantially parallel relationship with the thickness of the electrically insulating elastic sheet  51 . Each of the electrically conductive elastic bodies  52  has upper and lower surfaces  52   a  and  52   b , and is formed with a convexity  54  swollen upwardly and a protruding portion  55  protruded downwardly in FIG.  5  and away from the convexity  54 . 
     The electrically conductive elastic bodies  52  are substantially identical in structure to each other, and the projected portions  53  of the electrically insulating elastic sheet  51  are similarly substantially identical in shape to each other. This means that only one of the electrically conductive elastic bodies  52  and only one of the projected portions  53  of the electrically insulating elastic sheet  51  will be described hereinafter. 
     The electrically conductive elastic body  52  is positioned with respect to the electrically insulating elastic sheet  51  to cover the through bore  53   a  of the electrically insulating elastic sheet  51 . The electrically conductive elastic body  52  is thus supported by the projected portion  53  of the electrically insulating elastic sheet  51  with the lower surface  52   b  of the electrically conductive elastic body  52  and the lower surface  51   b  of the electrically insulated elastic sheet  51  forming a lower cavity  50   b.    
     The electrically conductive elastic bodies  52  are bonded with the electrically insulating elastic sheet  51  by molding, cementing, welding, fusion welding, depositing processes and the like. 
     Referring now to FIGS. 6 and 7, the connector structure  50  is arranged between the integrated circuit  60  and the electronic circuit  70 . The electrically conductive elastic body  52  of the connector structure  50  formed as above described is displaceable with respect to the electronic pads  71  of the electronic circuit  70  along the center axis  53   b  of each of the thorough bores  53   a  between a first position where the electrically conductive elastic bodies  52  are respectively held in contact with the IC terminals  61  of the integrated circuit  60  and spaced apart from the electronic pads  71  of the electric circuit  70 , and a second position where the electrically conductive elastic bodies  52  are respectively held in electrical contact with the IC-terminals  61  of the integrated circuit  60  and the electronic pads  71  of the electronic circuit  70  to complete electrical connection between the integrated circuit  60  and the electronic circuit  70 . 
     FIG. 6 shows the first position of the connector structure  50 . Each of the IC terminals  61  of the integrated circuit  60  is formed with a concavity to have each of the electrically conductive elastic bodies  52  of the connector structure  50  received therein and registered therewith. Under this state, the electrically conductive elastic bodies  52  are supported by the electrically insulating elastic sheet  51  to have their protruding portions  55  respectively face and spaced apart from the electronic pads  71  of the electronic circuit  70 . This means that the IC terminals  61  of the integrated circuit  60  and the electronic pads  71  of the electronic circuit  70  are not electrically connected with each other. 
     When the integrated circuit  60  is urged toward the electronic circuit  70  from the above state, the connector structure  50  assumes the second position as shown in FIG.  7 . While the integrated circuit  60  is moved toward the electronic circuit  70 , the electrically insulating elastic sheet  51  is deformed to have the electrically conductive elastic bodies  52  displaced with respect to and brought into contact with the electronic pads  71  of the electronic circuit  70 , respectively. It is thus to be noted that the IC terminals  61  of the integrated circuit  60  and the electronic pads  71  of the electronic circuit  70  can electrically be connected with each other by the deformable electrically conductive elastic bodies  52 . 
     The connector structures  20  and  50  according to the present invention are simple in construction, compared with the conventional IC socket  11  shown in FIGS. 12 and 13 by the reason that the connector structures  20  and  50  do not require the electrically conductive wires  15  and the first and second terminals  13   a  and  13   b  having the conductive wires  15  intervene therebetween. This results in the fact that the connector structures  20  and  50  are capable of having a plurality of terminals accommodated in a small space to test an integrated circuit which is small in size as well as of arranging a plurality of IC terminals in a extremely small space. 
     Moreover, the electrically conductive elastic bodies  22  of the connector structure  20  can respectively receive the IC terminals  31  of the integrated circuit  30  in their concavities  24  to protect the IC terminals  31  of the integrated circuit  30  from being damaged under the state that the IC terminals  31  of the integrated circuit  30  are held in contact with the electrically conductive elastic bodies  22   
     Furthermore, the convexity  54  of each of the electrically conductive elastic bodies  52  of the connector structure  50  can respectively be received in and registered with the concavity of each of the IC terminals  61  of the integrated circuit  60  to ensure electrical connection between the integrated circuit  60  and the connector structure  50 . 
     While it has been described that the electrically insulating elastic sheets  21  and  51  of the connector structure  20  and  50  are formed with projecting portions  23  and  53  shown in FIGS. 2 and 5, respectively, the electrically insulating elastic sheets  21  and  51  may be replaced by flat sheets as shown in FIGS. 8 and 9. 
     The third preferred embodiment of the connector structure  120  according to the present invention is illustrated in FIG. 8 as comprising an electrically insulating flat elastic sheet  121  and a plurality of electrically conductive elastic bodies  22  which are same as those of the connector structure  20  of the first preferred embodiment of the present invention. The operation of the connector structure  120  is same as that of the connector structure  20 , and thus will not be described hereinafter. The elements or parts of the connector structure  120  other than the electrically insulating flat elastic sheet  121  and the electrically conductive elastic bodies  22  in the third preferred embodiment of the connector structure  120  neither shown in FIG. 8 nor appeared in description are same in construction and operation as those of the connector structure  20  shown in FIG. 2 so that the elements or parts of the connector structure  120  will be omitted in description. 
     The fourth preferred embodiment of the connector structure  150  according to the present invention is illustrated in FIG. 9 as comprising an electrically insulating flat elastic sheet  151  and a plurality of electrically conductive elastic bodies  52  which are same as those of the connector structure  50  of the second preferred embodiment of the present invention. The operation of the connector structure  150  is same as that of the connector structure  50 , and thus will not be described hereinafter neither. In a similar reason, the elements or parts of the connector structure  150  other than the electrically insulating flat elastic sheet  151  and the electrically conductive elastic bodies  52  in the fourth preferred embodiment of the connector structure  150  neither shown in FIG. 8 nor appeared in description are same in construction and operation as those of the connector structure  50  shown in FIG. 5 so that the elements or parts of the connector structure  120  will be omitted in description. 
     While the present invention has thus been shown and described with reference to the specific embodiment, however, it should be noted that the invention is not limited to the details of the illustrated structures but changes and modifications may be made without departing from the scope of the appended claims.