Patent Document

CROSS-REFERENCE TO RELATED APPLICATION 
     This is a continuation application of PCT/JP2007/56389, filed on Mar. 27, 2007. 
    
    
     FIELD 
     The embodiments discussed herein are related to a semiconductor component in which a semiconductor element is enclosed, and a manufacturing method of the semiconductor component. 
     BACKGROUND 
     Recently, in semiconductor packages in which a semiconductor element is enclosed, the heat generation rate has been increasing as the operation frequency and the wiring density of the semiconductor element increase and the density of wiring increases, and there is a need to securely dissipate the generated heat and to effectively reduce the thermal resistance. Moreover, as a semiconductor package which is superior in the convenience of additional installation, version upgrading, and maintenance etc. of electronic equipment after it is brought into operation, semiconductor packages of an LGA (Land Grid Array) structure in which thin plate-shaped electrodes are arranged in a grid-like pattern on the surface are widely used. 
       FIG. 1  is a sectional view of a conventional semiconductor package of an LGA structure. 
     The semiconductor package  10  includes a wiring board  11  in the lower face of which thin plate-shaped electrodes are disposed, a semiconductor element  12  to which I/O terminals  14  are attached, a heat spreader  17  which dissipates heat generated in the semiconductor element  12 , a spacer  16  which supports the heat spreader  17 , where the semiconductor element  12  and the heat spreader  17  are joined by a joining member  13 , and the spacer  16 , the wiring board  11 , and the heat spreader  17  are bonded by an adhesive  15 . In order to reduce the thermal resistivity of the semiconductor element  12 , it is necessary to effectively transfer heat generated at the semiconductor element  12  to the heat spreader  17 , and therefore the thickness of the joining member  13  for joining the semiconductor element  12  with the heat spreader  17  is precisely adjusted. 
     The semiconductor package  10 , in which the wiring board  11  is displaced so as to face a socket with pins arranged in a grid-like pattern, is mounted into electronic equipment by being strongly pressed against the socket. Thus, a semiconductor package  10  of LGA structure has an advantage in that it may be attached to and detached from electronic equipment more easily and may be powered more efficiently compared with semiconductor packages including raised electrodes made up of pins and solder etc. 
     Incidentally, in a semiconductor package  10  of LGA structure, the registration with the socket is performed by the outer dimensions, and the semiconductor package  10  is mounted into electronic equipment by being strongly pressed against the socket. For this reason, if the wiring board  11 , the heat spreader  17 , and others are obliquely bonded due to the squeeze-out of the adhesive  15  or any other factor, the pressing force F from the socket will be applied leaning toward one part of the surface of the wiring board  11  posing risks of such as fracture of the wiring board  11  and breakage of the internal wiring. Further, if the adhesive  15  is squeezed out beyond the outer dimension of the semiconductor package  10 , misregistrations between the semiconductor package  10  and the socket may take place resulting in connection deficiencies. 
     In this respect, Japanese Laid-open Patent Publications No. 2006-80297 and No. 2004-296739 describe a technique in which there is provided a step in the end face of the spacer so that the squeezed-out adhesive is accommodated therein. According to the technique described by Japanese Laid-open Patent Publications No. 2006-80297 and No. 2004-296739, since an excess adhesive will be pressed out to the end face of the spacer entering into the step, it is possible to mitigate the squeeze-out of the adhesive. 
     However, since the semiconductor package  10  itself is small-sized, a problem remains in that the amount of adhesive which may be accommodated in the step in the spacer end face is very small and is not enough to solve the fracture of the wiring board and the connection deficiencies due to the squeeze-out of the adhesive. 
     SUMMARY 
     According to an aspect of the invention, a semiconductor component includes a semiconductor element that has a plurality of signals, a wiring board that is disposed below the semiconductor element and that draws the plurality of signals of the semiconductor element, a heat conduction member that dissipates heat generated by the semiconductor element, a joining member that is disposed between the semiconductor element and the heat conduction member and that joins the heat conduction member to the semiconductor element, a support member formed with an opening so as to surround the semiconductor element that supports the heat conduction member, a first adhesive member that is disposed between the support member and the wiring board to bond the support member with the wiring board and a second adhesive member that is disposed between the support member and the heat conduction member to bond the support member with the heat conduction member. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a sectional view of a conventional semiconductor package of an LGA structure; 
         FIG. 2A  is an exploded perspective view to illustrate a semiconductor component; 
         FIG. 2B  illustrates an outer perspective view of the semiconductor component; 
         FIG. 3A  illustrates an upper face of a spacer on a side facing a heat spreader; 
         FIG. 3B  illustrates a lower face of the spacer on a side facing the wiring board; 
         FIG. 4  illustrates a manufacturing method of a semiconductor component; 
         FIG. 5  illustrates a spacer in a second embodiment of the present invention; 
         FIG. 6  illustrates a spacer in a third embodiment of the present invention; 
         FIG. 7  illustrates a spacer in a fourth embodiment of the present invention; 
         FIG. 8  illustrates a manufacturing method of a semiconductor component to which the spacer illustrated in  FIG. 7  is applied; 
         FIG. 9  illustrates a spacer in a fifth embodiment of the present invention; 
         FIG. 10  is an exploded perspective view of a semiconductor component which is a sixth embodiment of the present invention; 
         FIG. 11  illustrates an adhesive sheet in a seventh embodiment of the present invention; 
         FIG. 12  illustrates an adhesive sheet in an eighth embodiment of the present invention; and 
         FIG. 13A  illustrates an exploded perspective view of the semiconductor component; 
         FIG. 13B  illustrates a sectional view of an outer peripheral section of the semiconductor component. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereafter, embodiments of the present invention will be described with reference to appended drawings. 
       FIG. 2  is a schematic block diagram of a semiconductor component which is an embodiment of the present invention. 
       FIG. 2A  is an exploded perspective view to illustrate a semiconductor component  100 . 
     The semiconductor component  100  is formed such that on a wiring board  110 , there are placed a joining member  123 , an adhesive sheet  130 , a spacer  140 , and a heat spreader  150  etc. on top of one another. 
     There are thin plate-shaped electrodes disposed in the lower face of the wiring board  110 , which exchanges signals and power with external apparatuses as the result of those electrodes being pressed against a socket. The wiring board  110  corresponds to an example of the wiring board referred to in the present embodiment. 
     There is disposed a semiconductor element beneath the joining member  123 , and the semiconductor element and the heat spreader  150  are bonded by the joining member  123 . The semiconductor element and the joining member  123  will be illustrated below. Moreover, the adhesive sheet  130  and the spacer  140  are provided with openings  131  and  142  respectively, and the semiconductor element and the joining member  123  are disposed inside those openings  131  and  142 . 
     The adhesive sheet  130  is made up of a thermosetting adhesive material and two sheets thereof are provided interposing the spacer  140  therebetween. The adhesive sheet  130  disposed between the wiring board  110  and the spacer  140  is an example of the first adhesive member referred to in the present embodiment and also corresponds to an example of the first thermosetting adhesive member referred to in the present embodiment. Further, the adhesive sheet  130  disposed between the spacer  140  and the heat spreader  150  is an example of the second adhesive member referred to in the present embodiment and also corresponds to an example of the second thermosetting adhesive member referred to in the present embodiment. 
       FIG. 3  illustrates the spacer  140 . 
       FIG. 3A  illustrates the face (hereafter, referred to as an upper face) of the spacer  140  on the side facing the heat spreader  150 , and  FIG. 3B  illustrates the face (hereafter, referred to as a lower face) of the spacer  140  on the side facing the wiring board  110 . 
     The spacer  140 , which is adapted to support the heat spreader  150 , is formed with grooves  141  having the same length with one another in the outer peripheral section of each of the upper and lower faces as illustrated in  FIG. 3 . The spacer  140  is an example of the support member referred to in the present embodiment, and the grooves  141  are an example of “the depressions” referred to in the present embodiment, and also correspond to an example of “the grooves” referred to in the present embodiment. 
     Now, description will return to  FIG. 2 . 
     The heat spreader  150  is adapted to dissipate heat generated by the semiconductor element disposed beneath the joining member  123 . The heat spreader  150  corresponds to an example of the heat conduction member referred to in the present embodiment. 
       FIG. 2B  illustrates an outer perspective view of the semiconductor component  100 . 
     The heat spreader  150  is formed, from outward appearances, such that a spacer  140  etc. is interposed between the wiring board  110  and the heat spreader  150  and, in the space formed by the wiring board  110 , the heat spreader  150 , and spacer  140 , the semiconductor element and the joining member  123  are enclosed. 
     Next, a manufacturing method of the semiconductor component  100  will be described. 
       FIG. 4  illustrates a manufacturing method of the semiconductor component  100 . 
     Upon manufacturing the semiconductor component  100 , first, a first adhesive sheet  130 , a spacer  140 , and a second adhesive sheet  130  are disposed in this order on a wiring board  110 , and a semiconductor element  122 , to which an I/O terminal  121  is bonded by a adhesive material  121   a , and a joining member  123  are successively disposed inside each of the openings  131  and  142  of the adhesive sheet  130  and the spacer  140  (step S 11  of  FIG. 4 ). The semiconductor element  122  is an example of the semiconductor element referred to in the present embodiment, and the joining member  123  corresponds to an example of the joining member referred to in the present embodiment. Moreover, the process of disposing the adhesive sheet  130  and the spacer  140  illustrated in step S 11  of  FIG. 4  corresponds to an example of “the step of disposing a first thermosetting adhesive member, a support member, and a second thermosetting adhesive member on top of one another” in the manufacturing method of the semiconductor component of the present embodiment. 
     It is noted that in the present embodiment, an adhesive sheet  130  having a thickness larger than conventionally used is applied so that the thickness of the two adhesive sheets  130  interposing the spacer  140  therebetween is larger than the thickness of the semiconductor element  122  with the joining member  123  placed thereon. 
     Then, a heat spreader  150  is overlaid on the joining member  123  and the adhesive sheet  130  to form a semiconductor component  100  in the state before various elements are bonded thereto (hereafter, the semiconductor component  100  before the bonding process is referred to as an “unbonded semiconductor component  100 ′”). In step S 12   —   a  of  FIG. 4 , a section taken across near the center of unbonded semiconductor component  100 ′ is illustrated and, in step S 12   —   b  of  FIG. 4 , a section view taken across the outer peripheral section of the unbonded semiconductor component  100 ′ is illustrated. As illustrated in step S 12   —   b , the grooves  141  are formed in the upper and lower faces of the spacer  140 , and at this time, the adhesive sheet  130  has not gotten into the inside of those grooves  141 . This step S 12  of overlaying the heat spreader  150  corresponds to one example of “the step of disposing the heat conduction member” in the manufacturing method of the semiconductor component of the present embodiment. 
     When the heat spreader  150  is overlaid and the unbonded semiconductor component  100 ′ is heated, the surface of the joining member  123  melts thereby increasing the viscosity, and two adhesive sheets  130  melt into a liquid. Further, the heat spreader  150  is pressed against the joining member  123  (step S 13  of  FIG. 4 ). In the present embodiment, an adhesive sheet  130  of a thickness larger than conventionally used is used, and as a result of the heat spreader  150  being pushed in up to the height of the upper face of the joining member  123 , the thermosetting adhesive material  132 , which has resulted from the melting of the two adhesive sheets  130 , is pushed out into the grooves  141  formed in the upper and lower faces of the spacer  140 . Step S 13  of pushing out the thermosetting adhesive material  132  into the grooves  141  corresponds to an example of “the step of filling the grooves with the thermosetting adhesive member” in the manufacturing method of the semiconductor component of the present embodiment. 
     Next, the unbonded semiconductor component  100 ′ is cooled down (step S 14  of  FIG. 4 ). As a result, the joining member  123  and the thermosetting adhesive material  132  are hardened, thereby the joining member  123  being bonded to the heat spreader  150 , and the spacer  140  being bonded to the heat spreader  150  and the wiring board  110 . This step S 14  of hardening the thermosetting adhesive material  132  corresponds to an example of “the step of hardening the thermosetting adhesive member” in the manufacturing method of the semiconductor component of the present embodiment. 
     The hardened thermosetting adhesive material  132 ′ is present between the spacer  140  and the heat spreader  150  and between the spacer  140  and the wiring board  110  thereby bonding them, and an excess part thereof has gotten into the grooves  141  of the spacer  140 . Thus, since the semiconductor component  100 , in which no squeeze-out of the thermosetting adhesive material  132  has occurred, has a uniform thickness, it is possible to avoid deficiencies such as that the wiring board  110  fractures by being pressed hard against the socket, and misregistration with the socket, which is registered by the outer dimension, takes place leading to connection deficiencies. Further, since as a result of a rather thick adhesive sheet  130  being used, the clearances between the spacer  140  and the wiring board  110 , and between the spacer and the heat spreader  150  are filled with an excess thermosetting adhesive material  132 , it becomes possible to omit the process of charging and hardening liquid resin such as underfill materials into clearances, which is conventionally carried out in a later stage of step S 14 , thus reducing the manufacturing cost. 
     So far, the description of the first embodiment of the present invention has been completed, and a second embodiment thereof will be described. Since the second embodiment of the present invention has a similar structure as the first embodiment excepting the shape of the grooves formed in the spacer, like elements as those of the first embodiment will be given like reference symbols to omit the description thereof and only the differences from the first embodiment will be described. 
       FIG. 5  illustrates a spacer  140 _ 2  in the second embodiment of the present invention. 
     The spacer  140 _ 2  of the present embodiment is formed, unlike the spacer  140  of the first embodiment illustrated in  FIG. 2 , such that the length L 1  of the groove in a corner portion is less than the length L 2  of the groove  141  in a middle side portion. Even if the spacer  140 _ 2  is bonded to the heat spreader  150  and the wiring board  110  illustrated in  FIG. 2 , the corner portions of the spacer  140 _ 2  are susceptible to peeling off. According to the spacer  140 _ 2  of the present embodiment, the length of the groove  141  is reduced as closer to a corner portion so that the contact area with the adhesive sheet  130  becomes larger, and thereby it is made possible to securely bond the corner portions to the heat spreader  150  and the wiring board  110 . 
     So far, the description of the second embodiment of the present invention has been completed, and a third embodiment thereof will be described. Since the third embodiment of the present invention has a similar structure as the first embodiment excepting the shape of the grooves provided in the spacer, like elements as those of the first embodiment will be given like reference symbols to omit the description thereof and only the differences from the first embodiment will be described. 
       FIG. 6  illustrates a spacer  140 _ 3  of the third embodiment of the present invention. 
     The spacer  140 _ 3  of the present embodiment is formed such that the grooves  141  in a corner portion P are radially provided at an angle with one another so as to intersect at the inside of the opening  142 . In the spacer  140 _ 3  illustrated in  FIG. 6 , the corner portion P, which is susceptible to peeling off even when bonded, is formed such that the spacing between grooves  141  becomes larger as closer to the outer peripheral side, and the contact area with the adhesive sheet  130  becomes larger. Thus, by providing radial grooves  141  in the corner portions P of the spacer  140 _ 3 , it is also possible to prevent the squeeze-out of the thermosetting adhesive material while maintain the bonding accuracy of the spacer  140 _ 3 . 
     So far, the description of the third embodiment of the present invention has been completed, and a fourth embodiment thereof will be described. Since the third embodiment of the present invention also has a similar structure as the first embodiment excepting that cut-outs instead of the grooves are provided in the spacer, like elements as those of the first embodiment will be given like reference symbols to omit the description thereof and only the differences from the first embodiment will be described. 
       FIG. 7  illustrates a spacer  160  in the fourth embodiment of the present invention. 
     The spacer  160  of the present embodiment is, unlike the spacer  140  of the first embodiment illustrated in  FIG. 2 , formed with cut-outs  161  instead of the grooves  141  in the outer peripheral section. Moreover, the spacer  160  of the present embodiment is formed such that the length L 1  of the cut-out  161  in a corner portion is less than the length L 2  of the cut-out  161  in a middle side portion, intending to maintain the bonding accuracy of the spacer  160 . 
       FIG. 8  illustrates a manufacturing method of a semiconductor component  101  to which the spacer illustrated in  FIG. 7  is applied. 
     Similarly to the manufacturing method of the semiconductor component  101  of the first embodiment illustrated in  FIG. 4 , the present embodiment also has a structure such that on the wiring board  110 , there are disposed a first adhesive sheet  130 , a spacer  160 , and a second adhesive sheet  130  in this order, and the semiconductor element  122  provided with the I/O terminals  121 , and the joining member  123  are successively disposed inside the respective openings  131  and  162  of the adhesive sheet  130  and the spacer  160  (step S 21  of  FIG. 8 ). 
     Next, the heat spreader  150  is overlaid to form an unbonded semiconductor component  101 ′. In step S 22   —   a  of  FIG. 8 , a section taken across near the center of the unbonded semiconductor component  101 ′ is illustrated, and in step S 22   —   b  of  FIG. 8 , a sectional view taken across the peripheral portion of the unbonded semiconductor component  101 ′ is illustrated. In the present embodiment, cut-outs  161  are provided in the spacer  160  as illustrated in step S 22   —   b.    
     Further, the unbonded semiconductor component  101 ′ is heated to melt the joining member  123  and the two adhesive sheets  130  (step S 23  of  FIG. 8 ). As a result, the thermosetting adhesive material  132  resulting from the melting of the two adhesive sheets  130  is pushed out and filled into the cut-outs  161  of the spacer  160 . Step S 23  of pushing out the thermosetting adhesive material  132  into the cut-outs  161  corresponds to an example of “the step of filling the cut-outs with the thermosetting adhesive member” in the manufacturing method of the semiconductor component of the present embodiment. 
     When the cut-outs  161  are filled with the thermosetting adhesive material  132 , the unbonded semiconductor component  100 ′ is cooled down (step S 24  of  FIG. 8 ). In the present embodiment, an excess part of the hardened thermosetting adhesive material  132 ′, which has not been used for bonding the spacer  160  with the heat spreader  150  and the wiring board  110 , has gotten into the cut-outs  161  of the spacer  160 . Thus, by providing the cut-outs  161  instead of grooves in the spacer  160 , it is possible to more efficiently accommodate the excess thermosetting adhesive material  132 ′. 
     So far, the description of the fourth embodiment of the present invention has been completed, and a fifth embodiment thereof will be described. Since the fifth embodiment of the present invention has a similar structure as the fourth embodiment of the present invention excepting the shape of the cut-outs provided in the spacer, like elements as those of the fourth embodiment will be given like reference symbols to omit the description thereof and only the differences from the fourth embodiment will be described. 
       FIG. 9  illustrates a spacer  160 _ 2  in the fifth embodiment of the present invention. 
     The spacer  160 _ 2  of the present embodiment is formed such that cut-outs  161  in a corner portion P are radially provided at an angle with one another so as to intersect at within the opening  162 . Since in the spacer  160  of the present embodiment, the contact area with the adhesive sheet  130  is larger in the corner portions P than in other portions, it is possible to achieve both the maintenance of the bonding accuracy and the prevention of the squeeze-out of the thermosetting adhesive material. 
     So far, the description of the fifth embodiment of the present invention has been completed, and a sixth embodiment thereof will be described. Since the sixth embodiment of the present invention has a similar structure as the first embodiment of the present invention excepting the shapes of the spacer and the adhesive sheet, like elements as those of the first embodiment will be given like reference symbols to omit the description thereof and only the differences from the first embodiment will be described. 
       FIG. 10  is an exploded perspective view of a semiconductor component  200  which is the sixth embodiment of the present invention. 
     Similarly to the semiconductor component  100  of the first embodiment illustrated in  FIG. 2 , the semiconductor component  200  of the present embodiment is formed such that on the wiring board  110 , there are placed two adhesive sheets  180 , a spacer  170 , and a heat spreader  150  on top of one another, and a semiconductor section  129  is disposed inside the respective openings  181  and  171  provided in the adhesive sheet  180  and the spacer  170 . Moreover, unlike the semiconductor component  100  of the first embodiment, neither groove nor cut-out is provided in the spacer  170  and instead, cut-outs  182  are formed in the respective outer peripheral sections of the two adhesive sheets  180 . 
     When the adhesive sheet  180  illustrated in  FIG. 10  is melted, an excess thermosetting adhesive material may spread over the portions of the cut-outs  182  of the adhesive sheet  180 . As a result of this, it is possible to securely bond the spacer  170  and to avoid the deficiency that the thermosetting adhesive member is squeezed out to the outer face of the semiconductor component  200 . 
     So far, the description of the sixth embodiment of the present invention has been completed, and a seventh embodiment thereof will be described. Since the seventh embodiment of the present invention has a similar structure as the sixth embodiment of the present invention excepting the shape of the cut-out of the adhesive sheet, only the differences from the sixth embodiment will be described. 
       FIG. 11  illustrates an adhesive sheet  180 _ 2  in the seventh embodiment of the present invention. 
     The adhesive sheet  180 _ 2  of the present embodiment is formed such that the length L 1  of the cut-out  182  of a corner portion is less than the length L 2  of the cut-out  182  of a middle side portion. Since, in the adhesive sheet  180 _ 2  of the present embodiment, the contact area between the adhesive sheet  180 _ 2  and the spacer  170  is larger in corner portions where spacer  170  is more susceptible to peeling off, it is possible to avoid the squeeze-out of the thermosetting adhesive material while maintaining the bonding accuracy of the spacer  170 . 
     So far, the description of the seventh embodiment of the present invention has been completed, and an eighth embodiment thereof will be described. Since the eighth embodiment of the present invention has a similar structure as the sixth embodiment of the present invention excepting the shape of the cut-out of the adhesive sheet, only the differences from the sixth embodiment will be described. 
       FIG. 12  illustrates an adhesive sheet  180 _ 3  in the eighth embodiment of the present invention. 
     Since the adhesive sheet  180 _ 3  of the present embodiment is formed such that the cut-outs  182  in a corner portion are radially provided at an angle with one another so as to intersect within the opening  181 , the contact area between the adhesive shut  180 - 3  and the space  170  becomes larger closer to the outer peripheral side where peeling off is more likely to take place. Thus, by providing radial cut-outs  182  in the corner portions P of the adhesive sheet  180 _ 3 , it is also possible to prevent the squeeze-out of the thermosetting adhesive material while maintaining the bonding accuracy of the spacer  170 . 
     So far, the description of the eighth embodiment of the present invention has been completed, and a ninth embodiment thereof will be described. Since the ninth embodiment of the present invention has a similar structure as the sixth embodiment excepting the shape of the spacer, only the differences from the sixth embodiment will be described. 
       FIG. 13  illustrates a semiconductor component  300  which is the ninth embodiment of the present invention. 
       FIG. 13A  illustrates an exploded perspective view of the semiconductor component  300  of the present embodiment. 
     Similarly to the semiconductor component  200  of the sixth embodiment illustrated in  FIG. 10 , the semiconductor component  300  of the present embodiment is formed such that cut-outs  182  are formed in an adhesive sheet  180 , and further cut-outs  142  are also formed in a spacer  140 . Moreover, two adhesive sheets  180  and spacer  140  are placed on top of one another with the respective cut-outs  182  and  142  being lined up. 
       FIG. 13B  illustrates a sectional view of the outer peripheral section of the semiconductor component  300 . 
     When the adhesive sheet  180  illustrated in  FIG. 13B  is melt, an excess thermosetting adhesive material, which has been left without been used for the bonding of the spacer  170  with the heat spreader  150  and the wiring board  110 , may spread over the portion of the cut-outs  182  of the adhesive sheet  180 , and also may be pushed out into the cut-outs  142  of the spacer  170 . For this reason, even when the adhesive sheet  180  has a larger thickness, it is possible to securely avoid the squeeze-out of the thermosetting adhesive material. 
     Here it is noted that although description has been made on the cases in which grooves are provided in both the upper and lower faces of the spacer, the support member according to the present invention may be one in which grooves are provided only in one face. 
     Further, although, in the above, description has been made on a case in which cut-outs are provided in each of the spacer and the adhesive sheet, the support member and the adhesive member according to the present invention may be formed such that cut-outs are provided in one of the members and grooves are provided in the other. 
     Although description has been made on the case in which grooves are provided only in the outer peripheral section of the spacer, the support member according to the present invention may be formed such that grooves are provided in the entire upper face. 
     As so far described, according to the present invention, it is possible to provide a semiconductor component in which the deficiencies due to the squeeze-out of the adhesive member are mitigated. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention has been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

Technology Category: h