Abstract:
The disclosure relates to a device for packaging and conveying components that uses a heat-formed bearing strip provided with cells. The cells preferably all have the same standard size, and the components are maintained in place in the cells using a filler material that can be configured at will. The disclosure also relates to a component supply device including such a device, and to a method for implementing such a device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a National Phase Entry of International Application No. PCT/FR2009/000242, filed on Mar. 9, 2009, which claims priority to French Application No. 08/01378, filed on Mar. 13, 2008, both of which are incorporated by reference herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a device for packaging and conveying components that uses a bearing strip provided with a series of cells having standard dimensions. The present invention also relates to an associated conveying and packaging method. 
       BACKGROUND 
       [0003]    During the processing or assembling of components, such components are taken from a storeroom and thus have to be conveyed to an assembling station that uses a supply device. The two most frequently used types of supply devices are a variable rate supply device and a variable component supply device. 
         [0004]    Variable rate supply devices most often include a bearing strip or a bearing roller, the feed speed of which is varied as requested. Then the components are contained in heat-formed cells specially adapted to match the shape of the components. In such a device, the strip is provided with a device for positioning each cell. In addition, each cell reproduces the shape of the components, which makes it possible to locate each component with accuracy and to guarantee the reproducibility of the positioning of the components in the cells. The bearing strips of such types of supply device are then fed at a certain rate under a gripping device, which takes the various components. Such a device is very advantageous since it makes it possible to work at quick and variable rates, while guaranteeing a very precise positioning of the components. 
         [0005]    However, variable rate supply devices can hardly be used when the components have different shapes and/or dimensions. As a matter of fact, the execution of cells with varying shapes in the bearing strip is costly and the thus formed strips cannot be used for conveying other components. 
         [0006]    Other component supply devices which do not require using cells trips are known. These are generally vibrating bowls which are devices dedicated to specific components and which position such components. However such devices accept only small changes in dimensions and the working rates of such devices cannot be adapted, whereas the request for components generally varies during the life of a manufactured product. 
         [0007]    Variable component supply devices are also known. Most of the time, such devices are composed of a strip whereon the components are fed in bulk, and a viewing member which makes it possible to spot and then to take the components. Such a device is adapted to any type of component. However, the working rates are slowed down to enable the viewing member to spot the components. In addition, such a device requires heavy infrastructures, since it requires using an apparatus for spotting the components in space. 
       SUMMARY 
       [0008]    The present invention aims at remedying the drawbacks of the state of the art by providing a device for packaging and conveying components that can be adapted to heterogeneous series of components and which can be used at a varying rate, while guaranteeing a very good reproducibility of the positioning of the components. For this purpose, the present invention provides to use a bearing strip that uses heat-formed cells, all having standard dimensions, filled with a plastic material that can be configured at will to maintain the component in a precise position and orientation. More precisely, the present invention relates to a device for packaging and conveying components that uses a bearing strip provided with cells, each one being able to, and being so configured as to receive at least one component, each cell being filled with a reversibly deformable filler material which defines a print corresponding to the shape of the component contained in the cell. More precisely, the filler material is re-formable, i.e. it can be conformed in different ways to adapt to the shapes of the various components. 
         [0009]    The same bearing strip may contain a set of components intended to be assembled together, for example on a printed circuit. In another embodiment, a set of components intended to be assembled together may be contained in the same cell, so that each cell contains a kit of parts ready to be assembled. Such a device thus makes it possible to store and to pack components having varying sizes and profiles in cells having a standard size: there is no longer a need for a specification or an adaptation of the cells to the components to be supplied, which facilitates the manufacture of bearing strips and the cells thereof. In addition, the bearing strips can be used for several types of components, which is economically advantageous. 
         [0010]    The components are maintained in the cells by the filler material. As a matter of fact, the cells have standard dimensions, that are, in most cases, greater than the dimensions of the components contained in the cells. A filler material is thus added to the cells so as to fill the voids between the walls of the cells and the components. Such filler material makes it possible to wedge and to maintain the components in a precise position and a precise orientation of the cell and it also makes it possible to prevent the components from leaving the cells. In addition, such material makes it possible to dampen the possible shocks for the components. Such material is preferably a plastic material. 
         [0011]    In addition, the material which fills the cells is reversibly deformable, i.e. it can be configured or formed at will. The print created in such a material, which corresponds to the profile of a particular component may also be erased under selected pressure and/or temperature conditions. The print can thus be re-modeled as many times as required, as a function of the type of component to be conveyed. As a matter of fact, when the component contained in one cell is taken out of the cell, the print of the components can be filled and a new print can be configured in the filler material. Thus, a large number of different components can be conveyed by the same bearing strip, the cells of which are filled with the same material. 
         [0012]    In practice, it may be necessary to add make up filler material in the cells upon changing the print, so as to make up for the loss. In addition, after a certain number of remodelling operations of the filler material, it may be useful to change it so as to guarantee a consistent quality of the filler material. 
         [0013]    Advantageously, all the cells have the same dimensions, with such dimensions being greater than the dimensions of the biggest component contained in the conveying device. Thus the bearing strip includes cells which all have the same size, which makes it possible to simplify the manufacturing of such bearing strip. Such bearing strip is preferably made in a heat-formable plastic material and the cells are then heat-formed. 
         [0014]    The bearing strip is preferably wound up which saves space, and it is preferably stored in a protective cassette. Then, the bearing strip, which contains the component, is stored wound up, and it is unwound in due time, so that the components can be taken out, for example using a gripping device. It is then rewound again, so as to be stored empty. The protective cassette can thus contain two rollers on which the bearing strip can wind: the first roller enables the winding of the strip when it is filled with components, the second roller enables the winding of the strip when it is empty. Such winding also makes it possible to obtain a closed packaging for the components and, if need be, a sealing of the cells. 
         [0015]    According to a first embodiment of the present invention, the material for filling the cells is heat-deformable, preferably at a temperature substantially above room temperature. Thus, it is sufficient to heat the material at a temperature substantially above room temperature to make it easily deformable, which makes it possible to make prints easily, without any excess consumption of energy by local melting of the material. Thereafter, it is sufficient to let the material harden with its print, by cooling it to room temperature. 
         [0016]    Advantageously, the filler material is deformable at a temperature between 40 and 70°. As a matter of fact, such temperatures are interesting since they are sufficiently different from room temperature to prevent the material from cooling by accident. In addition, they are not too high, which makes it possible, on the one hand, to avoid too important costs of energy during the making of prints, and on the other hand, to make prints by heating the components beforehand, and inserting components into the filler material. As a matter of fact, most of the components conveyed by this device can bear temperatures between 40 and 70° without any risk of being damaged, which enables an easy production of prints, without using an additional punch, die or mould. 
         [0017]    Advantageously, said prints are liable to be erased by melting the filler material. As a matter of fact, when the components are taken out of the cells, for example with the use of a gripping device, the prints can be erased by heating the filler material again. Thus the filler material softens or liquefies and it hardens back to its original shape. Subsequently, new prints can be made by heating the filler material again and by inserting into such material a punch or an object, the contour of which defines the requested form. Thus, the filler material can be modelled and re-modelled at will: this is what reversibly deformable material means. 
         [0018]    Advantageously, the selected filler material is polycaprolactone. As a matter of fact, polycaprolactone easily flows into the cells at a temperature above 60° C. and fills these easily and homogeneously. When in the cells, it returns to a solid state at room temperature. Thus filling the cells is a simple and quick operation. In addition, polycaprolactone can be modelled and re-modelled easily without any remanence and without keeping any track of the former print. 
         [0019]    In addition, polycaprolactone does not age untimely. In particular, it does not shrink when drying, which makes it possible not to modify the positioning marks of the prints and thus the components in the cells. In addition, polycaprolactone is particularly stiff at room temperature and consequently, the print cannot be deformed at room temperature and the components do not sink into polycaprolactone. The components can thus be precisely maintained inside the cells. In addition, polycaprolactone is chemically neutral and it is not mechanically aggressive, neither for the components, nor for the cells, while having a satisfactory adhesion onto the walls of the cells, which makes it possible to prevent the relative displacement of the print. Advantageously, the filler material is stiff at room temperature, so that the prints can keep their shapes when they contain the components. 
         [0020]    The invention also relates to a component supply device including a device for packaging and conveying components according to one of the embodiments described above, said supply device further including a device making it possible to feed the bearing strip at a selected rate. Thus, the supply device makes it possible to feed the bearing strip, for example in front of a gripping device which takes the components to assemble these. 
         [0021]    Advantageously, the bearing strip includes identifying elements making it possible to spot the position of a special component in the bearing strip, with the supply device including a device for reading such identifying elements. Thus, the components are precisely positioned in the cells, using the filler material, and the cells are also precisely positioned in space using the identifying elements. Indexing the cells thus makes it possible to precisely spot each component. Thus the gripping devices can spot and grip components very precisely, even with high feeding rates. 
         [0022]    The invention also relates to a method for packaging and conveying components that uses a bearing strip provided with cells, each one being so configured as to receive at least one component, characterized in that it includes the following steps:
       each cell is filled with a reversibly deformable material which includes at least one print, the profile of which corresponds to the shapes of the components to be conveyed in such cell,   a component is placed in each print.       
 
         [0025]    According to a first embodiment, the cell filling step includes the following steps:
       the deformable material is injected in liquid or pasty shape into each cell at a temperature above room temperature;   the deformable material is left to harden at room temperature;   the print of the component is made in the deformable material by local melting and punching.       
 
         [0029]    Advantageously, the method for packaging and conveying components further includes a step during which the bearing strip is wound up, thus sealing the cells. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0030]    Other advantageous characteristics provided by the present invention will appear upon reading the following description, while referring to the appended drawings, which show: 
           [0031]      FIG. 1  a component supply device according to one embodiment of the invention; 
           [0032]      FIG. 2  a bearing strip provided with cells according to one embodiment of the invention; and 
           [0033]      FIG. 3  a packaging and conveying device according to one embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    One exemplary embodiment is given in the case where the conveyed components are micro-electronic components. However, such device and such method can be used for packaging and conveying any type of component: such components can be, for example, micro-electronic, electro-mechanical, micro-mechanical, mechanical, optical components. . .  FIG. 1  shows a micro-electronic component supply device  7  intended to be associated with a robot mounting micro-electronic component onto printed circuit cards. The micro-electronic component supply device  1  includes a packaging and conveying device  8  wherein the components  3  making it possible to feed the mounting robot are stored. 
         [0035]    Such packaging and conveying device  8  is shown diagrammatically in  FIG. 3 . It includes two rollers  10  whereon the strip  1  winds up. The various components are stored in a bearing strip  1  provided with cells  2 . Such bearing strip  1  is composed of a strip of heat-deformable plastic wherein cells  2  have been heat-formed. All such cells  2  have the same dimensions and the same shape, i.e. a rectangular shape, whereas the components  3  have any varying shape. The free space between the components  3  and the walls of the cells  2  is filled by polycaprolactone  9  which makes it possible to maintain and to wedge the components  3  in the cells, in precise position and orientation. 
         [0036]    Such bearing strip  1  which contains the various components  3 , is wound onto a cassette  4 , and is unwound by a strip driving device  5  which feeds the strip in front of a gripping device  6 . Such a gripping device  6  takes the components  3  out of the cells  2  and conveys these to the mounting robot (not shown). The length of the empty strip is then wound onto a second cassette  4 ′. 
         [0037]    The bearing strip  1  bears a plurality of various components  3 . Each component is identified by its position in the strip, i.e. by the position of the cell which contains it, and by the position of such component in the cell. The latter position is fixed, using polycaprolactone, and more particularly using the print it contains and which allows guaranteeing the reproducibility of the components positioning in the cells. The gripping device  6  can thus select a particular component  3   a  in the strip  1  which contains a plurality of various components. 
         [0038]    The method for packaging and conveying components in the device  7  is more precisely described in  FIG. 2 . Thus, the packaging and conveying device  7  according to one embodiment of the present invention includes a bearing strip  1  provided with heat-formed cells  2 . Such cells  2  are all rectangular in this Figure, and they all have the same dimensions. The dimensions of such cells  2  are slightly greater than the dimensions of the biggest component  3   b  conveyed by the device  1 . Thus, such cells  2  have a standard size, which facilitates the manufacturing thereof, since, during the heat-forming operation, there is no longer any specification for adapting the cells to the components to be conveyed. 
         [0039]    Firstly, polycaprolactone  9  is heated to 60°, a temperature at which it is liquid, which enables an easy casting into the cells  2 . The quantity of polycaprolactone  9  poured into a cell  2   a  is equal to the volume of such cell  2   a minus the volume of the component  3   a  which it contains. Thus, when the component  3   a  is positioned in the cell  2   a,  the volume of the cell  2   a  is totally occupied by the volume of the component  3   a  and polycaprolactone  9 . Then polycaprolactone  9  is let to rest at room temperature until it has totally hardened. 
         [0040]    Polycaprolactone is a material particularly suitable for such type of application since it can easily be cast at a temperature substantially above room temperature. In addition, it easily and homogeneously fills the cells, without requiring any additional operation and it hardens relatively quickly. Finally, it is chemically inactive to the components and the cell walls. Of course, any other material having equivalent properties can be used. 
         [0041]    During the first utilisation of a bearing strip, each component  3   a  is heated to 60° and it is inserted into the cell  2   a  so as to make, in polycaprolactone  9 , a print  10   a  corresponding to the profile of each component by local melting of polycaprolactone  9 . When polycaprolactone  9  has hardened at room temperature, the strip is wound up and stored. Polycaprolactone  9  then makes it possible to maintain the components  3  in the cells  2 , in their original positions, by very precisely preserving, i.e. with a precision of the order of one micron, the distance between each component and the walls of the cell which contains it. Such method is all the more advantageous since such precise positioning and orientation do not vary over time, since polycaprolactone has no untimely ageing, no any shrinkage, nor any contraction or any risk of changing condition over time. In addition, polycaprolactone is sufficiently stiff to prevent any sinking of the components  3  into the cells  2 , so that the components  3  remain in their original positions. 
         [0042]    The strip  1  is then inserted into the supply device  7  which makes it possible to unwind the strip  1  at a selected rate and to take out the selected components  3  as requested, as a function of the positions thereof in the strip  1 , using the gripping device  6 . The print in polycaprolactone preferably includes passages enabling the gripping device to take the components. Polycaprolactone  9  then allows the passage of the gripping device  6  around the components, so that these can be taken out of the cells. 
         [0043]    When the strip  1  is empty, it can be used again. Two cases may then occur: in the first case, the strip is intended for receiving the same components as beforehand. In this case, it is sufficient to insert the new components, which have a shape identical to the previous ones, into the already formed prints. 
         [0044]    In the second case, the strip must be used for conveying a new series of components, the shapes of which are different from the shapes of the former components. In this case, polycaprolactone is heated again to 60° so that it liquefies, which makes it possible to erase the already formed prints. Then new prints can be modelled, as per an operating procedure which is similar to the one described hereabove, since polycaprolactone can easily be modelled again and again, in a reproducible way, without keeping tracks of the previous print models. 
         [0045]    Polycaprolactone may be added into the cells to make up possible losses of material during the various steps of the method. Besides, if polycaprolactone has already been modelled again and again several times, the cells may be emptied and cleaned, before being filled again with new polycaprolactone. 
         [0046]    Of course, many alternative solutions are possible: thus, in the case where the components cannot be heated to 60°, punches reproducing the shapes of the components can be used for making the prints in the filler material. In addition, the filler material used depends on the conditions of use of the supply device: for example, if the components supply a mounting robot at a high temperature, a filler material can be used which is plastically deformable at a temperature above such temperature. Besides, the same cell may contain several components as shown in  FIG. 2  in cell  12 , so long as their respective dimensions allow it. In this case, the filler material of such cell contains as many prints as there are components to be stored, with each print corresponding to the shape of one of the components to be stored.