Abstract:
Packages of varying dimensions are loaded into a plurality of electrical package tubes. A guide arrangement is provided, which is programmable to receive the electrical packages by automatically configuring to accommodate the varying dimensions of the electrical packages, the configuring being performed without manual intervention, and a receiving arrangement is provided to receive the electrical package tubes and configured to individually align the electrical package tubes with the guide arrangement to receive the electrical packages. Upon application of a feeding force to the electrical packages, the guide arrangement guides the electrical packages into the electrical package tubes.

Description:
FIELD OF THE INVENTION 
     This invention relates to an off-loading apparatus for placing electronic packages such as semiconductor devices into receptacles, commonly anti-static plastic tubes. Such receptacles are usually adapted to facilitate access by a pick and place handler. In particular, such off-loading apparatus is adaptable to accommodate packages and receptacles of different sizes. 
     BACKGROUND AND PRIOR ART 
     In the course of manufacturing electronic packages, singulation machines or test handlers are commonly equipped with an off-loading apparatus to load electronic packages into receptacles, such as tubes, for transporting electronic packages to the next process station or to the customer. The sizes of the packages may vary from time to time depending on the needs of the customer. Such prior apparatus generally requires significant tooling changes to the off-loading apparatus for the accommodation of these packages and of tubes of different sizes. Therefore, time is wasted for the conversion and as a result the overall up-time and productivity of the system is reduced. 
     Further, in prior apparatus, the conversion of tube off-loaders to accommodate electronic packages of various sizes is achieved by the use of replacement tool-sets. If the off-loader is required to handle a large variety of packages of different sizes, the user will need to keep a corresponding range of tool sets. If the conversion is done very often, the down-time can be significant. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to mitigate disadvantages of the prior art, in particular, the need to keep a whole range of replacement tool-sets to accommodate packages and receptacles of different sizes. 
     According to the invention, there is provided an apparatus for loading items of varying size such as electronic packages into a receptacle therefore, comprising means automatically to adjust dimension parameters of the apparatus whereby to accommodate at least packages of different size and load same into a receptacle therefor. 
     The present invention thus seeks to provide an improved mechanism for an off-loading apparatus. It enables automatic adjustment of the apparatus to programmable widths when the accommodation of packages of different sizes is required. If the conversion avoids the need to replace and align tooling, a shorter conversion time can be achieved. 
     It will be convenient to hereinafter describe the invention in greater detail by reference to the accompanying drawings which illustrate one embodiment of the invention. The particularity of the drawings and the related description is not to be understood as superseding the generality of the broad identification of the invention as defined by the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a tube off-loading apparatus for electronic packages according to an embodiment of the present invention. 
     FIG.  2 ( i ) and FIG.  2 ( ii ) are the top and side views respectively of a width adjustment mechanism usable with the tube off-loading apparatus of FIG.  1 . 
     FIG. 3 is the side view of the tube off-loading apparatus of FIG.  1 . 
     FIG. 4 is the top view of the tube off-loading apparatus of FIG.  1 . 
     FIG. 5 is a section view of a tube pressed by a tube presser inside L-shape guiding blocks of the width adjustment mechanism. 
     FIG.  6 ( i ) and FIG.  6 ( ii ) are front elevation views of the tube off-loading apparatus of the present invention, when it is (i) configured for loading packages, and (ii) configured for unloading tubes. 
     FIG.  6 ( iii ) is a detailed view of the tube-off loading apparatus of FIG.  6 ( i ). 
     FIG.  6 ( iv ) is a detailed view of a portion of the tube off-loading apparatus of FIG.  6 ( ii ). 
     FIGS.  7 ( i ), ( ii ), ( iii ), and ( iv ) are side views of the tube off-loading apparatus showing an operational sequence of tube renewal. 
     FIG. 8 is a flow diagram of the various operational sequences of the described embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 is a perspective view of a tube off-loading apparatus for electronic packages according to an embodiment of the present invention. 
     The tube off-loading apparatus  100  is mounted on a base plate  31  at an inclined angle such that electronic packages  24  being fed into the tube  38  can slide to the lower end of the tube  38  by gravity as shown in FIG.  3 . Tubes  20 ,  38 ,  39  are inserted into the off-loading apparatus  100  via the top of the apparatus and they are accommodated within an area defined by a fixed tube end stopper  30 , guiding brackets  4  and movable tube end stopper  43 . 
     Mounted on the base plate  31  are a pair of lower movable platforms  1  that are driven to close or open by a movable block  16  of the width adjustment mechanism, as explained below with reference to FIG.  2 ( i ). The movement of the lower movable platforms I is guided by a pair of the linear guides  2  to ensure linear motion. 
     Referring to FIG. 2, four cam followers  17  of which two cam followers are adjacent to each linear guide  15  are mounted on the movable block  16 . Cam follower guides  18 ,  19  for the cam followers  17  are correspondingly fixed on the left and right of the lower movable platform  1 , respectively. When the guiding block  16  moves up and down, the four cam followers  17  move along the sloped channels of their guides which are fixed on the lower movable platforms  1  and it then drives these movable platforms  1  in a direction substantially perpendicular to the motion of the movable block  16 . The inclined ramp or slope  40  on these cam follower guides  18 ,  19  will translate the vertical up-and-down reciprocal motion of the movable block  16  to the transverse opening and closing motions of the lower movable platforms  1 . With this mechanism, the pair of lower movable platforms  1  can open and close with their center-lines remaining unchanged. A pair of upper movable platforms  3  are built on top of the lower movable platforms  1 . These lower and upper movable platforms  1 ,  3  move symmetrically about a center-line for the placement of the packages  24  and tubes  20 ,  38 ,  39 . The guiding blocks  11  for the loading tubes  38 , the guiding plates  12  for the packages  24  and the guiding brackets  4  for the standby tubes  20  are all mounted on these upper movable platforms  3 . 
     The movable block  16  controlling the movement of the lower movable platforms  1  moves on another pair of linear guides  15  of the width adjustment assembly  101 . The movable block  16  in turn is driven by a rotary-to-linear mechanism. This rotary-to-linear mechanism consists of a motor with encoder  41 , a coupler  45 , a lead screw  22  and a mounting bracket  23  for the lead screw. The movable block  16  is mounted to the lead screw bracket  23 . The rotary motion of the motor  41  will then translate to linear motion of the lead screw bracket  23  and this drives the movable block  16  moving up and down as appropriate. 
     The side view and top view of the tube off-loading apparatus are shown in FIG.  3  and FIG. 4 respectively. A pair of guiding plates  12  and a pair of L-shape guiding blocks  10  are mounted on each side of the upper movable platforms  3  of programmable width. The width of the guiding plates  12  and the guiding block  10  are determined by the sizes of the package  24  and the tubes  20 ,  38 ,  39 , respectively. For the same type of tubes  20 ,  38 ,  39  of different sizes, the clearance for inserting the packages  24  into the tubes  20 ,  38 ,  39  are basically the same. Hence, there is a fixed relation between the width of the guiding plates  12  and the width of the guiding blocks  10  even for guiding the packages  24  and the tubes  20 ,  38 ,  39 , of various sizes. Therefore, by adjusting their widths together, it is possible to use the same pairs of guiding plates  12  and guiding blocks  10  for accommodating packages and tubes of various sizes. During tube loading, the tube is forced into these guiding blocks  10  by a tube end pusher  9  and a tube presser  11  above the tube  38  will move down to press it against the guiding blocks  10 . A stationary platform  13  plus the two guiding plates  12  of appropriate width form a track to guide the packages  24  being pushed into the tube  38  by an ejector  14 . This invention thus allows programmable widths for tubes  20 ,  38 ,  39  and packages  24  of different sizes to be used for off-loading the electronic packages  24 . 
     A standby tube guiding assembly consists of (i) a pair of stoppers (the fixed tube end stopper  30  and the movable tube end stopper  43 ) and (ii) two pairs of guiding brackets  4 . Among the two stoppers, the fixed tube end stopper  30  is fixed and located near the opening of the standby tube  20  where the packages  24  are being fed. The movable tube end stopper  43  is movable and located at the opposite end of the loading tube  38 . The location of the movable tube end stoppers  43  can be adjusted according to the length of the tube  38 . The two pairs of guiding brackets  4  are mounted on the upper movable platforms  3  of programmable width. One pair is mounted near each end of the upper movable platforms  3 . Each pair of the guiding brackets  4  is mounted on each side of the said upper movable platforms  3 . This width of this assembly can be programmable to provide guiding for the column of standby tubes  20 . 
     Thus, the guiding brackets  4 , the fixed tube stopper  30  and the movable tube end stopper  43  maintain a column of standby or subsequent tubes  20  in position. Again, the location of the movable tube end stopper  43  is adjusted according to the length of the standby tubes  20 . The separation of the standby tubes  20  and a tube  38  being loaded (which is the bottom tube in a column of tubes  20 ,  38 ,  39 ) is carried out by activating the tube separation assembly  28 . The tube separation assembly  28  consists of three fingers. Two lower level fingers  6  that extend into the stack of tubes  20 ,  39  at a level adjacent to the top of the loading tube  38 , are located at each end and are positioned at the location wherein these fingers  6  can clamp the loading tube  38  at the bottom of the column down onto a movable support platform  5 . However, an upper level finger  7  is located at the middle of the tube separation assembly  28  and is positioned at a level being equal to the thickness of one tube above the two lower level fingers  6 . When the tube separation assembly  28  moves outwards, the whole column of tubes will fall by force of gravity onto the support platform  5 . The loading tube  38  will be separated and left at the bottom, supported by the support platform  5  when the tube separation assembly  28  moves in and these fingers  6  and  7  insert into the standby tube  20 . The tube  39  above the last loading tube  38  will then be held by these fingers  6  and  7  and the rest of the standby tubes  20  are also supported by them. 
     By programming the number of revolutions of the motor  41 , one can change the width of the guiding bracket  4  for accommodating standby tubes governed by the separation between the pair of the upper movable platforms  3 . The guiding blocks  11  for fixing the loading tube  38 , the guiding plates  12  for guiding the incoming package  24  and the guiding brackets  4  for accommodation of the standby tubes  20  are all mounted on these upper movable platforms  3 . Hence, the width of the tube off-loader assembly on top of these upper movable platforms  3  is programmable. The width of these assemblies can be adjusted by programmable means through, for example, microprocessor control or even manual adjustment. 
     The system will return to its initial state by resetting the system or by forced initialization. The widths of the guiding blocks  10 , guiding plates  12  and guiding brackets  4  will not be changed during initialization unless it is commanded by the user. At its initial state, the tube separation assembly  28  will be at a forward position or ‘in’ position and is ready to hold the standby tubes  20 . The tube end pusher  9  which is driven by an air cylinder  29  retracts and stays at a rearward position. The tube presser  11  will be moved up to release any tube inside the L-shaped tube guiding blocks  10 . The ejector  14  will move to its extended tube eject position to clear up any remain package  24  in the guiding plates  12  or the loading tube  38  in L-shaped guiding blocks  10 . It is then retracted to its initial or home position. 
     All the guiding assemblies (such as the guiding plates  12 , the guiding blocks  10 , and the guiding brackets  4 ) should be preset to the appropriate width for loading the right size of packages  24  and tubes  20 ,  38 ,  39 . The guiding plates  12  at appropriate width together with a stationary platform  13  form a guiding track for loading the incoming packages  24 . The user will put the standby tubes  20  into the tube guiding brackets  4  up to the level above height sensor  33  that is used for warning about the level of the loaded standby tubes  20 . The user loads the tubes  20  in such a way that the open end faces the fixed tube end stopper  30  and the tube end with end plug  25  faces the movable tube end stopper  43 . If the orientation of the loading tube  38  is wrong, the orientation sensor  34  will detect the absence of end plug  25  and give an error signal to the controller. The normal operation will start with the loading of a new standby tube for feeding the incoming package  24 . 
     A sectional view of loading tube  38  pressed by the tube presser  11  inside the L-shape guiding blocks  10  is shown in FIG.  5 . The system is now ready to load the incoming packages  24  into the tube  38 . 
     FIG. 6 shows the front view of the present invention with (i) the configuration for loading the package and (ii) the configuration for unloading the tube. 
     With reference to FIG.  6 ( i ), two pairs of guiding brackets  4  of appropriate width provide a guide for the column of standby tubes  20 . The tubes  20  are stacked one above the other and are supported by the fingers  6 ,  7  of the tube separation assembly  28  except the last tube  38  at bottom, which is supported on a movable support platform  5 . The bottom tube  38  is the one for loading the incoming packages  24 . The tube separation assembly  28  is used to separate the tube  38  at the bottom and the ones above it. The separated tube  38  is pushed forward by the tube end pusher  9  into the tube and package guiding blocks  10  and then is pressed by the presser  11  tightly in the tube holder mechanism, where the tube  38  will receive the incoming packages  24 . The incoming packages  24  will be placed at the package placement location of the vacuum suction to help the landing of the package. An ejector  14  will push the package  24  on the stationary platform  13  along the guide into the loading tube. 
     The sequence of loading a new tube is explained in detail as follows: 
     (i) The tube separation assembly  28  will move out to rearward position and let the standby tubes  20  drop onto the support platform  5  by free fall. There is a slight delay to allow this action to complete. 
     (ii) Next, the tube separation assembly  28  moves back to a forward position. The fingers  6  and  7  of the tube separation assembly  28  will be inserted into the column of the tubes. The fingers  6  will separate and clamp the loading tube  38  at the bottom. The rest of tubes  20  on top of it will be supported by the finger  7  and the tube  39  is held inside the fingers  6  and  7 . 
     (iii) Next, the tube end pusher  9  will be actuated by a solenoid  29  to move forward and push the tube  38  into the tube guiding blocks  10 . If the tube  38  fails to insert into the guiding blocks  10 , the tube presence sensor  35  will be triggered and give an error signal. 
     (iv) The tube presser  11  will then move down to press the tube  38  against the guiding blocks  10 . The tube loading cycle is complete. 
     The exploded view of FIG.  6 ( iii ) shows the loading  38  on support platform  5  being clamped by the finger  6  of the separation assembly  28 . 
     Turning again to FIG. 3 to illustrate the loading of packages  24  into the loading tube  38 , the incoming package  24  is placed by a pick arm  27  onto the tube off-load landing position where a vacuum hole  32  can provide vacuum suction to assist in the landing of the package  24 . There is a vacuum pressure sensor (not shown) connecting to vacuum source  26 . If the package  24  is not placed on the landing position, the vacuum pressure sensor will trigger and give an error signal. The ejector  14  will then move forward to push the package  24  into the loading tube  38  along the track on the stationary platform  13 . The width of the said track is defined by the package guiding plates  12 . Before the ejector  14  retracts, it will move to a position such that the package  24  is received by the tube  38 . At the tip of the ejector  14  a small nozzle  45  blows air to the package  24  and prevents it from sticking to the ejector  14  during retraction. 
     The package  24  will then be pushed into the loading tube  38  and the ejector  14  will retract to its standby position and prepares for the loading of the next package. The number of packages  24  being fed to the loading tube  38  is programmable and a limit counter can be set to the tube off-load controller. For each package loading cycle, the value of a running counter will be increased by one. As this counter reaches the preset limit, the controller will initiate a sequence of motions to unload the loaded tube  38 . As the preset number of packages  24  being fed to the tube is reached, the tube end pusher  9  will retract and the standby tube  20  will be pushed out from the guiding blocks  10  by the ejector  14  moving to an extended position. Meanwhile, the movable support platform  5  moves transversely to one side away from the loaded tube  38 . This action allows the loaded tube  38  to free fall onto the tube collector  21  below it. The rest of the other tubes above it are still held by the support of the tube separation assembly  28 . 
     During this unloading the movable support platform  5  move to a rearward or ‘out’ position to allow the loading tubes  38  to drop into the tube collector  21  underneath. If in case the tube is not able to drop into the tube collector  21 , two tube sensors  36 , one near each end of the loading tube  38  and mounted underneath and along the center-line of the tube  38 , will trigger and give a warning signal to the controller. If it is clear, the movable support platform  5  will then move back to forward position or ‘in’ position and is ready to support the next loading tube  38 . 
     The tube unloading sequence is explained in detail as follows with reference to FIG.  6 ( ii ): 
     (i) the tube end pusher  9  will retract to its initial or home position, 
     (ii) the tube presser  11  will move up to release the tube  38 , 
     (iii) the ejector  14  will move forward to its extended position such that the tube  38  will be pushed out from the tube guiding blocks  10 , 
     (iv) the movable tube support platform  5  will move out to the backward position on the left, 
     (v) The loading tube  38  will then free fall and drop into the tube collector  21 . 
     The column of standby tubes  20  and the tube  39  just on the top of unloaded tube  38  will be held and supported by the fingers  6  and  7  of the tube separation assembly as shown in FIG.  6 ( iv ). After the loaded tube  38  is unloaded, the moveable platform  5  will more back into forward position where it is ready to support a new empty tube being set in place for loading the incoming packages  24 . The fingers  6 ,  7  of these separators will support the whole column of tubes and separate the last bottom tube  38  and the rest of the standby tubes  20  above it. The tube  39  just above the bottom tube  38  will be inserted into the three fingers of separators. 
     The tube renewal sequences and the tube separation mechanism are shown in FIG.  7 . FIG.  7 ( i ) shows that both the movable support platform  5  and tube separation assembly  28  are at ‘in’ or forward position to hold all the tubes in position. The fingers  6  of the separation assembly will clamp onto the loading tube  38 . Finger  6  together with finger  7  will hold onto the tube  39  and prevent it from tilting. The tube  39  is just on top of the loading tube  38 . The rest of the standby tubes  20  are supported by the fingers  6  and  7  of the tube separation assembly. 
     FIG.  7 ( ii ) shows that the support platform  5  moves out to the left; the tube  38  is unloaded and the rest of the tubes on the above are held by the fingers  6  and  7  of the tube separation assembly. The unloaded tube will drop into the tube collector  21  underneath. 
     FIG.  7 ( iii ) shows that the movable support platform  5  moves in and returns to its forward position. It is ready for supporting a new loading tube. 
     FIG.  7 ( iv ) shows that the tube separation assembly  28  moves out to its backward position. This allows the column of tubes  20  to free fall and drop on to the support platform  5  under the guiding of the guiding brackets  4 . The tube  39  will fall to the bottom and it becomes the bottom tube  38  for loading the incoming package  24 . 
     The cycle will be repeated as the tube separation assembly  28  moves back to its forward position and the fingers  6  and  7  will insert into the standby tubes  20  again as in FIG.  7 ( i ). The newly loaded tube will be pushed into the tube guiding blocks  10  for receiving the incoming packages  24  as mentioned before. During normal operation, the standby tubes  20  will be used up one by one and the filled tubes can be consolidated in the tube collector  21 . If the level of the standby tubes is lower than the sensor  33 , a warning signal will be given to ask the user to refill the tubes. 
     FIG. 8 is a flow diagram of the various operational sequences of the described embodiment of the present invention. 
     The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description.