Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B1/00—Cleaning by methods involving the use of tools
• • A—HUMAN NECESSITIES
  • A46—BRUSHWARE
  • A46B—BRUSHES
  • A46B17/00—Accessories for brushes
  • A46B17/02—Devices for holding brushes in use
• • A—HUMAN NECESSITIES
  • A46—BRUSHWARE
  • A46B—BRUSHES
  • A46B5/00—Brush bodies; Handles integral with brushware
  • A46B5/0004—Additional brush head
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B1/00—Cleaning by methods involving the use of tools
  • B08B1/20—Cleaning of moving articles, e.g. of moving webs or of objects on a conveyor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B1/00—Cleaning by methods involving the use of tools
  • B08B1/30—Cleaning by methods involving the use of tools by movement of cleaning members over a surface
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B1/00—Cleaning by methods involving the use of tools
  • B08B1/50—Cleaning by methods involving the use of tools involving cleaning of the cleaning members
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B1/00—Cleaning by methods involving the use of tools
  • B08B1/50—Cleaning by methods involving the use of tools involving cleaning of the cleaning members
  • B08B1/52—Cleaning by methods involving the use of tools involving cleaning of the cleaning members using fluids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B1/00—Cleaning by methods involving the use of tools
  • B08B1/50—Cleaning by methods involving the use of tools involving cleaning of the cleaning members
  • B08B1/54—Cleaning by methods involving the use of tools involving cleaning of the cleaning members using mechanical tools
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/70—Maintenance
  • B29C33/72—Cleaning
• • A—HUMAN NECESSITIES
  • A46—BRUSHWARE
  • A46B—BRUSHES
  • A46B2200/00—Brushes characterized by their functions, uses or applications
  • A46B2200/30—Brushes for cleaning or polishing

Definitions

• the invention relates to an assembly for cleaning an encapsulating device for electronic components provided with a displaceable brush with brush elements and to an encapsulating device provided with such a cleaning assembly.
• the invention also relates to a method for cleaning with a brush a contact side of a mould part of an encapsulating device for electronic components.
• the encapsulating material normally consists here of a thermocuring epoxy or resin incorporating a filler. During encapsulation
• mould parts can be clamped between mould parts such that, following clamping, mould cavities are defined around the components for encapsulating.
• Liquid encapsulating material is then introduced into these mould cavities, after at least partial curing of which the mould parts are moved apart and the carrier with encapsulated electronic components removed.
• the mould parts are cleaned of residual encapsulating material particles, since these may disrupt the controlled encapsulation of the electronic components. According to the prior art the mould parts are cleaned for this purpose with a brush in the opened and unloaded state.
• the present invention has for its object to provide means and a method for improved cleaning of an encapsulating device for electronic components.
• the invention provides for this purpose an assembly for cleaning an encapsulating device for electronic components, comprising: a brush provided with a number of brush elements, a drive for displacing the brush relative to the encapsulating device for electronic components, a protruding contact element coupled to the encapsulating device, and a suction device provided with at least one suction opening placed close to the protruding contact element, wherein the drive is adapted to move the brush along the protruding contact element such that the protruding brush elements are displaced relative to each other by the protruding contact element.
• the brush elements are formed here by bristles. The use of a brush element to clean residue from mould parts is per se known.
• Loose (dust) particles can be removed with a brush element and it is also possible to remove adhered residual material from the mould parts. Because the present invention now provides a contact element along which the brush can be moved, whereby the protruding brush elements move relative to each other, particles nestling between the brush elements (bristles) will be released more easily. During their relative movement the brush elements will be spread locally, whereby the space between the brush elements increases locally. This release of (dust) particles from the brush will particularly take place close to the contact element. It is precisely at this location that a suction opening is now provided through which the released (dust) particles will be suctioned away. The (dust) particles are
• the suction device displaced/discharged to a known location by the suction device. It is thus possible to remove from the brush (dust) particles which will consist particularly of residue of the (cured) encapsulating material but which possibly also comprise material from other sources (such as for instance the carrier). Cleaning of the brush will result in an increased brushing efficiency in a subsequent cleaning operation; the cleaner brush results in an improved cleaning action of the brush, and consequently to cleaner contact sides of the mould parts, and in an increased level of quality of the encapsulated electronic components.
• the bristles from plastic. It is moreover desirable here to manufacture the bristles from a material which is heat-resistant up to a minimum of 200 ° C, preferably up to 250 ° C or up to 300 ° C.
• An example of a suitable material is the plastic PEEK.
• the protruding contact element takes an elongate form and/or suction openings are arranged on opposite sides of the protruding contact element.
• Such an embodiment makes it possible to displace the brush along the contact element in simple manner (for instance with a linear movement).
• the advantage of arranging suction openings on opposite sides of the protruding contact element is that (dust) particles released on both sides are hereby suctioned away, so preventing the danger of contamination from the brush spreading in an undesired direction.
• the protruding contact element can also take a multiple form such that it comprises a plurality of adjacent edges.
• Yet another option is to provide the protruding contact element with a profiled profile edge, such as for instance a profile edge taking a corrugated form.
• the protruding contact element can also be manufactured from plate material provided with openings (for instance perforated plate material) in order to thus enable an improved suctioning of released material.
• the brush has an elongate form so that it can thereby clean a relatively large surface area of a contact side of a mould part with only a limited number of movements.
• Such an elongate brush is moreover advantageously movable in longitudinal direction relative to the protruding contact element, which can thereby have a limited size and wherein the suction opening(s) can also have a limited length.
• the brush is desirably displaced mechanically or automatically, and the drive can be formed here by an electric motor.
• the brush it is also possible for the brush to be displaceable in transverse direction relative to the protruding contact element.
• the brush is provided with at least one supply opening for gas.
• Blowing a gas out of the brush during displacement of the brush along the contact element can realize a further improved cleaning of the brush and further makes possible an improved control of the gas flow with which the released (dust) particles are discharged. This results in a further improvement in the cleaning result.
• Yet another option consists of arranging one or more air knives in a manner such that (dust) particles released from the brush cannot disperse freely but are guided to the suction opening. It is particularly advantageous here for the air knives to partially or wholly bound a space which connects to the suction opening and in which the brush can be moved along the contact element. The released particles are thus wholly (or
• the assembly can also be provided with ionizing means.
• the ionizing means will usually add an equal number of negative and positive charges to the brush, whereby insulators such as PVC, teflon and the like will discharge rapidly.
• the undesired and uncontrolled electrostatic charging of the brush can be prevented or at least reduced by means of ionization.
• the present invention also provides an encapsulating device provided with a cleaning assembly as described above, wherein the encapsulating device is provided with: at least two mould parts displaceable relative to each other and adapted to engage electronic components for encapsulating, and feed means for encapsulating material which connect to mould cavities defined by the mould parts and enclosing the electronic components for encapsulating.
• the cleaning assembly according to the present invention is integrated into such an encapsulating device. In order to limit the movement of the brush necessary for cleaning thereof it is possible to arrange the protruding contact element in the encapsulating device such that the contact element protrudes outside a contact surface of one of the mould parts.
• the encapsulating device can also be provided with a plurality of protruding contact elements in order to thus shorten or otherwise simplify the path a brush needs to travel to a contact element. It is also possible here to opt for a plurality of elongate, protruding contact elements with differing orientation.
• the present invention also provides a method for cleaning an encapsulating device for electronic components, comprising the processing steps of: A) cleaning a contact side of a mould part of the encapsulating device by relative displacement of a brush, B) bringing the brush into contact with a protruding contact element and moving the brush relative to the protruding contact element such that the brush elements of the brush are touched by the contact element and the brush elements displace relative to each other, and C) suctioning off ambient air, at least while performing processing step B), such that air is discharged at the position of the mutually displacing brush elements.
• A) cleaning a contact side of a mould part of the encapsulating device by relative displacement of a brush B) bringing the brush into contact with a protruding contact element and moving the brush relative to the protruding contact element such that the brush elements of the brush are touched by the contact element and the brush elements displace relative to each other
• processing steps B) and C) it is desirable for processing steps B) and C) to be performed while the brush is approaching the contact side to be cleaned of a mould part of the encapsulating device and/or while the brush is being removed from the cleaned contact side of a mould part of the encapsulating device. It thus becomes possible to integrate the cleaning step of the brush into the production cycle of encapsulation of electronic components such that the overall cycle time of an encapsulating operation is not influenced (or hardly so) by the additional cleaning process. This can be realized by having the cleaning of the brush take place outside the critical path or at least ensuring that cleaning of the brush does not extend the critical path defining the length of a production cycle.
• figure 1 is a perspective view of a part of an encapsulating device for electronic components according to the present invention
• figure 2 is a top view of an alternative embodiment variant of a part of an encapsulating device for electronic components according to the present invention
• figure 3 is a perspective view of a cleaning assembly according to the present invention during cleaning of the brush;
• figure 4 shows a cross-section through an alternative embodiment variant of a cleaning assembly according to the present invention during cleaning of the brush
• figure 5 is a perspective view of a protruding contact element with suction openings which takes a multiple form.
• Figure 1 shows a part of an encapsulating device 1 for electronic components provided with a cleaning assembly 2.
• the shown part of encapsulating device 1 is provided with a lower mould part 3 assembled from an exchangeable mould segment 4 and a permanent mould segment 5 holding the exchangeable mould segment 4.
• mould cavities 7, runners 8 and plunger housings 9 are recessed into the exchangeable mould segment 4. Liquid encapsulating material can be carried from plunger housings 9 through runners 8 (together also referred to as the feed means for encapsulating material) to mould cavity 7.
• protruding contact elements 10 protrude above contact surface 11.
• the protruding contact elements 10 are surrounded by suction openings 12 through which released dirt can be suctioned away.
• a double brush unit 13 which likewise forms part of encapsulating device 1.
• Brush unit 13 is provided with two brushes 14 with bristles 15.
• a spindle 17 can be driven by means of an electric motor 16, whereby (in an opened position of encapsulating device 1) brushes 14 of brush unit 13 can brush clean the mould cavities 7, runners 8 and/or plunger housings 9.
• brushes 14 pass over the protruding contact elements 10 at least once, whereby bristles 15 are moved apart locally with the result that at least some of the particles nestling between bristles 15 will be released and subsequently suctioned away through suction openings 12.
• brushes 14 can for instance be cleaned just after they are retracted after cleaning of mould part 3, although it is also possible to opt for one or more other cleaning sequences.
• FIG. 2 is a top view of a lower mould part 20 which is assembled, similarly to the lower mould part 3 shown in figure 1, from an exchangeable mould segment 21 and a permanent mould segment 22 holding the exchangeable mould segment 21. Columns 23 are again also visible.
• the mould cavities 7, runners 8 and plunger housings 9 recessed into the exchangeable mould segment 21 are designated with the same reference numerals as in figure 1.
• lower mould part 20 is now provided with two elongate, protruding contact elements 24, 25, both surrounded by suction openings 26, 27 with differing orientation. This creates more options for cleaning of the brush, whereby the cleaning result and the time required therefore can be better optimized.
• FIG 3 is a perspective view of a brush 30 provided with bristles 31, precisely in the situation where it is being carried in longitudinal direction as according to arrow Pi along a protruding contact element 32.
• bristles 31 are moved apart at the position of contact with the protruding contact element 32.
• discharge openings 33 are located on either side of the protruding contact element 32.
• a channel system 34 shown here in broken lines, with an opening 35 on the upper side into which a gas can be blown as according to arrow P2. The gas thus blown in will flow out between bristles 31 so as to thus further support the cleaning of brush 30.
• FIG. 4 The cross-section shown in figure 4 through a part of a cleaning assembly shows a protruding contact element 41 with suction openings 42 on either side through which gas is suctioned away as according to arrows P3. Further situated on either side of the protruding contact element 41 (at a greater distance than suction openings 42) are two blow nozzles 43 with which air knives can be generated as according to arrows P4.
• Figure 5 shows a protruding contact element 50 which takes a multiple form and is defined by three plate parts 52, 53, 54 in parallel arrangement and protruding relative to a surface 51.
• Surface 51 preferably lies in line here with the contact surface of a mould part for cleaning or is situated at an at least more or less similar height as the contact side of this mould part for cleaning.
• suction slits 55, 56 Provided between plate parts 52, 53, 54 are two suction slits 55, 56 through which (dust) particles can be suctioned away.
• Assembly for cleaning an encapsulating device for electronic components comprising:

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Cleaning In General (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=46639653

Family Applications (1)

Country Status (7)

Cited By (6)

Families Citing this family (7)

Citations (6)

Family Cites Families (9)

• 2011
  • 2011-07-14 NL NL2007110A patent/NL2007110C2/nl active
• 2012
  • 2012-07-12 SG SG2014002612A patent/SG2014002612A/en unknown
  • 2012-07-12 KR KR1020147003102A patent/KR102032866B1/ko active IP Right Grant
  • 2012-07-12 WO PCT/NL2012/050500 patent/WO2013009180A1/en active Application Filing
  • 2012-07-12 MY MYPI2014000091A patent/MY166565A/en unknown
  • 2012-07-12 CN CN201280043523.3A patent/CN103874549B/zh active Active
  • 2012-07-13 TW TW101125255A patent/TWI565534B/zh active

Patent Citations (6)

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