Classifications

• • 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
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
  • B29C45/14639—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles for obtaining an insulating effect, e.g. for electrical components
  • B29C45/14655—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles for obtaining an insulating effect, e.g. for electrical components connected to or mounted on a carrier, e.g. lead frame
• • 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
  • B29C31/00—Handling, e.g. feeding of the material to be shaped, storage of plastics material before moulding; Automation, i.e. automated handling lines in plastics processing plants, e.g. using manipulators or robots
  • B29C31/04—Feeding of the material to be moulded, e.g. into a mould cavity
• • 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
• • 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
  • B29C33/0077—Moulds or cores; Details thereof or accessories therefor characterised by the configuration of the mould filling gate ; accessories for connecting the mould filling gate with the filling spout
• • 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
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/03—Injection moulding apparatus
  • B29C45/04—Injection moulding apparatus using movable moulds or mould halves
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
  • H01L21/56—Encapsulations, e.g. encapsulation layers, coatings
• • 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
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/03—Injection moulding apparatus
  • B29C45/04—Injection moulding apparatus using movable moulds or mould halves
  • B29C45/0408—Injection moulding apparatus using movable moulds or mould halves involving at least a linear movement
  • B29C45/0416—Injection moulding apparatus using movable moulds or mould halves involving at least a linear movement co-operating with fixed mould halves
• • 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
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/72—Heating or cooling
  • B29C45/74—Heating or cooling of the injection unit

Definitions

• the present invention relates to a method for feeding encapsulating material to a mould cavity for the purpose of encapsulating electronic components.
• the invention also relates to a device for feeding encapsulating material to a mould cavity for the purpose of encapsulating electronic components, and to a mould for encapsulating electronic components which can be applied in combination with such a feed device.
• thermocuring material which is also referred to as epoxy or resin, which normally includes silicon as filler material.
• a carrier with semiconductors is clamped and in which spaces are also incorporated for placing pellets of encapsulating material. Provisions are also arranged in such a mould for heating the encapsulating material and for exerting pressure on the encapsulating material. Through being heated and/or placed under pressure the encapsulating material is activated such that, once it has been displaced to mould cavities closing around the electronic components, it cures after a limited time.
• the mould is opened and the carrier with encapsulated components is then taken out, including the remaining cured encapsulating material (such as remnants of the pellets and the encapsulating material cured in feed channels).
• the existing method results in a controllable encapsulating process with a relatively long cycle time, since placing the encapsulating material and the products in the mould, closing the mould, activating and displacing the encapsulating material, at least partially curing the encapsulating material, opening the mould, removing the encapsulated products and cleaning the emptied mould all successively form part of the critical path of the method.
• the object of the present invention is to provide a method, and the associated means, for shortening the cycle time for encapsulation of electronic components. It is also an object to increase the efficiency of the encapsulation.
• the invention provides for this purpose a method for feeding encapsulating material to a mould cavity for the purpose of encapsulating electronic components, comprising the processing steps of: A) at least partially activating in a feed device the encapsulating material for feeding, B) coupling to the feed device a mould cavity with an electronic component for encapsulating, C) carrying the at least partially activated encapsulating material from the feed device into the mould cavity, and D) uncoupling the feed device and the mould cavity at least partially filled with encapsulating material. It thus becomes possible to at least partly separate, and perform (at least partially) as parallel operations, the feeding and activating of the encapsulating material from the placing in the mould cavity of the electronic components for encapsulating.
• the encapsulating material is preferably at least partially activated during processing step A) by means of heating, optionally in combination with, or as alternative to, exerting pressure on the encapsulating material.
• the advantage here is that use can be made of the existing (and therefore accepted and readily obtainable) encapsulating material.
• Alternative methods of activating encapsulating material can however also be envisaged, such as for instance activating encapsulating material ultrasonically or with ultraviolet.
• a further improvement of the method can be realized by discharging the gases released from the feed device separately of the encapsulating material.
• the fluid released by degassing the encapsulating material can thus be discharged before it enters the mould.
• the method according to the invention now provides the option of removing (a part of) the gases developing during the at least partial activation of the encapsulating material before they enter the mould. This option is lacking in encapsulation according to the prior art because there the encapsulating material is fully activated in the mould.
• an opening of the feed device takes place during coupling of the feed device to the mould cavity as according to processing step B). It is thus possible to prevent encapsulating material being released in undesirable manner from the feed device when this latter is not coupled to a mould cavity (mould). Another significant advantage is that ageing of encapsulating material in the feed device can thus be limited or, in extreme situations, can be stopped. It is desirable for this purpose that closing of the feed device takes place during uncoupling of the feed device and the mould cavity as according to processing step D).
• the invention also provides a device for feeding encapsulating material to a mould cavity for the purpose of encapsulating electronic components, comprising: a container for containing inactivated encapsulating material, activating means connecting onto the container for at least partly activating the encapsulating material, transport means for displacing the encapsulating material from the container along the activating means, and an outlet connecting to the activating means for the at least partly (or fully) activated encapsulating material.
• the activating means are formed by heating means, for instance a contact heating and/or another radiation source.
• the heat can also be transmitted as infrared radiation, the heat can be generated with a heating element which excites microwaves, or use can be made of a high-frequency heating source (HF heating).
• HF heating high-frequency heating source
• At least partial activation is here understood to mean initiation (or acceleration) of the process of curing the encapsulating material, and this at least partial activation can be, but does not necessarily have to be, initiated by supplying heat. Other methods of activation can also be envisaged, such as for instance supplying an additional (for instance catalyst) substance, applying pressure and so forth.
• the transport means can comprise at least one plunger for urging the encapsulating material out of the container and along the activating means to the outlet.
• the encapsulating material can be fully activated in the feed device, but it is also possible to envisage the feed device only partially activating the encapsulating material and the encapsulating material subsequently being fully activated in for instance the mould cavity.
• the outlet is provided with a coupling adapted for co- action with a mould defining the mould cavity around an electronic component.
• a coupling makes it possible to realize a coupling between the components in rapid and medium-tight manner.
• the outlet is desirably provided with a closing valve.
• This can for instance be embodied in the form of for instance a closing valve which can only be opened, or automatically opens, by coupling the outlet to a mould.
• the closing valve can for instance be embodied as a closing pin for displacing in and out of a nozzle in flow direction.
• the device can also be provided for this purpose with cleaning means with which at least partly activated encapsulating material can be removed from the feed device after it has been present in the encapsulating device for a minimal period in at least partly activated state. If the at least partly activated encapsulating material is not removed quickly enough from the feed device, it can begin to cure in the encapsulating device and thus impede functioning thereof. This can be prevented by means of the cleaning means.
• the invention also provides a mould for encapsulating electronic components, comprising at least two mould parts displaceable relative to each other and adapted to receive a carrier provided with at least one electronic component such that the electronic component is received in a mould cavity, wherein the mould is also provided with a mating coupling which connects to the mould cavity and which is adapted for co-action with a feed device for encapsulating material.
• a mould has a simple construction compared to existing moulds, is therefore relatively inexpensive and can be embodied such that it is simple to clean.
• closing means for closing the mating coupling means can prevent encapsulating material which has not yet cured from leaving the mould in undesirable manner and/or prevent contaminants entering the mould in undesirable manner.
• the invention furthermore provides an encapsulating device for encapsulating electronic components, comprising an assembly of a feed device as described above and at least one mould, likewise as described above, co-acting with the feed device.
• an encapsulating device is preferably provided with a plurality of moulds which are displaced relative to the feed device with a (for instance endless) transport system.
• the number of moulds can now be adapted to the single feed device (or optionally the plurality of feed devices) such that optimal use is made of the capacity of both the feed device(s) and the moulds. In addition, such a device becomes less susceptible to malfunction and maintenance.
• Such a device can also be provided with a discharge device for removing from a mould an electronic component enclosed with encapsulating material, with stationary closing means for closing the mould parts displaceable relative to the closing means, and/or with stationary opening means for opening the mould parts displaceable relative to the closing means.
• the encapsulating process can thus be automated to a greater or lesser extent.
• figure 1 shows a schematic view of an encapsulating device according to the invention with a feed device and two moulds co-acting with the feed device
• figure 2A shows a section through an alternative embodiment variant of a feed device according to the invention during feed of encapsulating material
• figure 2B shows a section through the feed device of figure 2A in a closed position
• figure 2C shows a section through the feed device of figures 2 A and 2B in a situation where the feed device is cleaned
• figure 3 shows a cross-section through a mould according to the invention and a connection forming part of a feed device
• figure 4A shows a cross-section through a connection of a feed device in a situation where it connects to a mould
• figure 4B shows a cross-section through the connection and the mould of figure 4A in an uncoupled situation.
• FIG. 1 shows a feed device 1 provided with a supply container 2 which holds encapsulating material.
• Supply container 2 connects onto a transport tube 4 in which a spindle 5 is rotatable as according to arrow PI.
• Spindle 5 connects for this purpose to an electric motor 6.
• the encapsulating material 3 will be displaced in a direction as according to arrow P2.
• Encapsulating material 3 is thus urged to a heating space 7 which connects onto transport tube 4 and on the sides of which schematically shown heating elements 8 are disposed.
• Heating elements 8 transfer heat to encapsulating material 3 situated in heating space 7, whereby it is activated and whereby it can only remain for a limited time in heating space 8.
• Activated encapsulating material 3 can be extracted from heating space 8 by opening a tap 9 connecting onto heating space 8.
• Figure 1 also shows moulds 10, 10' whereby a carrier 11 with a chip 12 is enclosed such that a mould cavity 13 is left clear around chip 12.
• the moulds are provided for this purpose with two mutually connecting mould parts 14, 14', 15, 15'.
• Moulds 10, 10' are also provided with a feed channel 16, 16' for activated encapsulating material 3.
• Encapsulating material can be fed to moulds 10, 10' by connecting a mating coupling 17, 17' forming part of moulds 10, 10' to the feed device 1.
• a first mould 10' is already filled with encapsulating material 3 and a second mould 10 is not yet filled with encapsulating material 3.
• Moulds 10, 10' are displaceable as according to an arrow P3 along a schematically represented guide 18.
• FIG. 2A shows an alternative embodiment variant of a feed device 20 with a supply container 21 for encapsulating material which can be urged through a transport tube 23 by means of a plunger 22.
• a part of transport tube 23 is formed by a gas-permeable material 24 such that gas present in encapsulating material 25 can escape as according to arrows P5.
• the encapsulating material 25 can be activated, for instance by means of a microwave heating (not shown).
• a second plunger 27 leaves clear a discharge channel 28 for activated encapsulating material 25 such that it can flow out of feed device 20.
• FIG 2B the feed device 20 is shown in a situation where discharge channel 28 for encapsulating material 25 is closed by the second plunger 27.
• the first plunger 22 is also moved to the rear relative to the position the plunger 22 occupies in figure 2A.
• Plunger 22 will have an intermittent pattern of movement during the forward movement of which the encapsulating material 25 is displaced through feed device 20.
• Encapsulating material 25 can herein pass through successive zones in which there are different process conditions.
• FIG. 2C shows feed device 20 in yet another situation, i.e. a situation in which discharge channel 28 is opened by displacing a housing 29 of the second plunger 27 relative to supply container 21 and transport tube 23, which housing 29 simultaneously forms a part of discharge channel 28.
• a cleaning device 30 for instance a brush and/or a scraper
• P6 the cleaning device
• FIG 3 shows a schematically represented mould 40 with an upper mould part 41 and a lower mould part 42, between which a carrier 43 is enclosed such that mould cavities 45 are defined on two sides of a feed opening 44 for encapsulating material.
• Feed opening 44 is embodied such that it forms a runner 46 onto which mould cavities 45 connect by means of gates 47 (openings, optionally elongate openings or film gates).
• This figure 3 also shows a feed 48 for encapsulating material 49. Placed in feed 48 is a central pin 50 with which an outflow opening 51 of feed 48 is closed.
• Figure 4 A shows the feed 48 with a part of mould 40, wherein outflow opening 51 of feed 48 connects to the runner 46 of feed opening 44 in mould 40.
• Runner 46 and feed 48 are here in open connection with each other in that the central pin 50 is displaced such that it leaves clear the outflow opening 51 in feed 48.
• Encapsulating material 49 thus flows out of feed 48 into runner 46 and subsequently into mould cavities 45.
• the outer end of feed 48 is provided with two extra heating elements 52 with which heat (for instance in the form of infrared radiation or other heating means) can be generated as shown according to arrows P7.
• curing can also be accelerated by an influence other than an increased temperature, such as for instance increased pressure and/or a specific lighting.
• Figure 4B finally shows the feed 48 after it has been uncoupled from mould 40.
• Outflow opening 51 of feed 48 is now closed again by the central pin 50.
• a part of t ie delivered encapsulating material 49 is cured in runner 46 and the other part of this encapsulating material 49 is cured in mould cavities 45.
• the encapsulating material 49 cured in runner 46 thus forms a closure of mould cavities 45 and can be influenced by influencing for instance the temperature, the lighting, the pressure and/or a high- frequency radiation at the position of runner 46 so as to thus locally activate (cure) encapsulating material 49 in accelerated manner.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Microelectronics & Electronic Packaging (AREA)
• General Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• Physics & Mathematics (AREA)
• Power Engineering (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Robotics (AREA)
• Encapsulation Of And Coatings For Semiconductor Or Solid State Devices (AREA)
• Injection Moulding Of Plastics Or The Like (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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• 2004
  • 2004-04-08 NL NL1025905A patent/NL1025905C2/nl not_active IP Right Cessation
• 2005
  • 2005-04-07 KR KR1020067022919A patent/KR101199096B1/ko active IP Right Grant
  • 2005-04-07 JP JP2007507258A patent/JP4819796B2/ja active Active
  • 2005-04-07 WO PCT/NL2005/000265 patent/WO2005098932A2/en active Application Filing
  • 2005-04-07 CN CN200580017080A patent/CN100576479C/zh active Active

Patent Citations (4)

Non-Patent Citations (1)

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