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
• • 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
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/1703—Introducing an auxiliary fluid into the mould
• • 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
  • H01L21/565—Moulds
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
  • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
  • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
  • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
  • H01L2224/321—Disposition
  • H01L2224/32151—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
  • H01L2224/32221—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
  • H01L2224/32225—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
  • H01L2224/42—Wire connectors; Manufacturing methods related thereto
  • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
  • H01L2224/481—Disposition
  • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
  • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
  • H01L2224/48225—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
  • H01L2224/4824—Connecting between the body and an opposite side of the item with respect to the body
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/73—Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
  • H01L2224/732—Location after the connecting process
  • H01L2224/73201—Location after the connecting process on the same surface
  • H01L2224/73215—Layer and wire connectors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
  • H01L2924/181—Encapsulation

Definitions

• the invention relates to a method for encapsulating electronic components, in particular semiconductors, by receiving a component for encapsulating fixed on a carrier between two mould halves displaceable relative to each other and feeding a liquid encapsulating material under ove ⁇ ressure by means of a transfer mechanism to at least one mould cavity arranged for this purpose.
• the invention also relates to a device for encapsulating electronic components, in particular semiconductors, comprising: two mould halves displaceable relative to each other for receiving a component for encapsulating, which mould halves are provided with at least one mould cavity, and a transfer mechanism for feeding a liquid encapsulating material under overpressure to the mould cavity.
• the encapsulating of electronic components usually takes place by means of a so-called transfer press.
• Use is made herein of mould cavities defined by at least two mould parts displaceable relative to each other. In the opened position one or more carriers with components for encapsulating can be placed between the mould parts. After placing the carrier and closing the mould parts the encapsulating process can begin.
• Encapsulating material is herein pressed through runners to mould cavities by means of plungers. The liquid encapsulating material flows into a mould cavity and herein displaces the gas present which escapes by means of ventings arranged for the purpose.
• the present invention has for its object to improve the quality of encapsulation of electronic component while retaining the advantages of the prior art.
• the invention provides for this purpose a method of the type stated in the preamble, characterized in that during feeding of liquid encapsulating material to the mould cavity the part of the mould cavity not yet filled with encapsulating material is filled with a fluid under overpressure.
• the fluid pressure is realized by a gas, but it is also possible to employ a liquid for this purpose.
• the fluid pressure can be applied such that it exerts only unilateral pressure on a carrier to which the electronic component for encapsulating is fixed. A pressure difference will thus be created over the carrier whereby the carrier is urged against a part of the cavity. This contributes toward an improved positioning of the electronic component in the cavity.
• An improved positioning will result in an improved encapsulating result, owing to inter alia a smaller chance of damage to wires (wire jump), less chance of leakage of encapsulating material along the edges of the mould cavity (bleed and flash), an improved ability to control the size of the encapsulated component, and so on.
• the ove ⁇ ressure will be lower than the pressure on the encapsulating material and higher than the ambient pressure.
• a foil layer is placed between the mould cavity and the component for encapsulating.
• the chance of encapsulating material (or a fraction of the encapsulating material, also known as “flash” or “bleed”) passing between the mould halves can thus be reduced further.
• the fluid under ove ⁇ ressure can be situated between the cavity and the foil layer so that the fluid does not come into contact with the encapsulating material. In addition to preventing interaction between the fluid and the encapsulating material, this also has the advantage that the flow of the encapsulating material can be influenced by the foil which is present.
• An example hereof is the encapsulation of so-called flip-chips, wherein the encapsulating material must be carried between two stacked parts (the carrier and the chip placed thereon with contact points). Due to the presence of the foil material the flow of the encapsulating material can be guided specifically between the carrier and the chip.
• the fluid pressure (gas pressure) in the mould cavity is preferably maintained until the cavity is completely filled with encapsulating material.
• the fluid pressure (gas pressure) amounts to at least 1.5X10 5 Pa, preferably at least 5X10 5 Pa.
• Other factors which influence the process are for instance the composition of the encapsulating material, the temperature of the encapsulating material, the thickness of the carrier, the carrier material, the size of the mould cavity and the component for encapsulating.
• the fluid pressure can be applied by means of compressed air. This is a simple and thus inexpensive manner of creating the desired pressure. Another possibility is for the fluid pressure to be applied by means of an inert gas, such as for instance nitrogen. This gas can for instance be drawn off via a valve from a gas buffer such as a gas bottle.
• an inert gas such as for instance nitrogen. This gas can for instance be drawn off via a valve from a gas buffer such as a gas bottle.
• an inert gas is that the gas will not have any adverse effect on the component for encapsulating.
• the fluid pressure can be applied by at least one venting opening for excess gas connecting onto the mould cavity.
• a venting is already present in most existing moulds, so that these require little or no modification to apply the method according to the invention.
• the invention also provides a device of the type stated in the preamble, with the feature that a fluid feed connects onto the mould cavity for receiving liquid encapsulating material.
• the existing transfer presses for encapsulating electronic components require only a limited modification to make them suitable for use of the present method. It is of course desirable here that the fluid feed connects onto the cavity on the side remote from a gate for encapsulating material. An ove ⁇ ressure can thus be maintained in the cavity throughout filling of the cavity.
• the fluid feed can herein be used simultaneously to allow excess fluid (gas) to escape as the degree of filling of the cavity with encapsulating material increases. It is also possible for the mould cavity to be provided for this pu ⁇ ose at a distance from the fluid feed with at least one venting opening for fluid. The fluid feed and the fluid venting can thus be controlled separately. The chance of contamination of the fluid feed in particular is hereby also reduced.
• the fluid feed In order to generate the gas pressure the fluid feed connects onto means for generating an ove ⁇ ressure, such as a pump or pressurized gas container.
• means for generating an ove ⁇ ressure such as a pump or pressurized gas container.
• the fluid feed When the fluid feed is also employed to allow fluid to escape from the cavity, it is recommended that the fluid feed also connects onto means for generating an unde ⁇ ressure.
• this latter will be provided with a receiving space for a carrier.
• Use of the method according to the invention is found to be particularly advantageous when recesses for the purpose of forming encapsulating parts are located on either side of the receiving space for the carrier.
• Such a carrier with an encapsulation to be formed on two sides is very difficult to position in a cavity, even when it is positioned on one side with an unde ⁇ ressure (over a part of the surface in respect of the creating of encapsulating parts on two sides).
• Such components in particular can advantageously be positioned more accurately by the unilaterally applied ove ⁇ ressure of a fluid.
• the mould cavity may be provided with a medium-tight sealing edge.
• the present invention also comprises a method for encapsulating electronic components, in particular semiconductors, by receiving a component for encapsulating fixed on a carrier between two mould halves displaceable relative to each other and feeding a liquid encapsulating material under overpressure by means of a transfer mechanism to at least one mould cavity arranged for this pu ⁇ ose, with the feature that during feeding of liquid encapsulating material to the mould cavity a fluid pressure is exerted on the carrier on the side of the carrier remote from the cavity.
• a fluid pressure is exerted on the carrier on the side of the carrier remote from the cavity.
• the carrier can hereby also be urged into a desired position.
• the fluid under ove ⁇ ressure is preferably a gas.
• the fluid pressure can very advantageously be adjusted in relation to the pressure on the liquid encapsulating material. When the pressure of the encapsulating material is limited, the pressure of the fluid is also kept limited, this to avoid deformation of the carrier. When the pressure of the encapsulating material increases, the pressure of the fluid preferably also increases at the same time. For this pu ⁇ ose the adjustment range of the fluid pressure is preferably at least as large as the maximum pressure on the encapsulating material (the process pressure).
• the invention also provides a device for encapsulating electronic components, in particular semiconductors, comprising: two mould halves displaceable relative to each other for receiving a component for encapsulating, which mould halves are provided with at least one mould cavity, and a transfer mechanism for feeding a liquid encapsulating material under ove ⁇ ressure to the mould cavity by means of a feed for encapsulating material, with the feature that at a distance from the feed for encapsulating material at least one fluid feed connects onto the displaceable mould halves for positioning the component for encapsulating by means of fluid pressure.
• the mould cavity is preferably arranged at least substantially in one of the mould halves, and the fluid feed connects onto the mould half connecting to the mould half in which the cavity is arranged.
• the fluid feed connects onto means for generating an ove ⁇ ressure, or the fluid feed connects onto means for generating an unde ⁇ ressure.
• the mould cavity can be provided with a receiving space for a carrier and recesses for the pu ⁇ ose of forming encapsulating parts located on either side of the receiving space for the carrier.
• figure 1 shows a cross-section through a part of a mould cavity with a carrier provided with a component for encapsulating according to the prior art
• figure 2 shows a cross-section through a part of a mould cavity with a carrier on which an encapsulating part is arranged on two sides as according to the present invention.
• Figure 1 shows a mould part 1 with a mould cavity 2.
• a carrier 3 is placed against cavity 2 such that an electronic component 4 supported by carrier 3 is situated in cavity 2.
• Carrier 3 can be positioned such that a contact wire 5 with which the electronic component 4 is connected conductively to carrier 3 comes into contact with mould part 1. Proper functioning of electronic component 4 can thus be disturbed after arranging of an encapsulation.
• Figure 2 shows two mould parts 6,7 between which is placed a carrier 8 with an electronic component 9.
• Carrier 8 is provided with a central recess through which contact wires 10 of component 9 are fed to the opposite side of carrier 8.
• Encapsulating parts 11,12 are produced on two sides of carrier 8. Liquid encapsulating material is supplied for this pu ⁇ ose through a runner 13 and a gate 14.
• the encapsulating part 11 located on the upper side in figure 2 is not yet fully formed; an upper cavity 15 is still partially gas-filled.
• the gas-filled part of upper cavity 15 is connected by means of a venting 16 to a gas feed 17.
• the gas feed for creating an ove ⁇ ressure in the gas-filled part of upper cavity 15 is indicated symbolically by means of an arrow PI.
• the ove ⁇ ressure in the gas-filled part of upper cavity 15 is indicated symbolically by arrows P2. It is noted that during feed of encapsulating material the gas feed 17 can also be used to discharge gas so that the arrow PI can be in a direction opposed to the flow direction of the gas in the gas feed at the moment of encapsulation shown in the figure.
• the ove ⁇ ressure in the gas-filled part of upper cavity 15 ensures inter alia that carrier 8 is urged against the lower mould part 7, thereby increasing the reliability of the encapsulating process.
• the lower mould part 7 is also provided with an unde ⁇ ressure system 16 with suction lines 17, whereby an unde ⁇ ressure is created as according to arrows P3.
• the carrier 8 with a central opening enables positioning of carrier 8 in the desired manner using only the unde ⁇ ressure system 16.
• carriers 8 of the type as shown in this figure it is advantageous to apply an ove ⁇ ressure as according to the present invention in the gas- filled part of upper cavity 15.

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

Applications Claiming Priority (3)

Publications (1)

Family

ID=19774372

Family Applications (1)

Country Status (6)

Family Cites Families (6)

• 2001
  • 2001-12-07 NL NL1019514A patent/NL1019514C2/nl not_active IP Right Cessation
• 2002
  • 2002-12-05 AU AU2002347678A patent/AU2002347678A1/en not_active Abandoned
  • 2002-12-05 US US10/497,721 patent/US20050062199A1/en not_active Abandoned
  • 2002-12-05 EP EP02783856A patent/EP1456878A2/en not_active Withdrawn
  • 2002-12-05 WO PCT/NL2002/000797 patent/WO2003049177A2/en not_active Application Discontinuation
  • 2002-12-05 KR KR10-2004-7008741A patent/KR20040064729A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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