EP0000856B1 - Magnetische Wärmeleitungsanordnung für Halbleiterplättchen - Google Patents

Magnetische Wärmeleitungsanordnung für Halbleiterplättchen Download PDF

Info

Publication number
EP0000856B1
EP0000856B1 EP78430006A EP78430006A EP0000856B1 EP 0000856 B1 EP0000856 B1 EP 0000856B1 EP 78430006 A EP78430006 A EP 78430006A EP 78430006 A EP78430006 A EP 78430006A EP 0000856 B1 EP0000856 B1 EP 0000856B1
Authority
EP
European Patent Office
Prior art keywords
fluid
magnet
chip
heat sink
heat transfer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP78430006A
Other languages
English (en)
French (fr)
Other versions
EP0000856A1 (de
Inventor
Kenneth Selig Sachar
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of EP0000856A1 publication Critical patent/EP0000856A1/de
Application granted granted Critical
Publication of EP0000856B1 publication Critical patent/EP0000856B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L24/00—Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
    • H01L24/01—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
    • H01L24/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L24/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L24/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H01L23/3733—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon having a heterogeneous or anisotropic structure, e.g. powder or fibres in a matrix, wire mesh, porous structures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/42—Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/42—Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
    • H01L23/433—Auxiliary members in containers characterised by their shape, e.g. pistons
    • 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
    • H01L2224/10—Bump connectors; Manufacturing methods related thereto
    • H01L2224/15—Structure, shape, material or disposition of the bump connectors after the connecting process
    • H01L2224/16—Structure, shape, material or disposition of the bump connectors after the connecting process of an individual bump connector
    • H01L2224/161—Disposition
    • H01L2224/16151—Disposition the bump 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
    • H01L2224/16221—Disposition the bump 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
    • H01L2224/16225—Disposition the bump 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
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/2612—Auxiliary members for layer connectors, e.g. spacers
    • H01L2224/26152—Auxiliary members for layer connectors, e.g. spacers being formed on an item to be connected not being a semiconductor or solid-state body
    • H01L2224/26175—Flow barriers
    • 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
    • H01L2224/27—Manufacturing methods
    • H01L2224/27011—Involving a permanent auxiliary member, i.e. a member which is left at least partly in the finished device, e.g. coating, dummy feature
    • H01L2224/27013—Involving a permanent auxiliary member, i.e. a member which is left at least partly in the finished device, e.g. coating, dummy feature for holding or confining the layer connector, e.g. solder flow barrier
    • 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
    • H01L2224/3205—Shape
    • H01L2224/32057—Shape in side view
    • 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
    • H01L2224/73251—Location after the connecting process on different surfaces
    • H01L2224/73253—Bump and layer connectors
    • 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
    • H01L2224/73251—Location after the connecting process on different surfaces
    • H01L2224/73257—Bump and wire connectors
    • 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
    • H01L2224/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L2224/83—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a layer connector
    • H01L2224/83009—Pre-treatment of the layer connector or the bonding area
    • H01L2224/83051—Forming additional members, e.g. dam structures
    • 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
    • H01L2224/80—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected
    • H01L2224/83—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a layer connector
    • H01L2224/8338—Bonding interfaces outside the semiconductor or solid-state body
    • H01L2224/83385—Shape, e.g. interlocking features
    • 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
    • H01L2924/01—Chemical elements
    • H01L2924/01058—Cerium [Ce]
    • 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
    • H01L2924/01—Chemical elements
    • H01L2924/01079—Gold [Au]
    • 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
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/14—Integrated circuits

Definitions

  • the present invention relates to a magnetic heat transfer device for a semiconductor chip which can be used in the field of semiconductor integrated circuits.
  • the use of a magnet thermally bonded to a large cooling device allows the heat generated in the microchip to be removed thanks to the use of a magnetic fluid that the flux emanating from the magnet keeps in place and whose shape it defines, this fluid covering a large part of the rear face of the chip which does not have electrical contacts for input and output of electrical signals.
  • This fluid allows heat transfer by conduction and convection, and makes it possible to replace and repair the microchip.
  • This allows the different elements to move relative to each other which solves the problems posed by the different coefficients of thermal expansion.
  • the invention makes it possible to obtain maximum heat transfer because the quantity of magnetic fluid maintained by the magnet is greater than would be possible from simple viscosity.
  • a magnetic fluid is applied to the rear face of the chip.
  • the form adopted by this fluid and its thermal circulation are determined by the flux generated by a magnet thermally bonded to a large cooling device.
  • a substrate 1 which may be composed of one or more insulating layers containing conductors and contacts 2 connected to corresponding contacts on a chip 4 by means of connections 3.
  • the connections shown are made by soldering by reflow, a technique in which the surface tension of a quantity of solder whose surface is limited by the dimensions of the contacts raises the chip above the substrate while providing an electrical connection.
  • Another well known technique of connection with a microchip consists in ensuring the connection of the conductors by means of a mounting frame.
  • a magnetic fluid 5 is applied to the rear face of the microchip 4.
  • This fluid of which there are different known types, consists of a vehicle containing magnetic particles in suspension.
  • the viscosity of this fluid is such that it will not flow beyond the edges of the chip, and due to the presence of magnetic particles which are in suspension in the fluid, the shape of the latter can be modified by a magnetic flux.
  • a commercially available fluid is marketed by the firm Ferro Fluidics Corporation. The fluid must remain stable at the operating temperature of the chip.
  • Figure 2 is a section of Figure 1 and shows the details of the magnet 6 and the magnetic fluid 5.
  • the chip 4 is again shown, as well as the connections 3, made by reflow soldering , with the substrate 1.
  • the magnetic fluid 5 is shown on the rear face of the chip 4.
  • the magnet 6 has a shape such that the flux lines, as shown in the figure, go from a peripheral region 9 to a central region 10, so that, as a result of the flow, the fluid 5 assumes a shape which makes it possible to have a greater quantity of fluid than that which the viscosity would normally allow, thus increasing the heat transfer by convection and by conduction from the rear face of the chip to the magnet 6, which is thermally linked to the cooling device 7, which in turn transfers the heat via the fins 8, to the medium in which the assembly is located.
  • the configuration of the peripheral region 9 and of the central part 10 of the magnet 6 makes it possible to perform two functions, on the one hand, to give the magnetic fluid 5 a shape such that it allows, if necessary, to have a quantity of fluid greater than that which viscosity would normally allow, and, on the other hand, to keep the fluid in place during vibrations and thermal expansion.
  • the shape of the fluid is such that it allows the increase of heat transfer by conduction and by convection.
  • the non-uniform magnetic field generally attracts the fluid towards the region in which the magnetic field is most intense, this region being in principle the central part of the chip.
  • the description given above relates to the use of a magnet and a magnetic fluid to facilitate the conduction and convection of heat between the rear face of a microchip and a cooling device while at the same time maintaining contact. not rigid but thermally efficient.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
  • Cooling Or The Like Of Electrical Apparatus (AREA)

Claims (5)

1. Wärmesenke zum Übertragen von Wärme zwischen einem Halbleiterplättchen und einer Kühlvorrichtung, mit einem Wärmeübertragungsfluidum zwischen und in Kontact mit diesen, dadurch gekennzeichnet, dass: das Fluidum aus in einem Träger schwebenden magnetischen Teilchen besteht, und die Kühlvorrichtung ein Element besitzt, das ein auf das Fluidum einwirkendes Magnetfeld hervorruft, wobei die Flusslinien dieses Feldes so ausgelegt sind, dass das Fluidum in Stellung gehalten wird.
2. Wärmesenke nach Anspruch 1, dadurch gekennzeichnet, dass: das das Magnetfeld erzeugende Element aus einem Magneten besteht.
3. Wärmesenke nach Anspruch 2, dadurch gekennzeichnet, dass der Magnet so geformt ist, dass er einen Magnetfluss zwischen einem peripherischen Bereich und einem zentralen Bereich des Magneten erzeugt.
4. Wärmesenke nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass das Fluidum mit der Plättchenoberfläche, die mit keinen elektrischen Kontakten für den Eingang und Ausgang der elektrischen Signale versehen ist, in Berührung steht.
5. Wärmesenke nach Anspruch 2 oder 3, dadurch gekennzeichnet, dass das Fluidum mit dem Magneten in Berührung steht, der thermisch mit der Kühlvorrichtung verbunden ist.
EP78430006A 1977-08-12 1978-07-20 Magnetische Wärmeleitungsanordnung für Halbleiterplättchen Expired EP0000856B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US82419777A 1977-08-12 1977-08-12
US824197 1977-08-12

Publications (2)

Publication Number Publication Date
EP0000856A1 EP0000856A1 (de) 1979-02-21
EP0000856B1 true EP0000856B1 (de) 1981-12-16

Family

ID=25240847

Family Applications (1)

Application Number Title Priority Date Filing Date
EP78430006A Expired EP0000856B1 (de) 1977-08-12 1978-07-20 Magnetische Wärmeleitungsanordnung für Halbleiterplättchen

Country Status (5)

Country Link
EP (1) EP0000856B1 (de)
JP (1) JPS5432074A (de)
CA (1) CA1102010A (de)
DE (1) DE2861442D1 (de)
IT (1) IT1112288B (de)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2495846A1 (fr) * 1980-12-05 1982-06-11 Cii Honeywell Bull Dispositif de connexion electrique a haute densite de contacts
FR2495838A1 (fr) * 1980-12-05 1982-06-11 Cii Honeywell Bull Dispositif de refroidissement amovible pour supports de circuits integres
US5594355A (en) * 1994-07-19 1997-01-14 Delta Design, Inc. Electrical contactor apparatus for testing integrated circuit devices
JPH09210801A (ja) * 1996-02-05 1997-08-15 Yuji Inomata 流路内配置用検知装置
FR2811476B1 (fr) * 2000-07-07 2002-12-06 Thomson Csf Dispositif electronique avec encapsulant thermiquement conducteur
US7031160B2 (en) * 2003-10-07 2006-04-18 The Boeing Company Magnetically enhanced convection heat sink
US7516778B2 (en) 2005-09-06 2009-04-14 Sun Microsystems, Inc. Magneto-hydrodynamic heat sink
US8730674B2 (en) * 2011-12-12 2014-05-20 Toyota Motor Engineering & Manufacturing North America, Inc. Magnetic fluid cooling devices and power electronics assemblies
JP6036431B2 (ja) * 2013-03-18 2016-11-30 富士通株式会社 半導体装置
CN114390772B (zh) * 2021-12-29 2024-03-08 江苏密特科智能装备制造有限公司 一种半导体设备精密组件

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3706127A (en) * 1970-04-27 1972-12-19 Ibm Method for forming heat sinks on semiconductor device chips
GB1441433A (en) * 1973-09-18 1976-06-30 Ind Instr Ltd Heat conductive pastes

Also Published As

Publication number Publication date
DE2861442D1 (en) 1982-02-11
JPS5635026B2 (de) 1981-08-14
IT1112288B (it) 1986-01-13
CA1102010A (en) 1981-05-26
JPS5432074A (en) 1979-03-09
IT7826104A0 (it) 1978-07-26
EP0000856A1 (de) 1979-02-21

Similar Documents

Publication Publication Date Title
EP0321899B1 (de) Verfahren und Kühlungsanordnung für ein Gehäuse einer integrierten Schaltung
EP0000856B1 (de) Magnetische Wärmeleitungsanordnung für Halbleiterplättchen
CA2074436C (fr) Dissipateur thermique
EP0749160A1 (de) Verfahren zum Kühlen einer in einem Gehäuse montierten integrierten Schaltung
FR2541511A1 (fr) Substrat pour support de circuits integres
FR2747509A1 (fr) Structure de montage pour un circuit a semi-conducteur
FR2725305A1 (fr) Ensemble de connexion d'un dispositif electronique avec un substrat
FR2828765A1 (fr) Porte-puce de semiconducteur a systeme de refroidissement et radiateur adapte
FR2584534A1 (fr) Boitier comportant un puits thermique pour substrat en ceramique
EP1792526A1 (de) Mit integriertem wärmeverteiler ausgestattete elektronische einrichtung
FR2665799A1 (fr) Dispositif semi-conducteur encapsule a evacuation thermique amelioree.
EP0037301B1 (de) Verkapselungsgehäuse für Leistungsmodul in Hybridschaltung
EP0291400A1 (de) Leistungsmodul für Fahrzeuganlagen
EP0083265B1 (de) Verbindungsträger eines integrierten Schaltungsgehäuses auf einer gedruckten Schaltung, und Verbindungssystem mit solchem Träger
EP0446125B1 (de) Leistungshalbleiteranordnung
EP1979938B1 (de) Elektronisches modul und verfahren zur montage eines derartigen moduls
FR2629272A1 (fr) Support de circuit integre de haute densite et appareil d'etamage selectif des conducteurs du support
CA2915856A1 (fr) Capteur differentiel de temperature
CA2915853C (fr) Capteur differentiel de temperature
FR2574991A3 (fr) Conditionnement pour circuits integres, ayant des possibilites de dissipation de chaleur ameliorees, et procede pour augmenter la dissipation de la chaleur
EP0054597A1 (de) Kühlanordnung für Modul-Steckerstifte
EP0425841B1 (de) Anordnung von elektronischen Leistungsbauelementen
EP0619919A1 (de) Kühlungssystem für mehrchipmodul.
EP1192593A1 (de) Vorrichtung und herstellungsverfahren mit zumindest einem chip auf einem träger
FR2495838A1 (fr) Dispositif de refroidissement amovible pour supports de circuits integres

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB

17P Request for examination filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 2861442

Country of ref document: DE

Date of ref document: 19820211

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19830701

Year of fee payment: 6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19830727

Year of fee payment: 6

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19850329

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19850402

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19881117

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT