GB2041818A - Encapsulating a Magnetic Domain Component - Google Patents

Encapsulating a Magnetic Domain Component Download PDF

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Publication number
GB2041818A
GB2041818A GB7904786A GB7904786A GB2041818A GB 2041818 A GB2041818 A GB 2041818A GB 7904786 A GB7904786 A GB 7904786A GB 7904786 A GB7904786 A GB 7904786A GB 2041818 A GB2041818 A GB 2041818A
Authority
GB
United Kingdom
Prior art keywords
shield
mould
component
moulding
cavity
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.)
Withdrawn
Application number
GB7904786A
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.)
Plessey Co Ltd
Original Assignee
Plessey Co Ltd
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 Plessey Co Ltd filed Critical Plessey Co Ltd
Priority to GB7904786A priority Critical patent/GB2041818A/en
Priority to DE19803004437 priority patent/DE3004437A1/en
Publication of GB2041818A publication Critical patent/GB2041818A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/005—Impregnating or encapsulating
    • 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

Abstract

A method of producing a magnetic domain component comprising a magnetic part within a shield, is described in which the magnetically sensitive parts are encapsulated into the shield by injection or transfer moulding of epoxy or silicone resin, the shape of the component being defined during moulding at least partly by the shield, which is supported within a mould. The shield is located in the mould 1/2 between mould parts 6/9, flashing around the end of the shield being prevented by mould parts 5/8 which are adjustable by screws 11/12. The leads of the magnetically sensitive part are located in recesses 18/19. <IMAGE>

Description

SPECIFICATION Magnetic Domain Component This invention relates to magnetic domain components and is particularly concerned with a method of an apparatus for the production of such components.
A magnetic domain component has several constituent parts. These are usually a chip of magnetic domain material; a pair of coils arranged orthogonally around the chip and a pair of permanent magnets sandwiching the coils and the chip.
In order to protect the magnetically sensitive parts and hence any stored data from stray signals, the component is completed by a magnetic shield within which the other parts reside.
To give the component environmental protection the shield is filled with a plastics material and so far this has been done manually.
Whilst suitable for experimental components manual moulding is not adequate for production runs. This invention seeks to provide a method of making a magnetic domain component in which the above disadvantage of known encapsulation techniques is overcome.
According to one aspect of this invention there is provided a method of manufacturing a magnetic domain component including the steps of encapsulating magnetically sensitive parts of the component within a magnetic shield by injection moulding with a suitable material and in which a peripheral surface of the component is defined during moulding by a surface of the shield.
Any suitable moulding material may be used examples being epoxy, epoxy/silicone or silicone materials.
A suitable form of injection moulding is the transfer moulding process.
The moulding may be carried out in a mould on an injection moulding machine, the mould having a cavity into which the component is located, the cavity having dimensions to allow acceptance of the component shield whilst preventing substantial flashing of moulding material between the shield and the mould.
A two part mould may be used, the two parts together defining the cavity.
One part of the mould may have means for supporting the shield and electrical leads to which parts within the shield are connected in spaced apart relationship to one another.
The mould may include means for adjusting a dimension of the cavity to provide abutment of a surface of the cavity and the shield to a tolerance of within .001" and preferably within .0005".
The shield may be a hollow tubular shield and the adjustable dimension may be in the direction of the length of the shield so as to provide abutment between respective mould surfaces and the open ends of the shield to a tolerance of within 0.001" and preferably less than 0.0005".
According to a second aspect of this invention there is provided a method of manufacturing a magnetic domain component including the steps of assembling magnetically sensitive parts of the component within a hollow tubular shield with electrical leads extending from the shield; supporting the shield and leads in spaced apart relationship in one part of a two part mould; assembling a second part of the mould onto the first part with the two parts substantially abutting respective surfaces of the shield, adjusting an end surface of a cavity defined by the two parts and in which the component resides, until ends of the shield abut respective end surfaces of the cavity; injecting a suitable moulding material on an injection moulding machine to fill the shield and removing the component from the mould.
The invention will now be described further with reference to the accompanying drawings in which: Figure 1 is a sectional elevation of a mould in accordance with an aspect of this invention; and Figures 2 and 3 are respectively plan views of upper and lower halves of the mould of Figure 1 with the two halves folded back to reveal inside mating surfaces.
Referring to Figures 1 to 3 of the drawings there is shown a two part mould for the encapsulation of the magnetically sensitive parts of a magnetic domain component formed by upper and lower bolster plates 1 and 2 respectively which are separable along a mating surface 3. The upper bolster plate 1 has a cavity 4 which carries inserts 5 and 6 whilst the lower bolster plate 2 has a similar cavity 7 which carries inserts 8 and 9. The inserts 5, 6, 8 and 9 define acurately peripheral surfaces of a cavity 10 in which the magnetic domain device sits for encapsulation.
The upper bolster plate 1 is provided with a pair of cap screws 11 which pass through an end of the upper bolster plate to allow a small adjustment in the position of the insert 5 whilst in similar manner the lower bolster plate 2 is provided with a pair of cap screws 12 for adjusting the position of the insert 8. Extending through the inserts 4 and 7 respectively are a pair of ejector pins 13 and 15 which on separation of the bolster plates 1 and 2 after the moulding process may be tapped to eject the completed component.
The upper bolster plate 1 is provided with a moulding material feed hole 15 which extends through the bolster plate 1 and communicates with a U-shaped channel 16 in the lower bolster plate 2 along which the moulding material passes and enters the cavity 10 via a small feed hole 17 which is approximately 0.050" square.
In order to encapsulate a component the magnetically sensitive parts are assembled into a shield which is typically a hollow cylindrical shield of rectangular cross section so that electrical connecting leads extend from each end of the shield. The component is introduced into the mould which is at this stage split along the interface 3 and the component rests with the shield on the insert 7 with the leads supported spaced apart from the shield and seating in grooves 18 and 19 provided repectively in the lower bolster plates 2 and the insert 8.The upper bolster plate is then placed in position so that the insert 4 contacts an upper surface of the shield of the device which at this stage fills the cavity 10 and the two pairs of screws 1 1 and 12 are adjusted to move the inserts 5 and 8 so that cavity end surfaces abut the shield to a tolerance of within 0.001 " and typically to within 0.0005".
To facilitate alignment of the two bolster plates 1 and 2 during assembly of the mould diagonally opposed guide pins 20 are provided to pass through the plates 1 and 2.
After assembly of the mould and adjustment of the cap screws 1 1 and 12 the mould is placed in an injection moulding machine and moulding material is injected into the aperture 15, along the channel 16 and passes into the shield through the aperture 1 7. A transfer moulding machine is preferred and the mould described so far is suitable for use on a Lauffer model VSKO 25 ton transfer moulding press. The moulding pressure and rate of flow of moulding material may be adjusted on the machine so that the shield is completely filled with material whilst at the same time damage to the delicate parts located within the shield is avoided.
Any suitable moulding material may be used but typical materials are of epoxy, epoxy/silicone or silicone form, examples of proprietary materials being Polyset 41 0C (Polyset is a registered trade mark) and Dow Corning 631 semiconductor grade moulding compound.
After moulding the mould is removed from the moulding machine and the upper and lower bolster plates 1 and 2 are separated at the interface 3 and the completed component is removed from the mould if necessary by tapping one or other of the ejector pins 1 3 and 14.
As can be seen by injecting the moulding material at a controlled rate and pressure a solid moulded component is formed in which the material has a good adhesion to the shield. It is therefore possible to achieve a high rate of component production since the high throughput rates of transfer moulding may be utilised and this high throughput is coupled with the environmental protection which is normally associated with semiconductor components. The shape of the component is not defined by the mould cavity as in conventional injection moulding techniques but is defined by the shield and therefore a magnetic domain device package with shield attached is produced in one shot.
Although this invention has been described with reference to the drawings showing a mould for use on a particular transfer moulding machine any convenient form of injection moulding may be used. Similarly any material which may be injection moulded and which provides the required amount of environmental protection may be used for filling the shield.
Other modifications may be made without departing from the scope of this invention. For example although a mould only having a single cavity for accepting a single magnetic domain device component has been described moulds may be used having a number of cavities so that several components can be produced by a single moulding shot.

Claims (13)

Claims
1. A method of manufacturing a magnetic domain component including the steps of encapsulating magnetically sensitive parts of the component within a magnetic shield by injection moulding with a suitable material and in which a peripheral surface of the component is defined during moulding by a surface of the shield.
2. A method as claimed in claim 1 in which the moulding material is epoxy.
3. A method as claimed in claim 1 in which the moulding material is epoxy/silicone.
4. A method as claimed in claim 1 in which the moulding material is a silicone material.
5. A method as claimed in anyone of claims 1-4 in which the injection moulding is carried out by means of the transfer moulding process.
6. A method as claimed in anyone of claims 1-5 in which the moulding is carried out in a mould on an injection moulding machine, the mould having a cavity into which the component is located, the cavity having dimensions to allow acceptance of the component shield whilst preventing substantial flashing of moulding material between the shield and the mould.
7. A method as claimed in claim 6 in which a two part mould is used, the two parts together defining the cavity.
8. A method as claimed in claim 7 in which one part of the mould has means for supporting the shield and electrical leads to which parts within the shield are connected, in spaced apart relationship to one another.
9. A method as claimed in anyone of claims 6-8 in which the mould includes means for adjusting a dimension of the cavity to provide abutment of a surface of the cavity and the shield to a tolerance of within 0.001".
10. A method as claimed in claim 9 in which the tolerance is within 0.0005".
1 A method as claimed in claim 9 or 10 in which the shield is a hollow tubular shield and the adjustable dimension is in the direction of the length of the shield so as to provide abutment between respective mould surfaces and the open ends of the shield.
12. A method of manufacturing a magnetic domain component including the steps of assembling magnetically sensitive parts of the component within a hollow tubular shield with electrical leads extending from the shield; supporting the shield and leads in spaced apart relationship in one part of a two part mould; assembling a second part of the mould onto the first part with the two parts substantially abutting respective surfaces of the shield, adjusting an end surface of a cavity defined by the two parts and in which the component resides, until ends of the shield abut respective end surfaces of the cavity; injecting a suitable moulding material on an injection moulding machine to fill the shield and removing the component from the mould.
13. A method of manufacturing a magnetic domain component substantially as herein described with reference to Figures 1-3 of the drawings.
GB7904786A 1979-02-10 1979-02-10 Encapsulating a Magnetic Domain Component Withdrawn GB2041818A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB7904786A GB2041818A (en) 1979-02-10 1979-02-10 Encapsulating a Magnetic Domain Component
DE19803004437 DE3004437A1 (en) 1979-02-10 1980-02-07 METHOD FOR PRODUCING A MAGNETIC DOMAIN COMPONENT

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB7904786A GB2041818A (en) 1979-02-10 1979-02-10 Encapsulating a Magnetic Domain Component

Publications (1)

Publication Number Publication Date
GB2041818A true GB2041818A (en) 1980-09-17

Family

ID=10503126

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7904786A Withdrawn GB2041818A (en) 1979-02-10 1979-02-10 Encapsulating a Magnetic Domain Component

Country Status (2)

Country Link
DE (1) DE3004437A1 (en)
GB (1) GB2041818A (en)

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3336173A1 (en) * 1983-10-05 1985-04-25 Maschinenfabrik Lauffer GmbH & Co KG, 7240 Horb PRESS WITH SEVERAL INJECTION PISTON FOR THE SIMULTANEOUS PRODUCTION OF SEVERAL PLASTIC COMPRESSED PARTS
US7426780B2 (en) 2004-11-10 2008-09-23 Enpirion, Inc. Method of manufacturing a power module
US7462317B2 (en) * 2004-11-10 2008-12-09 Enpirion, Inc. Method of manufacturing an encapsulated package for a magnetic device
US7544995B2 (en) 2007-09-10 2009-06-09 Enpirion, Inc. Power converter employing a micromagnetic device
US7688172B2 (en) 2005-10-05 2010-03-30 Enpirion, Inc. Magnetic device having a conductive clip
US7920042B2 (en) 2007-09-10 2011-04-05 Enpirion, Inc. Micromagnetic device and method of forming the same
US7952459B2 (en) 2007-09-10 2011-05-31 Enpirion, Inc. Micromagnetic device and method of forming the same
US7955868B2 (en) 2007-09-10 2011-06-07 Enpirion, Inc. Method of forming a micromagnetic device
US8018315B2 (en) 2007-09-10 2011-09-13 Enpirion, Inc. Power converter employing a micromagnetic device
US8133529B2 (en) 2007-09-10 2012-03-13 Enpirion, Inc. Method of forming a micromagnetic device
US8139362B2 (en) 2005-10-05 2012-03-20 Enpirion, Inc. Power module with a magnetic device having a conductive clip
US8153473B2 (en) 2008-10-02 2012-04-10 Empirion, Inc. Module having a stacked passive element and method of forming the same
US8266793B2 (en) 2008-10-02 2012-09-18 Enpirion, Inc. Module having a stacked magnetic device and semiconductor device and method of forming the same
US8339802B2 (en) 2008-10-02 2012-12-25 Enpirion, Inc. Module having a stacked magnetic device and semiconductor device and method of forming the same
US8541991B2 (en) 2008-04-16 2013-09-24 Enpirion, Inc. Power converter with controller operable in selected modes of operation
US8631560B2 (en) 2005-10-05 2014-01-21 Enpirion, Inc. Method of forming a magnetic device having a conductive clip
US8686698B2 (en) 2008-04-16 2014-04-01 Enpirion, Inc. Power converter with controller operable in selected modes of operation
US8692532B2 (en) 2008-04-16 2014-04-08 Enpirion, Inc. Power converter with controller operable in selected modes of operation
US8698463B2 (en) 2008-12-29 2014-04-15 Enpirion, Inc. Power converter with a dynamically configurable controller based on a power conversion mode
US8701272B2 (en) 2005-10-05 2014-04-22 Enpirion, Inc. Method of forming a power module with a magnetic device having a conductive clip
US8867295B2 (en) 2010-12-17 2014-10-21 Enpirion, Inc. Power converter for a memory module
US9054086B2 (en) 2008-10-02 2015-06-09 Enpirion, Inc. Module having a stacked passive element and method of forming the same
US9246390B2 (en) 2008-04-16 2016-01-26 Enpirion, Inc. Power converter with controller operable in selected modes of operation
US9509217B2 (en) 2015-04-20 2016-11-29 Altera Corporation Asymmetric power flow controller for a power converter and method of operating the same
US9548714B2 (en) 2008-12-29 2017-01-17 Altera Corporation Power converter with a dynamically configurable controller and output filter

Cited By (34)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3336173A1 (en) * 1983-10-05 1985-04-25 Maschinenfabrik Lauffer GmbH & Co KG, 7240 Horb PRESS WITH SEVERAL INJECTION PISTON FOR THE SIMULTANEOUS PRODUCTION OF SEVERAL PLASTIC COMPRESSED PARTS
US8043544B2 (en) 2004-11-10 2011-10-25 Enpirion, Inc. Method of manufacturing an encapsulated package for a magnetic device
US7426780B2 (en) 2004-11-10 2008-09-23 Enpirion, Inc. Method of manufacturing a power module
US7462317B2 (en) * 2004-11-10 2008-12-09 Enpirion, Inc. Method of manufacturing an encapsulated package for a magnetic device
US8528190B2 (en) 2004-11-10 2013-09-10 Enpirion, Inc. Method of manufacturing a power module
US8701272B2 (en) 2005-10-05 2014-04-22 Enpirion, Inc. Method of forming a power module with a magnetic device having a conductive clip
US8139362B2 (en) 2005-10-05 2012-03-20 Enpirion, Inc. Power module with a magnetic device having a conductive clip
US7688172B2 (en) 2005-10-05 2010-03-30 Enpirion, Inc. Magnetic device having a conductive clip
US8384506B2 (en) 2005-10-05 2013-02-26 Enpirion, Inc. Magnetic device having a conductive clip
US8631560B2 (en) 2005-10-05 2014-01-21 Enpirion, Inc. Method of forming a magnetic device having a conductive clip
US10304615B2 (en) 2005-10-05 2019-05-28 Enpirion, Inc. Method of forming a power module with a magnetic device having a conductive clip
US7920042B2 (en) 2007-09-10 2011-04-05 Enpirion, Inc. Micromagnetic device and method of forming the same
US8133529B2 (en) 2007-09-10 2012-03-13 Enpirion, Inc. Method of forming a micromagnetic device
US9299489B2 (en) 2007-09-10 2016-03-29 Enpirion, Inc. Micromagnetic device and method of forming the same
US7952459B2 (en) 2007-09-10 2011-05-31 Enpirion, Inc. Micromagnetic device and method of forming the same
US8339232B2 (en) 2007-09-10 2012-12-25 Enpirion, Inc. Micromagnetic device and method of forming the same
US8018315B2 (en) 2007-09-10 2011-09-13 Enpirion, Inc. Power converter employing a micromagnetic device
US7955868B2 (en) 2007-09-10 2011-06-07 Enpirion, Inc. Method of forming a micromagnetic device
US7544995B2 (en) 2007-09-10 2009-06-09 Enpirion, Inc. Power converter employing a micromagnetic device
US8618900B2 (en) 2007-09-10 2013-12-31 Enpirion, Inc. Micromagnetic device and method of forming the same
US9246390B2 (en) 2008-04-16 2016-01-26 Enpirion, Inc. Power converter with controller operable in selected modes of operation
US8541991B2 (en) 2008-04-16 2013-09-24 Enpirion, Inc. Power converter with controller operable in selected modes of operation
US8692532B2 (en) 2008-04-16 2014-04-08 Enpirion, Inc. Power converter with controller operable in selected modes of operation
US8686698B2 (en) 2008-04-16 2014-04-01 Enpirion, Inc. Power converter with controller operable in selected modes of operation
US8339802B2 (en) 2008-10-02 2012-12-25 Enpirion, Inc. Module having a stacked magnetic device and semiconductor device and method of forming the same
US9054086B2 (en) 2008-10-02 2015-06-09 Enpirion, Inc. Module having a stacked passive element and method of forming the same
US8266793B2 (en) 2008-10-02 2012-09-18 Enpirion, Inc. Module having a stacked magnetic device and semiconductor device and method of forming the same
US8153473B2 (en) 2008-10-02 2012-04-10 Empirion, Inc. Module having a stacked passive element and method of forming the same
US8698463B2 (en) 2008-12-29 2014-04-15 Enpirion, Inc. Power converter with a dynamically configurable controller based on a power conversion mode
US9548714B2 (en) 2008-12-29 2017-01-17 Altera Corporation Power converter with a dynamically configurable controller and output filter
US8867295B2 (en) 2010-12-17 2014-10-21 Enpirion, Inc. Power converter for a memory module
US9627028B2 (en) 2010-12-17 2017-04-18 Enpirion, Inc. Power converter for a memory module
US9509217B2 (en) 2015-04-20 2016-11-29 Altera Corporation Asymmetric power flow controller for a power converter and method of operating the same
US10084380B2 (en) 2015-04-20 2018-09-25 Altera Corporation Asymmetric power flow controller for a power converter and method of operating the same

Also Published As

Publication number Publication date
DE3004437A1 (en) 1980-08-21

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