Source: http://www.google.com/patents/US20070074907?dq=6,757,682
Timestamp: 2014-07-13 12:27:40
Document Index: 337366328

Matched Legal Cases: ['art 201', 'art 202', 'art 202', 'art 202', 'art 201', 'art 201', 'art 201', 'art 202', 'art 202', 'art 202', 'art 202', 'art 201', 'art 202', 'art 202', 'art 201', 'art 202', 'art 201', 'art 202', 'art 201', 'arts 21', 'arts 21']

Patent US20070074907 - Method of manufacturing an electronic device and an electronic device - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsThe sensing device (100) comprises a first sensing element (10) having a reference plane (1), between which sensing element (10) and a contacting side (3) of the device (100) a predefined angle is present. Conductors couple the sensing element (10) to external contacting means (30). The sensing device...http://www.google.com/patents/US20070074907?utm_source=gb-gplus-sharePatent US20070074907 - Method of manufacturing an electronic device and an electronic deviceAdvanced Patent SearchPublication numberUS20070074907 A1Publication typeApplicationApplication numberUS 10/571,627PCT numberPCT/IB2004/051598Publication dateApr 5, 2007Filing dateAug 30, 2004Priority dateSep 16, 2003Also published asCN1853113A, CN1853113B, EP1664817A1, US7446383, WO2005026761A1Publication number10571627, 571627, PCT/2004/51598, PCT/IB/2004/051598, PCT/IB/2004/51598, PCT/IB/4/051598, PCT/IB/4/51598, PCT/IB2004/051598, PCT/IB2004/51598, PCT/IB2004051598, PCT/IB200451598, PCT/IB4/051598, PCT/IB4/51598, PCT/IB4051598, PCT/IB451598, US 2007/0074907 A1, US 2007/074907 A1, US 20070074907 A1, US 20070074907A1, US 2007074907 A1, US 2007074907A1, US-A1-20070074907, US-A1-2007074907, US2007/0074907A1, US2007/074907A1, US20070074907 A1, US20070074907A1, US2007074907 A1, US2007074907A1InventorsJohannus Weekamp, Mark Gortemaker, John PetersOriginal AssigneeKoninklijke Philips Electronics N.V.Export CitationBiBTeX, EndNote, RefManReferenced by (2), Classifications (17), Legal Events (5) External Links: USPTO, USPTO Assignment, EspacenetMethod of manufacturing an electronic device and an electronic deviceUS 20070074907 A1Abstract The sensing device (100) comprises a first sensing element (10) having a reference plane (1), between which sensing element (10) and a contacting side (3) of the device (100) a predefined angle is present. Conductors couple the sensing element (10) to external contacting means (30). The sensing device (100) is further provided with a body (21), which encapsulates the first sensing element (10) and at the same time acts as a carrier for the conductors, so that the contacting side (3) is a face of the body (21). The sensing device (100) may contain more than one sensing element (10,20), which are by preference magneto-resistive sensors. It can be suitably manufactured in that parts (21 A, 21 B) of the body are rotated with respect to the contacting side (3), the parts (21 A, 21 B) of the body having complementary shapes. Images(8) Claims(13)
The Figures are not drawn to scale and identical reference numerals in different Figures refer to the same or similar parts. FIG. 1 shows a diagrammatical, perspective view on the electronic device 100. In this example, but that is not essential, the device 100 is provided with a first sensing element 10 at a first side face 1, and with a second sensing element 20 at a second side face 2. Reference planes through the sensing elements 10, 20 are in this case oriented in parallel with the side faces 1, 2, and mutually enclose a predefined angle of in this case 90�. The sensing elements 10, 20 are in this case constituted by magneto-resistive sensors which are known per se. Particularly, each sensing element comprises a plurality of magneto-resistive sensor elements connected together to form a Wheatstone bridge circuit and situated in one plane, each of the sensor elements within one sensing element having the same privileged direction of magnetization. Preferably four magneto-resistive sensors elements are provided per sensing element. It is suitable that a silicon substrate is used and that the sensor elements are formed by a meander-like strip of permalloy having a privileged direction of magnetization parallel to the longitudinal direction of the strip. The ends of the sensor elements are interconnected so that they form the four branches of a Wheatstone bridge. The degree of unbalance of the bridge can be used as a measure of the variation of the magnetic field strength in the reference plane of the sensor elements and perpendicularly to the direction of an electric current flowing through the sensor elements. The bridge circuit is coupled on one side to a power supply circuit and on the other side to a signal processing circuit Suitable signal processing circuits are known per se to the skilled person. The sensing elements 10, 20 are encapsulated by an electrically insulating body 21. The device 100 is further provided with a contacting side 3 at which contact means 30 are present. The contact means are in this case solder balls of a suitable composition, which are electrically connected to contact pads (not shown). These contact pads are part of a pattern of electrical conductors 52 (not shown), which is present near or at the surface of the body 21. A first conductor extends from the first side face 1 to the contacting side 3 and a second conductor extends from the second side face 2 to the contacting side 3. The pattern of conductors further includes contact pads to the sensing elements 10, 20, such that the first and the second conductor are electrically coupled to the first and the second sensing element 10, 20, respectively. These conductors are further coupled electrically to the contact means 30. In addition to the first and the second sensing element 10, 20, a third sensing element may be present. Such a third sensing element is located at the same side face as the first sensing element 10, but directed differently. Particularly, the first and third sensing elements will be directed orthogonally, so that the first, second and third sensing elements are directed in the three cartesian directions. FIG. 2 shows diagrammatically a perspective view on the semi-manufactured article 101 of the invention. This article 101 comprises a plurality of first sensing elements 10 and second sensing elements 20. Although the shown article 101 corresponds to a single row of devices 100, it may extend laterally. The first sensing elements 10 are encapsulated by electrically insulating material into a first molded structure 21A. The second sensing elements 20 are encapsulated by electrically insulating material into a second molded structure 21B. Each of the molded structures 21A, 21B is provided with respectively a first top face 12, 22 and a second top face 13, 23. The molded structures 21A, 21B are kept together by a carrier 50. This carrier 50 also carries the pattern of conductors. Within the carrier 50 three areas can be defined, corresponding to the first side face 1, the second side face 2 and the contacting side 3. Although not shown here, the carrier 50 may be provided with an elastic top layer. The device 100 as shown in FIG. 1 can be obtained from the semi-manufactured article 101 in that the article 101 is folded, separated into individual devices and provided with contact means. In this case the separation step is preferably carried out after the folding step, as the article 101 comprises just a single row of devices 100. However, if the article were to comprise a plurality of rows, any separation is necessary before the folding step. In the folding step, the first and the second molded structures 21A, 21B are rotated with respect to the contacting side 3, such that the first top faces 12, 22 face each other and the second top faces 13, 23 face the carrier 50. By a suitable adhering step, for instance a heat treatment, the first and second molded structures 21A, 21B are attached to each other and the carrier 50, thereby forming the body 21 with its respective contacting side 3, and its first and second side faces 1, 2. The contact means 3 could contain a suitable anisotropically conductive adhesive, metal or alloy or paste with conducting particles instead of solder. Also a suitable foil could be used. It is further observed that the contact means 3 include not only the solder balls, but possibly also contact pads in the pattern of conductors and a suitable adhesion layer. Contact means are presumed to be present, without any solder balls or the like being attached. As will be understood, the semi-manufactured article 101 is suitable as well for the provision of devices with only a single, first sensing element 10. In that case, the semi-manufactured article 101 is subdivided in a different way, and there is more freedom of rotation. Particularly in that case it is possible as well that not the molded structures 21A, 21B are rotated with respect to the contacting side 3, but that the free part of the carrier 50 is folded with respect to the molded structures 21A or 21B, respectively. In that case, a further structure may be present on top of the carrier, acting as a corresponding structure to the molded structure 21A, 21B. FIGS. 3 a-e show results after a number of consecutive steps in the method of the invention. The Figures are related to a specific embodiment of the method of the invention, in which a carrier 50 is used with a pattern of conductors 52 and a base layer 51. In this case use is made of Al for the base layer 51 and copper for the conductors 52. This is not necessary however. A suitable alternative is the use of a three layered carrier comprising for instance copper, aluminum and copper. At both sides thereof layers of NiPd or NiAu or Sn may be provided, acting both as lithographic masks and as adhesion layers. Alternatively, use could be made of a base layer of silicon or glass, that can be removed by grinding and etching. Also use can be made of a base layer that is connected to the pattern of conductors through a UV-releasable foil. Furthermore, use can be made as well of a carrier 50, which is a single layered or multi-layered flexible board with internal vertical interconnects extending from the first side 58 to the second side 59. FIG. 3 a shows a cross-sectional view of the carrier 50 having a first and a second side 58, 59 opposite to each other. The carrier comprises a base layer 51, here of Al or an aluminum alloy, and a pattern of conductors 52 including individual conductors 52A, 52B. The conductor 52B functions here as an interconnect and will extend from the first side of the body to the connecting side. The base layer will have a suitable thickness so as to act as a mechanical support. Its thickness is for instance in the range of 20 to 100 μm, preferably 30 to 60 μm. The pattern of conductors generally has a thickness, and thus a resolution, in the order of 1 to 30 μm, preferably 5 to 15 μM. Generally, it will be provided with an adhesion layer for improvement of the adhesion to solder balls. The material of the adhesion layer depends on the material of the solder balls, as is known by the skilled person. Materials generally used for adhesion layers include NiAu, Sn and the like. FIG. 3 b shows a cross-sectional view of the carrier 50 after an etching step, whereby the conductors 52A, 52B are provided with under-etched spaces 53. This etching step is done using a solution of sodium hydroxide, whereas the copper is patterned with ferrichloride. These etchants are selective to aluminum and copper respectively. FIG. 3 c shows a cross-sectional view of the carrier 50 after a first sensing element 10 has been provided on the conductors 52A, 52B with intermediate solder balls 54. It is through definition of the contact pads in the copper pattern that the position of the sensing element 10 in the final device is defined, at least partially. Use can be made of sensing elements 10 that have not been encapsulated beforehand (e.g. naked dies). In order to provide a good connection, use can be made of solder processes in which solder material is provided both at the pattern of conductors and at the contact pads of the sensing element. Furthermore, use can be made of alternative connection techniques, such as Ultra Sonic bonding, conductive glues and particularly wire bonding. In order to establish a good electrical connection between the solder balls 54 and the pattern of conductors 52, a heating step is usually carried out. This heating step can be applied either before or after molding, as is known to the skilled person. Use is preferably made of a reflow oven. FIG. 3 d shows a cross-sectional view after encapsulation steps. As a result, the carrier 50 is transformed into the semi-manufactured article 101. In this case, use is made of encapsulation steps. The first encapsulation step, carried out using a molding technique such as insert molding or transfer molding, encapsulates the first sensing element 10 and results in the first molded structure 21A with a first and a second top face 12, 13. For the electrically insulating material use can be made of glass-filled epoxies and of engineering plastics such as polyphenylenesulfide (PPS). Other suitable materials are known to the skilled person. This material will depend on the type of molding process used. The second encapsulation step can be carried out using a molding technique, but alternatively use may be made of any other type of deposition technique, including spincoating, webcoating, sputtering, various forms of printing. The material used therefor may be an organic material, a polymer material or an inorganic material. A material that is primarily an adhesive or the adhesive properties of which increase on heating, is preferred. Flexible materials are highly preferred. Good examples are acrylates, silicon rubbers, polyimides, Parylene and for instance materials which are also used for wafer coating purposes. This material may also be an underfill type material, which is generally used to fill spaces between the sensing element 10 and the carrier 50. The second encapsulation step must not necessarily take place after the first step. On the contrary, a very good embodiment is achieved by using a material that melts on heating and thus allows solder balls to sink through this layer. Such a layer is for instance an acrylate and is preferably provided, for instance by spincoating or as a film, before the provision of the sensing element 10. It is even possible that the first and second encapsulation steps are integrated into one step, or that the structure 21C is not provided at all. The latter is particularly suitable if the base layer 51 is removed only after folding. FIG. 3 e shows the semi-manufactured article 101 after removal of the base layer 51. This removal is for instance done by grinding and wet-chemical etching. As a result, the under-etched spaces, which have been filled with the electrically insulating material, are provided at the surface 1 as protruding portions 57 which at the same time provide mechanical anchoring of the conductors 52A, 52B. FIG. 4 shows a cross-sectional view of the semi-manufactured article 101 at the same stage, however on a larger scale and after the provision of contact means 30, in this case solder balls. In addition to the first molded structure 21A a second molded structure 21B is present having a second sensing element 20 and a first and second top face 22, 23. Indicated are the areas corresponding to the first and second side face 1,2 and the contacting side 3. Conductors 52 extend so as to provide the interconnection. FIG. 5 shows a cross-sectional view of the device 100, after subdivision into rows of devices or individual devices, during the folding step. Herein, the first and second molded structure 21A, 21B are rotated. The folding process of this embodiment includes simultaneous rotation of both molded structures 21A, 21B. This is not necessary however. Preferably, a specific tool is used for the folding, which is shown in FIGS. 7 a-d. FIG. 6 shows a cross-sectional view of the device 100 after completion of the rotation step and attachment of the molded structures to each other and to the carrier, thereby providing the electrically insulating body. As a result, the first top faces 12, 22 of the molded structures face each other, whereas the second top faces 13, 23 face the carrier. The adhesion is brought about in this case by a heating step. Usually, the materials chosen for the molding structures will be thermo-set, e.g. they will be thermally stable and do not melt on heating. Generally this is achieved by cross linking the polymeric chains in known manner. To improve the adhesion it is preferred to use mechanical anchoring or to apply of a thin layer of adhesive. Such adhesive is able to fixate the conductor tracks, resulting in an embodiment in which no flexible part is needed. Although not shown here, it is generally preferred within such devices that a magnetization coil is present. The magnetization coil can be part of the pattern of conductors and be located parallel to the contacting side of the device. If desired, this coil can be covered by a medium having a high magnetic susceptibility, such as a layer of ferrite material, or an organic material with ferrite or other magnetic particles embedded therein. This magnetization coil is present to produce an auxiliary magnetic field parallel to a central axis. Preferably, it is positioned such that an angle enclosed by the central axis relative to a normal to the plane of the sensing elements is the same for each of the sensing elements, i.e. the angle α in between 0 and 90�. The preferred location of the coil is chosen such that the auxiliary magnetic field at the area of each of the sensing elements contains a component which extends parallel to the privileged direction of magnetization of the magnetic field sensor elements of the relevant sensing element. FIGS. 7 a-d show diagrammatically and in cross-section the device 100 of the invention during the folding step, and a tool 200 adapted for implementation of the folding step. The tool 200 comprises a top part 201, at least one bottom part 202 and a support 203. The bottom part 202 can be constructed as a single part that surrounds the support 203. However, it may also be constructed as several parts that cooperate. The tool is preferably provided with motors and any kind of necessary equipment so as to allow movement of the bottom part 202, the top part 201 and the support 203 in the vertical direction with respect to each other. The tool 200 may include further functions, such as transport and separation. The terms bottom part and top part are used herein for clarity and in conformity with the preferred embodiment. However, it is not excluded that the tool is used upside down, or that the bottom and top part 201, 202 are located transversely to the support 203, in a suitable construction. FIG. 7 a shows the device 100 with the tool 200 before the folding operation. The device 100 in this case is provided with solder bumps 30, which could alternatively be applied after the folding operation. The top part 201 comprises an inner surface 208, and the bottom part 202 comprises an upper surface 209. These surfaces 208, 209 are complementary. The shape of the inner surface 208 is chosen so as to correspond to the desired angle between the first and second sensing element 20. The choice of this angle was explained above. FIG. 7 b explains the first step, in which the bottom part 202 is moved with respect to the support 203. As a result the upper surfaces 209 of the bottom part 202 push the faces 1,2 of the bodies 21A and 21B. As a consequence, the bodies 21A and 21B are rotated. The upper surfaces 209 are provided with rounded edges so as to prevent any damage. The force and speed of the movement of the bottom part 202 can be chosen so as to optimize the process, as will be clear to the skilled person. It is moreover dependent on the degree of flexibility of the foil 3. FIG. 7 c shows the second step, in which the top part 201 is moved towards the bottom part 202. The corresponding shapes of the upper surface 208 and the inner surface 209 ensure that the bottom and top part 202, 201 are properly aligned, and that the force and speed with which the top part 201 is moved towards the device 100 can be balanced by the bottom part 202. FIG. 7 d shows the third and final step, in which the support 203 is moved with respect to the top part 201, or alternatively, the bottom and top part 202, 201 are moved towards the support 203. As a consequence, the bodies 21A, 21B are joined together to form the body 21. In order to provide any adhesive, the top part 201 can be provided with one or more distribution channels. However, such adhesive might alternatively be applied before the folding process. In short the sensing device 100 of the invention comprises a first sensing element 10 having a reference plane 1, between which sensing element 10 and a contacting side 3 of the device 100 a predefined angle is present. Conductors couple the sensing element 10 to external contacting means 30. The sensing device 100 is further provided with a body 21, which encapsulates the first sensing element 10 and at the same time acts as a carrier for the conductors, so that the contacting side 3 is a face of the body 21. The sensing device 100 may contain more than one sensing element 10, 20, which mutually include a predefined angle, the predefined angle to the contacting side 3 being of no or negligible importance. The sensing elements 10, 20 are by preference magneto-resistive sensors. The device 100 can be suitably manufactured in that parts 21A, 21B of the body 21 are rotated with respect to the contacting side 3, the parts 21A, 21B of the body having complementary shapes. Referenced byCiting PatentFiling datePublication dateApplicantTitleEP2551691A1 *Dec 6, 2011Jan 30, 2013Paul Scherrer InstitutA method for manufacturing a Hall sensor assembly and a Hall sensor assemblyWO2013014203A1 *Jul 25, 2012Jan 31, 2013Paul Scherrer InstitutA method for manufacturing a hall sensor assembly and a hall sensor assembly* Cited by examinerClassifications U.S. Classification174/525, 174/260, 324/247, 174/521, 174/254International ClassificationG01R33/02, H05K1/18, H05K1/00, H01L23/28, H05K1/16, G01R33/09, H05K3/20Cooperative ClassificationG01R33/09, H05K1/185, H05K1/187, H05K3/20European ClassificationG01R33/09Legal EventsDateCodeEventDescriptionDec 25, 2012FPExpired due to failure to pay maintenance feeEffective date: 20121104Nov 4, 2012LAPSLapse for failure to pay maintenance feesJun 18, 2012REMIMaintenance fee reminder mailedMar 15, 2006ASAssignmentOwner name: KONNINKLIJKE PHILIPS ELECTRONICS, N.V., NETHERLANDFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HENDRIKS, ROBERT FRANS MARIA;REEL/FRAME:017712/0938Effective date: 20051110Mar 14, 2006ASAssignmentOwner name: KONINKLIJKE PHILIPS ELECTRONICS, N.V., NETHERLANDSFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:WEEKAMP, JOHANNUS WILHELMUS;GORTEMAKER, MARK HERMANUS;PETERS, JOHN ANTOINE;REEL/FRAME:017694/0861;SIGNING DATES FROM 20050407 TO 20050411RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google