Electronic component assembly

An electronic component assembly including an electrical connector and an electronic subassembly. The electrical connector has a housing with a receiving area, electrical contacts connected to the housing, and fusible elements. The electrical contacts include first electrical connection sections in the receiving area and second electrical connection sections proximate a first exterior side of the housing. The fusible elements are connected to the second electrical connection sections. The electronic subassembly includes a printed wiring assembly and electronic components connected to opposite sides of the printed wiring assembly. The printed wiring assembly includes a relatively rigid section with the electronic components connected thereto and a flex cable forming deflectable lateral side sections with contact areas contacting the first electrical connector sections of the electrical contacts.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to interconnection of electronic components and, more particularly, to an interconnection within an electronic package, which uses a flex cable, and electrical interconnection between components and assembly substrates.

2. Brief Description of Prior Developments

Flex cables, such as flat flexible cables (FFC) and flexible printed circuits (FPC) are generally well know. Currently the most typical interconnection method between electronics packages and motherboards is ball grid array (BGA) or land grid array (LGA) type of solderable interconnection. In large modules (containing a lot of functionalities and components) usage of this interconnection method set demands for motherboard technology selection (e.g. wiring of the module requires micro via technology in motherboard).

Referring toFIG. 1, there is shown a side view of an electronic component assembly10known in the prior art. The assembly10generally comprises a substrate12, a plurality of electronic components14,15, and fusible elements16. The electronic components14,15are electrically connected to the fusible elements16by conductive paths (not shown) on and/or through the substrate12. The fusible elements16can provide a soldered ball grid array (BGA) or land grid array (LGA) interconnection. These types of array interconnections are currently a very typical interconnection method for connecting complicated electronics packages in applications, such as a microprocessor to another component (for example). One problem which exists with BGA or LGA interconnections is that components cannot be assembled on the bottom side of the module; the side which comprises the fusible elements16. Thus, the electronic components14,15can be mounted on only the top side18of the substrate12.

Another typical or conventional method of interconnection comprises a board edge plating process. Board edge plating processes are used in existing printed wiring board technology. Electrical contact interconnection areas are formed on lateral side edges of a rigid printed circuit board by a plating process. This type of manufacturing process is difficult and does not always provide an accurate process.

Due to limitations of single sided component assembly on the module, the total area (physical size of the module) is larger than it could be if a double-sided component assembly were used on a physical module. This is solved by improving component assembly processes with the present invention. An example of these are shrinkage of component-to-component spacing rules and usage of smaller component packages in assembly lines. This adds unnecessary complexity to the module electronics manufacturing processes.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, an electronic component assembly is provided including an electrical connector and an electronic subassembly. The electrical connector has a housing with a receiving area, electrical contacts connected to the housing, and fusible elements. The electrical contacts include first electrical connection sections in the receiving area and second electrical connection sections proximate a first exterior side of the housing. The fusible elements are connected to the second electrical connection sections. The electronic subassembly includes a printed wiring assembly and electronic components connected to opposite sides of the printed wiring assembly. The printed wiring assembly includes a relatively rigid section with the electronic components connected thereto and a flex cable forming deflectable lateral side sections with contact areas contacting the first electrical connector sections of the electrical contacts.

In accordance with another aspect of the invention, an electronic component assembly is provided comprising a flex cable and a plurality of electronic components connected to the flex cable. The flex cable comprises a general folded shape with the electronic components arranged in a general stacked orientation. Portions of the flex cable at bent sections of the folded shape form lateral side contact areas for contacting electrical connection areas of another member.

In accordance with one method of the present invention, a method of assembling an electronic component assembly is provided comprising connecting an electrical connector to a first electronic component comprising fusing fusible elements of the electrical connector to the first electronic component; and inserting an electronic subassembly into the electrical connector, wherein the electronic subassembly comprises printed wiring assembly with a flex cable and second electronic components connected to the printed wiring assembly, wherein the flex cable forms lateral side sections with bent contact areas contacting contacts inside the electrical connector.

In accordance with another aspect of the present invention, a method of assembling an electronic component assembly is provided comprising connecting a plurality of electronic components to a flex cable; and folding the flex cable to arrange the electronic components in a general stacked orientation, wherein an exterior portion of the flex cable at a bend of the flex cable between the electronic components forms a contact area for electrically connecting the flex cable to another electronic component.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 2, there is shown a schematic sectional view of an electronic component assembly20incorporating features of the present invention. Although the present invention will be described with reference to the exemplary embodiments shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used.

The electronic component assembly20generally comprises an electrical connector22and an electronic subassembly24. Referring also toFIGS. 3 and 4, the electronic subassembly24generally comprises a printed wiring assembly26and electronic components28,29, such as integrated circuits. In alternate embodiments, more than two electronic components could be provided on the printed wiring assembly26. The printed wiring assembly26comprises a flex cable30and a relatively rigid section32. In the embodiment shown, the relatively rigid section32is located on top and bottom sides of the flex cable30. The flex cable30has lateral side sections34which extend outward past the sides of the rigid section32. The flex cable30comprises electrical conductors on a flexible electrically insulating substrate. The conductors of the flex cable30are electrically connected to conductors on the rigid section32, or are located at holes through the rigid section32which are adapted to receive conductors of the electronic components28,29. Thus, the conductors of the flex cable30are electrically connected to the contacts of the electronic components28,29at the rigid section32. The electrical conductors of the flex cable30extend along the lateral side sections34and are preferably exposed along at least the bottom sides36of the lateral side sections34.

The rigid section32could be comprised of any suitable type of printed wiring member, such as two thin printed circuit boards, for example. The rigid section32preferably sandwiches the middle section of the flex cable30therein. When the printed wiring assembly26is formed, the rigid section32and flex cable30are preferably formed into a unitary one piece structure. As used herein, this combined flexible substrate and rigid or semi-rigid substrate configuration is referred to as a “flex-rigid printed wiring board” technology. The printed wiring assembly26functions as an interposer between the electronic components28,29and the electrical connector22. The electronic components28,29are stationarily attached to the printed wiring assembly26at the top and bottom sides of the rigid section32. The electronic components28,29are preferably attached to the printed wiring assembly26after the printed wiring assembly is formed. However, in an alternate embodiment, the electronic components28,29could be attached to the rigid section(s)32prior to connection of the rigid section with the flex cable30.

Referring also toFIG. 5, the electrical connector22generally comprises a housing38, electrical contacts40and fusible elements42. The housing38comprises a receiving area44. The receiving area extends into the housing from a second side of the housing opposite the first side50. The electrical contacts40are mounted to the housing38. The electrical contacts40comprise first electrical connection sections46which extend into the receiving area44. More specifically, the first electrical connection sections46extend into the receiving area44from lateral sides of the receiving area. The first electrical connection sections46can comprise deflectable spring sections. Alternatively, the first electrical connection sections46could comprise stationary contact areas. The electrical contacts40also comprises second electrical connection sections48proximate a first exterior side50of the housing38. The fusible elements42are mounted on the second electrical connection sections48.FIG. 7shows a top view of one embodiment of the electrical connector22having a square shaped receiving area44and four arrays of the electrical contacts40located on the four sides of the receiving area. The embodiment shown inFIG. 7is merely one example of how the receiving area could be shaped and the electrical contacts arranged relative to that shape. In alternate embodiments, the receiving area could comprise any suitable type of shape including round or polygonal.

As seen inFIG. 2, the electronic subassembly24is adapted to be inserted into the receiving area44of the electrical connector22. The length and/or width of the electronic subassembly24is larger than the length and/or width of the receiving area44. As the subassembly24is inserted into the receiving area44the lateral side sections34are bent or deform. This causes the electrical conductors on the bottom sides36of the lateral side sections34to come into contact with the first electrical connection sections46of the electrical contacts40. This electrical connection provides an electrical connection between the electronic components28,29of the subassembly24with the fusible elements42.

As seen inFIG. 6, the fusible elements42are melted when the electrical connector22is electrically connected to another member52, such as a printed circuit board, for example. In a preferred method of the present invention, the electrical connector22is connected to the member52before the electronic subassembly24is connected to the electrical connector. Thus, the subassembly24can be connected to the member52after the fusible elements42have been melted. This reduces the exposure of the subassembly24to the heat required to melt the fusible elements42. After the subassembly24is connected to the electrical connector22a suitable device or system could be used to prevent the subassembly24from subsequently unintentionally moving relative to the electrical connector. For example, a potting material or adhesive could the inserted into the receiving area44. As another example, a cover could be located on top of the subassembly24and stationarily attached to the connector22to prevent the subassembly24from moving. Suitable guides, registrations, or fixation means could be used to prevent misalignment of the conductors on the flex cable30with the electrical connectors40. The lateral side sections34of the flex cable30preferably comprise suitable rigidity, in view of the limited space for bending, to resiliently bend and exert a suitable biasing force against the contacts40to retain the conductors of the flex circuit against the contacts40, and provide a frictional force to at least partially retain the subassembly inside the retaining area44.

Referring now toFIG. 8, an alternate embodiment of the present invention is shown. The electronic component assembly52generally comprises an electrical connector54and an electronic subassembly56. The electrical connector54generally comprises a housing58, electrical contacts60and fusible elements42. The housing58comprises a receiving area62. The electrical contacts60are mounted to the housing58. The electrical contacts60comprise four levels64,65,66,67of first electrical connection sections68which extend into the receiving area62. More specifically, the first electrical connection sections68extend into the receiving area62from lateral sides of the receiving area. The first electrical connection sections68can comprise deflectable spring sections. Alternatively, the first electrical connection sections68could comprise stationary contact areas. The electrical contacts60also comprises second electrical connection sections proximate a first exterior side70of the housing58. The fusible elements42are mounted on the second electrical connection sections. In an alternate embodiment, the electrical connector54might not comprise fusible elements42. Instead, second ends of the electrical contacts60could comprise solder tales such as through-hole solder tales or surface mount solder tales.

The subassembly56comprises multiple electronic components or devices72,73,74,75and a flex cable76. In alternate embodiments, more or less than four components could be used. The components72–75are electrically and mechanically attached to the flex cable76at connections78. Any suitable type of connection could be used for the connections78. The electronic components72–75could comprise any suitable type of electronic component such as an integrated circuit for example. The flex cable76has a general folded shape with the electronic components72–75arranged in a general stacked orientation. The flex cable76comprises electrical conductors which form portions of the flex cable at the bent sections of the folded shape to form lateral side contact areas80which contact the electrical connection areas of the electrical contacts60. The bent lateral side sections of the flex cable76comprise suitable rigidity, in view of the limited space for bending, to resiliently bend and exert a suitable biasing force against the contacts60to retain the conductors of the flex circuit against the contacts60, and provide a frictional force to at least partially retain the subassembly inside the receiving area62. The top sides of the electronic components72–75(i.e., the sides of the electronic components located opposite their respective connections78) can be placed against a side of the flex circuit76in this sandwiched configuration.

Referring now also toFIGS. 10–16, one method of forming an alternate embodiment of the subassembly will be described.FIG. 16shows a top plan view of the subassembly82. In this embodiment, the subassembly82comprises a single flex cable84and a plurality of electronic components86–91. The flex cable84has been folded to arrange the electronic components86–91in a general stacked figuration.FIGS. 10–15show, respectively, the steps used to fold the flex cable84to form the subassembly82.

FIG. 10shows the flex cable84before the flex cable84is folded. Electronic components86–91are arranged in two orthogonal rows and mounted to a same side of the flex cable84. In an alternate embodiment, the electronic components could be mounted to more than the same side. In addition, more than two rows could be provided. The flex cable84comprises a general L shape with two orthogonal leg sections92,94. In alternate embodiments, a “T” shape, or single row “|” shape, or a “+” shape could be provided. These are only some examples. Any suitable shapes prior to folding of the flex circuit could be provided.

ComparingFIG. 10toFIG. 11, the first leg section92is folded over a center section96as indicated by arrow98. This locates the first electronic component86over the center section96as seen inFIG. 11. Referring also toFIG. 12, the second leg section94is then folded over the center section96as indicated by arrow100. This locates the second electronic component87over the center section96. Referring also toFIG. 13, the first leg section92is then folded over the center section96as indicated by arrow102. This locates the third electronic component88over the center section96. Referring also toFIG. 14, the second leg section94is then folded over the center section96as indicated by arrow104. This locates the fourth electronic component89over the center section96. Referring also toFIG. 15, the first leg section92is then folded over the center section96as indicated by arrow106. This locates the fifth electronic component90over the center section96. Referring finally also toFIG. 16, the second leg section94is then folded over the center section96as indicated by arrow108. This locates the sixth electronic component91over the center section96.

With this type of arrangement, the flex cable84forms connection sections110at the four sides of the subassembly82at the bends of the flex cable84. The connection sections110are located at different heights or levels of the subassembly and can be subsequently connected to contacts of an electrical connector or equivalent connection system. The folding order can allow substantially simultaneous interconnection of contact surfaces located on the package edge.

The present invention can provide easier rework of the assembly after sale. In service (in the other words after the initial sale), service personnel can just pull out the damaged component from the socket and replace it with a new one without using any soldering. This provides a fast, simple and straightforward service or rework process. This invention can improve protection against physical damages of the electronic components by locating the electronic components inside the housing of the electrical connector as well as at least partially surrounded by the flex circuit. If solder ball connections are used with the electrical connector to another electronic device, such as a mother printed circuit board, the electronic components do not need to be soldered which enables avoiding heat treatments for the electronic components during their production. The subassembly can be pushed into a receiving socket electrical connector in a relatively simple and fast assembly.

Principles of physical modularity are getting more popular in the field of electronics. Usage of conventional interconnection methods between component packages/physical modules and motherboards set limitations for effective usage of module area. One limitation is that components can be added only on one side of the physical module substrate. To solve that limitation, the interconnections of the present invention are provided on physical module's edge area. This enables double sided component assembly on the module. This provides a possibility to shrink the size of the module.

Electronics miniaturization requires multiple integrated circuits assembled into one component package. For BGA interconnections, an increased number of input/output signals force manufacturers to implement and introduce higher BGA pin densities for component packages. This adds special demands for application motherboard technologies and thereby adds cost into all electronics applications. To solve that limitation, the interconnections of the present invention are at least partially provided on component packages edge area(s). This enables smaller physical dimensions for component packages without cost penalty for motherboard technologies.

The present invention provides an interconnection method in-between physical modules and electronics enabling double sided component assembly of the physical modules. The present invention provides interconnections of the module on the edges of the device. The present invention enables double sided component assembly in the module. The interconnections can be produced with flex or flex-rigid PWB technology. There is no need for complicated board-edge plating technologies commonly used in PWB manufacturing. For the socket on the motherboard, intelligent board-to-board connector can be provided because the solution does not waste module surface area.

The present invention enables a smaller total size for physical modules and more functionalities to existing area. The present invention can provide smaller size for physical modules due to double-sided component assembly for the module. The present invention can provide the possibility to simplify motherboard technology. With the present invention, there is easier rework of application in after sales. The module is possible to be disassembled from socket without any soldering. The present invention improves protection against physical damages and dust in the case of a socket which can be closed. The Module electronics can be sealed inside of the socket. There is also the possibility to improve Electro Static Discharge (ESD) and Electro Magnetic Charge (EMC) protection with shielding construction added into socket.

The present invention can enable higher Integrated Circuit (IC) count for components packages within a same physical dimensions (more functionalities to existing area). The present invention can avoid the component going through high temperature soldering process. The present invention can use a Lead Free soldering process which is about to be legislated in Europe in the near future. Soldering process heat profile can be higher than conventional ones. More demanding heat treatment for electronics during assembly can be provided.

The present invention can provide an interconnection method in-between component packages containing multiple integrated circuits and an assembled application. The present invention can provide interconnections of the component on the edges of the device. The present invention can provide interconnections between integrated circuits which can be done within the component package by using a high-density flex interposer. This enables less I/O's for a component itself. This then leads to low-density need in motherboard technology. The present invention can provide interconnections between a component and a socket produced with flex PWB technology. Interconnections between a socket and a motherboard can be done by using conventional gull-wing leads (such as Thin Quad Flat Package (TQFP) packages are using). Usage of a flex cable enables bendable package philosophy and the possibility to locate interconnection surfaces in multiple levels on package edges without extra cost. Customized socket on the motherboard can be provided for an intelligent component-to-board connector.

Referring also toFIG. 17, one example of a hand-held mobile communications device or mobile station210is shown which can include a component assembly of the present invention. In alternate embodiments, the component assembly could be used in any suitable device. The mobile station210typically includes a housing212, a user interface (UI)220, and electronic circuitry222connected to the user interface and located inside the housing. The electronic circuitry can comprise a micro control unit (MCU) having an output coupled to an input of a display214and an input coupled to an output of a keyboard or keypad216of the user interface. The electronic circuitry comprises the assembly of the present invention, such as20or52.

The mobile station210may be considered to be a hand-held radio telephone, such as a cellular or mobile telephone, or a personal communicator, or a PDA, or a gaming device, and may have a microphone and a speaker for conducting voice communications. The mobile station210could also be contained within a card or module that is connected during use to another device. For example, the mobile station210could be contained within a PCMCIA or similar type of card or module that is installed during use with a portable data processor, such as a laptop or notebook computer, or even a computer that is wearable by the user.

The MCU is assumed to include or be coupled to some type of memory, including a read only memory (ROM) for storing an operating program, as well as a random access memory (RAM) for temporarily storing require data, scratchpad data memory, received data packets and data packets prepared for transmission, etc. A separate removable SIM (not shown) can be provided as well. The SIM could store, for example, a preferred public land mobile network (PLMN) list and other subscriber related information.

The mobile station210also contains a wireless section that includes a digital signal processor (DSP), or equivalent high-speed processor, as well as a wireless radio frequency (RF) transceiver218comprising a transmitter and a receiver. The transceiver is coupled to an antenna234for communication with a network operator via a base station236. In an alternate embodiment, features of the present invention could be used with any suitable type of wireless communications device or mobile phone.

As seen inFIG. 17, the keypad216includes an alphanumeric key section216aand a control key section216b. The control key section of216bincludes two soft keys224,225and an up/down scroll key226. However, in alternate embodiments, the control key section could be comprised of any suitable number or type of keys or cursor control device. The two soft keys224,225are located beneath two control indicator sections227,228of the display214. When one of the soft keys224,225are depressed, the controller can perform the menu function listed in the control indicator section227,228located above the depressed soft key.