WO2007081721A2

WO2007081721A2 - Electrical connector

Info

Publication number: WO2007081721A2
Application number: PCT/US2007/000106
Authority: WO
Inventors: William E. Spink Jr.; Robin Johnson; Brian M. Rohrbaugh
Original assignee: Fci Americas Technology, Inc.; Fci
Priority date: 2006-01-05
Filing date: 2007-01-03
Publication date: 2007-07-19
Also published as: WO2007081721A3

Abstract

Disclosed herein is an insert molded lead frame assembly (IMLA). The IMLA includes a lead frame and an overmolded member. The lead frame has at least two electrically separate contacts. The overmolded member surrounds the lead frame. The IMLA includes removed areas of the lead frame and the overmolded member between the electrically separate contacts. A size of the removed areas is a function of a desired impedance of the contacts.

Description

Electrical Connector

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to an electrical connector and, more particularly, to an electrical connector having a contact subassembly.

Brief Description of Prior Developments

[0002] Double Data Rate (DDR) memory is generally known, such as DDR SDRAM (Synchronous Dynamic Random Access Memory), DDR SODIMM, DDR2 SDRAM, DDR2 DIMM, etc. An electrical connector is used to connect DDR memory to another component, such as a mother printed circuit board of a laptop computer for example. U.S. Patent Nos . 6,821,144 and 6,159,040 disclose stacked type electrical connectors having various contact row configurations . Installation and alignment of these contacts within the electrical connectors has become increasingly difficult as connector configurations have become more complex and space limited. There is a desire to provide a double deck 0.6 mm pitch (staggered to 0.3 mm pitch) 400 position memory DDR connector in a right angle format. There is also a desire to solve Printed Circuit Board (PCB) routing issues.

SUMMARY OF THE INVENTION

[0003] In accordance with one aspect of the present invention, an insert molded lead frame assembly (IMLA) is disclosed. The IMLA includes a lead frame and an overmolded member. The lead frame has at least two electrically separate contacts. The overmolded member surrounds the lead frame. The IMLA includes removed areas of the lead frame and the overmolded member between' the electrically separate contacts. A size of the removed areas is a function of a desired impedance of the contacts .

[0004] In accordance with another aspect of the present invention, a method of manufacturing an insert molded lead frame assembly (IMLA) is disclosed. A lead frame is formed having at least two electrical contacts. The at least two electrical contacts are connected by a first area. An overmold member is overmolded over the lead frame. The at least two electrical contacts are separated. The separating of the at least two electrical contacts includes removing the first area and a portion of the overmold member on the first area.

[0005] In accordance with yet another aspect of the present invention, a right angle electrical connector is disclosed. The right angle electrical connector includes a housing and an insert molded lead frame assembly (IMLA) . The housing subassembly includes a top side, a bottom side opposite the top side, and a main section between the top side and the bottom side. The main section includes a first deck and a second deck. The second deck is offset from and above the first deck. The first deck comprises a plurality of first slots. The second deck comprises a plurality of second slots. The IMLA is located within the housing subassembly. The IMLA includes a lead frame and an overmolded member surrounding a portion of the lead frame. The lead frame includes a first contact arm and a second contact arm. The first contact arm is disposed within one of the plurality of first slots. The second contact arm is disposed within one of the plurality of second slots.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The foregoing aspects and other features of the present invention are explained in the following description, taken in connection with the accompanying drawings, wherein:

[0007] Fig. 1 is an exploded perspective view of an electrical connector;

[0008] Fig. 2 is a perspective view a housing subassembly of the electrical connector shown in Fig. 1;

[0009] Fig. 3 is an enlarged view of a portion of the housing subassembly of the electrical connector shown in Fig. 1;

[0010] Fig. 4 is an enlarged view of a portion of the housing subassembly of the electrical connector shown in Fig. 1;

[0011] Fig. 5 is an enlarged view of a portion of the housing subassembly of the electrical connector shown in Fig. 1;

[0012] Fig. 6 is a perspective view of an insert molded lead frame assembly (IMLA) of the electrical connecter shown in Fig. 1;

[0013] Fig. 7 is a perspective view of a lead frame of the IMLA of the electrical connecter shown in Fig. 6; [0014] Fig. 8 is a perspective view of an overmolded member of the IMLA of the electrical connecter shown in Fig. 6;

[0015] Fig. 9 is an enlarged view of a portion of the electrical connector shown in Fig. 1; and

[0016] Fig. 10 is a perspective view of a base of the electrical connector shown in Fig. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] Referring to Fig. 1, there is shown an exploded perspective view of an electrical connector 10 incorporating features of the invention. Although the invention will be described with reference to the exemplary embodiment shown in the drawings, it should be understood that the 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.

[0018] In this embodiment the connector 10 is a double deck, right angle DDR memory connector having Ball Grid Array (BGA) technology. However, in alternate embodiments, features of the invention could be used in other types of connectors including, for example, a connector which is not a double deck connector, or a connector which is not a right angle connector, or a connector which does not use BGA technology.

[0019] In the embodiment shown, the connector 10 comprises a housing subassembly 12, a plurality of Individual (or Insert) Molded Lead Frame Assemblies

(IMLAs) 14 (only one of which is shown), a base 16, and fusible elements 18. The fusible elements may be any suitable fusible elements, such as 0.508 mm (63/37) eutectic solder spheres for example. Referring also to Figs. 2-4, the housing subassembly 12 generally comprises a one-piece housing member 20 and latches 22. The housing member 20 could be comprised of multiple members. The housing member 20 is preferably comprised of molded plastic or polymer material, such manufactured by LCP, Eastman Kodak or Titan for example. The housing member 20 comprises a main section 24 and two side sections 26. The main section 24 comprises two decks 28, 29; one located above the other. The top deck 28 has top and bottom facing slots 30a, 31b therein. The bottom deck 29 has top facing slots 30b therein. The main section 24 also has bottom facing slots 31a located above the top deck 28 (between a top side 33 and the top deck 28) . The slots 30, 31 extend through the main section 24 from an open rear area 32 (see Fig. 9) at the back of the main section, and forward into the decks 28, 29. In the embodiment shown, the bottom slots are offset from the opposing top slots by a 0.3 mm jog. However, any size jog could be provided. It should be understood that although the figures illustrate the main section 24 comprising two decks, any suitable number of decks may be provided. Additionally, although the figures show the housing assembly 12 as comprising two rows of top facing slots and two rows of bottom facing slots, other suitable combinations (or orientations) of top facing and bottom facing slots is envisioned.

[0020] The side sections 26 extend forward from the main section 24 from opposite ends of the main section. The main section 24 and side sections 26 form a bottom side 34 of the housing member 20 which can be placed against and mounted on another member, such as a printed circuit board for example. The side sections 26 each have a slot 36 for receiving a rear end 38 and a bottom section 40 of the latches 22. The side sections 26 each comprise a forward cantilevered, deflectable arm 42 and a bottom section 44. The latches 22 and the side sections 26 combine to form latch assemblies. The latches 22, in this embodiment, each comprise a single metal member with the rear end 38, a bottom arm 50, a top arm 46 and a middle arm 48. The bottom arm 50 and middle arm 48 are stationarily attached to the bottom section 44 by tabs 52, 54 as seen best in Fig. 5. The top arm 46 is attached to the deflectable arm 42 by tab 56. The latch assemblies 22 contain anti-overstress features and a common tab. As seen in Fig. 5, in this embodiment the latches 22 also comprise fusible elements 58, such as solder balls for example, on the bottom of the latches 22 to function as hold downs. In an alternate embodiment, the latches 22 and/or the housing member 20 could comprise any suitable type of hold down, such as a pin section (or pin in paste) for example.

[0021] Referring also to Figs. 6-9, each IMLA 14 generally comprise a lead frame 60 and an overmolded member 62. Fig. 7 shows the lead frame 60 before the member 62 is overmolded into the lead frame. Fig. 8 illustrates merely the overmolded member 62, but the overmolded member 62 does not exist without the lead frame 60. In addition, Fig. 7 shows the lead frame 60 before slug-outs (or removed areas) are made at areas 64. The dimensions shown in the drawings are for exemplary purposes only. [0022] The lead frame 60 comprises four solder tails 66, two retention features 68, 70, -and four contact arms 72-75. The top two arms 72, 73 are located in the top and bottom slots 30a, 31a, respectively^". Contact areas at the ends of the arms 72, 73 project (beyond the slots 30a, 31a) into the space above the top deck 28. The bottom two arms 74, 75 are located in the top and bottom slots 30b, 31b, respectively. Contact areas at the ends of the arms 74, 75 project (beyond the slots 30b, 31b) into the space above the bottom deck 29. The contact areas of the two top arms 72, 73 are offset from each other by about 0.3 mm by jog 76 in the arm 73. The contact areas of the two bottom arms 74, 75 are offset from each other by about 0.3 mm by jog 78 in the arm 75. It should be noted that although the figures illustrate the IMLAs 14 as having four contact arms, either a greater or fewer number of contact arms may be provided. Furthermore, the lead frame 60 may be formed from any suitable electrically conductive material such as metal for example. In one embodiment, the lead frame 60 may be formed from 0.15 mm thick Phosphor Bronze (C521 - Hard) . Additionally, another alternative embodiment may comprise plating at the contact areas at the ends of the arms 72, 73, 74, 75. The plating may preferably comprise at least about 8 μin. Au (Gold) and at least about 50 μin. Ni (Nickel) for example.

[0023] After the overmold member 62 is overmolded onto ^•the lead frame 60, slug-out (or removed) areas 64 of the lead frame and part of the overmold member are removed to electrically separate the arms 72-75 from each other (as shown at areas "A" in Fig. 6) . Thus, each arm 72-75 can transmit a separate individual signal therethrough. The overmolded member 62 preferably surrounds a portion of the lead frame 60 which comprises the areas 64. In one embodiment, the areas "A" may preferably be at least about 0.25 mm wide for example. It should be noted that although the figures illustrate two removable areas 64 between adjacent contact arms, alternative embodiments may provide any suitable number of removable areas 64 between adjacent contact arms. As seen in Fig. 9, the IMLAs 14 are inserted into the rear of the housing member 20 at area 32. The IMLAs 14 are assembled to the housing member 20 using an interference fit, or press fit, between the lead frame retention features 68, 70 and the housing member 20 (illustrated at area ^Λ>B" in Fig. 9) . The solder tails 66 face towards the bottom side 34, but are contained in the area 32.

[0024] Fig. 10 shows a perspective view of the base or wafer 16. The base 16 is preferably comprised of plastic or polymer material. The base 16 comprises holes 80. The ' base 16 is adapted to be mounted to the housing member 20 at the bottom of the area 32 with the ends of the solder tails 66 at the holes 80. The solder balls 18 can be attached to the base 16 at the holes 80 by paste and heated to attach the solder balls onto the solder tails 66. This ball attach may provide an additional securing mechanism of the IMLAs 14 to the housing subassembly 12. In alternate embodiments, any suitable system for attaching the solder balls to the solder tails could be provided. Alternatively, solder balls might not be used, such as when the solder tails are surface mount solder tails or through-hole solder tails. It should also be noted that the dimensions shown in the drawings are for exemplary purposes only. [0025] Insert molding of plastic onto metal contacts is known. The use of slug-outs on a metal lead frame to separate contacts is generally known, such as in Metral® 1000 2000, 4000 series connector manufactured by FCI USA, Inc. which are made with Individual Molded Lead Frame Assemblies (IMLAs) and the carrier is then slug out. The invention, on the other hand, slugs out or removes both connecting portions of the metal lead frame as well as portions of the overmolded plastic member. The insert molding, then slug-out of the connector is unique in that the slug-out operation (size) is what actually determines, or is a function of, the impedance of the conductors. With the invention, edges of stamped contacts can be used for contact with the memory module. Staggering of the solder tails is done so there is physical room between the balls 18 of the BGA. This concept is unique in its stacking concepts and because of the BGA application.

[0026] One basic concept is the use of a stamped lead frame that contains upper and lower sets of DDR card connector contacts . The lead frames are overmolded and punched at the slug-out location^'s . There can be two different lead frame configurations (left and right) . Latch subassemblies can be provided on the housing subassembly. The overmolded stacked card contacts and the combination of the individual molded lead frame assemblies (IMLAs), the bottom base, the housing subassembly, and the solder balls provide a new type of connector.

[0027] The invention can be a solution to the dilemma of manufacturing a double deck 0.6 mm pitch (staggered to 0.3 mm pitch) 400 positions memory DDR connector in right angle format. This concept also solves PCB routing issues via the Ball Grid Array (BGA) approach. BGA eliminates PCB routing issues that are encountered when considering implementing a standard gull wing or j-lead Surface Mount Technology (SMT) approach for this type of 400 pin memory connector.

[0028] It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the" present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims .

Claims

CLAIMSWhat is claimed is:

1. An insert molded lead frame assembly (IMLA) comprising:

a lead frame comprising at least two electrically separate contacts; and

an overmolded member surrounding the lead frame, wherein the IMLA comprises removed areas of the lead frame and the overmolded member between the electrically separate contacts, and wherein a size of the removed areas is a function of a desired impedance of the contacts .

2. The IMLA of claim 1 wherein each of the at least two electrically separate contacts is configured to be disposed within an electrical connector housing slot.

3. The IMLA of claim 2 wherein each of the at least two electrically separate contacts comprises a contact area configured to project beyond the slot.

4. The IMLA of claim 1 wherein each of the at least two electrically separate contacts comprises a solder tail configured to be connected to a base.

5. The IMLA of claim 1 wherein an end of a first one of the contacts is offset from an end of a second one of the contacts .

6. The IMLA of claim 1 further comprising a retention feature configured to engage with a housing in an interference fit.

7. The IMLA of claim 1 wherein a first one of the contacts is configured to be disposed within a first slot having a first orientation and a second one of the contacts is configured to be disposed within a second slot having a second orientation.

8. An electrical connector comprising a housing subassembly having at least two offset decks, and an insert molded lead frame assembly as in claim 1 insertable into a rear area of the housing subassembly.

9. A method of manufacturing an insert molded lead frame assembly (IMLA) comprising:

forming a lead frame comprising at least two electrical contacts, wherein the at least two electrical contacts are connected by a first area;

overmolding an overmold member over the lead frame; and

separating the at least two electrical contacts, wherein the separating comprises removing the first area and a portion of the overmold member on the first area.

10. The method of claim 9 wherein the forming further comprises offsetting an end of a first one of the contacts from an end of a second one of the contacts.

11. The method of claim 9 wherein the forming further comprises providing a second area connecting the at least two electrical contacts.

12. The method of claim 11 wherein the overmolding further comprises surrounding a portion of the lead frame comprising the first area and the second area with the overmold member.

13. The method of claim 12 wherein the separating further comprises removing the second area and a portion of the overmold member on the second area.

14. A right angle electrical connector comprising:

a housing subassembly comprising a top side, a bottom side opposite the top side, and a main section between the top side and the bottom side, wherein the main section comprises a first deck and a second deck, wherein the second deck is offset from and above the first deck, wherein the first deck comprises a plurality of first slots, and wherein the second deck comprises a plurality of second slots; and

an insert molded lead frame assembly (IMLA) disposed within the housing subassembly, wherein the IMLA comprises a lead frame and an overmolded member surrounding a portion of the lead frame, wherein the lead frame comprises a first contact arm and a second contact arm, wherein the first contact arm is disposed within one of the plurality of first slots, and wherein the second contact arm is disposed within one of the plurality of second slots.

15. The right angle electrical connector of claim 14 further comprising a base having a plurality of holes, wherein the base is disposed within a rear area of the main section, and wherein a plurality of fusible elements are disposed within the plurality of holes.

16. The right angle electrical connector of claim 15 wherein a solder tail of the first contact arm is attached to one of the fusible elements .

17. The right angle electrical connector of claim 14 wherein an end of the first contact arm is offset from an end of the second contact arm.

18. The right angle electrical connector of claim 14 further comprising a side section extending from an end of the main section, wherein the side section comprises a bottom section and a deflectable arm, and wherein a latch is attached to the bottom section and the deflectable arm.

19. The right angle electrical connector of claim 14 wherein the plurality of first slots are facing the top side and the plurality of second slots are facing the bottom side .

20. The right angle electrical connector of claim 14 wherein the second deck further comprises a plurality of third slots, wherein the main section further comprises a plurality of fourth slots, wherein the lead frame further comprises a third contact "arm and a fourth contact arm, and wherein the third contact arm is disposed within one of the plurality of third slots and the fourth contact arm is disposed within one of the plurality of fourth slots .