CA2143685F

CA2143685F - Pcmcia standard memory card package

Info

Publication number: CA2143685F
Application number: CA002143685A
Authority: CA
Inventors: James J. Farquhar; Charlie Centofante; Kenneth Dorf; Iggoni Fajardo; Brandt Weibezahn
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-07-15
Filing date: 1994-07-13
Publication date: 1995-01-26
Anticipated expiration: 2014-07-13
Also published as: EP0884163A1; DE69432196T2; USRE36540E; DE69423960D1; DE69432196D1; EP0884163B1; KR950702904A; DE69424324T2; EP0962884B1; DE69432324T2; AU677085C; US5490891A; AU677085B2; JPH08505727A; KR100192074B1; WO1995002499A1; AU7221194A; DE69423960T2; EP0682597A4; EP0967571A3

Abstract

A package (10) for a memory card (28) and the process by which the package i s manufactured. The package comprises chiefly two stamped steel covers, (an upper (12) and a lower cover (14) half), each secured to a plastic frame element (16 and 18). The cover halves (16 and 18) are secured by extended fingers (26) which wrap around the plast ic frame (16 and 18). This provides a double layer of metal at the perimeter of the frame. The two cover halves (12 and 14) are situated so as to encapsulate the subject PCB (28) and to affix it in its proper position. The two cover halves (12 and 14) are then welded together using sonic welding on the plastic frame. The package (10) has been designed to meet all PCMCIA standards, including polarizing keys an d grounding points.

Description

~~VO 95/02499 . ~ ~ ~ ~ ~ ~ PCT/US94I07903 PCMCIA STANDARD MEMORY CARD PACKAGE
FIELD OF THE INVENTION ' The present invention relates generally to memory media and I/O device containers, and more particularly to a package for printed circuit boards (PCB's) that conforms to standards set by PCMCIA, JEDIC, ISO, etc. for peripheral l0 devices.
$ACKGROUND OF THE INVENTION
Current technology computing devices are so small that there is very little room for storage devices such as a hard disk drive or I/O device. In order to expand a portable, 15~ laptop, or any other type of computer's capacity and functioning capability, manufacturers have devised "plug-in"
peripheral cards in the form of printed circuit boards (PCB's) contained within an exterior package. These devices are termed "PCMCIA style peripheral devices".
20 The PCMCIA style devices can be used to perform the functions of software, resident memory in hardware devices, or in the place of a hard drive. The cards can be used as flash memory, to facilitate LAN networking, paging devices, and as FAX modems. They may be used in cellular telephones, 25 PROMS, EPROMS, EEPROMS, RAMS, SRAMS, and DRAMS. In short, the cards are very versatile as well as inexpensive.

03/08/01 THU 18: 50 FAX 604 922 2957 - _. _ _ L~~~PAT-9VEST YANCOUYER
---.-_.__ X007 W/O 95/02A99 PCf/U59A/~'7903 Due to the myxiad methods possible to construct the interface of the mempry caxd with the computer, the gersanal Computer Memory Card intsrnat;.onal Association (PCMCIA) and comparable organizations have established certain standards for the construction pf the memory cards within their packages.
Use constraints rewire that a gC8 be sealed within a rigid package far insertion into the PC. One problem in thc~ current art methods of fix~.ng the card in metallic packages is that adhesives, solvents and/or epoxies are generally used to secure the two halves of the package. Since the banding requires the adhesion of twc~ disaimilar metals, current art processes can lead to functional problems with the 'card, as well as to failuxes of the band.
Another disadvantage is that current art constructions use many components, leading to greater manufacturing cost, and a higher likelihood of failures.
CT T S TH I TION
Accordingly, it is an object of tlye present invent~.on to pr4vide a PCMCIA style peripheral device package that meets PCMCIA, JrEpIC, and I8U s~tandaxds. It is a further objBCt of the present. invention to provide a package that comprises few 3o components to reduce manufacturing coat.

03/08/01 THLf 18:50 FAX 809 922 2957-_--U~NPAT=WgST VANCOUVER
__- _ -------_-._ - ~ 0 0 8 W/0 95/02499 PCT/US9a/07903 Acaord.ing to the present invention, there is disclosed a pe~ripharal devioe gCB package comprising two stamped metal covers With a plastic frame el~nent corresponding to each cover, wherein the metal covers are fixedly s~cu=ed to the plastic frame elements, the pla,stia frame elements forming an integral unit with the covers, the plastic frame elements being injection molded around a plurality of fingers extending from the periphery of the metal Govexs; and wherein the plastic frame element r~xtends beyond the plane of the metal cortrer so that a plastic perimeter surface is exposed, thereby Facilitating the bonding of tt7~ tW0 cOVBrB
According to a further asspect of the inv~ntion, there is provided a method of rcvanufaoturing a package for a memory card comprising the following steps:
A. Stamping metal Govexs to a size marginally larger than a mold in an injection molding process:
H. inserting the covers into a mold in an injection molding prooess where they are slightly sprung and thus secure themselves in position;
C. Shooting pla,stia frame elements into the mold so that fingers included on the covers become embedded in the frames;
fl . positioni.ng a PC8 betvreen ttao covers , the PCB being held in the proper location by means of ejaat4r pines on the plastic Frames, the ejector pins being inherent to ~Ghe molding process;
E. Bonding the two covers together so that a memory Card is foamed.

0.3/08/01 T3fU 1B: S1 Fig B04 922 2957 ~-- Ugg~p~T_yyEST VANCOLIVER

Advantages of the present inver~tion are as follows:
1. Joi.nder of the two package halves can be accomplished without the use of adhesives. This leads to greater reliability of the memory card.
2. Vary few components are used, m.inimvzitig manufacturing costs.
3. More space for the PCB is availabls~ within a given package volume.
ri. Th$ present invention provides a memory card package that is stronger than prior art packages.
5. The device can~dtruated according to the present invention lends itself td au~:omated assembly.
6. The device of the present invent~.on ~.s very versatile, and can be used for types I, II, III, and Iv boards.
It is envisioned that future board designs will 08/03/2001 419:48 ~,A604 922 ~y57 ----.-----~_ received WO 95/02499 PCTIITS941f190~
-~~~'y,~ ~ 8 also be compatible with the present invention.
7. The process will allow a card manufacturer to bond only similar materials, plastic to plastic, since the bonding of the dissimilar materials, plastic to metal, is V
accomplished by the package manufacturer. -8. Application of a non-conductive layer to the two cover halves prior to stamping allows the package to have a non-conductive interior.
9. The design allows the PCB to be fixed in place by opposing plastic elements ("bosses") at any level within the package.
10. The PCB connectors and/or other I/O devices can be clamped between the cover halves.
11. Overall package thickness can be controlled to a very strict tolerance.
12. The package provides variable grounding locations along the length of the package sides.
These and other objects and advantages of the present invention will become apparent to those skilled in the art in view of the description of the best presently known mode of carrying out the invention as described herein and as illustrated in the drawings.
~RTEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective exploded view of the metal covers and plastic frame of the package of the present ~'VO 95/02499 . PCT/US94/07903 ' ~'~.~~~5:~
invention:
Fig. 2 is a detail view of the plastic frame showing the energy director utilized in the sonic welding process;
Fig. 3 is an exploded front end view of the metal 5 package covers and plastic frame:
Fig. 4 is side cross-sectional view of a memory card and package as embodied by the present invention.
BEST MODE OF CARRYING OUT THE INVENTION
The present invention is a PCMCIA style peripheral device package 10. Referring to Fig. l, it can be seen that the package l0 comprises chiefly an upper cover 12, a lower cover 14, an upper frame element 16, and a lower frame element 18. The covers 12 & 14 are formed from stamped metal, and the frame elements 16 & 18 are molded plastic.
While the material for the covers is chosen to be stamped metal, there is no requirement that it be so. Any rigid material will suffice. However, if the cover is of a conductive material, it will serve to reduce EMI, RF and ESD
problems, these being factors which electronic devices seek to minimize. It should be further noted that conductive material cannot be eliminated completely as PCMCIA requires a grounding point. The covers 12 & 14 will generally be mirror images of each other, but may nat be in certain applications.
An optional addition to the present invention is to coat the interior of the covers 12 & 14 with a thin layer of PCT/US94/0790~

a non-conductive material. This allows the finished product to have a conductive exterior with a non-conductive interior, thus isolating the conductivity of the interior of the package.
Referring now to Figs . 2 & 3 , a lower energy director "
20 extends above one-half of the perimeter upper surface of the lower frame element 18. A corresponding energy director element 22 extends along one-half of the lower perimeter surface of the upper frame element 16. These energy directors 20 & 22 mate with the corresponding frame surface to form the weld during the sonic welding process.
A polarizing key 24 is located at a corner of the lower frame element 18. The polarizing key 24 defines how the PCMCIA style peripheral device mates with the device in which it is being used. The polarizing key is defined for a given use by PCMCIA.
In order to facilitate bonding, the edges of the covers 12 & 14 are bent to conform generally to the shape of the frame elements 16 & 18. In addition, metal fingers 26 are provided on each end of the covers 12 & 14. The metal fingers 26 curl inward, and are encased in the plastic frame elements 16 & 18 during the molding process. The fingers may be further secured during the bonding process. The free ends of the fingers 26 may be provided with a non-liner shape to cause them to be more securely embedded in the plastic frame elements 16 & 18. In one embodiment, the ends "

~'O 95102499 . PCT/US94/07903 of the fingers 26 have a diamond shape to ensure that once embedded in the plastic, they cannot be pulled out.
This procedure of embedding the fingers 26 in the plastic frame elements 16 & 18 ensures that when the two frame elements are bonded, the two halves of the package are securely affixed to each other. The covers 12 & 14 being wrapped around the frame elements 16 & 18 also serves to strengthen the package due to there being a double layer of metal at the perimeter.
The manufacture of the PCMCIA style peripheral device with its package is accomplished as follows: first, the upper and lower covers 12 & 14 are stamped. The covers 12 &
14 are then mated with the frame elements 16 & 18. This is accomplished by injection molding. The covers 12 & 14 are placed into a mold, where they are "self-secured" in position. The self-securing is accomplished by the geometry and dimensions of the covers 12 & 14. The covers 12 & 14 are stamped to be slightly wider than the mold. Thus the covers are slightly sprung when they are placed into the mold, and remain in the proper position for the injection process. Certainly there is no requirement that the covers be self-sec~~ared in the mold. Any means of securing will suffice.
The plastic frame elements 16 & 18 are then shot into the mold. As the plastic frames are molded, the metal fingers 26 on the covers 12 & 14 become embedded in the 2 ~. 4Yrr~ '~ ~i :-.
frame elements 16 & 18 so that separation of the covers 12 &
14 from the frame elements 16 & 18 cannot take place. The end result of the molding process is that the covers 12 & 14 have a metal surface exposed at their sides to create a grounding point when bonded together. Further toward the ' interior of the unit, the plastic energy directors 20 & 22 are also exposed to facilitate bonding.
One aspect of using an injection molding process is that injection molding requires that ejector pins 17 be provided on the frame elements 16 & 18. In the present invention, the ejector pins 17 are also used to position a PCB 28 that is to be packaged in the package 10. The pins 17 provide a supporting surface for the PCB 28 which can be adjusted to any height desired for a particular application.
Thus an element necessary for the injection process becomes a key for the positioning of the board in the package.
Positioning of the PCB is therefore accomplished easily and at minimal additional cost.
The energy directors 20 & 22 are then sonic welded to the opposing plastic frame element so that the upper frame ' element 16 is permanently bonded to the lower frame element 18, both of which encase the PCB 28.
Thus the covers are secured to the frame elements, which in turn are welded to each other. This ensures that the memory card package will be very reliable and durable, and that the package height is controlled.

~O 95/02499 PCT/US94/07903 2~.~~~~~
It should be noted that it is envisioned that the bonding process between the cover elements may also be performed by resistance welding.
A further option is to inject a foam into the interior of the package which would crystallize and act as an insulator or a heat sink.
It should also be noted that in practice, a card manufacturer will receive the two cover halves ready for welding, and will be the supplier of the board. Because the package has a modular design, it will accommodate many different connectors. Further, because the package manufacturer has accomplished a secure bonding of dissimilar materials, the metal covers bonded to the plastic frame, the bonding required by the card manufacturer is a simple process involving only bonding of like materials, i.e.
plastic to plastic sonic gelding.
The above disclosure is not intended as limiting.
Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention.
Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.

Claims

We claim:

1.~A peripheral device PCB package comprising:
two stamped metal covers with a plastic frame element corresponding to each cover, wherein the metal covers are fixedly secured to the plastic frame elements, the plastic frame elements forming an integral unit with the covers, the plastic frame elements being injection molded around a plurality of fingers extending from the periphery of the metal covers;
and wherein the plastic frame element extends beyond the plane of the metal cover so that a plastic perimeter surface is exposed, thereby facilitating the bonding of the two covers.

2. ~The package as claimed is claim 1 wherein:
ejector pins are provided on the plastic frames, the pins being used during the molding process and also to position a PCB.

3. ~The package as claimed in claim 1 wherein: the plastic frame elements include a polarizing key.

4.~The package as claimed in clam 1 wherein: the plastic frame elements include energy directors to facilitate the bonding process.

5. The package as claimed in claim 1 wherein: a grounding point is established by metal-to-metal contact of the covers.

6. The package as claimed in claim 1 wherein; the bonding of the two covers is accomplished by sonic welding.

7. The package as claimed in claim 1 wherein: the bonding of the two where is accomplished by resistance welding.

8. The package as claimed in claim 1 wherein: the bonding process is accomplished by adhesives.

9. The package as claimed in claim 1 wherein: the interiors of the covers are coated with a thin layer of noon-conductive material.

10. A method of manufacturing a package for a memory card, the method comprising the steps of:
A ~stamping metal covers;
B ~bending edges of said covers to conform to an intended shape of a frame element, the edges including fingers extending from the cover sides:
C ~inserting the covers into a mold;
D ~shooting plastic into the mold to form the frame element around the fingers;
E ~removing said covers from said mold:
F ~positioning a PCB between two covers, and;
G ~bonding the plastic frame elements together so that a package is formed.

11. A method of manufacturing a package as claimed in claim 10 wherein; the metal covers in step A are stamped to a size marginally larger than the mold in the injection molding process and the covers in step C are inserted into an injection molding process where they are slightly sprung and thus secure themselves into position.

12. The package as claimed in claim 10 wherein; the bonding process (G) is sonic welding.

13. The package as claimed in claim 10 wherein; the bonding process (G) is resistance welding.

14. The package as claimed in claim 10 wherein: the bonding process (G) utilizes adhesives.

15. The package as claimed in claim 10 wherein: the interiors of the covers are coated with a thin layer of non-conductive material.

16. A peripheral device PCB package comprising: two stamped metal covers with a plastic frame element corresponding to each cover, wherein each of the metal covers is fixedly secured to the corresponding one of the plastic frame elements, each of the plastic frame elements forming an integral unit with the corresponding one of the covers, the plastic frame elements being injection molded around a plurality of fingers extending from the periphery of each of the metal covers and each of the plurality of fingers terminating in a free end which is embedded in a respective plastic frame element; and wherein at least one of the plastic frame elements extends beyond the plane of the metal cover so that a plastic perimeter surface is exposed between the plastic frame elements thereby facilitating the bonding of the two covers.