CA1329261C - Head assembly for rotating storage device - Google Patents

Abstract

Abstract of the Disclosure A slider bearing (i) a head for accessing information on a rotating medium and (ii) conductive terminals for the head, is designed with the conductive terminals mounted on the largest surface of the slider that is not the surface closest to the rotating medium;
or on a surface of the slider parallel to the surface closest to the rotating medium; or the terminals and the head are mounted on different surfaces of the slider.
In another aspect, an apparatus for supporting, on an arm, a head for accessing information on a rotating medium comprises a slider on which the head is mounted in a position for accessing the information, the slider bearing conductive terminals electrically connected to the head; and suspension elements supporting the slider on the arm, the suspension elements having a fixed configuration defining predetermined mechanical characteristics to enable the slider to assume a desired orientation relative to the rotating medium; the suspension elements provide conductive paths from the terminals to the arm.
Another general feature of the invention is a method of making multiple sliders in a batch process by depositing multiple copies of the head in an array of rows and columns on one surface of a block of material, slicing the block into bars along one dimension, depositing multiple copies of the conductive terminals for the head on a surface of the bar adjacent to the surface on which the head is deposited, wherein the conductive paths between the head and the conductive terminals wrap over a corner between the adjacent surfaces, and slicing the bar into individual sliders.

Description

HEAD ASSEMBLY FOR ROTATING STORAGE DEVICE
~ackqround of the Invention This invention relates to sliders on which heads are mounted for accessing information stored on a rotating medium.
A magnetic disk, for example, is typically read from and written on by a magnetic head, held on a movable arm near the surface of the disk. The head is mounted on the rear or trailing edge of a slider, downstream with respect to disk rotation, as part of a head assembly supported by the arm. The head assembly also includes a suspension system and electronic circuitry to connect the head via the arm to the disk drive electronics. Electrical connection from the end of the arm to the head is usually made by a pair of twisted wires welded to the head's terminal pads on the rear edge of the slider. The wires are dressed to form a service loop between the arm and the head. The head and slider do not actually ride on the surface of the rotating disk but instead fly over the disk surface on an air boundary layer created by the rotation of the disk. The slider and suspension are carefully designed to achieve the desired flight characteristics, and the service loop between the arm and the head is arranged to have minimal influence on the suspension/slider mechanical system.
Summary of the Invention The invention features a slider with the conducting terminals for the head mounted on the largest surface of the slider that is not the surface closest to the rotating medium; or on a surface of the slider parallel to the surface closest to the rotating medium;
or the terminals and the head are mounted on different surfaces of the slider.

, . .

., .

2 60412-1~48 In another aspect, the suspension elements ~which have a fixed conflguratlon definlng predetermlned mechanical characteristics to control the movement of the slider) also functlon as the conductlve paths between the arm and conductlve terminals that are located on the slider and are connected to the head.
Another general feature of the lnvention ls a method of maklng multiple sllders ln a batch process by deposltlng multiple copies of the head ln an array of rows and columns on one surface of a block of materlal, sllclng the block into bars along one dlmension, deposlting multlple copies of the conductlve terminals for the head on a surface of the bar ad~acent to the surface on which the head is deposlted, whereln the conductlve paths between the head and the conductlve termlnals wrap over a corner between the ad~acent surfaces, and sllclng the bar lnto lndlvidual sllders.
Preferred embodlments of the lnventlon lnclude the followlng features. Two thln film heads are posltloned on the rear edge of the slider. Thln fllm conductlng clrcultry connects the head on the rear edge of the sllder wlth termlnal pads on the upper surface of the sllder. The head termlnal pads are dlrectly connected, wlthout wlres, to the suspenslon clrcultry elements of the head assembly system and thus to the dlsk drlve electronlcs.
Connectlng the head termlnal pads dlrectly to the termlnal polnts of the suspenslon clrcult ellmlnates the need for a wlre cable servlce loop and, therefore, ellmlnates any mechanlcal lnfluence on the sllder's lntended fllght characterlstlcs. Placlng the head termlnal pads on the large ~, ~J
" ' ~

." ' : , , - ' ~ .

2a 60412-1948 upper surface of the slider enables the sllder to accommodate a larger number of connectlons per head, and allows the overall slider slze to be reduced.
In summary, a flrst broad aspect of the lnventlon provldes a slider bearlng a head for accesslng lnformatlon on a rotatlng rnedium and conductlve termlnals for sald head, sald conductlve termlnals belng mounted on the largest surface of sald sllder that ls not the surface closest to sald rotatlng medlum.
Accordlng to a second broad aspect, the lnventlon provldes a sllder bearlng a head for accesslng lnformatlon on a rotatlng medlum and conductlve termlnals for sald head, sald conductlve termlnals belng mounted on a surface of sald sllder parallel to the surface closest to sald rotatlng medlum.
Accordlng to a thlrd broad aspect, the lnventlon provldes a sllder bearlng a head for accesslng lnformatlon on a rotating medlum and conductlve termlnals for sald head, said conductlve termlnals belng mounted on a surface of sald sllder dlfferent from the surface on whlch sald head ls mounted.
Accordlng to a fourth broad aspect, the lnventlon provldes a method of maklng a sllder of the kind bearlng a head for accesslng lnformatlon on a rotatlng medium and conductlve termlnals for said head, said method comprlsing depositing multlple coples of sald head ln an array of rows and columns on one surface of a block of materlal, sllclng sald block lnto bars along one dlmenslon, depositing multlple coples of sald conductlve termlnals on a surface of sald bar ad~acent to the surface on whlch sald head ls deposlted, whereln conductlve paths between sald head and sald conductlve termlnals wrap over a corner between , ' - ~ : ':
,. ~
~' :
: . .

2b 6041~-1948 said ad~acent surfaces, and slicing sald bar into lndivldual sald sllders.
According to a fifth broad aspect, the lnventlon provldes apparatus for supportlng, on an arm, a head for accesslng lnformatlon on a rotatlng medium, sald apparatus comprlslng a sllder bearlng (1) sald head ln a positlon for accesslng sald lnformatlon, and (11) conductlve termlnals electrlcally connected to sald head, and suspenslon elements supportlng said sllder on sald arm, sald suspenslon elements havlng a fixed conflguratlon deflnlng predetermlned mechanlcal characterlstlcs to enable sald sllder to assume a desired orlentatlon relatlve to sald rotating medium, and sald suspenslon elements provldlng conductlve paths from sald termlnals to sald arm.
Accordlng to a slxth broad aspect, the inventlon provldes a sllder bearlng a head for accesslng lnformatlon on a rotating medlum, comprlslng a rear edge on whlch sald head ls mounted, a rear face perpendlcular to sald rear edge and bearlng electrlcal termlnals for connectlon to a suspenslon element for supportlng sald sllder, and contlnuous conductlve paths leadlng from sald head on sald rear edge to sald termlnals on sald rear face.

" , ,, ~

.: .

.. .

1~29261 Other features and advantages of the invention will be apparent from the following description of the preferred embodiment and from the claims.
Description of the Preferred Embodiment We first briefly describe the drawings.
Fig. l is an exploded isometric view, not to scale, of a portion of a slider suspension system.
Fig. 2 is an isometric view, cut away, not to scale, of a slider attached to other sliders in t~e final stage of slider fabrication.
Fig. 3 is an isometric view, cut away, not to scale, of a block of slider substrate material at the first stage in the slider fabrication process.
Structure Referring to Fig. 1, a movable arm 10 supports, near a magnetic disk 12, a head assembly 20 which includes a suspension circuit 30, a slider 40 attached to the suspension circuit 30, and two thin film heads 50 with appropriate conducting circuitry s2 formed on the slider 40.
The suspension circuit 30, chemically etched or stamped from an electrically conducting material, such as beryllium-copper, is 0.378" x 0.346". It is composed of a set of fingers 36 which are organized in generally concentric tiers. These fingers form a spring suspension for slider 40. The conducting fingers end at terminal points 38 and ground 39, which are welded to the head's eight terminal pads 54 and the common ground terminal pad 56, on the rear (upper) surface 42 of the slider 40. The opposite ends of the conducting fingers are welded at eight terminals 32 to corresponding circuitry on arm 10. Although Fig. l shows the suspension 30 generally in a single plane, for clarity, it is preferred to bend the fingers to form a recess to -` 1329261 receive the slider in order that the center of gravity of the slider lie on the main plane of the suspension.
The fingers of the suspension circuit 30 thus both (i) provide direct electrical connections from the thin film heads 5d via conducting circuitry 52 on the movable arm (not shown) that lead to the disk drive electronics and (ii) have a fixed, carefully designed configuration which defines predetermined mechanical characteristics to enable the slider and suspension system to have desired flight characteristics relative to the magnetic disk.
The slider 40 (Fig. 2) is made of alsimag (which is somewhat conductive) and has a width 43 of 0.126", a length 44 of 0.158", and a thickness 45 of 0.034". Two thin film magnetic heads 50 are deposited on the rear edge 46 of the slider and connected by thin film conductors 52, which extend up over the corner 48 and onto the rear (upper) surface 42 of the slider, to terminal pads 54 located on the rear surface. The thin film conductive paths 52 are 0. 005" wide and 2 microns thick with a minimum of 0. 005" separation between each path. Conductive paths 52 terminate at eight terminal pads 54, four for each head, each terminal pad being 0.020" X 0.015" x 0.0005". An additional conductor from each head terminates in a common ground terminal pad 56 ( 0 . 050" X 0 . 050" X 0 . 0005" ) . The positioning of the conductive paths and the terminal pads is symmetrical and corresponds to the positioning of the terminal points on the suspension circuitry. An encapsulating layer of alumina 60 as an electrical insulator surrounds . .

.
:

the thin film heads and the conductive paths, and underlays the terminal pads, leaving only the top surfaces of the terminal pads exposed.
Prior to the attachment of the suspension circuit to the slider, the thin film heads are tested, and the better one is designated the head to be activated. The suspension circuit is oriented as it is attached to the slider so that the ground terminal pad 39 will also contact two of the terminals (shown as 55 in Fig. 1) from the head that is not to be activated, thus shorting out that head.
Manufacture The slider is manufactured by batch processing. In general, in the first stage, multiple copies of two thin film heads for the rear edges of the sliders are laid down on a block of material in an array of rows and columns. The block is then sliced into bars on which multiple copies of the conductive paths, or thin film circuitry, and conductive terminals for the rear face of the slider are deposited in rows. The conductive paths between the thin film heads and the conductive terminals wrap over a corner between adjacent bar faces. The bars are then sliced into individual sliders for final finishing.
More specifically, referring to Fig. 3, a block 41 of alsimag is polished to produce an extremely flat and smooth surface 61. Next a thin film of alumina 62 is sputtered over the entire surface 61. Each head 50, including its conducting circuitry 52, is then constructed by depositing thin films of different materials on this prepared surface 61. These films are patterned using photoresist techniques; the structure is laminate in form. The conductors of a slider are patterned to reach the edge 63 of the intended rear face ,,, , ., -, of the slider. Another insulating film of alumina 64 is then sputtered over the entire surface, and the block is sliced into bars, along edges such as 63, each bar having a thickness approximately equal to the thickness of the slider.
Referring again to Fig. 2, the rear face of each bar 42, including the exposed ends 53 of the conductor elements 52 that were deposited on the rear edge of the slider, is also polished to produce an extremely flat and smooth surface finish. The ends of the conductors 53 are masked while a thin film of alumina 66 is sputtered over the remaining unmasked surface. The ends of the conductors are then unmasked, and the required thickness of copper to form the remainder of the head conductors 5~ (on the rear face) is sputtered over this prepared surface. A two-axis programmable stage laser is used to remove the copper coating between the elements of the intended circuit pattern. The registration of the pattern must ensure that the start of each conductor element on the rear face of the slider coincides with the corresponding conductor end on the edge of the bar 48. This will form the electri.cal interconnect. A final insulating layer of alumina 60 is sputtered over the surface leaving exposed only the terminal pads and ground which are then plated with copper to the desired additional thickness.
Conventional manufacturing procedures are followed to create an air bearing surface, including rails 72, on the front face of each bar 70. The bar is sliced into individual sliders along edges such as 49 to complete the batch manufacturing process.
Referring again to Fig. 1, the heads are tested to determine the one to be activated and the terminal points 38 and ground 39 of the suspension circuit 30 are welded directly to the terminal pads 54 and the common ground terminal pad 56 on the slider 40 in nine places, shorting out the head that is not to be activated.
Other embodiments are within the following claims.

Claims (19)

1. A slider bearing a head for accessing information on a rotating medium and conductive terminals for said head, said conductive terminals being mounted on the largest surface of said slider that is not the surface closest to said rotating medium.

2. A slider bearing a head for accessing information on a rotating medium and conductive terminals for said head, said conductive terminals being mounted on a surface of said slider parallel to the surface closest to said rotating medium.

3. A slider bearing a head for accessing information on a rotating medium and conductive terminals for said head, said conductive terminals being mounted on a surface of said slider different from the surface on which said head is mounted.

4. The slider of claims 1, 2, or 3 wherein said head is mounted on the rear edge of said slider.

5. The slider of claims 1, 2, or 3 wherein said head comprises a thin film head.

6. The slider of claims 1, 2, or 3 wherein conductive paths between said head and said conductive terminals wrap over a corner of said slider.

7. The slider of claims 1, 2, or 3 wherein said conductive terminals are arranged symmetrically.

8. The slider of claims 1, 2, or 3 wherein two said heads are mounted on the rear edge of said slider.

9. A method of making a slider of the kind bearing a head for accessing information on a rotating medium and conductive terminals for said head, said method comprising depositing multiple copies of said head in an array of rows and columns on one surface of a block of material, slicing said block into bars along one dimension, depositing multiple copies of said conductive terminals on a surface of said bar adjacent to the surface on which said head is deposited, wherein conductive paths between said head and said conductive terminals wrap over a corner between said adjacent surfaces, and slicing said bar into individual said sliders.

10. Apparatus for supporting, on an arm, a head for accessing information on a rotating medium, said apparatus comprising a slider bearing (i) said head in a position for accessing said information, and (ii) conductive terminals electrically connected to said head, and suspension elements supporting said slider on said arm, said suspension elements having a fixed configuration defining predetermined mechanical characteristics to enable said slider to assume a desired orientation relative to said rotating medium, and said suspension elements providing conductive paths from said terminals to said arm.

11. The apparatus of claim 10 wherein said conductive terminals are mounted on the largest surface of said slider that is not the surface closest to said rotating medium.

12. The apparatus of claim 10 wherein said conductive terminals are mounted on a surface of said slider parallel to the surface closest to said rotating medium.

13. The apparatus of claim 10 wherein said conductive terminals are mounted on a surface of said slider different from the surface on which said head is mounted.

14. The apparatus of claims 11, 12, or 13, wherein said head is mounted on the rear edge of said slider.

15. The apparatus of claims 11, 12, or 13 wherein said head comprises a thin film head.

16. The apparatus of claims 11, 12, or 13 wherein conductive paths between said head and said conductive terminals wrap over a corner of said slider.

17. The apparatus of claims 11, 12, or 13 wherein said conductive terminals are arranged symmetrically.

18. The apparatus of claims 11, 12, or 13 wherein two said heads are mounted on the rear edge of said slider.

19. A slider bearing a head for accessing information on a rotating medium, comprising a rear edge on which said head is mounted, a rear face perpendicular to said rear edge and bearing electrical terminals for connection to a suspension element for supporting said slider, and continuous conductive paths leading from said head on said rear edge to said terminals on said rear face.