Cable bonding protection for head dimensional stability

Abstract

An apparatus including a beam, a chip coupled to the beam, a cable coupled to the beam by a first material located at an opposing end of the cable, and wire bonds extending from pads on the cable to pads on the chip. An apparatus including a beam and a chip coupled to the beam. The chip includes an array of magnetic transducers for transducing data on a magnetic recording tape. An apparatus including a cable coupled to the beam by a first material located at an opposing end of the cable, wire bonds extending from pads on the cable to pads on the chip, and a second material sealing ends of the wire bonds located adjacent the cable. The second material does not contact the chip.

Description

Technical Field

[0001] The present invention relates to a data storage system, and more particularly, to cable bonding protection for head dimension stability.

Background Art

[0002] In a magnetic storage system, a magnetic transducer reads data from and writes data to a magnetic recording medium. Data is written to the magnetic recording medium by moving the magnetic recording transducer to a position on the medium where the data is to be stored. The magnetic recording transducer generates a magnetic field and encodes the data onto the magnetic medium. Data is read from the medium by similarly positioning a magnetic read transducer and sensing the magnetic field of the magnetic medium. The read and write operations can be synchronized independently of the movement of the medium to ensure that data can be read from and written to desired locations on the medium.

[0003] An important and ongoing goal in the data storage industry is to increase the density of data stored on the medium. In the case of tape storage systems, this goal has led to an increase in the track density and linear bit density of the recording tape and a reduction in the thickness of the magnetic tape medium. However, the development of small and high-performance tape drive systems has presented various challenges, from the design of the tape head assembly used in such systems to addressing tape dimension instability.

Summary of the Invention

[0004] An apparatus according to one embodiment includes a beam, a chip coupled to the beam, a cable coupled to the beam by a first material located at opposite ends of the cable, and a wire bond extending from a pad of the cable to a pad of the chip.

[0005] An apparatus according to one embodiment includes a beam and a chip coupled to the beam. The chip includes an array of magnetic transducers for converting data on a magnetic recording tape. The apparatus includes a cable coupled to the beam by a first material located at opposite ends of the cable, a wire bond extending from a pad on the cable to a pad on the chip, and a second material sealing the end of the wire bond located adjacent to the cable. The second material does not come into contact with the chip.

[0006] Any of these embodiments may be implemented in a magnetic data storage system, such as a tape drive system, which may include a magnetic head, a drive mechanism for passing a magnetic medium (e.g., a recording tape) over the magnetic head, and a controller electrically coupled to the magnetic head.

[0007] Other aspects and embodiments of the present invention will become apparent from the following detailed description and, in conjunction with the drawings, the principle of the present invention will be illustrated as an example. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a schematic diagram of a simplified tape drive system according to one embodiment. [Figure 1B] This is a schematic diagram of a tape cartridge according to one embodiment. [Figure 2A] This is a side view of a flat wrap bidirectional 2-module magnetic tape head according to one embodiment. [Figure 2B] This is a view of the tape bearing surface as seen from line 2B in Figure 2A. [Figure 2C] This is a detailed view from circle 2C in Figure 2B. [Figure 2D] This is a detailed view of a partial tape bearing surface of a pair of modules. [Figure 3] This is a partial tape bearing view of a magnetic head having a write-read-write configuration according to one embodiment. [Figure 4]This is a partial tape bearing view of a magnetic head having a read-write-read configuration according to one embodiment. [Figure 5] This is a side view of a magnetic tape head comprising three modules according to one embodiment, in which all modules are arranged along a plane that is generally almost parallel to each other. [Figure 6] This is a side view of a magnetic tape head equipped with three modules arranged tangentially (at an angle) according to one embodiment. [Figure 7] This is a side view of a magnetic tape head with three overlapping modules. [Figure 8A] This is a schematic diagram illustrating the principle of tape tenting. [Figure 8B] This is a schematic diagram illustrating the principle of tape tenting. [Figure 8C] This is a schematic diagram illustrating the principle of tape tenting. [Figure 9] This is a diagram illustrating a representation of files and indexes stored on magnetic tape according to one embodiment. [Figure 10A] This is a side view of a device according to one embodiment. [Figure 10B] This is a cross-sectional view of the apparatus in Figure 10A along line 10B-10B. [Figure 11A] This is a side view of a device according to one embodiment. [Figure 11B] This is a detailed diagram of a device according to one embodiment. [Figure 11C] This is a cross-sectional view of a device according to one embodiment. [Figure 12A] This is a side view of a device according to one embodiment. [Figure 12B] Another embodiment of the apparatus shown in Figure 12A is shown. [Figure 12C] Another embodiment of the apparatus shown in Figure 12A is shown. [Modes for carrying out the invention]

[0009] The following description is made for the purpose of explaining the general principles of the present invention and does not limit the inventive concept claimed in this specification. Further, the specific features described herein can be used in combination with other described features in each of various conceivable combinations and permutations.

[0010] Unless otherwise specifically defined herein, all terms are to be construed as broadly as possible including meanings implied from this specification, meanings understood by those skilled in the art, or meanings defined in dictionaries or treatises, or combinations thereof.

[0011] Also, note that when used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless otherwise specified.

[0012] In the following description, some preferred embodiments of a magnetic storage system, as well as its operation or components or both, are disclosed.

[0013] In a general embodiment, the device includes a beam, a chip coupled to the beam, a cable coupled to the beam by a first material located at opposite ends of the cable, and a wire bond extending from a pad of the cable to a pad of the chip.

[0014] In another general embodiment, the device includes a beam and a chip coupled to the beam. The chip includes an array of magnetic transducers for converting data on a magnetic recording tape. The device includes a cable coupled to the beam by a first material located at opposite ends of the cable, a wire bond extending from a pad of the cable to a pad of the chip, and a second material for sealing an end of the wire bond located adjacent to the cable. The second material does not contact the chip.

[0015] Figure 1A shows a simplified tape drive 100 of a tape-based data storage system that may be employed in the context of the present invention. While Figure 1A shows one particular embodiment of the tape drive, it should be noted that the embodiments described herein may be implemented in the context of any type of tape drive system.

[0016] As shown in the figure, a tape supply cartridge 120 and a take-up reel 121 are provided to support the tape 122. One or more of the reels may form part of a removable cartridge and are not necessarily part of the tape drive 100. The tape drive, as shown in Figure 1A, may further include drive motors(s) for driving the tape supply cartridge 120 and the take-up reel 121 to move the tape 122 onto any type of tape head 126. Such heads may include an array of read converters (also called readers), write converters (also called writers in the art), or both.

[0017] Guide 125 guides the tape 122 to the tape head 126. Such a tape head 126 is coupled to a controller 128 via a cable 130. The controller 128 may be a processor or any logic, or both, for controlling any subsystem of the drive 100. For example, the controller 128 typically controls head functions such as servo tracking, data writing, and data reading. The controller 128 may include at least one servo channel and at least one data channel, each of which includes data flow processing logic configured to process and store, or both, information that is written to or read from the tape 122, or both. The controller 128 may operate under logic known in the art, as well as any logic disclosed herein, and can therefore be considered in various embodiments as any processor in the tape drive descriptions included herein. The controller 128 may be coupled to a memory 136 of any known type, which may store instructions executable by the controller 128. Furthermore, the controller 128 may be configured, programmable, or both capable of executing or controlling some or all of the methodologies presented herein. Thus, the controller 128 is thought to be configured to perform various operations by one or more chips, modules, or blocks, or combinations thereof, programmed logic; one or more processors, available software, firmware, or other instructions, or combinations thereof; and combinations thereof.

[0018] Cable 130 may include read / write circuits for transmitting data to be recorded on tape 122 to tape head 126 and for receiving data read from tape 122 by tape head 126. Actuator 132 controls the position of tape head 126 relative to tape 122.

[0019] Furthermore, an interface 134 may be provided, as will be understood by those skilled in the art, for communication between the tape drive 100 and the host (internal or external) for sending and receiving data, controlling the operation of the tape drive 100, and communicating the status of the tape drive 100 to the host.

[0020] Figure 1B shows an exemplary tape cartridge 150 according to one embodiment. Such a tape cartridge 150 can be used with a system such as the one shown in Figure 1A. As shown, the tape cartridge 150 includes a housing 152, a tape 122 within the housing 152, and a non-volatile memory 156 coupled to the housing 152. In some methods, the non-volatile memory 156 can be embedded inside the housing 152, as shown in Figure 1B. In more methods, the non-volatile memory 156 may be mounted inside or outside the housing 152 without modifying the housing 152. For example, the non-volatile memory may be embedded in a self-adhesive label 154. In one preferred embodiment, the non-volatile memory 156 may be embedded inside or outside the tape cartridge 150, or may be a flash memory device, read-only memory (ROM) device, etc., coupled thereto. The non-volatile memory is accessible by the tape drive and tape operating software (driver software), or another device, or both.

[0021] As an example, Figure 2A shows a side view of a flat-lap bidirectional two-module magnetic tape head 200 that may be implemented in the context of the present invention. As shown, the head includes a pair of bases 202, each comprising a module 204, fixed at a small angle α to each other. The bases may be “U-beams” bonded to each other. Each module 204 includes a substrate 204A and a closure 204B having a thin film portion commonly called a “gap,” within which a read converter or a write converter or both 206 are formed. During use, the tape 208 moves along the module 204 along the medium (tape) bearing surface 209 in the manner shown to read and write data on the tape 208 using the read converter and the write converter. The lap angle θ of the tape 208 at the ends entering and exiting the flat medium bearing surface 209 is typically between about 0.1 degrees and about 3 degrees.

[0022] The substrate 204A is typically made of a wear-resistant material such as ceramic. The closure 204B may be made of the same or similar ceramic as the substrate 204A.

[0023] Cable 211 is provided to enable communication between the controller and the transducer 206 of each module 204. The pads of cable 211 are typically wire-bonded to the pads of the associated module 204.

[0024] The read and write converters can be arranged in a piggyback or merged configuration. An exemplary piggyback configuration places the (magnetically inductive) write converter above (or below) the (magnetically shielded) read converter (e.g., a magnetoresistive reader), with the poles of the write converter and the shield of the read converter being largely separated. An exemplary merged configuration consists of one reader shield in the same physical layer as one writer pole (hence "merged"). The read and write converters can also be arranged in an interleaved configuration. Alternatively, each array in a channel may contain only a read converter or only a write converter. Either of these arrays may include one or more servo readers for reading servo data on the medium.

[0025] Figure 2B shows one tape bearing surface 209 of module 204 as seen from line 2B in Figure 2A. A typical tape 208 is shown by a dashed line. Module 204 is preferably long enough to support the tape as the head moves between data bands.

[0026] In this example, tape 208 contains 4 to 32 data bands; for example, a half-inch wide tape 208 has 16 data bands and 17 servo tracks 210, as shown in Figure 2B. The data bands are defined between the servo tracks 210. Each data band can contain a number of data tracks, such as 1024 data tracks (not shown). During a read / write operation, the read converter or write converter or both 206 are positioned at a specific track location within one of the data bands. An outer reader, sometimes called a servo reader, reads the servo tracks 210. Servo signals are used conventionally to align the read converter or write converter or both 206 to a specific set of tracks during a read / write operation.

[0027] Figure 2C shows multiple read-and-write converters or both 206 formed in a gap 218 on module 204 of circle 2C in Figure 2B. As shown in Figure 2C, the array of read-and-write converters 206 includes, for example, 16 write converters 214, 16 read converters 216, and 2 servo readers 212, but the number of elements may vary. Exemplary embodiments include 8, 16, 32, 40, and 64 active read-and-write converters or both 206 per array, and alternatively include interleaved designs with odd numbers of read-and-write converters such as 17, 25, and 33. Exemplary embodiments include 32 read-and-write converters or 32 write converters per array, or both, and the actual number of converter elements can be greater, for example, 33, 34, etc. Multiple converters operating simultaneously allow the tape to move at a moderate speed while maintaining a high data transfer rate. Lower speeds are desirable to mitigate mechanical difficulties due to tracking caused by speed.

[0028] As shown in Figure 2C, the read converters and write converters may be arranged in a piggyback configuration, but the read converter 216 and write converter 214 may also be arranged in an interleaved configuration. Alternatively, each array of read converters or write converters or both 206 may consist of only read converters or only write converters, and the array may include one or more servo readers 212. As pointed out by considering Figures 2A and 2B-2C together, each module 204 may include a complementary set of read converters or write converters or both 206 for bidirectional read and write, read-while-writing capability, backward compatibility, etc.

[0029] Figure 2D shows a partial tape bearing view of a complementary module of a magnetic tape head 200 according to one embodiment. In this embodiment, each module has multiple read / write (R / W) pairs in a piggyback configuration formed on a common substrate 204A and an optional electrically insulating layer 236. The write converter 214 and read converter 216 are aligned parallel to the intended direction of movement of the tape medium traversing thereto to form R / W pairs, as exemplified by R / W pair 222. Note that in this specification, the intended direction of tape movement may be referred to as the tape movement direction, and such terms may be used interchangeably. Such a tape movement direction can be inferred from the system design, for example, by examining the guides; observing the actual tape movement direction relative to a reference point; and so on. Furthermore, in a system capable of operating for bidirectional reading or writing or both, the tape movement directions in both directions are typically parallel, and therefore can be considered equivalent to each other.

[0030] There may be multiple R / W pairs 222, such as 8 pairs, 16 pairs, or 32 pairs. The R / W pairs 222 shown in the figure are aligned linearly in a direction roughly perpendicular to the direction of movement of the tape crossing them. However, the pairs may also be aligned diagonally or in other directions. The servo leader 212 is located outside the array of R / W pairs, and its function is well known.

[0031] Generally, the magnetic tape medium moves either forward or backward, as indicated by arrow 220. The magnetic tape medium and the head assembly 200 operate in a conversion relationship in a manner well known in the art. The head assembly 200 includes two thin-film modules 224 and 226 of substantially identical structure.

[0032] Modules 224 and 226 are joined together in the space (partially illustrated) between their closures 204B to form a single physical unit, providing write-while-read capability by operating the write converter of the preceding module and the read converter of the succeeding module, which is aligned parallel to the direction of tape movement relative to the write converter of the preceding module. When modules 224 and 226 of the magnetic tape head 200 are configured, layers are generally formed in the following order for R / W pairs 222 in a gap 218 formed above, for example, an AlTiC conductive substrate 204A (partially shown): an insulating layer 236, a first shield 232 of an iron alloy such as NiFe (e.g., 80 / 20 at% NiFe, also known as permalloy), a first shield 232 of an iron alloy such as cobalt-zirconium-tantalum (CZT) or Al-Fe-Si (Sendust), a sensor 234 for sensing the data track on the magnetic medium, a second shield 238 of a nickel-iron alloy (e.g., permalloy), first and second lighter poles 228 and 230, and a coil (not shown). The sensor may be any known type, including those based on magnetoresistance (MR), GMR, AMR, tunnel magnetoresistance (TMR), etc.

[0033] The first and second lighter poles 228 and 230 can be made from a high magnetic moment material such as CoFe. These materials are illustrative, and other materials may be used. Additional layers may be present, such as insulation between the shield and / or pole tips and an insulating layer surrounding the sensor. Exemplary materials for insulation include alumina and other oxides, insulating polymers, and the like.

[0034] The configuration of the tape head 126 according to one embodiment includes multiple modules, preferably three or more modules. In a write-read-write (WRW) head, an outer module for writing sandwiches one or more inner modules for reading. Referring to Figure 3, which shows a WRW configuration, the outer modules 252 and 256 each include an array of one or more write transducers 260. The inner module 254 in Figure 3 similarly includes one or more arrays of read transducers 258. Variations of the multi-module head include an RWR head (Figure 4), an RRW head, a WWR head, and the like. In further variations, one or more of the modules may have read / write pairs of transducers. Furthermore, there may be three or more modules. In a further technique, two outer modules may sandwich two or more inner modules, for example, in a WRRW, RWWR configuration. For simplicity, the WRW head is mainly used in this specification to illustrate embodiments of the present invention. Those skilled in the art who are familiar with the teachings herein will understand how the permutations of the present invention apply to configurations other than the WRW configuration.

[0035] Figure 5 shows a magnetic head 126 according to one embodiment of the present invention, including first, second, and third modules 302, 304, and 306, each having tape bearing surfaces 308, 310, and 312, respectively, where the tape bearing surfaces 308, 310, and 312 may be flat or contoured. Note that the term “tape bearing surface” might seem to mean that the surface facing the tape 315 is in physical contact with the tape bearing surface, but this is not necessarily the case. Rather, only a portion of the tape may be in constant or intermittent contact with the tape bearing surface, while the rest of the tape is above the tape bearing surface, riding (or “flying”) on a layer of air, sometimes called “air bearing.” The first module 302 is called the “leading” module because, in a three-module design for tape moving in a specified direction, it is the first module the tape encounters. The third module 306 is called the “successor” module. The successor module follows the intermediate module and is the last module visible to the tape in a three-module design. The preceding and succeeding modules 302 and 306 are collectively referred to as the outer modules. It should also be noted that the outer modules 302 and 306 are used alternately as the preceding module depending on the direction of movement of the tape 315.

[0036] In one embodiment, the tape bearing surfaces 308, 310, and 312 of the first, second, and third modules 302, 304, and 306 are on substantially parallel planes (meaning including parallel planes and substantially parallel planes, for example, between parallel and tangent as in Figure 6), and the tape bearing surface 310 of the second module 304 is above the tape bearing surfaces 308 and 312 of the first and third modules 302 and 306. As will be described later, this has the effect of forming a desired wrap angle α2 of the tape with respect to the tape bearing surface 310 of the second module 304.

[0037] If the tape bearing surfaces 308, 310, and 312 are aligned along a plane that is parallel or nearly parallel but offset, intuitively, the tape should peel away from the tape bearing surface 308 of the leading module 302. However, experiments have shown that the vacuum created by the skiving edge 318 of the leading module 302 is sufficient to keep the tape adhering to the tape bearing surface 308 of the leading module 302. The rear end 320 of the leading module 302 (the end where the tape separates from the leading module 302) is an approximate reference point that defines the wrap angle α2 on the tape bearing surface 310 of the second module 304. The tape is close to the tape bearing surface up to near the rear end 320 of the leading module 302. Therefore, the transducer 322 can be positioned near the rear ends of the outer modules 302 and 306. These embodiments are particularly suited to write-read-write applications.

[0038] An advantage of this embodiment and other embodiments described herein is that, since the outer modules 302, 306 are fixed at a predetermined offset from the second module 304, the inner lap angle α2 is fixed when modules 302, 304, 306 are coupled to each other or otherwise fixed to the head. The inner lap angle α2 is approximately tan -1 The formula is (δ / W), where δ is the height difference between the planes of the tape bearing surfaces 308 and 310, and W is the width between the opposing ends of the tape bearing surfaces 308 and 310. An example inner lap angle α2 is in the range of approximately 0.3° to approximately 1.1°, but any angle required for the design is acceptable.

[0039] Beneficial enough, since tape 315 rests on the following module 306, the inner lap angle α2 on the tape-receiving side (front end) of module 304 is greater than the inner lap angle α3 on the rear end. This difference is generally beneficial, as a smaller α3 previously tended to counteract the effective lap angle at steep exits.

[0040] It should be noted that the tape bearing surfaces 308 and 312 of the outer modules 302 and 306 are positioned to achieve a negative overlap angle at the rear end 320 of the preceding module 302. This is generally beneficial in reducing friction due to contact with the rear end 320, provided that appropriate consideration is given to the location of the burl area formed on the tape as it peels away from the head. This negative overlap angle also reduces flutter and scrub damage to the elements on the preceding module 302. Furthermore, in the succeeding module 306, since the tape 315 flies over the tape bearing surface 312, there is virtually no wear on the elements as the tape moves in this direction. In particular, since the tape 315 entrains air, it does not significantly rest on the tape bearing surface 312 of the third module 306 (some contact may occur). This is acceptable because the succeeding module 306 is idle while the preceding module 302 is writing.

[0041] The write and read functions are performed by different modules at any given time. In one embodiment, the second module 304 includes multiple data and optional servo readers 331, but does not include a write converter. The first and third modules 302, 306 include multiple write converters 322, but do not include data read converters, with the exception that the outer modules 302, 306 may include optional servo readers. Servo readers can be used to position the head during read or write operations or both. Servo readers on each module are typically positioned toward the ends of the read or write converter array.

[0042] The gap length can be significantly reduced by placing only the read transducer, or a combination of the write transducer and servo reader, in the gap between the substrate and the closure. In typical heads, the read and write transducers are piggybacked, with the write transducer formed above each read transducer. A typical gap is 20–35 microns. However, irregular bumps on the tape tend to sag into the gap, leading to gap erosion. Therefore, the smaller the gap, the better. In this specification, reducing the gap reduces wear-related problems.

[0043] In some embodiments, the second module 304 has a closure, while the first and third modules 302 and 306 do not. When there is no closure, a hard coating is preferably applied to the module. One preferred coating is diamond-like carbon (DLC).

[0044] In the embodiment shown in Figure 5, the first, second, and third modules 302, 304, and 306 each have closures 332, 334, and 336 that extend the tape bearing surface of the associated module, thereby effectively positioning the read / write elements away from the edges of the tape bearing surface. The closure 332 of the second module 304 can be a ceramic closure of the type commonly found in tape heads. However, the closures 334 and 336 of the first and third modules 302 and 306 can be shorter than the closure 332 of the second module 304 when measured parallel to the direction of tape movement on each module. This allows the modules to be positioned closer together. One way to manufacture the shorter closures 334 and 336 is to add an additional amount of overlap to the standard ceramic closure of the second module 304. Another way is to plate or deposit a thin-film closure onto the elements during thin-film processing. For example, thin-film closures made of hard materials such as Sendust or nickel-iron alloys (e.g., 45 / 55) can be formed on the module.

[0045] The thickness of the ceramic or thin-film closures 334, 336 of the outer modules 302, 306 can be reduced, or the closures can be omitted altogether, to reduce the gap between write and read to less than approximately 1 mm, for example, about 0.75 mm, or 50% smaller than the gap of commonly used linear tape open (LTO) tape heads. The open space between modules 302, 304, 306 can still be set to about 0.5 to 0.6 mm, which in some embodiments is ideal for stabilizing the movement of the tape on the second module 304.

[0046] Depending on the tension and rigidity of the tape, it may be desirable to incline the tape bearing surface of the outer module with respect to the tape bearing surface of the second module. Figure 6 shows an embodiment in which modules 302, 304, and 306 are in contact or nearly contact (angled) configuration. In particular, the tape bearing surfaces of the outer modules 302 and 306 are nearly parallel to the tape at a desired wrap angle α2 of the second module 304. In other words, the planes of the tape bearing surfaces 308 and 312 of the outer modules 302 and 306 are oriented at approximately the desired wrap angle α2 of the tape 315 with respect to the second module 304. In this embodiment, wear on the elements of the subsequent module 306 is reduced because the tape extends beyond the subsequent module 306. These embodiments are particularly useful for write-read-write applications. Additional aspects of these embodiments are similar to those given above.

[0047] Typically, the tape wrap angle can be set to approximately midway between the embodiments shown in Figures 5 and 6.

[0048] Figure 7 shows an embodiment in which modules 302, 304, and 306 are in an overlapping configuration. In particular, the tape bearing surfaces 308 and 312 of the outer modules 302 and 306 are angled slightly more than the tape 315 when set to a desired overlap angle α2 with respect to the second module 304. In this embodiment, the tape does not protrude from the subsequent module and can be used for writing or reading. Thus, both the preceding and intermediate modules can perform read or write functions or both, while the subsequent module can read the data that has just been written. Therefore, these embodiments are preferred for write-read-write, read-write-read, and write-write-read applications. In the latter embodiment, the closure needs to be wider than the tape canopy to ensure readability. A wider closure may require wider gap isolation. Therefore, a preferred embodiment has a write-read-write configuration, which can use a shortened closure that allows for closer gap isolation.

[0049] Additional embodiments of the models shown in Figures 6 and 7 are the same as those described above.

[0050] The 32-channel version of the multi-module tape head 126 can use cable 350 with lead pitches the same as or smaller than those of current 16-channel piggyback LTO modules, or the connections on the module can be made organ keyboard to reduce cable span by 50%. Over-under, writing pair unshielded cables can be used with write converters that may have built-in servo readers.

[0051] The outer wrap angle α1 can be set in the drive unit by any kind of guide known in the art, such as adjustable rollers or slides, or by outriggers integrated into the head. For example, a roller with an offset axis can be used to set the wrap angle. The offset axis forms a rotating arc, allowing for precise alignment of the wrap angle α1.

[0052] Conventional U-beam assembly can be used to assemble any of the embodiments described above. Thus, the mass of the resulting head may be maintained or even reduced compared to previous generation heads. Alternatively, the module can be configured as a single body. Those skilled in the art who understand this teaching will understand that other known methods for manufacturing such heads can be adapted for use in constructing such heads. Furthermore, unless otherwise specified, as will be apparent to those skilled in the art who read this disclosure, processes and materials of the kind known in the art can be adapted for use in various embodiments conforming to the teachings herein.

[0053] When a tape travels along a module, it is preferable that the tape passes close enough to the magnetic transducers on the module so that reading, writing, or both can be performed efficiently, for example, with a low error rate. According to some methods, tape tenting may be used to ensure that the tape passes close enough to the module portion containing the magnetic transducers. To better understand this process, the principle of tape tenting is shown in Figures 8A-8C. Figure 8A shows a module 800 having an upper tape bearing surface 802 extending between opposing ends 804, 806. It is shown that a fixed tape 808 is wrapped around the ends 804, 806. As shown, the bending stiffness of the tape 808 lifts the tape away from the tape bearing surface 802. The tension of the tape tends to flatten the contour of the tape, as shown in Figure 8A. When the tension of the tape is minimal, the curvature of the tape is more parabolic than shown.

[0054] Figure 8B shows the moving tape 808. The front end, i.e., the first end encountered as the tape moves, acts to expel air from the tape, thereby creating a pressure below ambient air pressure between the tape 808 and the tape bearing surface 802. In Figure 8B, when the tape is moving from left to right, the front end is the left end and the right end is the rear end. As a result, the atmospheric pressure above the tape presses the tape toward the tape bearing surface 802, causing tape tenting near each end. The bending stiffness of the tape resists the effect of atmospheric pressure, resulting in tape tenting near both the front and rear ends. According to the modeling, the shapes of the two tents are predicted to be very similar.

[0055] Figure 8C shows how a pressure below atmospheric pressure biases the tape 808 toward the tape bearing surface 802, even when the trailing guide 810 is positioned above the plane of the tape bearing surface.

[0056] This indicates that tape tenting may be used to guide the tape's path as it passes over the module. As mentioned above, tape tenting can preferably be used to ensure that the tape passes close enough to the module portion containing the magnetic transducer so that reading or writing or both can be performed efficiently, for example, with a low error rate.

[0057] Magnetic tape is stored in tape cartridges, which are stored in storage slots within a data storage library. Tape cartridges may be stored in the library in a way that allows for physical removal. In addition to magnetic tape and tape cartridges, the data storage library may include data storage drives that store data on the magnetic tape, retrieve data from the magnetic tape, or both. Furthermore, the tape library and its components may implement a file system that enables access to the tape and the data stored on it.

[0058] A file system is sometimes used to control how data is stored in and retrieved from memory. Therefore, a file system includes processes and data structures that an operating system uses to track files in memory, such as how files are organized in memory. A linear tape file system (LTFS) is an exemplary form of a file system that can be implemented in a given library to enable access to compliant tapes. It should be understood that the various embodiments described herein can be implemented in a wide range of file system forms, including, for example, IBM® Spectrum® Archive Library Edition (LTFS LE) (IBM, and all IBM-based trademarks and logos are trademarks or registered trademarks of International Business Machines Corporation or its affiliates or both). However, for contextual purposes and to assist the reader, some of the embodiments described below may refer to LTFS, a type of file system form. This is done for illustrative purposes only and should not be considered to limit the invention as defined in the claims.

[0059] A tape cartridge may be "loaded" by inserting it into a tape drive, and a tape cartridge may be "unloaded" by removing it from the tape drive. Once loaded into a tape drive, the tape inside the cartridge may be "passed" into the drive by physically pulling the tape (the magnetic recording portion) out of the cartridge and passing it over the tape drive's magnetic head. Furthermore, the tape can also be mounted on a take-up reel (see, for example, 121 in Figure 1A above) to move it over the magnetic head.

[0060] Once inserted into the tape drive, the tape in the cartridge can be "mounted" by reading the metadata on the tape and making it available for LTFS to use as a component of the file system. Furthermore, to "unmount" the tape, it is preferable to first write the metadata to the tape (for example, as an index), and then remove the tape from a state where LTFS can use it as a component of the file system. Finally, to "remove" the tape, it is removed from the take-up reel and physically returned to the inside of the tape cartridge. The cartridge remains loaded into the tape drive after the tape has been removed and can, for example, await another read or write request or both. However, in other examples, as described above, the tape cartridge may be unloaded from the tape drive when the tape is removed.

[0061] Magnetic tape is a sequential access medium. Therefore, new data is written to the tape by appending it to the end of previously written data. Consequently, when recording data on a tape with only one partition, metadata (such as allocation information) is frequently updated and continuously appended to the end of previously written data, overwriting the tape accordingly. As a result, the information at the end of the tape is read when the tape is first mounted in order to access the latest copy of the metadata corresponding to the tape. However, this introduces a considerable delay in the process of mounting a particular tape.

[0062] To overcome this delay caused by single-partition tape media, the LTFS format includes a tape divided into two partitions: an index partition and a data partition. The index partition may be configured to record metadata (meta-information), such as file allocation information (index), while the data partition may be configured to record the data itself, such as the data itself.

[0063] Referring to Figure 9, a magnetic tape 900 having an index partition 902 and a data partition 904 is illustrated according to one embodiment. As shown in the figure, data files and indexes are stored on the tape. In the LTFS format, as will be understood by those skilled in the art by reading this specification, index information can be recorded in the index partition 902 at the beginning of the tape 906.

[0064] When index information is updated, it is preferable to overwrite the previous version of the index information so that the currently updated index information can be accessed at the beginning of the tape in the index partition. In the specific example shown in Figure 9, the latest version of metadata index 3 is recorded in the index partition 902 at the beginning of tape 906. Conversely, all three versions of metadata index 1, index 2, and index 3, and data files A, B, C, and D are recorded in the data partition 904 of the tape. Although index 1 and index 2 are old (e.g., outdated) indices, the information is written to the tape by appending it to the end of previously written data, as described above, so these old indices, index 1 and index 2, remain stored in the data partition 904 of tape 900 without being overwritten.

[0065] The metadata may be updated in the same or different way in the index partition 902, the data partition 904, or both, depending on the desired embodiment. According to some embodiments, the metadata of the index or the data partition or both 902, 904 may be updated in response to the tape being unmounted, for example, so that the index can be quickly read from the index partition when the tape is remounted. The metadata is preferably also written to the data partition 904 so that the tape can be mounted using the metadata recorded in the data partition 904, for example, as a backup option.

[0066] Without intending to limit the present invention, according to one embodiment, LTFS LE may be used to provide the ability to write an index to a data partition when the user explicitly instructs the system or at a time specified by a predetermined period that the user can configure, for example, to mitigate data loss in the event of a sudden power outage.

[0067] To compensate for tape dimensional stability (TDS), the head must typically be within a certain dimensional specification. For example, current product designs allow a converter span tolerance of + / - 200 nm. If the head expands or contracts too much, for example, exceeding the tolerance, the drive may be unable to read from or write to a particular tape. Experimental data has shown that a significant factor in head-to-head dimensional variation lies in the cable bonding process. In particular, the strain relief protection applied to wire bonds contributes significantly to head dimensional variation. Strain relief shrinks as it hardens, and typically, the head dimensions shrink due to contact between the strain relief and the head. Alternative strain relief formulations have not been able to address this shrinkage problem by reducing or eliminating the shrinkage. Furthermore, reducing the amount of strain relief would reduce the amount of protection provided by the wire bond, so this was not an option. For example, reducing the amount of strain relief increases the yield loss from less than 1% with conventional strain relief to approximately 20% when strain relief is reduced. Therefore, a person skilled in the art would expect that reducing the material associated with strain relief will increase the yield loss. A solution is needed that adequately protects the cable coupling while minimizing the impact on the dimensional stability of the head.

[0068] At least some aspects of this disclosure reduce or eliminate head dimensional shrinkage. Strain relief and strain relief materials used throughout this disclosure may refer to any material conventionally used to protect wire bonds. For example, strain relief materials may include various known types of ultraviolet (UV) curing epoxy, two-component epoxides, acrylates, etc. In a preferred method, the strain relief material has high viscosity and, for example, does not deform significantly after application; preferably exhibits low shrinkage upon curing, for example, no volume change exceeding 20%, more preferably 10%, and ideally 5%; and also preferably has a low coefficient of thermal expansion, for example, as can be determined by reading this disclosure to a person skilled in the art, no volume change exceeding 20%, more preferably 10%, and ideally 5% under the highest temperature conditions expected during use.

[0069] Protective mechanisms for cable bonding that protect wire bonds and minimize headspan variations are described in at least some aspects of this disclosure. In at least one exemplary embodiment, in contrast to conventional methods of sealing the entire wire bond area with strain relief, at least two portions of strain relief (e.g., forming a “dot” of strain relief) are applied to the ends of the cable to provide protection from stress on the wire bond due to twisting or bending of the cable or both, and to bond the cable to the underlying structure. In another exemplary embodiment, strain relief is applied only to the ends of the cable, and sealing is performed at the lower end of the wire bond. The strain relief can be applied so as to form a ledge projecting above the loop of the wire bond, thereby providing protection from mechanical damage due to handling (e.g., with tweezers) or operation of equipment or both. In further exemplary embodiments, an optional cable stabilization process consisting of adding strain relief to the back of the module further reduces cable movement and bending stress on the wire bond.

[0070] Headspan variations were significantly reduced using at least some of the techniques described herein. This is a significant advantage, especially considering the desire to further reduce the track density on the tape. Furthermore, at least some embodiments described herein surprisingly resulted in a reduction of yield loss from approximately 20% to approximately 0%, despite the overall reduction in strain relief material applied to the apparatus. As mentioned above, this was unexpected. Thus, the various embodiments described herein proceeded contrary to conventional wisdom.

[0071] Figures 10A and 10B show an apparatus 1000 according to one embodiment. Optionally, the apparatus 1000 may be implemented in combination with features from other embodiments listed herein, such as those described with reference to other figures. However, naturally, such apparatus 1000 presented herein may be used in a variety of applications or permutations, or both, which may or may not be specifically described in the exemplary embodiments listed herein. Furthermore, the apparatus 1000 presented herein can be used in any desired environment.

[0072] As shown in the figure, the apparatus 1000 includes a beam 1002 and a tip 1004 coupled to the beam 1002. The apparatus 1000 includes a cable 1006 coupled to the beam 1002 by a first material 1008 located at opposite ends of the cable 1006, as shown in Figure 10A. The apparatus 1000 includes a wire bond 1010 extending from the pad of the cable 1006 to the pad of the tip 1004.

[0073] In a preferred embodiment, the first material 1008 is positioned at the opposing ends of the cable 1006 in a configuration of at least two “dots” (e.g., one dot at each end of the cable 1006). For example, the first material 1008 may be applied as two lateral portions (e.g., two dots). In some methods, to provide protection to the wire bond, the first material 1008 extends upward 1012 above the height of the wire bond 1010. Preferably, the first material does not come into contact with the wire bond 1010.

[0074] In at least some methods, the first material 1008 includes a strain relief material. In a preferred embodiment, the first material 1008 is a UV-curing epoxy. The beam 1002, the tip 1004, and the cable 1006 can be composed of any combination of materials known in the art, or described in detail above, or both. Furthermore, the beam 1002, the tip 1004, and the cable 1006 may be of a conventional design.

[0075] In various preferred embodiments, the chip 1004 includes an array of magnetic transducers for converting data on a magnetic recording tape, according to at least some of the embodiments described herein and known in the art.

[0076] In various embodiments, the apparatus 1000 may further include a drive mechanism (not shown) for passing a magnetic medium (e.g., tape) over the chip 1004, in a manner that would be apparent to those skilled in the art by reading this disclosure, and a controller (not shown) electronically coupled to the cable 1006.

[0077] Referring to Figures 11A to 11C, the apparatus 1100 is depicted according to another embodiment. Optionally, the apparatus 1100 can be implemented in combination with features of other embodiments listed herein, such as those described with reference to other figures, including Figures 10A to 10B. Specifically, Figures 11A to 11C show modifications of the embodiments of Figures 10A to 10B, illustrating several exemplary configurations of the apparatus 1100. Therefore, the various components in Figures 11A to 11C share the same reference numerals as the components in Figures 10A to 10B.

[0078] It should be noted that such apparatus 1100 etc. presented herein may be used in a variety of uses, permutations, or both, which may or may not be specifically described in the exemplary embodiments listed herein. Furthermore, the apparatus 1100 presented herein can be used in any desired environment. Therefore, Figures 11A to 11C (and other figures) may be considered to include any possible permutations.

[0079] The apparatus 1100 includes a second material 1102. The second material 1102 preferably seals the end of the wire bond 1010 adjacent to the cable 1006. The second material 1102 does not come into contact with the tip 1004.

[0080] In various embodiments, the first material 1008 and the second material 1102 have the same composition. In other embodiments, the first material 1008 and the second material 1102 consist of the same material. For example, in various embodiments, the second material 1102 is the same type of UV-curable epoxy as the first material 1008. In other embodiments, the first material 1008 and the second material 1102 have different compositions. For example, the first material 1008 may contain UV-curable epoxy and the second material 1102 may contain acrylate, or vice versa.

[0081] In at least some embodiments, the second material 1102 extends above the cable 1006 by a distance greater than the distance the wire bond 1010 extends above the cable 1006 in a direction perpendicular to the cable 1006 1012. Preferably, the second material 1102 protrudes above the wire bond 1010 (e.g., the wire bond loop) to protect the wire bond 1010 from mechanical damage, as will be apparent to those skilled in the art by reading this disclosure. For example, the position of the second material 1102 preferably prevents various components from touching the wire bond 1010, and the second material 1102 acts as a barrier against mechanical movement during the operation of the apparatus 1100, as described herein.

[0082] In various embodiments, the device 1100 may further include a drive mechanism (not shown) for passing a magnetic medium over the chip 1004 and a controller (not shown) electronically coupled to the cable 1006.

[0083] Referring to Figures 12A to 12C, the apparatus 1200 is depicted according to another embodiment. Optionally, the apparatus 1200 can be implemented in combination with features from other embodiments listed herein, such as those described with reference to other figures, including Figures 10A to 10B and Figures 11A to 11C. Specifically, Figures 12A to 12C show modifications of the embodiments of Figures 10A to 10B, illustrating several exemplary configurations within the apparatus 1200. Thus, the various components in Figures 12A to 12C share common reference numerals with the components in Figures 10A to 10B and Figures 11A to 11C.

[0084] It should be noted that such apparatus 1200 etc. presented herein may be used in a variety of uses or permutations, or both, which may or may not be specifically described in the exemplary embodiments enumerated herein. Furthermore, the apparatus 1200 presented herein can be used in any desired environment. Therefore, Figures 12A to 12C (and other figures) may be considered to include any possible substitutions.

[0085] The apparatus 1200 consists of a third material 1202. The third material 1202 can be applied to the back surface of the apparatus 1200 to connect the cable 1006 to the beam 1002. The third material 1202 is beneficial in providing the apparatus 1200 with cable support and rigidity. In various methods, the third material 1202 may be applied to a portion of the back surface of the apparatus 1200 (in some embodiments, as shown in Figures 12B to 12C). In other methods, the third material 1202 may be applied to at least two distinct sections (for example, where the third material 1202 is present). For example, at least two distinct sections of the third material 1202 may be applied behind the cable 1006 as dots, strips, rectangles, triangles, squares, ellipses, etc., or any combination thereof.

[0086] In various embodiments, the third material 1202 includes a strain relief material as described elsewhere in this specification. In a preferred embodiment, the third material 1202 is a UV-curing epoxy. Thus, in some methods, the first material 1008, the second material 1102 (not shown in Figures 12A-12C), and the third material 1202 can all consist of UV-curing epoxies. The first material 1008, the second material 1102 (not shown in Figures 12A-12C), and the third material 1202 may consist of the same type of UV-curing epoxy, or any combination of types of UV-curing epoxies known in the art. In various other methods, the first material 1008, the second material 1102 (not shown in Figures 12A-12C), and the third material 1202 may each individually be any combination of strain relief materials described herein.

[0087] In at least one exemplary embodiment, the third material 1202 extends along the beam 1002 and cable 1006 between opposing ends of the cable to connect the cable 1006 to the beam 1002, as shown in Figure 12B, which depicts the back of the device 1200. Specifically, the third material 1202 preferably extends along the beam 1002 and cable 1006 over at least a portion of the distance between opposing ends of the cable 1006 to connect the cable 1006 to the beam 1002, as shown in Figure 12C, which depicts the back of the device 1200.

[0088] In one exemplary embodiment, the third material 1202 extends along at least half (e.g., 1 / 2, 50%) of the width W of the cable 1006 measured between its opposing ends. In another exemplary embodiment, the third material extends along at least 80% of the width of the cable 1006. In at least one other exemplary embodiment, the third material 1202 extends along no more than 1 / 4 (e.g., 1 / 4, 25%) of the width of the cable 1006 measured between its opposing ends. For example, the third material 1202 can be applied to the center of the back surface of the device 1200, for example, as shown in Figure 12C.

[0089] In various embodiments, the device 1200 may further include a drive mechanism (not shown) for passing a magnetic medium over the chip 1004 and a controller (not shown) electronically coupled to the cable 1006.

[0090] In at least one embodiment, the first material 1008 may be applied to at least two sections, as shown in Figure 10B, and the third material 1202 may be applied to the back surface of the apparatus in any manner described herein with reference to Figures 12A-12C, for example, but the second material 1102 is not applied in this exemplary embodiment. In this exemplary embodiment, the wire bond 1010 may be exposed. The inventors were surprised to find that, even in the absence of the second material, the wire bond is not pulled by the mechanical processes involved in the operation of the apparatus, which is beneficial. Contrary to conventional wisdom, the first material 1008 and the third material 1202 remarkably provide sufficient support and rigidity to prevent mechanical damage while reducing the total amount of strain relief material.

[0091] Any of the materials described herein (e.g., the first material 1008, the second material 1102, the third material 1202, etc.) can be applied in any manner that will be apparent to those skilled in the art by reading this disclosure. In various exemplary methods, one or more materials may be applied manually using a syringe, by automated methods, by methods known in the art, or in any combination thereof. In a preferred embodiment, the materials are applied in such a manner that the dimensions and / or volume of the material are controlled so that the material does not overflow into notches, tips, or other unwanted areas or combinations of the apparatus, as will be apparent to those skilled in the art by reading this disclosure. Furthermore, in a preferred embodiment, each material may be applied such that the “peak” of each formation is at least higher than the wire bond of the apparatus.

[0092] The various features of the aforementioned systems, methodologies, or both can be combined in any way, and it should be clear from the above explanation that multiple combinations can be created.

[0093] It will be further understood that embodiments of the present invention may be provided in the form of a service deployed on behalf of the customer to provide services on demand.

[0094] The descriptions of various embodiments of the present invention are presented for illustrative purposes only and are not intended to be exhaustive or limiting to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the described embodiments. The terms used herein have been selected to best describe the principles of the embodiments, the practical application or technical improvement to the art available on the market, or to enable those skilled in the art to understand the embodiments disclosed herein.

Claims

1. A beam and, A chip coupled to the beam, the chip comprising at least one magnetic transducer, A cable coupled to the beam by a first material located at the opposing ends of the cable, A wire bond extending from the pad of the cable to the pad of the chip, A second material for sealing the end of the wire bond located adjacent to the cable, Includes, The apparatus wherein the second material does not come into contact with the chip.

2. The chip includes an array of multiple magnetic converters for converting data on a magnetic recording tape. The apparatus according to claim 1.

3. The first and second materials have the same composition, The apparatus according to claim 1.

4. The second material extends above the cable in a direction perpendicular to the cable, by a distance greater than the distance the wire bond extends above the cable in the same direction. The apparatus according to claim 1.

5. To connect the cable to the beam, a third material is provided between the opposing ends of the cable, extending along the beam and the cable. The apparatus according to claim 1.

6. The third material extends along at least half of the width of the cable as measured between the opposing ends of the cable. The apparatus according to claim 5.

7. The third material extends along at least 80% of the width of the cable. The apparatus according to claim 6.

8. The third material extends along a length of no more than one-quarter of the width of the cable as measured between the opposing ends of the cable. The apparatus according to claim 5.

9. The third material is present in at least two separate sections. The apparatus according to claim 5.

10. The second material is UV-curing epoxy. The apparatus according to claim 1.

11. The first material is UV-curing epoxy. The apparatus according to claim 1.

12. A drive mechanism for passing a magnetic medium over the chip, A controller electrically coupled to the aforementioned cable, The apparatus according to claim 1, further comprising:

13. A beam and, A chip coupled to the beam, the chip including an array of magnetic transducers for converting data on a magnetic recording tape, A cable coupled to the beam by a first material located at the opposing ends of the cable, A wire bond extending from the pad of the cable to the pad of the chip, A second material for sealing the end of the wire bond located adjacent to the cable, Includes, The second material described above does not come into contact with the chip. Device.

14. The first and second materials have the same composition, The apparatus according to claim 13.

15. The second material extends above the cable in a direction perpendicular to the cable, by a distance greater than the distance the wire bond extends above the cable in the same direction. The apparatus according to claim 13.

16. To connect the cable to the beam, a third material is provided between the opposing ends of the cable, extending along the beam and the cable. The apparatus according to claim 13.

17. The third material extends along at least half of the width of the cable as measured between the opposing ends of the cable. The apparatus according to claim 16.

18. The third material extends along a length of no more than one-quarter of the width of the cable as measured between the opposing ends of the cable. The apparatus according to claim 16.

19. A drive mechanism for passing a magnetic medium over the chip, A controller electrically coupled to the aforementioned cable, The apparatus according to claim 13, further comprising:

Images