Flexible printed circuit copper clad for temperature management

Abstract

This invention is entitled "Flexible Printed Circuit Copper Clad for Temperature Management". A hard disk drive flexible printed circuit (FPC) is disclosed that includes a plurality of fingers extending from a main portion, wherein each finger has a first wiring layer including a first conductive trace layout, a second wiring layer including a second conductive trace layout, and a base film interposed between the first and second wiring layers, wherein the first conductive trace layout includes at least one thermally conductive protective island covering a corresponding portion of the second trace layout to provide a protective thermal barrier to the base film. As a result, the maximum temperature on the various layers of the FPC laminate article can be reduced, damage to the FPC is prevented, and manufacturing yield is improved.

Description

Technical Field

[0001] Embodiments of the present invention may relate generally to hard disk drives, and more specifically, to methods for managing temperature on flexible printed circuits (FPCs) during interconnection processes. Background Technology

[0002] A hard disk drive (HDD) is a non-volatile storage device housed in a protective casing that stores digitally encoded data on one or more disks with magnetic surfaces. When an HDD is in operation, each magnetic recording disk is rapidly rotated by a spindle system. Read / write heads (or "transducers") positioned above specific locations on the disk by actuators read data from and write data to the magnetic recording disk. The read / write heads use magnetic fields to write data onto and read data from the surface of the magnetic recording disk. The write head operates by utilizing current flowing through its coils, thereby generating a magnetic field. Electrical pulses are sent to the write head in different modes of positive and negative current. The current in the coils of the write head generates a localized magnetic field in the gap between the head and the disk, which in turn magnetizes a small area on the recording medium.

[0003] To write data to or read data from a medium, the read / write head must receive instructions from the controller. Therefore, the head is electrically connected to the controller so that not only does it receive instructions to read / write data, but it can also send back information to the controller about the data being read and / or written. Typically, flexible printed circuit (FPC) laminates are used to electrically transmit signals from the read / write head to other electronic components within the HDD via a suspension tail. The FPC and suspension tail are usually located in the comb section or "E-block" portion of the head stack assembly (HSA) (see, for example...). Figure 1 The brackets 134 are welded together. To join them with solder, the suspension pads and FPC pads are heated. If the welding temperature is too low, the solder may not melt, and if the welding temperature is too high, these components may be damaged by the heat. For example, one or more layers constituting the FPC laminate may delaminate or blister in response to the heat generated by the welding process. Therefore, it is desirable not to overheat the FPC during the electrical interconnection process, otherwise the FPC may be damaged, and the corresponding production yield will be reduced.

[0004] Any method that may be described in this section is a feasible method, but not necessarily a method that has been previously conceived or implemented. Therefore, unless otherwise stated, no method described in this section should be considered prior art simply because it is included in this section. Attached Figure Description

[0005] The embodiments are illustrated in the accompanying drawings by way of example rather than limitation, in which the same reference numerals refer to similar elements and wherein:

[0006] Figure 1 This is a plan view of a hard disk drive according to one embodiment;

[0007] Figure 2A This is a perspective view showing the actuator assembly according to one embodiment;

[0008] Figure 2B This is a perspective view showing the electrical interconnection between the rear suspension and the flexible printed circuit (FPC) according to one embodiment;

[0009] Figure 2C It is a floor plan of the FPC according to one implementation scheme;

[0010] Figure 2D It is based on an implementation plan illustration Figure 2C A cross-sectional view of the FPC.

[0011] Figure 3A This is a plan view showing the FPC fingers according to one embodiment;

[0012] Figure 3B It is a plan view showing the superimposed FPC fingers according to one embodiment;

[0013] Figure 3C It is based on an implementation plan illustration Figure 3B A cross-sectional view of the FPC;

[0014] Figure 4 It is a plan view showing the superimposed FPC fingers according to one embodiment;

[0015] Figure 5 This is a plan view illustrating a flexible printed circuit (FPC) according to one embodiment; and

[0016] Figure 6 This is a flowchart illustrating an embodiment of a method for manufacturing a flexible printed circuit (FPC) laminate composition. Detailed Implementation

[0017] Generally, a method for providing substantially uniform temperature on a flexible printed circuit (FPC) during the interconnect process is described. In the following description, numerous specific details are set forth for purposes of explanation in order to provide a thorough understanding of the embodiments of the invention described herein. However, it will be apparent, however, that the embodiments of the invention described herein can be practiced without these specific details. In other instances, well-known structures and devices may be shown in block diagram form to avoid unnecessarily obscuring the embodiments of the invention described herein.

[0018] introduction

[0019] the term

[0020] References to "implementation," "an embodiment," etc., herein are intended to mean that a particular feature, structure, or characteristic described is included in at least one embodiment of the invention. However, instances of such phrases do not necessarily refer to the same embodiment.

[0021] The term "substantially" should be understood as describing features that are mostly or nearly structured, constructed, or dimensionally defined, but in practice, manufacturing tolerances and other factors may cause the structure, configuration, dimensions, etc., to not always or necessarily be as precise as described. For example, describing a structure as "substantially vertical" would give the term its general meaning, implying that the sidewalls are vertical for all practical purposes, but may not be precisely at 90 degrees throughout.

[0022] While terms such as “optimal,” “minimum,” “maximum,” “maximize” may not have certain values ​​associated with them, if used herein, it is intended that those skilled in the art will understand that such terms will encompass values, parameters, measures, etc., that influence in a beneficial direction consistent with the whole of this disclosure. For example, describing the value of something as “minimum” does not require that the value is actually equal to some theoretical minimum (e.g., zero), but should be understood in a practical sense as the corresponding objective being to move that value toward the theoretical minimum in a beneficial direction.

[0023] Context

[0024] At the far end of the suspension, there is a read / write transducer (or "head") for reading and writing data. At the other near end of the suspension, there are conductive pads (or simply "pads") for electrical connection to corresponding conductive pads on a flexible printed circuit (FPC). These suspension pads and the FPC pads are typically electrically interconnected using solder reflow (in this case, orthogonal), and hot air or a laser can be used to heat the material during the bonding process.

[0025] Figure 2A This is a perspective view illustrating an actuator assembly according to one embodiment. The actuator assembly 200 includes a bracket 201 (see, for example...). Figure 1 The bracket 134 can be accessed via a pivot bearing assembly (not shown here, see example). Figure 1 The pivot bearing assembly 152) is rotatably coupled to the central pivot shaft (not shown here, see example). Figure 1 The actuator assembly 200 is connected to a pivot shaft 148 and is rotatably driven by a voice coil motor (VCM), the voice coil 204 of which is shown here. The actuator assembly 200 further includes one or more actuator arms 206 (see, for example...). Figure 1 Each actuator arm of the 132 is coupled to the suspension assembly 208 (see, for example, arm 132). Figure 1 The front suspension 110c), which houses the read / write head 210 (see, for example...). Figure 1 The read / write head 110a typically includes a forged substrate 208a and a load bundle 208b (see example...). Figure 1 The load bundle 110d) and the suspension tail 208c. Each suspension assembly 208 is electrically connected to a flexible printed circuit (FPC) 212 connected to the rear bracket 201 via the suspension tail 208c.

[0026] Figure 2B This is a perspective view showing the electrical interconnection between the rear suspension and the flexible printed circuit (FPC) according to one embodiment. Figure 2B The suspension tail section 208c is depicted as being mechanically and electrically connected to the corresponding FPC finger 212a of the FPC 212 via solder 211 (or some other electrical connection means). Figure 2A The suspension tail tip 208e. Specifically, the solder pad 208d on the suspension tail tip 208e is electrically connected to the solder pad 212d of the FPC 212. As mentioned earlier, in welding and other similar joining techniques, the suspension solder pad and the FPC solder pad are heated, and if the welding temperature is too low, the solder may not melt, and if the welding temperature is too high, the FPC may be damaged by heat. In the worst case, bubbles can be caused on the FPC. That is, one or more layers constituting the FPC laminate may delaminate in response to the heat generated by the welding / interconnection process. For example, delamination can occur between one or more wiring layers and adjacent insulating film layers, such as through the failure of the corresponding adhesive layer. Therefore, it is desirable to heat the FPC uniformly to avoid generating excessive heat that may damage the FPC.

[0027] Figure 2C This is a plan view illustrating a flexible printed circuit according to one embodiment. Here, FPC 212 includes a plurality of FPC fingers 212a, each FPC finger including a plurality of solder pads 212d located on each of the upper and lower sides. Each FPC finger 212a typically serves an UP head (an upward-facing read / write head serving the bottom surface of the corresponding disk) and a DN head (a downward-facing read / write head serving the top surface of the same disk), thereby electrically connecting each corresponding UP and DN head to a preamplifier 220 mounted on (or beyond) the FPC 212. A cross-section of the FPC finger 212a is labeled AA.

[0028] Figure 2D It is based on an implementation plan illustration Figure 2CA cross-sectional view of an FPC. Cross-sectional view AA depicts the layers of an FPC (such as FPC 212) including a base film 254 (e.g., a polyimide insulating layer), which is inserted into a top first wiring layer 252 (e.g., including copper traces) and a bottom second wiring layer 256 (e.g., including copper traces), whereby each of the first wiring layer 252 and the second wiring layer 256 can be used for both UP and DN heads, and these can be varied depending on the specific implementation. The first wiring layer 252 is covered by a first cover film 250 (e.g., a polyimide insulating layer), and the second wiring layer 256 is covered by a second cover film 258 (e.g., a polyimide insulating layer). These wiring layers 252, 256 can be electrically connected through one or more through-holes. In addition, an adhesive layer is typically present between each wiring layer 252, 256 and the adjacent film layers 250, 254, 258. Finally, all the aforementioned layers are connected to and supported by the bottom reinforcing layer 260 (e.g., containing aluminum, or some other rigid and durable material). The precise layout of this FPC 212 can vary depending on the specific implementation, therefore... Figure 2D The layout is presented as an example. However, the techniques described in this article are widely applicable to alternative FPC layouts.

[0029] Copper plating for thermal management of flexible printed circuit finger components

[0030] Figure 3A This is a plan view illustrating FPC fingers according to one embodiment. Here, the white area / pattern of FPC 300 represents the upper first wiring layer 352 (similar to...). Figure 2D The layout of the first wiring (e.g., copper) layer 252), and the cross-shading area / pattern represents the lower second wiring (e.g., copper) layer 356 (similar to...). Figure 2D (Layout of the second wiring layer 256). To keep the temperature of the FPC 300 relatively low, it is effective to keep the overall copper area relatively small, as copper absorbs heat. Figure 3A A relatively large second wiring layer 356 is shown compared to the relatively small first wiring layer 352. When these wiring layers 352, 356 are heated, the larger second wiring layer 356 will become hotter. Therefore, a relatively smaller second wiring layer 356 would be better for heat absorption. However, it may not be feasible to minimize the area of ​​the second wiring layer 356 beyond a certain point while still achieving its intended purpose.

[0031] Figure 3B This is a front view illustrating the superimposed FPC fingers, and Figure 3C This is an example Figure 3B A cross-sectional view of the FPC. Figure 3B and Figure 3C All are based on one implementation scheme. A section of an FPC355 with through-hole 374 is shown in... Figure 3B The middle part is marked as BB, see reference. Figure 3C The cross-section BB depicts an FPC laminate composition consisting of a bottom reinforcing layer 370, a second cover film 368 (e.g., a polyimide insulating layer), a second wiring layer 366, a base film 364 (e.g., a polyimide insulating layer), a first wiring layer 362 connected to the second wiring layer 366 through vias 374, and a cover film 360 (e.g., a polyimide insulating layer). Here, thermally conductive protective islands 372 (e.g., copper) are added to the first wiring layer 362 to cover a portion of the second wiring layer 366, providing a thermal barrier to the second wiring layer 366 and the other layers surrounding it (e.g., the base film 364, the second cover film 368), and thus protecting the second wiring layer 366 and the other layers from overheating. Similarly, the white area / pattern of FPC 355 represents the upper portion or the first wiring layer 362 (similar to...). Figure 2D The layout of the first wiring layer 252), and the cross-shaded areas / patterns indicate the lower or second wiring layer 366 (similar to). Figure 2D The layout of the second wiring layer 256). Figure 3B A plurality of thermally conductive protective islands 372 constituting a first wiring layer 362 are shown, and these islands are positioned to protect or cover portions of a second wiring layer 366. Preferably, each protective island 372 of the first wiring layer 362 is thermally connected to the second wiring layer 366 via a corresponding through-hole 374. This connection prevents excessive heat accumulation within the protective island 372, which could otherwise damage other layers (e.g., the first cover film 360, the base film 364, and the second cover film 368).

[0032] Note that due to the function of the protective islands and / or the corresponding signals for each protective island, some pairs of the upper and lower solder pads of the FPC 355 are electrically connected to each other. Therefore, upper pad 380a is connected to lower pad 380b, upper pad 382a is connected to lower pad 382b, upper pad 384a is connected to lower pad 384b, and upper pad 386a is connected to lower pad 386b. Therefore, it is possible to connect pads 384a and 384b via adjacent protective islands 372. However, this has been shown to result in excessively low temperatures for pads 384a and 384b for proper solder joints due to the large area of ​​the adjacent protective islands and the heat they absorb. Figure 4 The proposed implementation plan can solve this problem.

[0033] Figure 4 This is a plan view illustrating the superimposed FPC fingers according to one embodiment. Similarly, thermally conductive protective islands 372 (e.g., with...) Figure 3BSimilar to FPC 355, a portion of the first wiring layer 462 is added to cover the second wiring layer 466 to provide a thermal barrier to the second wiring layer 466 and other layers, protecting them from overheating. Likewise, the white area / pattern of FPC 400 represents the first wiring layer 462 (similar to...). Figure 3B , 3C The layout of the first routing layer 362), and the cross-shaded area / pattern represents the second routing layer 466 (similar to...). Figure 3B , 3C (Layout of the second wiring layer 366). Figure 4 A narrow wiring trace 401a electrically connects the upper pad 484a to the protective island 372, and a similar narrow wiring trace 401b electrically connects the lower pad 484b to the same protective island 372. These wiring traces 401a, 401b are used to increase heat resistance compared to connecting the pads 484a and 484b more directly through adjacent protective islands 372, and thus allow sufficient heat to be generated to each pad 484a, 484b for proper solder bonding. According to the embodiment, "narrow" here is characterized as the width of each wiring trace 401a, 401b being equal to or less than one-fifth (1 / 5) of the width of the corresponding upper pad 484a and lower pad 484b. Therefore, for a non-limiting example, each of the wiring traces 401a and 401b may have a width of approximately 30 μm or less relative to each of the upper pad 484a and lower pad 484b, which have a width of approximately 150 μm.

[0034] Figure 5 This is a plan view illustrating a flexible printed circuit (FPC) according to one embodiment. FPC 512 includes a plurality of FPC fingers 512a, each FPC finger including a plurality of solder pads 512d located on each of its upper and lower sides. Here, because a colored cover film (e.g., white) will reflect more light and more heat than a normally transparent cover film, at least a portion 513 of the cover film (similar to...) Figure 2D The layout of the cover film 250, or Figure 3C The cover film (360° layout) is made of colored material. According to the implementation scheme, the colored portion 513 of the cover film is white.

[0035] In summary, the foregoing embodiments each characterize a method for managing temperature on flexible printed circuits during the pad interconnection process (e.g., soldering) using the various described techniques individually or in combination. Therefore, the maximum temperature on each layer of the FPC laminate can be reduced, preventing damage to the FPC and improving manufacturing yield.

[0036] Methods for manufacturing flexible printed circuits

[0037] Figure 6 This is a flowchart illustrating a method for manufacturing a flexible printed circuit (FPC) laminate composition according to one embodiment.

[0038] At frame 602, a lower wiring layer including a lower conductive trace layout is formed. For example, the second wiring layer 366 ( Figure 3B , Figure 3C ), 466 Figure 4 ) forms a conductive trace layout, such as in the base reinforcement 370 ( Figure 3C ) and second covering film 368 ( Figure 3C Above.

[0039] At frame 604, a base film is formed on the lower wiring layer. For example, base film 364 ( Figure 3C It is formed above the second wiring layers 366 and 466.

[0040] At frame 606, an upper wiring layer including an upper conductive trace layout is formed on the base film, including at least one thermally conductive protective island covering a corresponding portion of the lower trace layout to provide a thermal barrier to the base film. For example, a first wiring layer 362 including an upper conductive trace layout is formed on the base film 364. Figure 3B , Figure 3C ), 462 Figure 4 ), including at least one thermally conductive protective island 372 forming a corresponding portion of the lower trace layout covering the second wiring layers 366, 466. Figure 3B , Figure 4 This provides a thermal barrier to the base film 364. According to the embodiment, the first wiring layers 362, 462 are electrically connected to the second wiring layers 366, 466 via vias 374. Figure 3C ).

[0041] Physical description of illustrative operational scenarios

[0042] The implementation scheme can be used in contexts such as digital data storage devices (DSDs) like hard disk drives (HDDs). Therefore, according to one implementation scheme, Figure 1 A floor plan of a typical HDD 100 is shown to help illustrate how a typical HDD usually operates.

[0043] Figure 1The functional arrangement of components of an HDD 100, including a slider 110b, is shown. The slider 110b includes a magnetic read / write head 110a. The slider 110b and the head 110a can be collectively referred to as the head slider. The HDD 100 includes at least one head gimbal assembly (HGA) 110 with the head slider, a lead suspension 110c typically attached to the head slider via a bend, and a load beam 110d attached to the lead suspension 110c. The HDD 100 also includes at least one recording medium 120 rotatably mounted on a spindle 124 and a drive motor (not visible) attached to the spindle 124 for rotating the medium 120. The read / write head 110a (also referred to as a transducer) includes a write element and a read element for writing and reading information stored on the medium 120 of the HDD 100, respectively. The medium 120 or multiple disk media can be attached to the spindle 124 using a disk clip 128.

[0044] HDD 100 also includes an arm 132, a carriage 134, and a voice coil motor (VCM) attached to HGA 110. The VCM includes an armature 136 containing a voice coil 140 attached to the carriage 134 and a stator 144 containing a voice coil magnet (not visible). The armature 136 of the VCM is attached to the carriage 134 and configured to move the arm 132 and HGA 110 to access the media 120, both mounted together on a pivot 148 with an inserted pivot bearing assembly 152. In the case of an HDD with multiple disks, the carriage 134 may be referred to as an "E-block" or comb because the carriage is arranged to carry a linked array of arms, thus giving it a comb-like appearance.

[0045] An assembly including a head universal joint assembly (e.g., HGA110) with a bend to which the head slider is coupled, an actuator arm (e.g., arm 132) and / or load beam to which the bend is coupled, and an actuator (e.g., VCM) to which the actuator arm is coupled, can be collectively referred to as a head stack assembly (HSA). However, an HSA may include more or fewer components than those described above. For example, an HSA may refer to an assembly that also includes electrical interconnect components. Generally, an HSA is an assembly configured to move the head slider to access portions of the medium 120 for read and write operations.

[0046] Further reference Figure 1Electrical signals, including write signals to and read signals from the magnetic head 110a (e.g., current to the voice coil 140 of the VCM), are transmitted by a flexible cable assembly (FCA) 156 (or “flexible cable”, or “flexible printed circuit” (FPC)). The interconnect between the flexible cable 156 and the magnetic head 110a may include an arm electronics (AE) module 160, which may have an onboard preamplifier for the read signal and other read and write channel electronics. The AE module 160 may be attached to a carriage 134, as shown. The flexible cable 156 may be coupled to an electrical connector block 164, which in some configurations provides electrical communication via an electrical feedthrough provided by the HDD housing 168. The HDD housing 168 (or “housing base”, “substrate”, or simply “base”) together with the HDD cover provides a semi-sealed (or hermetically sealed, in some configurations) protective enclosure for the information storage components of the HDD 100.

[0047] Other electronic components, including the disk controller and servo electronics including a digital signal processor (DSP), provide electrical signals to the drive motor, the voice coil 140 of the VCM, and the magnetic head 110a of the HGA 110. The electrical signals provided to the drive motor cause it to rotate, thereby providing torque to the spindle 124, which is then transmitted to the medium 120 attached to the spindle 124. The medium 120 thus rotates in direction 172. The rotating medium 120 forms an air cushion that acts as an air bearing on which the air bearing surface (ABS) of the slider 110b is mounted, allowing the slider 110b to fly above the surface of the medium 120 without contacting the thin magnetic recording layer on which information is recorded. Similarly, in HDDs utilizing gases lighter than air (such as helium used in a non-limiting example), the rotating medium 120 forms an air cushion that acts as a gas or fluid bearing on which the slider 110b is mounted.

[0048] The electrical signal supplied to the voice coil 140 of the VCM enables the head 110a of the HGA 110 to access the track 176 on which information is recorded. Therefore, the armature 136 of the VCM swings through an arc 180, allowing the head 110a of the HGA 110 to access the individual tracks on the medium 120. Information is stored in multiple radially nested tracks on the medium 120, which are arranged in sectors (such as sector 184) on the medium 120. Accordingly, each track is composed of multiple sectorized track portions (or “track sectors”) such as sectorized track portions 188. Each sectorized track portion 188 may include recorded information and a data header containing error correction code information and a servo burst signal pattern, such as the ABCD-servo burst signal pattern (which is information identifying track 176). When accessing track 176, the read element of the head 110a of the HGA 110 reads a servo burst signal pattern, which provides a positioning error signal (PES) to the servo electronics. This controls the electrical signal supplied to the voice coil 140 of the VCM, enabling the head 110a to follow track 176. Upon locating track 176 and identifying a specific sectored track portion 188, the head 110a either reads information from track 176 or writes information to track 176 according to instructions received by the disk controller from an external agent (e.g., the microprocessor of a computer system).

[0049] The electronic architecture of an HDD includes multiple electronic components for performing their respective HDD operating functions, such as a hard disk controller (“HDC”), an interface controller, an arm electronics module, a data channel, a motor driver, a servo processor, a buffer memory, etc. Two or more of these components may be combined on a single integrated circuit board called a “system-on-a-chip” (“SOC”). Several (if not all) of these electronic components are typically arranged on a printed circuit board coupled to the bottom side of the HDD, such as to the HDD housing 168.

[0050] This article references hard drives, such as references Figure 1The HDD 100 shown and described may include an information storage device sometimes referred to as a “hybrid drive.” A hybrid drive generally refers to a storage device that combines the functionality of a conventional HDD (see, for example, HDD 100) with a solid-state storage device (SSD) that uses non-volatile memory (such as flash memory or other solid-state (e.g., integrated circuit) memory) that is electrically erasable and programmable. Because the operation, management, and control of different types of storage media typically differ, the solid-state portion of a hybrid drive may include its own corresponding controller functionality, which may be integrated with the HDD functionality into a single controller. Hybrid drives can be built and configured to operate and utilize the solid-state portion in a variety of ways, such as, as a non-limiting example, using the solid-state memory as cache memory for storing frequently accessed data, for storing I / O-intensive data, etc. Additionally, hybrid drives can be built and configured essentially as two storage devices, namely a conventional HDD and an SSD, in a single housing, with one or more interfaces for host connectivity.

[0051] Expansion and Replacement

[0052] In the foregoing description, embodiments of the invention have been described with reference to numerous specific details, which may vary depending on the specific implementation. Therefore, various modifications and changes can be made without departing from the broad spirit and scope of the embodiments. Accordingly, the invention, and the applicant's intended sole and exclusive indicator of the invention, is the set of claims in the specific form issued by this patent application, including any subsequent amendments. Any definitions of terms expressly set forth herein that are included in these claims shall determine the meaning of those terms as used in the claims. Therefore, any limitations, elements, characteristics, features, advantages, or attributes not expressly cited in the claims shall not in any way limit the scope of these claims. Therefore, this specification and the accompanying drawings are to be considered exemplary rather than restrictive.

[0053] Furthermore, in this description, certain process steps may be shown in a specific order, and alphanumeric labels may be used to identify certain steps. Unless explicitly specified in the specification, the implementation is not necessarily limited to any particular order in which such steps are performed. Specifically, these labels are used only for the convenience of identifying the steps and are not intended to specify or require a particular order in which such steps are performed.

Claims

1. A flexible printed circuit (FPC), the FPC comprising: Multiple finger-like elements extending from the main portion, each finger-like element comprising: A first wiring layer, the first wiring layer including a first conductive trace layout. The second wiring layer includes a second conductive trace layout, and A base film, wherein the base film is inserted between the first wiring layer and the second wiring layer; The first conductive trace layout includes at least one thermally conductive protective island covering a corresponding portion of the second conductive trace layout to provide a protective thermal barrier to the base film.

2. The FPC according to claim 1, wherein the at least one thermally conductive protection island is electrically connected to the second wiring layer via a via.

3. The FPC according to claim 1, wherein each finger further comprises: A top narrow conductive trace connects the top pad of the first wiring layer to an adjacent specific protective island. as well as A bottom narrow conductive trace connects the opposite pad of the first wiring layer to the adjacent specific protective island, thereby electrically connecting the top pad to the bottom pad.

4. The FPC according to claim 1, further comprising: A non-transparent cover film located above the first wiring layer.

5. The FPC according to claim 1, further comprising: A white cover film located above the first wiring layer.

6. The FPC according to claim 1, further comprising: A transparent cover film located above the first wiring layer; as well as A white second covering film located above at least a portion of the transparent covering film of each finger.

7. A hard disk drive comprising the FPC according to claim 1.

8. A method for manufacturing a flexible printed circuit (FPC) lamination composition, the method comprising: A lower wiring layer is formed, including the layout of the lower conductive traces; A base film is formed above the lower wiring layer; as well as An upper wiring layer is formed, comprising an upper conductive trace layout located above the base film, and at least one thermally conductive protective island is formed covering a corresponding portion of the lower conductive trace layout to provide a protective thermal barrier to the base film.

9. The method according to claim 8, further comprising: A through-hole is formed to connect at least one thermally conductive protective island of the upper wiring layer to the lower wiring layer.

10. The method of claim 8, further comprising: A top narrow conductive trace is formed, which connects the top pad of the upper wiring layer to an adjacent specific protective island; as well as A narrow conductive trace is formed at the bottom, which connects the opposite pad of the upper wiring layer to the adjacent specific protective island, thereby electrically connecting the top pad to the bottom pad.

11. The method of claim 8, further comprising: A non-transparent cover film is formed over at least a portion of the upper wiring layer.

12. The method according to claim 8, further comprising: A white covering film is formed over at least a portion of the upper wiring layer.

13. The method of claim 8, further comprising: A transparent cover film is formed above the upper wiring layer; as well as A white second covering film is formed over at least a portion of the transparent covering film.

14. An FPC produced by the method according to claim 8.

15. A hard disk drive (HDD), the HDD comprising: Multiple recording media, the multiple recording media being rotatably mounted on a spindle; Multiple magnetic head sliders, each magnetic head slider accommodating a corresponding read / write transducer, the read / write transducer being configured to read from at least one of the multiple recording media and to write to at least one of the multiple recording media; A means for moving the plurality of magnetic head sliders to access at least one portion of the recording medium; as well as An apparatus for transporting signals from the plurality of magnetic head sliders to an HDD electronic device, the apparatus comprising: Multiple finger-like elements extending from the main portion, each finger-like element comprising: A first wiring layer, the first wiring layer including a first conductive trace layout. The second wiring layer includes a second conductive trace layout, and A base film, wherein the base film is inserted between the first wiring layer and the second wiring layer; The first conductive trace layout includes at least one thermally conductive protective island covering a corresponding portion of the second conductive trace layout to provide a protective thermal barrier to the base film.

16. The HDD of claim 15, wherein the at least one thermally conductive protection island is electrically connected to the second wiring layer via a via.

17. The HDD of claim 15, wherein each finger further comprises: Top conductive traces connect the top pads of the first wiring layer to adjacent specific protective islands; as well as A bottom conductive trace connects the opposite pad of the first wiring layer to the adjacent specific protective island, thereby electrically connecting the top pad to the bottom pad.

18. The HDD of claim 15, wherein the means for transporting signals from the plurality of head sliders to the HDD electronics further comprises: A non-transparent cover film located above the first wiring layer.

19. The HDD of claim 15, wherein the means for transporting signals from the plurality of head sliders to the HDD electronics further comprises: A white cover film located above the first wiring layer.

20. The HDD of claim 15, wherein the means for transporting signals from the plurality of head sliders to the HDD electronics further comprises: A transparent cover film located above the first wiring layer; as well as A white second covering film located above at least a portion of the transparent covering film of each finger.

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