Printed circuit boards with repairable features

Abstract

The present invention provides a PCB including a solder mask and / or conductive traces that can be repaired quickly and cost-effectively. [Solution] A printed circuit board includes at least one solder mask formed from a repairable dielectric material and / or a conductive trace formed from a repairable conductive material. Thus, the solder mask and / or conductive trace can be selectively repaired. The repairable dielectric material may flow when heated to a repair temperature. The repairable conductive material may flow when a repair voltage is applied. As with methods for repairing the solder mask and conductive trace of the PCB of an electronic device assembly, an electronic device assembly is also disclosed.

Description

【Technical Field】 【0001】 The printed circuit board (PCB) of a data storage device typically includes a solder mask on each main surface of the PCB. The solder mask facilitates the electrical coupling of memory devices (e.g., NAND devices), controllers, and other devices to the circuit board. Conventional solder masks are initially effective but are susceptible to physical damage (e.g., scratches, cracks, etc.) that can impair the electronic connection between the circuit board and the memory device. Any physical damage degrades the performance of the memory device, reduces the potential lifespan of the memory device, and ultimately leads to its failure. 【0002】 The PCB also includes conductive traces that transmit electrical signals between devices mounted on the PCB or otherwise electrically coupled to the PCB. The conductive traces of the PCB are typically formed from copper, which has a low resistivity and a high conductivity. Over time and with repeated use, the copper conductive traces can be damaged, affecting the performance and reliability of the PCB and the electronic device containing the PCB, and resulting in data errors, communication failures, and device malfunctions. 【0003】 Therefore, it would be beneficial for the PCB to include a solder mask and / or conductive traces that can be repaired. Further, it would be beneficial to have a PCB that includes a solder mask and / or conductive traces that can be repaired quickly and cost-effectively. 【Summary of the Invention】 【0004】 The printed circuit boards (PCBs) of this disclosure include features that can be restored when damaged. Such PCBs may be designed for use with one or more memory devices (e.g., one or more NAND devices) and / or as part of a solid-state drive (SSD). In some examples, the features of a repairable PCB may have a configuration that allows them to be selectively repaired or restored. In other examples, the PCB may be part of an electronic device (e.g., an SSD) that can be programmed to repair the features. 【0005】 In some examples, a PCB may include a solder mask that can be selectively repaired when damaged. The solder mask may include a dielectric material that can be repaired when exposed to a sufficient temperature. The dielectric material may be referred to as the “repairable dielectric material”. The temperature that enables the repairable dielectric material to repair may be referred to as the “repair temperature”. The repairable dielectric material may include one or more dynamic covalent polymers (DCPs), Diels-Alder (DA) adducts, and / or metal-ligand coordination polymers (e.g., zinc-ligand coordination polymers). In some examples, the repairable dielectric material may include at least one dynamic covalent polymer, at least one DA adduct, and at least one metal-ligand coordination polymer. 【0006】 The repair temperature of such repairable dielectric materials may be approximately the same as, or higher than, the operating temperature of the electronic device in which the PCB is part, but low enough to prevent thermal damage to the PCB and / or other devices and features of the electronic device assembly in which the PCB is part. As an example, the repair temperature may be below the solder reflow temperature of the electronic device assembly in which the PCB is part. Repairable dielectric materials may have a repair temperature between approximately 100°C and approximately 180°C. In some examples, the repair temperature of repairable dielectric materials may be in the range of approximately 100°C to approximately 150°C, or approximately 100°C to approximately 130°C. 【0007】 A method for repairing such damage to the solder mask of a PCB may optionally include detecting the damage to the solder mask. This method may also include applying heat to the damage and then cooling the solder mask material. The heat may be applied in particular to the damaged area of ​​the solder mask. Alternatively, the heat may be applied in general to the entire solder mask, as well as to the PCB and the electronic device assembly (e.g., an SSD) of which the PCB is part. The solder mask may be heated to a repair temperature that allows the solder mask material to recover without damaging the PCB supporting the solder mask, or any other components or features of the PCB and the electronic device assembly of which the solder mask is part. For example, the solder mask may be heated to temperatures in the range of about 100°C to about 130°C, temperatures in the range of about 100°C to about 150°C, and up to about 180°C. 【0008】 When heat is applied to the solder mask, hydrogen bonds in the repairable dielectric material of the solder mask may be broken, covalent bonds of DCP in the repairable dielectric material of the solder mask may be broken, bonds formed by DA reactions in the repairable dielectric material of the solder mask may be broken, and / or metal-ligand bonds in the repairable dielectric material of the solder mask may dissociate. As the repairable dielectric material of the solder mask cools, hydrogen bonds in the repairable dielectric material of the solder mask may be re-established, bonds formed by DA reactions in the repairable dielectric material of the solder mask may be re-established, and / or metal-ligand bonds in the repairable dielectric material of the solder mask may be re-established, thereby repairing damage to the solder mask. 【0009】 In some cases, a PCB may contain conductive traces, which may be more simply referred to as “traces,” that can be selectively repaired or automatically repaired if destroyed or otherwise damaged. Such conductive traces in a PCB may contain polyimide along with sufficient silver and copper nanoparticles dispersed throughout the polyimide to enable the traces to transmit electrical signals at the operating voltage (e.g., approximately 3.3V to approximately 5V) of the electronic device (e.g., an SSD) in which the PCB is part. If such traces are destroyed or otherwise damaged, they can be repaired by exposure to a repair voltage exceeding the operating voltage (e.g., approximately 5V to approximately 10V). Therefore, such materials may be referred to as “repairable conductive materials.” 【0010】 A PCB may be part of an electronic device assembly (e.g., an SSD) that includes two or more semiconductor devices, such as memory devices (e.g., NAND devices) and controllers, that communicate with each other through traces on the PCB. Each of the semiconductor devices may apply a repair voltage to a damaged trace. If one of the semiconductor devices is a memory device, the memory device may include a multiplier circuit that increases its operating voltage to a repair voltage and selectively applies the repair voltage to the damaged trace. 【0011】 A method for repairing a fracture in a PCB trace or other damage to a trace may include identifying each trace having a fracture or other damage, and applying a repair voltage to the trace to repair the fracture. The repair voltage (e.g., about 5V to about 10V) may exceed the operating voltage of the electronic device in which the PCB is part (e.g., about 3.3V to about 5V). When a repair voltage is applied to a fractured or otherwise damaged trace, a repairable conductive material may repair the fracture or other damage. More specifically, polymers of the repairable conductive material, as well as silver nanoparticles and copper nanoparticles, may flow across the fracture or other damage. Applying the repair voltage to both sides of the fracture or other damage (e.g., from both ends of the trace) can ensure that the repair is properly carried out across the fracture or other damage. For example, the repair voltage may be applied from one side by a controller of an electronic device assembly. In cases where the repair voltage can be applied to both sides of the damaged area or other damage, the repair voltage may be applied from the other side of the trace by a multiplication circuit of a memory device (e.g., a NAND device) in an electronic device assembly. 【0012】 Other aspects of the disclosed subject matter, as well as the features and advantages of various aspects of the disclosed subject matter, should become apparent to those skilled in the art by considering the following description, the accompanying drawings, and the accompanying claims. [Brief explanation of the drawing] 【0013】 The drawing is as follows: [Figure 1] This diagram schematically depicts a repairable solder mask on a printed circuit board (PCB). [Figure 2] Figure 1 schematically illustrates the process for repairing damage to a repairable solder mask. [Figure 3] Figure 1 schematically illustrates the process for repairing damage to a repairable solder mask. [Figure 4] Figure 1 schematically illustrates the process for repairing damage to a repairable solder mask. [Figure 5]Figure 1 schematically illustrates the process for repairing damage to a repairable solder mask. [Figure 6] A schematic diagram of an electronic device assembly having a PCB with repairable traces is shown. The PCB before any damage or other damage to any of the traces is shown. [Figure 7] Schematically depict an electronic device assembly with a PCB containing repairable traces. Depict a PCB with traces that are destroyed or otherwise damaged. [Figure 8] A schematic diagram of an electronic device assembly having a PCB with repairable traces is provided. An example of applying a repair voltage to a trace that is broken or otherwise damaged from both sides of the fracture or other damage is illustrated. [Figure 9] A schematic description of an electronic device assembly having a PCB with repairable traces is provided. An example of applying a repair voltage to another damaged or otherwise damaged trace from both sides of a fracture or other damage is illustrated. [Figure 10] Schematically depict an electronic device assembly with a PCB containing repairable traces. Depict a PCB with repaired traces. [Modes for carrying out the invention] 【0014】 In SSD manufacturing and assembly, solder mask damage can have significant economic consequences. Yield loss due to solder mask damage typically ranges from 2% to 5% of manufactured SSDs. Traditional repair methods are costly and time-consuming. However, there may be situations where the SSD's solder mask is so severely damaged that it cannot be repaired using conventional techniques and must be discarded. Therefore, the total annual loss from repairing and discarding SSDs with faulty solder masks can be substantial. The substantial financial impact highlights the need for improved solutions to effectively address solder mask damage. 【0015】 Conventional methods to improve solder mask durability include increasing the thickness of the coating or applying an additional protective layer. While these methods are somewhat effective, they can increase manufacturing costs and complicate the manufacturing process without addressing minor damage repairs. Other approaches to improving SSD yield include manual repair techniques and frequent inspections, both of which are labor-intensive and therefore not cost-effective. 【0016】 In addition to causing problems during SSD assembly, damage to the solder mask can also become a problem over time, as it serves to protect the PCB, the memory devices supported by the PCB, and the electrical connections between the memory devices and the PCB. Damage to the solder mask can compromise the integrity of the SSD, allowing contaminants to come into contact with the SSD's delicate components and features, and potentially interfering with the communication of electrical signals necessary for the SSD to function properly. 【0017】 The ability of an SSD to function reliably over a long period also depends on the integrity of the SSD's conductive paths, including the conductive traces on the SSD's PCB. Conductive traces, typically formed from copper, can degrade over time due to various factors, including physical stress, thermal cycling, and electrical overstress. These and other factors can lead to the destruction or disconnection of the conductive traces, resulting in data errors, communication failures, and device malfunctions. 【0018】 Traditional solutions for repairing damaged conductive traces, such as manual intervention including resoldering or the use of conductive adhesive, are not feasible in highly integrated systems with complex microscale circuits. Additionally, when multiple damaged traces are in close proximity to each other, manual repairs pose a risk of accidental short circuits or misconnections, leading to device failure. While some systems include redundant paths to mitigate single-point failures, the use of redundant paths increases design complexity and necessitates increasing the size of the SSD's PCB. 【0019】 Referring to FIG. 1, an example of a printed circuit board (PCB) 10 is depicted. The PCB 10 includes a surface 12 that carries a solder mask 20. The solder mask 20 includes a material that can be repaired, or a reparable dielectric material 22. Thus, the solder mask 20 includes a reparable solder mask. The reparable dielectric material 22 of the solder mask 20 can facilitate the repair of damage to the solder mask 20 (e.g., scratches on the solder mask 20, microcracks or cracks in the solder mask 20, etc.). 【0020】 The reparable dielectric material 22 can include bonds that are broken upon heating and can be re-established upon cooling. More specifically, the reparable dielectric material 22 can include a base resin, one or more thermoplastic polymers, and at least one heat-activated reversible polymer (HARP) 24. The HARP 24 can include at least one dynamic covalent polymer (DCP), at least one Diels-Alder (DA) adduct, and / or at least one metal-ligand coordination polymer (e.g., a zinc-ligand coordination polymer, etc.). 【0021】 The base resin of the reparable dielectric material 22 can include materials that are durable, electrically insulating, resistant to moisture, resistant to high temperatures, and resistant to etching by solder flux. Examples of materials suitable for use as the base resin for a solder mask include, but are not limited to, epoxy, acrylic resin, polyester resin, etc. The base resin can be a material that has been conventionally used to form a solder mask. Using such a base resin can ensure that the reparable dielectric material 22 can be integrated into existing PCB manufacturing processes and that the solder mask 20 formed from the reparable dielectric material 22 can be compatible with existing manufacturing processes (e.g., assembly, solder reflow, etc.). 【0022】 In addition to the base resin, the repairable dielectric material 22 may include one or more thermoplastic polymers. These one or more thermoplastic polymers may include polyurethane. Polyurethane is durable and flexible. The properties of polyurethane can be adjusted by changing their polyol and isocyanate components. Alternatively or additionally, these one or more thermoplastic polymers may include polyimide. Polyimide is thermally stable, chemically resistant, and can contribute to the mechanical properties of the solder mask 20 (e.g., strength, toughness, hardness, ductility, brittleness, etc.). 【0023】 In addition to hydrogen bonding in the repairable dielectric material 22, the HARP 24 of the repairable dielectric material 22 (e.g., DCP, DA adducts, and / or metal-ligand coordination polymers, etc.) may impart further properties (e.g., additional types of bonding, etc.) to the repairable dielectric material 22 that enable the repair of physical damage to the repairable dielectric material 22, and therefore the repair of damage to the solder mask 20 formed by the repairable dielectric material 22. 【0024】 Hydrogen bonds 26 in the repairable dielectric material 22 are non-covalent interactions between molecules having electronegative atoms. These hydrogen bonds 26 can be reversed, or broken, by heating the repairable dielectric material 22. The hydrogen bonds 26 can be re-established by cooling the repairable dielectric material 22. 【0025】 The DCP includes covalent bonds 27 that can be reversed or broken and reformed under certain conditions. For example, applying heat to a repairable dielectric material 22 can break the covalent bonds 27 of the DCP, while as the repairable dielectric material 22 cools, the covalent bonds 27 of the DCP can be reformed. 【0026】 In DA adducts, a [4+2] cycloaddition reaction or DA reaction occurs between the diene and the dienophile, forming two pi bonds and two sigma bonds 28 between the diene and the dienophile. The pi and sigma bonds 28 can be broken by heating the repairable dielectric material 22 (i.e., retro-DA reaction). The pi and sigma bonds 28 can be reformed by cooling the repairable dielectric material 22 (i.e., DA reaction). 【0027】 Metal-ligand coordination polymers are composed of metal ions (e.g., zinc ions, or Zn 2+ The material includes a metal-ligand coordination bond 29 in which a ligand (etc.) coordinates to one or more ligands. The metal-ligand coordination bond 29 can be broken by heating the repairable dielectric material 22. The metal-ligand coordination bond 29 can be reformed by cooling the repairable dielectric material 22. 【0028】 By breaking the bonds 26, 27, 28, and 29 in the repairable dielectric material 22, at least some components of the repairable dielectric material 22 can re-inflow into the damaged area of ​​the solder mask 20. The temperature at which the various bonds 26, 27, 28, and 29 in the repairable dielectric material 22 can be broken may be the repair temperature of the repairable dielectric material 22. The repair temperature of the repairable dielectric material 22 may be about 180°C or less. In some examples, the repair temperature of the repairable dielectric material 22 may be in the range of about 100°C to about 150°C, or in the range of about 100°C to about 130°C. In some examples, the repair temperature of the repairable dielectric material 22 may be the operating temperature of the PCB 10 covered by the solder mask 20, which may allow any damage to the solder mask 20 to self-repair during the operation of the electronic device in which the PCB 10 and the solder mask 20 are part. When the repairable dielectric material 22 re-flows into the damaged area of ​​the solder mask 20, it can cool down. As the repairable dielectric material 22 cools, the bonds 26, 27, 28, and 29 are reformed, the integrity of the solder mask 20 formed by the repairable dielectric material 22 is re-established, and the repair of the solder mask 20 is completed. 【0029】 In addition to the materials described above, the repairable dielectric material 22 may include one or more curing agents. The curing agents react with the resin to define the strength and other properties (e.g., hardness, ductility, brittleness, etc.) of the repairable dielectric material 22 and the solder mask 20 formed from the repairable dielectric material 22. 【0030】 The repairable dielectric material 22 may also contain one or more additives. Some non-limiting examples of additives include fillers, colorants, and ultraviolet (UV) absorbers. Fillers can optimize the mechanical properties, heat resistance, and chemical resistance of the repairable dielectric material 22 and the solder mask 20 formed from the repairable dielectric material 22. Colorants can define the color of the repairable dielectric material 22 and the solder mask 20 formed from the repairable dielectric material 22. UV absorbers can enable the use of UV exposure and chemical development processes to fabricate the solder mask 20 or other structures from the repairable dielectric material 22. 【0031】 In a specific but non-limiting example, the repairable dielectric material 22 may be formulated as follows: 【0032】 [Table 1] 【0033】 Figures 2 to 5 illustrate a process for repairing damage 23 to a solder mask 20 formed from an exemplary and described repairable dielectric material 22. 【0034】 In Figure 2, the solder mask 20 may be damaged. Some examples of damage 23 to the solder mask 20 include scratches, microcracks, and cracks. Damage 23 can occur after the solder mask 20 is formed on the PCB 10, during assembly of the PCB 10 and solder mask 20 with other components (e.g., controllers, memory devices such as NAND devices, etc.), during handling of the assembly including the PCB 10 and solder mask 20 (e.g., during the manufacture of an electronic device), or during use of the electronic device including the PCB 10 and solder mask 20. Any damage 23 to the solder mask 20 may be detected in some situations, such as during inspection of the solder mask 20 immediately after manufacture, or during inspection of the assembly including the PCB 10 and solder mask 20. In other situations, such as during the manufacture or use of the electronic device including the PCB 10 and solder mask 20, any damage 23 to the solder mask 20 may not be detected. 【0035】 In Figure 3, heat may be applied to the solder mask 20 to repair any damage 23 to the solder mask 20. The heat may be applied in any preferred manner. For example, heat may be applied by placing the PCB 10 supporting the solder mask 20 in a furnace heated to a preferred temperature. The heat may be applied to intentionally repair damage 23 to the solder mask 20. Alternatively, heat applied to the solder mask 20 may repair damage 23 to the solder mask 20 automatically, and therefore unintentionally. For example, as part of a subsequent process of the PCB 10 supporting the solder mask 20, heat may be applied to the solder mask 20, for example, in a reflow oven, when solder electrically couples one or more semiconductor devices (e.g., controllers, memory devices, etc.) to the PCB 10. As another example, heat may be applied during the operation of an electronic device including the PCB 10 supporting the solder mask 20. 【0036】 The amount of heat applied to the solder mask 20 may be the repair temperature of the repairable dielectric material 22 of the solder mask 20. The repair temperature may be approximately 180°C or less. In some examples, the repair temperature may be in the range of approximately 100°C to approximately 150°C, or in the range of approximately 100°C to approximately 130°C. In some examples, the repair temperature may be the operating temperature of the PCB 10 covered by the solder mask 20, or the temperature of the PCB 10 during normal operation of an electronic device in which the PCB 10 is part. 【0037】 When heat is applied to the solder mask 20, bonds in the repairable dielectric material 22 of the solder mask 20 may be broken. These bonds may include hydrogen bonds 26, covalent bonds 27 of DCP, π and σ bonds 28 of DA adducts, and / or metal-ligand coordination bonds 29 of metal-ligand coordination polymers. When the bonds are broken, the repairable dielectric material 22 may re-enter. 【0038】 The repairable dielectric material 22 can re-enter any damage 23 (e.g., scratches, microcracks, cracks, etc.) in the solder mask 20. When the repairable dielectric material 22 re-enters any damage 23, heat can be removed from the solder mask 20 and the repairable dielectric material 22, causing the repairable dielectric material 22 to cool. As the repairable dielectric material 22 cools, as shown in Figure 4, bonds 26, 27, 28, and 29 in the repairable dielectric material 22 can be reformed. These bonds may include hydrogen bonds 26, covalent bonds 27 of DCP, π and σ bonds 28 of DA adducts, and / or metal-ligand coordination bonds 29 of metal-ligand coordination polymers. As the bonds in the repairable dielectric material 22 are reformed, the complete structural and chemical integrity of the solder mask 20 can be re-established, as shown in Figure 5. 【0039】 By using a repairable dielectric material 22 to form the solder mask 20, it may be possible to repair damage to the solder mask 20 at any point after the solder mask 20 has been manufactured, including before the PCB 10 on which the solder mask 20 is formed is assembled with other devices (e.g., semiconductor devices such as memory devices and controllers). For example, a PCB 10 that fails inspection because the solder mask 20 is damaged (e.g., scratches, cracks, etc.) can be simply heated (e.g., placed in a furnace) to repair the damage and then reinspected. Enabling the recovery of PCB 10 with damaged solder masks 20 may improve the overall efficiency of the PCB manufacturing process. 【0040】 A solder mask 20 formed from a repairable dielectric material 22 can be repeatedly repaired. In some cases, a solder mask 20 formed from a repairable dielectric material 22 can be subjected to the repair temperature multiple times. 【0041】 By using a repairable dielectric material 22 to form a solder mask 20 on the PCB 10, the integrity of the solder mask 20 can be maintained over time, increasing the durability and lifespan of the PCB 10 and potentially increasing the reliability of the electronic device (e.g., SSD) in which the PCB 10 is incorporated. Therefore, using a solder mask 20 formed from the repairable dielectric material 22 in an electronic device can reduce the likelihood of needing costly repairs or replacements. 【0042】 Referring here to Figure 6, an example of an electronic device assembly 100 is depicted, which includes a printed circuit board (PCB) 110 having conductive traces, which may also be referred to as traces 130, formed from a repairable or repairable conductive material 132. Thus, the traces 130 include repairable conductive traces. The repairable conductive material 132 of the traces 130 can facilitate the repair of damage to the traces 130 (e.g., breakage in the traces 130). 【0043】 The repairable conductive material 132 may include a high-performance plastic in which conductive particles are dispersed. 【0044】 A high-performance plastic for a repairable conductive material 132 that can be used to define very fine features such as traces 130 of a PCB 110 by a process suitable for use in the manufacture of PCBs. By including a high-performance plastic in the repairable conductive material 132, the traces 130 can be given greater flexibility than conventional copper traces. The increased flexibility can allow the traces 130 to withstand physical trauma better than conventional copper traces, and thus can increase the potential lifespan of the PCB 110 including traces 130 formed from the repairable conductive material 132. In addition, the high-performance plastic of the traces 130 can be highly crosslinked to increase its stability, and the high-performance plastic can withstand the operating conditions under which PCBs are typically served (e.g., temperature changes, relatively high operating temperatures, etc.) better than conventional copper traces. In a specific example, the high-performance plastic of the repairable conductive material 132 may include polyimide that can withstand repeated temperature fluctuations. For example, a conventional PCB with copper traces may function at operating temperatures up to approximately 85°C, while a PCB 110 with traces 130 formed from a repairable conductive material 132 containing polyimide may function at operating temperatures up to approximately 120°C. Therefore, defining the traces 130 of the PCB 110 using the repairable conductive material 132 can enhance the performance of the PCB 110 in demanding environments compared to the performance of a conventional PCB with copper traces in demanding environments. In some examples, high-performance plastics (e.g., polyimide) may account for approximately 79% to 90% of the weight of the repairable conductive material 132. 【0045】 The conductive particles of the repairable conductive material 132 may include silver (Ag) particles and copper (Cu) particles. The particles may include nanoparticles having a size (e.g., diameter, etc.) of about 20 nm to about 50 nm. Depending on the concentration of conductive particles in the repairable conductive material 132, the trace 130 formed from the repairable conductive material 132 may be able to reliably conduct electrical signals at low voltages such as the operating voltage of the electronic device assembly 100 including the PCB 110 (e.g., about 3.3 V, about 5 V, etc.). For example, the repairable conductive material 132 may have a resistivity comparable to that of copper, which is about 1.7 × 10⁻¹⁶. -8 It is Ω·m. For example, the repairable conductive material 132 is approximately 5.0 × 10 -8 It may have a resistivity of Ω·m or less. In non-limiting examples, conductive particles may constitute about 10% to about 15% of the weight of the repairable conductive material 132. 【0046】 Optionally, the repairable conductive material 132 may include conductive additives, which may further improve the electrical properties of the repairable conductive material 132. Conductive additives may enable the repairable conductive material 132 to reliably conduct low-voltage electrical signals. Conductive additives may contribute to the repairability of the repairable conductive material 132, and therefore to its ability to repair the fractured portion of the trace 130. Without limitation, carbon nanotubes and / or graphene may be included in the repairable conductive material 132. In a more specific example, the repairable conductive material 132 may include both carbon nanotubes and graphene. More specifically, carbon nanotubes and graphene may each constitute about 2% to about 3% by weight of the repairable conductive material 132. 【0047】 Such repairable conductive material 132 can be used to form traces 130 having a width of approximately 500 μm to approximately 1,000 μm and a thickness of approximately 20 μm to approximately 50 μm, compared to conventional PCB traces which are typically about 1,000 μm wide and about 35 μm thick. 【0048】 In addition to enabling the design of traces 130 that are potentially thinner than those of conventional PCB copper traces, the use of repairable conductive material 132 may allow for the use of thinner insulating layers than those of conventional PCBs. For example, while a conventional PCB with copper traces may have an insulating layer as thin as approximately 50 μm, a PCB 110 with traces 130 formed from repairable conductive material 132 may have an insulating layer as thin as approximately 30 μm. Furthermore, tests have shown that traces 130 formed from repairable conductive material 132 fail at a rate of only about 1%, in contrast to the 10% failure rate of conventional copper traces, indicating that PCB 110 with traces 130 formed from repairable conductive material 132 is far more reliable (e.g., up to approximately 10 times more reliable) than conventional PCBs with copper traces. Therefore, forming traces 130 using repairable conductive material 132 may enable the design and manufacture of PCB 110 that is significantly thinner and substantially more reliable than conventional PCB 110 with copper traces. 【0049】 Such repairable conductive material 132 has been found to be able to flow over short distances when exposed to an electric field having a voltage exceeding the typical operating voltage of an electronic device. For example, the repairable conductive material 132 can flow when exposed to a voltage greater than 5V. More specifically, the repairable conductive material 132 can flow when a voltage greater than 5V and up to about 10V is applied. By subjecting the repairable conductive material 132 to such a voltage, the repairable conductive material 132 can be heated (for example, to a temperature such as about 120°C, which is higher than the normal operating temperature of about 60°C to about 85°C), thereby causing the repairable conductive material 132 to flow. The voltage at which the repairable conductive material 132 flows can be called the "repair voltage". 【0050】 Applying a repair voltage to a trace 130 formed from a repairable conductive material 132 can cause the repairable conductive material 132 to flow beyond a fractured area 134 (Figure 7) in the trace 130 that is approximately 10 μm in size. When the repairable conductive material 132 flows, it can bridge the fractured area 134 and thus restore the function of the trace 130. 【0051】 The trace 130, formed from the repairable conductive material 132, can be repeatedly repaired. In some cases, the trace 130, formed from the repairable conductive material 132, can be subjected to the repair voltage multiple times. 【0052】 Continuing to refer to Figure 6, the electronic device assembly 100 may additionally include a first semiconductor device 140 and a second semiconductor device 150 on the PCB 110. Trace 130 can establish a conductive link between the first semiconductor device 140 and the second semiconductor device 150, thus enabling the first semiconductor device 140 and the second semiconductor device 150 to communicate with each other. 【0053】 In an example where the electronic device assembly 100 includes an SSD, the first semiconductor device 140 may include a controller. Such a first semiconductor device 140 may be programmed to control the operation of the electronic device assembly 100 and enable the electronic device assembly 100 to communicate with other electronic devices. Such a first semiconductor device 140 may also be for identifying any broken or otherwise damaged traces 130 of the PCB 110. For example, the first semiconductor device 140 may include circuitry that is dedicated to and programmed for monitoring problems. In addition, such a first semiconductor device 140 may be programmed to apply a repair voltage to one or more broken or otherwise damaged traces 130. In some examples, the first semiconductor device 140 applies a repair voltage to the fractured or otherwise damaged trace 130 on one side of the fracture 134 or other damage, but the first semiconductor device 140 may be further programmed to cause the second semiconductor device 150 to apply a repair voltage to the fractured or otherwise damaged trace 130 from the other side of the fracture 134 or other damage. 【0054】 The second semiconductor device 150 of the electronic device assembly 100, which includes the SSD, may be a memory device such as a NAND device. In an example where a repair voltage can be applied to a damaged or destroyed trace 130 of the second semiconductor device 150, the second semiconductor device 150 may include a multiplier circuit 152. The multiplier circuit can increase or step up a relatively low operating voltage (e.g., about 3.3V or about 5V) to a higher repair voltage (e.g., a voltage in the range of over 5V to about 10V). 【0055】 During normal operation, the electronic device assembly 100 (e.g., an SSD) functions as expected, and electrical signals flow through the traces 130 of the PCB 110. The first semiconductor device 140 (e.g., a controller) can monitor the performance of the electronic device assembly 100, including the PCB 110 and its traces 130, to ensure that the electronic device assembly 100 functions optimally (e.g., with optimal read / write speeds and data integrity of the second semiconductor device 150 (memory device), without any interruptions). 【0056】 The first semiconductor device 140 continues to monitor the performance of the electronic device assembly 100, but may detect a fracture 134 or other damage to one or more conductive traces 130 of the PCB 110, as shown in Figure 7. Programming of the first semiconductor device 140, or a dedicated monitoring circuit for the first semiconductor device 140, may enable the first semiconductor device 140 to identify traces 130 that have a fracture 134 or other damage. In Figure 7, two traces 130, which Figure 7 identifies as trace 130a and trace 130b, are fractured. 【0057】 As depicted in Figure 8, when a fracture 134 or other damage to trace 130a is detected, the first semiconductor device 140 may apply a repair voltage 145 to trace 130a on one side of the fracture 134a or other damage. Optionally, the first semiconductor device 140 may cause the second semiconductor device 150, or a multiplier circuit 152 of the second semiconductor device 150, to apply a repair voltage to trace 130a on the opposite side of the fracture 134a or other damage. Applying a repair voltage to trace 130a from both sides of the fracture 130a or other damage ensures that the repairable conductive material 132 flows into the fracture 134a or other damage along the original path of trace 130a, rather than towards other traces 134a or conductive features of the PCB 110. Optionally, PCB 110 may include additional insulators adjacent to the sides and / or bottom of each trace 130 to prevent the repairable conductive material 132 of the trace 130 from flowing beyond the original path of the trace 130 and potentially creating electrical problems (e.g., short circuits) between the repaired trace 130 and other electrical features of PCB 110 (e.g., other traces 130, etc.). 【0058】 The first semiconductor device 140 may monitor the conductivity of trace 130a when the damaged portion 134a or other damage to trace 130 is being repaired. When the ability of trace 130a to conduct electrical signals is restored, the first semiconductor device 140 may terminate the repair process. Additionally, if the repair process continues for a predetermined duration without restoring the ability of trace 130a to conduct electrical signals, the first semiconductor device 140 may terminate the repair process and provide an output indicating that trace 130a is irreparably damaged. 【0059】 Figure 9 illustrates the repair of a fracture 134b in another trace 130b of PCB 110 in the same manner as described with reference to Figure 8. The repair of trace 130b may be performed at least partially simultaneously with the repair of trace 130a, or after the repair of trace 130a is completed. The local electric field generated by applying a repair voltage across each fracture can prevent the formation of cross-connections between adjacent fractures 134a and 134b. 【0060】 Figure 10 shows the electronic device assembly 100 including the repaired traces 130a and 130b. Once the damage 134 or other damage to the trace 130 of the PCB 110 is repaired, the normal operation of the electronic device assembly 100 can be resumed. 【0061】 Some examples of PCBs include at least one solder mask 20 formed from a repairable dielectric material 22 as described with reference to Figure 1, and traces 130 formed from a repairable conductive material 132 of the type described with reference to Figure 6. Similarly, some examples of electronic device assemblies, such as the electronic device assembly 100 described with reference to Figure 6, include PCBs 10, 110 having at least one solder mask 20 formed from a repairable dielectric material 22 as described with reference to Figure 1, and traces 130 formed from a repairable conductive material 132 as described with reference to Figure 6. 【0062】 Based on the foregoing, an example of the present disclosure describes a printed circuit board (PCB) comprising at least one of the following: a solder mask containing a repairable dielectric material that flows at a repair temperature above the operating temperature of the electronic device in which the PCB is incorporated; and traces defined from a repairable conductive material that flows when a repair voltage is applied to one of the traces, wherein the repair voltage exceeds the operating voltage of the electronic device in which the PCB is incorporated. In one example, the solder mask comprises a base resin, at least one thermoplastic resin, and at least one heat-activated reversible polymer (HARP). In one example, the at least one HARP comprises a dynamic covalent polymer (DCP), a Diels-Alder (DA) adduct, and / or a metal-ligand coordination polymer. In one example, the repair temperature is in the range of 100°C to 130°C. In one example, the repairable conductive material comprises a polyimide, the polyimide having silver nanoparticles and copper nanoparticles dispersed throughout the polyimide. In one example, at least one of the silver nanoparticles and copper nanoparticles has a size in the range of 20 (nanometers) nm to 50 nm. In one example, the polyimide further comprises at least one of carbon nanotubes and graphene. In one example, the repair voltage is in the range of 5 volts (V) to 10 V. In one example, the PCB supports a controller and a memory device, and the controller is programmed to monitor the performance of the PCB, detect fractures in the traces, and apply a repair voltage to the traces from the first side of the fracture. In one example, the memory device includes a multiplication circuit, and the controller is further programmed to cause the multiplication circuit of the memory device to apply a repair voltage to the traces on the second side of the fracture, opposite to the first side of the fracture. 【0063】 The embodiments also describe a method for repairing a damaged area in a trace of a printed circuit board (PCB), comprising identifying the trace having the damaged area and applying a repair voltage to the trace to repair the damaged area, wherein the repair voltage exceeds the operating voltage of the electronic device on which the PCB is installed. In one example, applying the repair voltage includes applying a voltage in the range of 5V to 10V to the damaged area. In another example, applying the repair voltage includes applying the repair voltage to the trace from both sides of the damaged area. In yet another example, applying the repair voltage from both sides of the damaged area includes applying the repair voltage from a first side of the damaged area using a processor that communicates with the trace, and applying the repair voltage from a second side of the damaged area. In yet another example, applying the repair voltage from the second side of the damaged area includes applying the repair voltage from a multiplier circuit associated with the electronic device. 【0064】 The examples also describe a method for repairing damage to a solder mask on a printed circuit board (PCB), comprising detecting the damage to the solder mask, applying heat to the damage, including breaking Diels-Alder bonds in the solder mask material, breaking hydrogen bonds in the solder mask material, and dissociating metal-ligand bonds in the solder mask material, and cooling the solder mask material, including re-establishing Diels-Alder bonds in the solder mask material, re-establishing hydrogen bonds in the solder mask material, and re-forming metal-ligand bonds in the solder mask material. In one example, applying heat to the damage includes applying heat to the entire solder mask. In one example, applying heat includes exposing the solder mask to a temperature in the range of 100°C to 130°C. In one example, the PCB is contained within a data storage device. In one example, applying heat is performed while the data storage device is in operation. 【0065】 The descriptions and examples of one or more aspects provided in this disclosure are not intended in any way to limit or restrict the scope of this disclosure. The aspects, examples, and details provided in this disclosure are considered sufficient to convey ownership and enable others to create and use the best form of the claimed disclosure. 【0066】 The claimed disclosure should not be construed as being limited to any aspects, examples, or details provided herein. Various features (both structural and methodological), whether shown and described in combination or separately, are intended to be selectively rearranged, included, or omitted to produce examples having a particular set of features. While descriptions and examples of this disclosure have been provided, those skilled in the art may envision variations, modifications, and alternative embodiments that fall within the spirit of the broader aspects of the general inventive concept embodied herein, without departing from the broader scope of the claimed disclosure. 【0067】 References to elements in this specification using designations such as "first," "second," etc., generally do not limit the number or order of those elements. Rather, these designations can be used as a way to distinguish two or more elements or instances of elements. Thus, references to first and second elements do not mean that only two elements can be used, or that the first element precedes the second element. In addition, unless otherwise specified, a set of elements may include one or more elements. 【0068】 Terms used in the description or claims in the form of “at least one of A, B, or C” or “A, B, C, or any combination thereof” mean “A, B, or C, or any combination of these elements.” For example, this term may include A, B, or C, or A and B, or A and C, or A and B and C, or 2A, or 2B, or 2C, or 2A and B, etc. As a further example, “at least one of A, B, or C” is intended to include A, B, C, AB, AC, BC, and ABC, as well as multiples of the same member. Similarly, “at least one of A, B, and C” is intended to include A, B, C, AB, AC, BC, and ABC, as well as multiples of the same member. 【0069】 Similarly, as used herein, the phrase “and / or” referring to a list of linked items refers to any combination of items. For example, “A and / or B” is intended to include A alone, B alone, or A and B together. As another example, “A, B, and / or C” is intended to include A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C.

Claims

[Claim 1] A printed circuit board (PCB), A solder mask comprising a repairable dielectric material that flows at a repair temperature above the operating temperature of the electronic device in which the PCB is incorporated, and A printed circuit board comprising at least one of the traces, wherein the trace is defined from a repairable conductive material that flows when a repair voltage is applied to one of the traces, and the repair voltage exceeds the operating voltage of the electronic device in which the PCB is incorporated. [Claim 2] The PCB according to claim 1, wherein the solder mask comprises a base resin, at least one thermoplastic resin, and at least one thermoactivated reversible polymer (HARP). [Claim 3] The PCB according to claim 2, wherein the at least one HARP comprises a dynamic covalent polymer (DCP), a Diels-alder (DA) adduct, and / or a metal-ligand coordination polymer. [Claim 4] The PCB according to claim 1, wherein the repair temperature is within the range of 100°C to 130°C. [Claim 5] The PCB according to claim 1, wherein the repairable conductive material comprises a polyimide, and the polyimide has silver nanoparticles and copper nanoparticles dispersed throughout the polyimide. [Claim 6] The PCB according to claim 5, wherein at least one of the silver nanoparticles and the copper nanoparticles has a size in the range of 20 nm to 50 nm. [Claim 7] The PCB according to claim 5, wherein the polyimide further comprises at least one of carbon nanotubes and graphene. [Claim 8] The PCB according to claim 5, wherein the repair voltage is within the range of 5 volts (V) to 10 V. [Claim 9] The PCB according to claim 1, comprising a controller and a memory device, wherein the controller is programmed to monitor the performance of the PCB, detect a damaged portion of the trace, and apply the repair voltage to the trace from the first side of the damaged portion. [Claim 10] The memory device includes a multiplication circuit, The PCB according to claim 9, wherein the controller is further programmed to cause the multiplication circuit of the memory device to apply the repair voltage to the trace on the second side of the damaged part opposite to the first side of the damaged part. [Claim 11] A method for repairing damaged traces on a printed circuit board (PCB), Identifying the trace having the aforementioned damaged portion, A method for repairing the damaged portion, comprising applying a repair voltage to the trace, wherein the repair voltage exceeds the operating voltage of the electronic device on which the PCB is located. [Claim 12] The method according to claim 11, wherein applying the repair voltage includes applying a voltage in the range of 5V to 10V to the damaged part. [Claim 13] The method according to claim 11, wherein applying the repair voltage includes applying the repair voltage to the trace from both sides of the damaged portion. [Claim 14] Applying the repair voltage from both sides of the damaged area is Using a processor that communicates with the tracer, the repair voltage is applied from the first side of the damaged part, The method according to claim 13, comprising applying the repair voltage from the second side of the damaged portion. [Claim 15] The method according to claim 14, wherein applying the repair voltage from the second side of the damaged portion includes applying the repair voltage from a multiplier circuit associated with the electronic device. [Claim 16] A method for repairing damage to a solder mask on a printed circuit board (PCB), To detect damage to the solder mask, Applying heat to the aforementioned damage, To break the Diels-Alder bonds in the material of the aforementioned solder mask, To break the hydrogen bonds in the material of the solder mask, and The process of applying heat to the damage includes dissociating the metal-ligand bonds in the material of the solder mask, The method involves cooling the material of the solder mask, To re-establish the Diels-Alder bond in the material of the solder mask, To re-establish hydrogen bonds in the material of the solder mask, and A method comprising cooling the material of the solder mask, which includes recombining the metal-ligand bonds in the material of the solder mask. [Claim 17] The method according to claim 16, wherein applying heat to the damage includes applying heat to the entire solder mask. [Claim 18] The method according to claim 16, wherein applying heat includes exposing the solder mask to a temperature in the range of 100°C to 130°C. [Claim 19] The method according to claim 16, wherein the PCB is contained within a data storage device. [Claim 20] The method according to claim 19, wherein the application of heat is performed while the data storage device is in operation.

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