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Construction and Assembly of the Wire Planes for the MicroBooNE Time Projection Chamber

In this paper we describe how the readout planes for the MicroBooNE Time Projection Chamber were constructed, assembled and installed. We present the individual wire preparation using semi-automatic winding machines and the assembly of wire carrier boards. The details of the wire installation on the detector frame and the tensioning of the wires are given. A strict quality assurance plan ensured the integrity of the readout planes. The different tests performed at all stages of construction and installation provided crucial information to achieve the successful realisation of the MicroBooNE wire planes.


Introduction
MicroBooNE is a 170t Liquid Argon Time Projection Chamber (LArTPC) that is deployed in the Booster Neutrino Beam (BNB) at Fermilab [1]. High purity liquid argon serves as the neutrino target and tracking medium for the particles produced in neutrino interactions [2]. The TPC active volume forms a rectangular solid of dimensions 2.3 m × 2.6 m × 10.4 m and the readout plane is constructed out of wires, reading out ionization electron signals.
MicroBooNE detects neutrino interactions via the outgoing charged particles (and neutral particles that have converted to charged) from the neutrino-nucleon interaction which ionize the liquid argon. Ionization electrons produced by the passage of these charged particles are made to drift at constant velocity by application of a uniform electric field. This ionization charge drifts to three wire planes situated on the beam-right side of the detector. Electrostatic potentials of the three wire planes are set up to allow the ionization electrons to pass by the first two wire planes, leaving only induced charge signals, to reach the third wire plane, where they are collected on the wires.
The successful operation of the LArTPC, and subsequent analysis of the collected data, relies on a precise knowledge of the location and orientation of all wires in the detector. Reconstruction of the charged particle trajectory is derived from the known wire positions and the arrival times of ionization electron signals on the wires, combined with the time that the interaction took place in the detector within the 1.6 µs Booster Neutrino Beam (BNB) spill. The 3 mm wire pitch enables position resolutions on the order of a millimeter. The amplitude of the ionization electron signals measures the energy loss of the particles, which, with range information, allows for determination of momentum and particle type.

Description of the MicroBooNE wire planes
The design of the MicroBooNE wire planes is based partly on the ICARUS detector [3]. The TPC is composed of three wire planes Y, U and V, oriented vertically and at ± 60 • from the vertical, respectively, as shown in figure 1. The plane-to-plane separation is 3 mm, and the wire-to-wire separation is also 3 mm. The vertical Y-plane, which serves as the collection plane, is comprised of 3456 individual wires mounted in groups of 32 on wire carrier boards, with a total of 108 wire carrier boards installed for the Y plane. The wire carrier boards are described in greater detail in section 2.1. The two angled planes, U and V, serve as the two induction planes and are each comprised of 2400 wires, mounted in groups of 16 on 150 carrier boards. The wires are made of 150 ± 5 µm diameter Type-304V stainless steel, plated with 2 µm of copper (to decrease the resistivity of the wire in order to reduce series noise in the readout electronics) and covered with a thin flash (0.1 µm) of gold to prevent the copper oxidation. During detector operation, appropriate electric fields are maintained to prevent collection of electrons on the U and V wires. At an electric field of 500 V/cm, the nominal bias voltages of -204 V for the U plane, 0 V for the V plane and +440V for the Y plane will achieve maximal transmission of electrons through the first two induction planes.

The wire carrier boards
The wire carrier boards, shown schematically in figure 2, are made of FR4, comprised of three parts, a base, a cover, and a spacer, which are made using standard printed circuit board fabrication techniques. Rows of counter-bored pockets are machined into the base and cover. Once assembled, they form pockets that securely capture the brass wire-termination rings, described in section 3. The spacer maintains a small gap between the leading edge of the base and cover so the wires can move slightly around the terminating brass rings. Electrical contact to each wire is made by gold plated brass pins pressed in at the leading edge of the base board. To ensure good electrical contact to the wires, two rows of pins are used for the Y board, where each wire makes an S-shaped bend between two pins (shown in figure 4). A single row of pins are used on the U & V boards, since the wires are pulled against the pins at a 60 degree angle which ensures good contact. These pins also define the location of the wires as they exit the wire carrier modules.  Figure 2: Exploded-view schematic of the wire carrier board assemblies for the three planes. This drawing shows how the boards stack once installed. Each board assembly consists of a base (where the wires are individually inserted), a spacer and a cover (that secures the wires in place and is closed using rivets in the central holes).
A double row square-pin header (connector) is soldered on the Y carrier base board to connect to the detector readout. 32 pins on one row of this connector are connected to the 32 Y wires. 32 pins on the other row are alternately connected to the 16 U and 16 V wires from the other two carrier base boards via through-hole sockets. Once the U, V & Y modules are stacked together, 64 wires from the 3 modules are coupled to this common connector. The bias voltages for the Y and U wires are provided to the modules through 4 additional pins on one end of this connector.
High voltage capacitors of 2.2 nF/1kV and 4.7 nF/630V are mounted on the wire carrier base boards to AC-couple the Y and U wires to the readout electronics. NP0-type ceramic capacitors are used to avoid temperature-and voltage-dependence of the capacitance. 22 MΩ current-limiting resistors are placed between the bias voltage bus and each wire in case a wire is shorted to a different wire plane. Figure 3 shows the schematic diagram of the U and Y wire carrier boards. The V boards do not have any electrical components on the board since they are DC coupled to the readout electronics.

Wire winding and carrier board assembly
In order to construct the MicroBooNE wire planes, each TPC wire is prepared (cut to length and twisted around a brass ring as shown on the left in figure 4 and attached individually on a wire carrier board (center of figure 4). Once the wire carrier board is fully populated, a board spacer is inserted and the board is closed by a cover, and secured with two rivets (partial view shown in right panel of figure 4, shown without rivets). The preparation of each individual wire is facilitated by the use of automated wire winding machines designed for this purpose. In this section, we describe the wire winding machines and the winding procedures.

Wire winding machines
The winding of MicroBooNE's wires is performed via a semi-automated procedure using wire winding machines designed to measure and cut the desired wire lengths and to consistently wind the wires on the wire termination brass ring. Two machines were designed and built. One is used for fixed-length wires (for the vertical Y plane) and the other for variable-length wires (for the angled U and V planes). Figure 5 shows a schematic view of a wire winding machine. The first component of the machine is the distribution and tension station. A spool of wire is attached to the machine frame and the wire is unrolled with a robotic arm and pulley system. A weight of 1.4 kg is suspended from a mobile pulley in order to apply the nominal 0.7 kg tension on the wire. This procedure ensures that the wires are cut to the correct length under tension at room temperature. The nominal The two rows of pressed-in pins that guide the wires and maintain the 3 mm spacing are visible at the top of the board. These pins also ensure the electrical connections between the wires and the board electronics. Right: Example of a completed wire carrier module before rivets have been placed in the large central holes (only one shown here) to hold the module securely closed. tension of 0.7kg was chosen to be small enough to prevent wire breakage during cooldown, and large enough to limit the maximum wire sag due to gravity to be less than 0.5 mm. Figure 5: Simplified schematic of the wire winding machine. On the left, the distribution station where the wire is unrolled and adjusted to the desired tension. The linear translation stage shown at the top is used to measure and cut the wires to precise lengths. Two winding heads, described in more detail below, are also shown that wrap the wire ends around a brass ring.
The second part of the machine is composed of a robotic arm mounted on a linear translation stage, as shown in figure 6. The arm is used to pick up the wire from the distribution station and pull it to the desired length. The linear stage provides excellent control on the length (better than 50 µm precision) and is operated by computer and a step motor. The Y plane has a fixed length of 2.5 m for all wires, but the U and V planes have variable lengths for the wires because of their 60 • orientation.
Finally, the third part of the machine consists of two winding stations (see figure 7) designed to attach each end of the wires to a small brass ring. The brass rings are 3 mm in diameter and 1.5 mm thick. The robotic arm deposits the wire just behind the brass rings (pre-installed manually on the winding heads) where it is clamped in place by electrically actuated grippers, and cutters automatically cut the wire. Once the wire is released by the arm, the winding heads rotate by 120 • and start spinning in the plane perpendicular to the initial rotation, winding the wire around the ring six times. A twisted wire on the ring is shown on the left in figure 2. Once the winding is performed, the machine's work, the automated part of the procedure, is complete. It goes to rest and operators take over to complete the procedures described in the next section.

Procedures for the assembly of the wire carrier boards
After the automated stage, the wire (of the correct length) is left twisted around the brass rings. The final step of the wire preparation requires an operator to manually cut the the excess wire remaining at the end of the twisted wire (cutting away the wire section from the brass ring to block C, as well as the section from the other brass ring to block F, both shown in figure 7), ensuring that the cut is very close to the twist to avoid sharp edges and short-circuits in the boards. Once a wire has been prepared, the operators manually remove it from the machine by lifting the rings from the winding machine's pins. The wire is then strength-tested. Each individual wire is placed on a tensioning station, where a tension of 2.5 kg (more than three times the nominal TPC tension) is applied for ten minutes. This ensures that the wire preparation has not caused any weaknesses that could result in a breakage later on. Figure 8 shows the wire tension testing station, where springs mounted on levers create the force equivalent to 2.5 kg on the wires when the lever is completely pulled down. One extremity of the wire is attached to the spring and the other one is fixed to the station. Having controlled the quality (strength) of each wire, the wires are placed manually in wire carrier modules, shown in figure 9. The holes (pockets) in the carrier boards, which are the same size as the brass rings, ensure that the wires are secured inside the boards. Once the board is fully populated, the board spacer and cover are installed and the module is sealed by holding rings (rivets) pressed on the board. The assembled board is then placed in a stand for stress-testing, and a tension of 2.5 kg per wire is reapplied to the fully populated board for 10 min. This is to ensure that the wires have not been weakened during the board assembly process. The stress stand is shown in figure 10, where a design similar to that of the individual wire tension station is shown. Strong springs are attached to a bigger lever that is pulled down to apply a force of 80 kg for the Y plane boards and 40 kg for the U and V plane boards.   the whole procedure is shown in figure 12, where the winding machine, the tension station, stress stand, and storage boxes are illustrated for the Y plane wire preparation.

Tests and quality controls of the wires and the boards
One of the biggest risks to a TPC is that a wire might break after installation in a sealed cryostat filled with liquid argon. If even one of the 8256 wires happens to break once installed, it could short-circuit a significant portion of the signal wires if the broken wire makes contact with neighboring wires. In the worst case scenario, a broken wire could short-circuit the entire TPC if it were to make contact with the cathode plane where the high voltage is applied. Re-opening the cryostat to repair a broken wire would be both time-consuming and expensive, causing serious problems to the experiment. In order to ensure that no wires break after their installation, a series of tests are performed to understand the wire limitations.   Every aspect of the wire preparation was previously studied carefully to optimize the quality of the wires. The wire diameter, number of twists on the brass rings, the twisting angle and the post-preparation tests were all studied in great detail. The different tests and studies are presented in this section.

Wire strength and breakloads
It was found that 150 µm wire diameter was sufficient to withstand the nominal tension of 0.7 kg in the TPC. The wire manufacturer reports a breakload of 4.37 kg and a yield load of 3.65 kg. Tests to verify the wire breakload are performed and the results for 20 wires are shown in figure 13. The wire breakload is shown to be in agreement with the vendor specifications and is safely over 4 times the nominal TPC tension at room temperature and over 5 times the tension at liquid nitrogen (LN 2 ) temperature.

Wire strength and breakloads of damaged wires
Defects or damages on the wires may reduce the breakload considerably. One type of damage that can occur is if the wire gets kinked, as demonstrated in figure 14. To test the effect of kinks on the breakloads, wires are kinked around pins of differing diameters (0.15 mm, 0.53 mm and 1 mm). The range of diameters tests the effect of sharper kinks. The results of these tests are summarized in figure 17, showing that the breakload decreases by as much as 20% for small-diameter kinks (8% for larger-diameter kinks). As expected, the sharper the kink, the greater the reduction in breakload. The breakload of damaged wires is considerably higher in LN 2 than at room temperature, as seen in figure 17.  Another effect to consider when studying wire breakage is the effect of bending wires. For the U and V planes of the TPC, the wires are bent around 1 mm pins on the wire carrier boards, angled at 60 • once installed in the TPC (see figure 15). Tests are performed to understand if bending a wire around a small object may reduce its breakload. To perform these tests, the wires are bent at 60 • around pins of 1 mm and 1.2 mm in a way similar to how they are bent around the pins on the wire carrier boards. The results of these tests are also summarized in figure 17.
Bending the wires has an effect on the breakload similar to that of kinking the wires; as expected, the smaller diameter pins decrease the breakload more than larger pins. The MicroBooNE wire carrier boards have 1 mm pins.

Effects of wire termination and attachment
The winding of the wires around the brass rings is also studied in order to optimize the number of twists and the twist angle. It is found that 6 twists are optimal to combine maximal strength and minimal length inside the carrier board, providing a safety margin of about 4 times the breakload (for both room and LN 2 temperatures). The angle at which the winding machines twist the wires

Effect of cold temperature shock
A final test is performed to see the effect of a very rapid change from room temperature to LN 2 temperature on a fully-populated wire carrier board. This test uses pre-assembled Y plane wire boards placed under different tensions equal to or above the nominal detector tension. The tensioned (or over-tensioned) boards are then plunged into a LN 2 bath to test if any wires will break. The different tensions applied to the wires during the test are shown in figure 18. No wire breakage is observed for any of the applied tensions.

Discussion of the tests performed
The tests show that extreme conditions applied to the wires reduce the breakload. However, the minimum breakload observed in all of these tests is around 3.4 kg at room temperature. This tension is still almost five times higher than the nominal tension applied in the TPC (0.7 kg). In addition,  this value is for room temperature. In LN 2 (77K), the lowest breakload observed is 4.35 kg, which is more than six times the nominal tension in the TPC, which is at LAr temperature (87K). It is therefore clear that the margin of error is more than sufficient to prevent wire breakage in the case of damage to a wire. In addition to the tests described here, the quality assurance procedures described earlier ensure that all wires and wire carrier boards are systematically tested before installation.

Wire installation
The wire carrier boards attach to tensioning bars that are held inside a C-channel frame, shown in the renderings of figure 19. The exact positions of the tensioning bars are controlled by adjusting assemblies that allow a small amount of pitch, roll, and yaw in each of the bars and many tensioning screws (not shown in these figures). There are a total of 12 tensioning bar segments, and these are grouped in four spans: two horizontal spans (top and bottom of the anode frame) which are each constructed from 5 adjoining segments, and two vertical spans (upstream and downstream sides of the anode frame) which are each a single tensioning bar segment. There are 24 adjusting assemblies; two per tensioning bar segment. The adjusting assemblies allow fine-tuning during the Figure 18: Summary of all overload tests where the completed wire carrier board is loaded with more than the nominal tension before being plunged into a LN2 bath. No failure of either the wires or the wire carrier boards is observed during testing.
installation and initial alignment of the wire planes, but the bars are eventually fixed in place and tension on the wires is applied by bronze tensioning screws, shown in figure 20. Figure 19: Renderings of one corner of the anode frame (left) and close-up of adjusting assembly (right). The tensioning bar position (pitch, roll, yaw) is controlled by the shaft that extends through the adjusting assembly, C-channel, and tensioning bar and by tensioning screws (not shown). The holes in the tensioning bar are for precision mounting pins onto which the wire carrier boards are attached. Figure 20: Photograph of a section of the anode frame with adjusting assembly. A wire carrier board is installed on the tensioning bar, and held in the correct position by the precision mounting pins. Tension is tuned by adjusting the bronze tensioning screws (only one shown in this image, but each threaded hole has a tensioning screw in the final installation). Note that there are also threaded holes for tensioning screws on the bottom of the C-channel frame, not visible in this image.
Before installing any wires, the tensioning bars must be squared and aligned. This is done with the help of a team from the Fermilab metrology group to adjust the bars within the C-channel frame such that the top and bottom horizontal bars are parallel to each other, the upstream and downstream vertical bars are parallel to each other, horizontal bars meet vertical bars at right angles, and all four sides lie in a plane that is parallel to the cathode plane. The wire carrier boards are installed after this alignment, and upon completion of the wire plane installation, tension on the wires is tuned to the desired value by tightening the tensioning screws to apply force on the tensioning bars. The tensioning process is described in more detail in section 5.3.
In preparation for installing the wires on the TPC, a trial installation using sparsely populated wire carrier boards is undertaken. This trial installation, known as the mock installation, is described in this section, followed by a description of the full installation of real wires.

Mock installation
The mock wire installation is designed to test the installation procedures with a set of full-length prototype wires, allowing the installation team to practice handling techniques and to identify areas in which procedures should be modified before attempting to install the real set of 8256 wires. This trial run allows the team to detail the full installation and tensioning procedure of the U, V, and Y wire planes. A temporary floor installed over the field cage tubes in the TPC interior floor allows access inside the TPC without damaging the field cage tubes during the installation process.
Wires for the mock installation are prepared using the wire winding machine shown in figure 5. The only difference between the mock wires and the real wires is the fact that the mock wires are entirely stainless steel, while the real wires are stainless steel with copper coating and gold flash. All other specifications are identical, and the mock wire carrier boards are assembled according to the same procedures detailed in section 3.
In order to reduce the total amount of time spent winding wires and producing boards, only five wires are installed per wire carrier board, as shown schematically in figure 21. These sparselypopulated wire carrier boards allow the team to fully test the installation procedures for each of the multiple wire planes (U, V, and Y) in the correct order and to understand and test the wire tensioning procedure along the full length of the TPC. The reduced number of wires per carrier board does not affect the installation or tensioning procedures.  Figure 22 shows the layout of the Y plane boards for the mock installation. The mock board installation locations are chosen to cover the areas of the anode frame that are the most challenging to install (corners) and the areas that are most critical for tensioning (joints), while covering as large a fraction of the anode frame area as possible. Boards located near the joints in the anode frame, where two stainless steel tensioning bars adjoin, are an example of an area that is critical for consistent wire tensioning. The vertical wire carrier boards labeled as "21" and "22" in figure 22, shown in more detail in figure 23, are installed to test how the joints behave and how the wire tensions on adjacent boards change under tensioning in these regions.
After the installation of the Y plane wires, the V plane wire carrier boards stack onto the installed Y-plane boards; for the mock wire test, they are installed in the configuration shown in figure 24. The shortest wires of the V plane are in the "upper left" and "lower right" corners of the anode frame in this view. The longest wires of the V plane, attaching to the anode frame from the "upper right" (not shown) and extending to the "lower left" (shown), are stacked on empty spacer boards to achieve the correct plane-to-plane spacing. The main objective of installing these particular wire carrier boards is to practice handling these 5-meter-long wires.
Similarly, the U plane wires are installed in the configuration shown in figure 25. The U plane wires have the shortest connections in the "lower left" corner and in the "upper right" corner (not shown). These boards are stacked on the previously installed Y and V wire carrier boards. The longest U plane wires attach to the anode frame at the "upper left" and extend to the "lower right"; these are installed to provide additional practice handling 5-meter-long wires.
The mock wire installation successfully tested the procedure and highlighted steps that required special care; the quality assurance steps and installation plan were modified to reflect the lessons learned here. This activity also trained installers with a technical rehearsal that ensured smooth and coordinated operation during the full wire installation. Figure 22: Y plane wire configuration for the mock-wire installation. Note that only the "left" side of the TPC anode frame is shown here. The "right" side of the TPC anode frame is populated with wire carrier boards according to the same prescription. Figure 23: A close-up of one section of the TPC anode frame where two horizontal tensioning bars join together. One Y-plane mock wire carrier board is installed on each side of the joint, corresponding to the two boards labeled as "21" and "22" in figure

Full installation
The full set of wires are installed following the plan developed and tested in the mock wire installation. After the initial alignment of the tensioning bars, the entire structure is cleaned with lint-free wipes and ethyl alcohol. Then the wire carrier boards are installed serially, starting with the Y plane, followed by the V plane, and finally the U plane. The wires on each wire carrier board are visually inspected for damage before installation. In the case that a damaged wire is found, the board is partially disassembled, the damaged wire is replaced with a new wire, and the board reassembled and tested again. Replacement of wires was only necessary in a few cases where the wire sustained minor damage during installation. In total, it took approximately one week to install all three planes of wires.
Since the U and Y plane wires are designed to have applied bias voltages during detector Figure 24: V plane wire configuration for the mock-wire installation (red), with Y plane installation (yellow), for the "left" side of the TPC. The "right" side of the anode frame (not shown) is populated with wire carrier boards according to the same prescription. Figure 25: U plane wire configuration for the mock-wire installation (cyan) with previously installed Y plane (yellow) and V plane (red), for the "left" side of the TPC . The "right" side is populated with wire carrier boards according to the same prescription.
operation, as described in section 2, leakage current tests of the capacitors on these wire carrier boards are performed just prior to installation. Leakage currents, if too large, will affect the readout signals from these wires. For the test, a bias voltage is applied to the wire carrier board and current is measured for each individual capacitor. Only boards with leakage currents below 1 µA at their designed operating voltage (-220 V for U plane and +440 V for Y plane) are installed. V plane wire carrier boards are not tested, as they have no electrical components.
Upon completing installation of each wire plane, a simple continuity test is performed for each wire in that plane to ensure good electrical contact between the wire and the carrier board pins, shown in figure 26. Before beginning installation of the next plane, the wires in the installed plane are also examined by eye, looking for any kinked wires, abrasions, or other forms of damage. The final step, after all wire planes are installed and inspected, is the addition of cover plates that secure the stacked wire carrier boards to the tensioning bar, shown in figure 27.

Wire tensioning
Proper tension of the wires is important for safe commissioning and successful operation of the experiment. It is especially important to account for wire tension during the initial cool-down phase of the experiment. During this phase, the detector moves from a state where the cryostat is filled with room temperature air to the state where it is filled with cold gaseous argon, and although the wires and the TPC frame have similar thermal expansion coefficients, the thin wires are subject to faster cool-down, and therefore faster thermal contraction, than the rest of the massive stainless steel TPC frame. If the wire contraction occurs much more quickly than the frame contraction, wires could break or become permanently stretched. For this reason, a thermal gradient limit is set during cool-down, requiring that the temperatures at the top and bottom of the TPC frame never differ by more than 20 K. The nominal 0.7 kg (6.86 N) of tension established for the wires is small enough to prevent wire breakage during cool down, but large enough to limit the maximum wire sag due to gravity to less than 0.5 mm for any 5-meter-long U or V wire.
Tension is put on the wires by adjusting the bronze tensioning screws to push on the tensioning bar, as shown in figure 20. Since the wires are grouped in sets of 16 or 32 on the wire carrier boards, and the wire carrier boards are grouped together on adjoined rigid tensioning bars, it is not possible to fine-tune the tension of individual wires. Instead, it is necessary to adjust the positions of the tensioning bars to achieve as uniform a map of wire tensions as possible across the full set of wire carrier boards.
The tensioning process is necessarily iterative, as the adjustments in one area of the TPC anode frame affect tensions in other areas due to the angled U and V wire planes. The tensions of approximately 95% of the wires were measured with a custom-designed apparatus designed and constructed by the Physical Sciences Lab of University of Wisconsin-Madison [4], shown in figure 28. This device consists of an LED that is focused onto a wire, and a photodiode that measures light reflected from the wire. When the wire is lightly strummed, the output of the photodiode is fed into a laptop with a spectrum analyzer that performs a fast Fourier transform to convert the pulses into the frequency domain, and the peak frequency is recorded for each board/wire measured. The frequencies measured can be converted to tensions for known wire lengths.
Tension is measured using the characteristic resonance frequency of each wire, which is related to its length (L in cm), tension (T in N), and linear mass density (ρ, measured to be 0.00014 g/cm) through equation 5.1 f = 1 2L T ρ (5.1) Figure 29 shows the tension measurement results for each of the three planes. Tensions were measured for 2256 of the 2400 U wires, 2256 of the 2400 V wires, and 3312 of the 3456 Y wires, corresponding to 94.8% of the wires installed in the detector. The U-and V-plane wires are installed on the anode frame in groups of 16, and the Y-plane wires are in groups of 32.
The overall average tensions of the U, V, and Y planes, respectively, are 0.589±0.012 kg, 0.664±0.014 kg, and 0.525±0.009 kg. As mentioned previously, lower-tension values were preferred to over-tension ones to prevent wire breakage during cooldown, resulting in an overall average slightly lower than the 0.7kg nominal value.  : Tension map of all measured wires in each plane, as viewed from inside the TPC (beam enters from the right). The nominal tension (0.7 kg or 6.86 N) is marked on the legend with the black line and is represented by gray in the maps. Blue corresponds to wires with lower than nominal tensions, and red to higher than nominal tensions.

Conclusion
The MicroBooNE TPC anode readout wire planes were assembled, installed, and tested according to the procedures described in this document. The use of semi-automatic wire winding machines considerably helped the preparation of the individual wires. A strict quality assurance program was followed to ensure that the wires were intact at every step of the process. This was vital to the success of the plane construction, since a broken wire could have had disastrous consequences on the experiment. Inspection of the wires inside the cryostat few months after the transport of the MicroBooNE cryostat also demonstrated the integrity of the planes [6]. Several tests were performed at different stages of the process to inform design decisions. The method described in this paper is appropriate for any medium-sized LArTPC. For larger scale detectors, a more automated process should be considered.