Geometric features for aligning and inspecting layers and features for use in layered additive manufacturing of passive and active radio frequency (RF) electronic circuits.

Abstract

A method for manufacturing a radio frequency (RF) or electron beam structure, comprising the steps of forming each layer of a multilayer to be aligned and assembled and joined together, the step of forming a first via segment of a first specific shape and size in the layer at a first position in the layer, so that when the multilayer first via segments are aligned and assembled, a number of first via segments are aligned and form first vias; and the step of inserting first similar pins into the first vias, the first similar pins being formed based on the first specific shape and size of each of the first via segments, thereby assisting in the alignment and assembly of the multilayer by inserting the first similar pins into the first vias.

Description

Technical Field

[0001] The present invention generally relates to radio-frequency (RF) electronic circuits, and more particularly provides geometric features for aligning and inspecting for use in the layered additive fabrication of passive and active RF electronic circuits.

Background Art

[0002] The Layered Additive Multi-Material Manufacturing (LAM3) process has been developed to create millimeter-wave structures with high-quality radio-frequency (RF) performance suitable for the ultra-high vacuum operation of vacuum electronic circuits. The LAM3 process improves the manufacturing process for RF electronic devices having multi-material layers joined together to simultaneously form one or more RF electronic elements. The LAM3 process has been exemplified in the manufacture of vacuum electronic devices and is applicable to active and passive elements at microwave frequencies, millimeter-wave frequencies, as well as sub-terahertz and terahertz frequencies, elements operating in vacuum or other atmospheric conditions, and elements fabricated with metal or other multi-materials. See U.S. Patent No. 11,894,208, which is incorporated herein by reference.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] Embodiments of the present invention include the addition of geometric features for use in layered additive manufacturing of passive and active radio frequency (RF) electronic circuits for the purpose of (1) alignment, for example, to align assembled RF structures with respect to external components, to align features with respect to external components, and / or to align individual layers with respect to each other before or during bonding, and / or (2) quality inspection after bonding, for example, to inspect the positional accuracy (e.g., in the x, y, and / or z directions) and / or rotational accuracy of layers assembled and bonded together, to inspect the positional accuracy and / or rotational accuracy of feature fabrication, and / or to inspect the positional accuracy and / or rotational accuracy of feature alignment. Examples of RF structures include RF interacting structures such as waveguides and traveling wave tubes (TWTs).

[0005] For layer alignment, embodiments of the present solution may use geometric features manufactured from appropriately matched feature materials to ensure alignment, looseness, or interference under joining conditions. For example, embodiments of the present solution may include pockets or bosses formed using layers assembled and joined to form an RF or beam-interacting structure. Pockets and bosses may be used to align the structure and / or structural features with respect to external components. Embodiments of the present solution may include pin pockets in the structure and external components, so that pins can be inserted into two pin pockets to align the structure with respect to external components. Embodiments of the present solution may include vias formed across adjacent layers, so that pins can be inserted into vias to align adjacent layers before and / or during joining of adjacent layers.

[0006] For alignment inspection, embodiments of this solution may include geometric features formed within the surface of the RF or electron beam structure, or at the edges of the structure, penetrating the multilayer. After bonding, the geometric features can be examined to verify the positional and / or rotational accuracy of the layers. Examples of geometric inspection features may include concentric alignment inspection features, stepped alignment inspection features, and stepped pattern alignment inspection features. By examining these inspection features, positional and / or rotational deviations across layers can be evaluated and detected.

[0007] Some geometric features can assist not only with alignment before and / or during joining, but also with inspection after joining.

[0008] In some embodiments, the present invention provides a method for manufacturing a radio frequency (RF) or electron beam structure, comprising the steps of forming each layer of a multilayer to be aligned, assembled together and joined, the first via segment having a first specific shape and dimensions in the layer at a first location in the layer, so that when the multilayer first via segments are aligned and assembled, the numerous first via segments are aligned to form a first via; and inserting a first similar pin into the first via, the first similar pin being formed based on the first specific shape and dimensions of each of the first via segments, the first similar pin being inserted into the first via, thereby assisting in the alignment and assembly of the multilayer.

[0009] The structure may include waveguides, beam transport apertures, electron beam transport structures, or RF interaction structures. The first particular shape may include a circular cross-section. The first particular shape may include a polygonal cross-section, and as a result, the step of inserting the first similar pin into the first via further helps to rotate and align to assemble the multilayer. Each via segment may include the same shape and dimensions, and the via may include a cross-section that does not change over its length. The first similar pin may include a top surface, a bottom surface, and a length, and the length of the first similar pin may be the same as the length of the first via, so that when the first similar pin is inserted into the first via, the top surface and bottom surface, respectively, are coplanar with the surface of the multilayer. The first similar pin may include a top surface, a bottom surface, and a length, the length of which may be shorter than the length of the first via, so that when the first similar pin is inserted into the first via, each of the top and bottom surfaces is recessed from the surface of the multilayer. The first similar pin may include a top surface, a bottom surface, and a length, the length of which may be longer than the length of the first via, so that when the first similar pin is inserted into the first via, at least one of the top and bottom surfaces extends beyond the surface of the multilayer. The method may further comprise the steps of joining the multilayer together and removing the first similar pin after joining the multilayer. After removing the first similar pin, the method may further comprise the step of evaluating one or more walls of the first via to check for alignment.The step of forming each layer of a multilayer to be aligned and assembled and joined together may include the step of forming a second via segment of a second specific shape and dimensions within the layer at a second location within the layer, so that when the second via segments of the multilayer are aligned and assembled, the multilayer aligns to form the second vias, and the method may further include the step of inserting a second similar pin into the second via, the second similar pin being formed based on the second specific shape and dimensions of each of the second via segments, so that the steps of inserting a first similar pin into the first via and inserting a second similar pin into the second via help to assemble the multilayer by aligning and rotating them.

[0010] In some embodiments, the present invention may provide an RF or electron beam structure comprising a multilayer that is aligned and assembled together and joined, each layer comprising a first via segment of a first specific shape and dimensions within the layer at a first position within the layer, and as a result when the first via segments of the multilayer are aligned and assembled, a number of first via segments align to form a first via, and first similar pins are configured to be inserted into the first vias and are configured to have a first specific shape and dimensions based on each of the first via segments, and as a result when the first similar pins are inserted into the first vias, the first similar pins help to align and assemble the multilayer.

[0011] The structure may include waveguides, beam transport apertures, electron beam transport structures, or RF interaction structures. The first particular shape may include a circular cross-section. The first particular shape may include a polygonal cross-section, and the first similar pins may further help to assemble the multilayer by rotating alignment when inserted into the first via. Each via segment may include the same shape and dimensions, and the via may include a cross-section that does not change over its length. The first similar pin may include a top surface, a bottom surface, and a length, and the length of the first similar pin may be the same as the length of the first via, and the first similar pin may be configured such that when inserted into the first via, the top and bottom surfaces of each are coplanar with the surface of the multilayer. The first similar pin may include a top surface, a bottom surface, and a length, the length of the first similar pin may be shorter than the length of the first via, and the first similar pin may be configured such that when inserted into the first via, each of its top and bottom surfaces is recessed from the surface of the multilayer. The first similar pin may include a top surface, a bottom surface, and a length, the length of the first similar pin may be longer than the length of the first via, and as a result, when the first similar pin is inserted into the first via, at least one of its top and bottom surfaces extends beyond the surface of the multilayer. The first similar pin may be configured to be removed after the multilayer bond. One or more walls of the first via may be configured to help establish positional alignment when inserted. Each layer of a multilayer, which is aligned and assembled and joined together, may contain a second via segment of a second specific shape and dimensions within the layer at a second position within the layer, so that when the second via segments of the multilayer are aligned and assembled, the multilayer aligns to form a second via, and a second similar pin is configured to be inserted into the second via, formed based on the second specific shape and dimensions of each of the second via segments, so that the first similar pin when inserted into the first via, and the second similar pin when inserted into the second via, help to assemble the multilayer by aligning and rotating.

[0012] In some embodiments, the present invention may provide integrated rectangular (including square) alignment cutouts within individual layers to accommodate rectangular alignment pins. In some embodiments, the present invention may provide integrated rotated rectangular (including square) alignment cutouts within individual layers. In some embodiments, the present invention may provide rectangular features (including squares) with integrated recesses within individual layers. In some embodiments, the present invention may provide combinations of alignment features for multilayer assembly. In some embodiments, the present invention may provide concentric circular features of different sizes, carved within different layers. In some embodiments, the present invention may provide beams carved within different layers at different positions. [Brief explanation of the drawing]

[0013] [Figure 1A] This is a cross-sectional view of an exemplary radio frequency (RF) or electron beam structure according to some embodiments of the present invention. [Figure 1B] Figure 1A shows a left side view of an exemplary RF or electron beam structure according to several embodiments of the present invention. [Figure 1C] Figure 1A shows a right side view of an exemplary RF or electron beam structure according to several embodiments of the present invention. [Figure 1D] Figure 1A shows a lower side view of an exemplary RF or electron beam structure according to several embodiments of the present invention. [Figure 2A] Figure 1A is a front view of an exemplary RF or electron beam structure according to some embodiments of the present invention. [Figure 2B] Figure 1A shows a perspective view of aligned vias and aligned pins of an exemplary RF or electron beam structure, such as the RF or electron beam structure, according to some embodiments of the present invention. [Figure 3A] This is a cross-sectional side view across the diameter of the concentric circular inspection feature shown in Figure 2A, according to some embodiments of the present invention. [Figure 3B] This is a perspective view of the concentric circle inspection feature shown in Figure 2A, according to some embodiments of the present invention. [Figure 4A]This is a top view of an RF or electron beam structure having stepped pattern inspection features according to some embodiments of the present invention. [Figure 4B] Figure 4A is an exploded cross-sectional side view of an RF or electron beam structure having the stepped pattern inspection feature according to some embodiments of the present invention. [Figure 5] This is a top view of a cross-shaped alignment and / or inspection feature according to some embodiments of the present invention. [Figure 6] This is a perspective view of an RF or electron beam structure having a stepped inspection feature according to some embodiments of the present invention. [Figure 7] This flowchart illustrates a method for forming an RF or electron beam structure by forming a multilayer with alignment vias formed within it, which are configured to accept alignment pins that may help to position and / or rotationally align the multilayer before and / or during bonding. [Figure 8] This flowchart illustrates a method for forming an RF or electron beam structure using a multilayer with pin pockets formed inside for receiving alignment pins to assist in alignment with external components, according to some embodiments of the present invention. [Figure 9] This flowchart illustrates a method for forming an RF or electron beam structure using multilayers, according to some embodiments of the present invention, such that one or more layers have one or more geometric features that form pockets or bosses to assist in alignment with external components. [Figure 10] This flowchart illustrates a method for forming an RF or electron beam structure using a multilayer having geometric features formed in two or more layers, configured to cooperately assist in post-joining inspection of positional and / or rotational alignment, according to some embodiments of the present invention. [Modes for carrying out the invention]

[0014] The following description of embodiments is provided to enable those skilled in the art to make and use various embodiments of the present invention. Modifications are possible. The general principles defined herein may be applied to the disclosed embodiments and other embodiments without departing from the spirit and scope of the present invention. Accordingly, the claims are not intended to be limited to the disclosed embodiments, but should be adapted to the broadest scope consistent with the principles, features, and teachings herein.

[0015] Embodiments of the present invention include the addition of geometric features for use in the layer-by-layer fabrication of passive and active radio frequency (RF) electronic circuits for (1) alignment purposes, e.g., aligning features with external components, such as aligning an assembled RF or electron beam structure with an external component, aligning individual layers with each other before and / or during bonding, and / or (2) quality inspection after bonding, e.g., inspecting the positional accuracy and / or rotational accuracy of layers assembled and bonded together (e.g., in the x, y, and / or z directions), inspecting the positional accuracy and / or rotational accuracy of feature fabrication, and / or inspecting the positional accuracy and / or rotational accuracy of feature alignment. Feature design and the accuracy (measurability) of the location of features assist in enabling alignment before and / or during bonding and enable inspection (e.g., verification) of alignment after bonding. Examples of RF or electron beam structures include waveguides such as couplers, splitters, and filters, and RF interaction structures such as circuits for traveling wave tubes (TWTs) and klystrons.

[0016] For layer alignment, embodiments of the present solution may ensure alignment, relaxation, or interference under bonding conditions using geometric features fabricated from appropriately matched feature materials. For example, embodiments of the present solution may include pockets or bosses formed using layers assembled and bonded to form an RF or electron beam structure. Pockets and bosses may be used to align an RF structure with respect to an external component and / or features of an RF or electron beam structure. Embodiments of the present solution may include pin pockets within each of the RF or electron beam structure and the external component, such that alignment pins can be inserted into the two pin pockets to align the RF or electron beam structure with respect to the external component. Embodiments of the present solution may include alignment vias formed across adjacent layers, such that alignment pins can be inserted into the alignment vias to align adjacent layers before and / or during bonding of the adjacent layers.

[0017] For alignment inspection, embodiments of the present solution may include geometric features formed through multiple layers within the surface of an RF or electron beam structure or at the edge of an RF or electron beam structure. After bonding, the geometric features can be examined to confirm the positional accuracy and / or rotational accuracy of the layers. Examples of geometric inspection features may include concentric inspection features, stepped inspection features, and stepped pattern inspection features. By examining these inspection features, positional offsets and / or rotational offsets across layers can be evaluated and detected.

[0018] Some geometric features can assist in alignment before and / or during bonding, as well as inspection after bonding.

[0019] Figure 1A shows an exemplary RF or electron beam structure 100, for example, a waveguide, in a cross-sectional side view, according to several embodiments of the present invention. The RF or electron beam structure 100 includes a first path 108 extending from a left-side opening 112 to a right-side opening 114 along the length of the RF or electron beam structure 100, and a second path 116 extending downward from the first path 108 to a bottom-down opening 110. The left-side opening 112 may be positioned within a pocket 102 formed on the left side of the RF or electron beam structure 100. The right-side opening 114 may be positioned within a boss 104 extending outward on the right side of the RF or electron beam structure 100. Alignment features (pockets, bosses) can also be used to align other components in structures not intended for RF. For example, electron guns and collectors can be aligned relative to a beam tunnel on a TWT circuit.

[0020] Each of the pockets 102 and bosses 104 may serve as alignment features for additional external components such as RF or electron beam structures, electron guns, collectors, etc. In some embodiments, the pocket 102 may be formed to receive bosses for different external components, such as RF circuits, electron guns, or other waveguides. Similarly, in some embodiments, the boss 104 may be formed to be inserted into the pockets for different external components, such as RF circuits, electron guns, or other waveguides. In some embodiments, the shape of each of the pockets 102 and bosses 104 may be cubic (including cubes). Other shapes are also possible.

[0021] The RF or electron beam structure 100 may include, for example, one or more pin pockets 106 configured at the bottom to receive alignment pins for aligning external components to, for example, one or more features of the RF or electron beam structure 100. For example, one or more pin pockets 106 may be configured to cooperate with pin pockets on external components to align the bottom opening 110 to features of the external components (e.g., an opening, a magnet, a collector, etc.). In some embodiments, each pin pocket 106 may be formed to receive alignment pins of a particular shape and size, for example, cylindrical alignment pins, alignment pins having a rectangular (including square) cross-section, etc. In some embodiments, the alignment pins may be designed to be shorter than, or longer than, the depth to which the pin pocket of the component into which the pin is inserted is equal to, or longer than, the depth to which the pin pocket is joined. In some embodiments, the alignment pins may be permanent or removable from the pin pocket 106. The cross-sectional shape of the alignment pin may, but does not have to be, similar to the cross-sectional shape of the pin pocket 106. Alignment pins having a circular cross-section fit into pin pockets 106 having a square cross-section. Therefore, other shapes also fit. The cross-sectional shapes of the alignment pins and / or pin pockets 106 may be circular, elliptical, polygonal, cruciate, rotated polygon, etc. Furthermore, pin pockets spanning two components may have different shapes and / or sizes. Accordingly, different segments of the alignment pin may have different shapes and / or sizes based on the shape and / or size of the pin pocket into which the alignment pin is inserted.

[0022] Figure 1B shows a left side view of an exemplary RF or electron beam structure 100 according to several embodiments of the present invention. As shown, the pocket 102 is formed within a layer 118 that forms the RF or electron beam structure 100. Accordingly, in some embodiments, the pocket 102 may have dimensions that align with one or more surfaces of one or more layers 118. As shown, the pocket 102 aligns with the left surface of a third layer 118 and the right surface of a fifth layer 118. Furthermore, the left opening 112 may have dimensions that align with one or more surfaces of one or more layers 118. As shown, the left opening 112 aligns with the left and right surfaces of a fourth layer 118. The thicknesses of the layers 118 may be the same, or one, some, or all may be different.

[0023] Figure 1C shows a right side view of an exemplary RF or electron beam structure 100 according to several embodiments of the present invention. As shown, a boss 104 is formed within a layer 118 that forms the RF or electron beam structure 100. Accordingly, in some embodiments, the boss 104 may have dimensions that align with one or more surfaces of one or more layers 118. As shown, the boss 104 aligns with the left surface of a third layer 118 and the right surface of a fifth layer 118, as a pocket 102. Furthermore, a right-side opening 114 may have dimensions that align with one or more surfaces of one or more layers 118. As shown, the right-side opening 114 aligns with the left and right surfaces of a fourth layer 118, as a left-side opening 112. The pocket 102 and the boss 104 align with the same layer 118 surface, but may align with different layers 118. Similarly, the left opening 112 and the right opening 114 may align with the surface of the same layer 118, but they may also align with different layers 118.

[0024] Figure 1D is a bottom view of an exemplary RF or electron beam structure 100 according to several embodiments of the present invention. As shown, the bottom opening 110 and pin pocket 106 are formed within the layers 118 that form the RF or electron beam structure 100. Accordingly, in some embodiments, the bottom opening 110 may have dimensions that align with one or more surfaces of one or more layers 118. As shown, the bottom opening 110 aligns with the surface of a third layer 118 and the surface of a fifth layer 118. Furthermore, the pin pocket 106 may have dimensions that align with one or more surfaces of one or more layers 118. As shown, the pin pocket 106 aligns with the surface of a third layer 118 and the surface of a fifth layer 118, similar to the bottom opening 110. The bottom opening 110 and the pin pocket 106 may align with the surface of the same layer 118, but with different layers 118. Similarly, each pin pocket 106 aligns with the surface of the same layer 118, although the pin pockets 106 may align with different layers 118. In some embodiments, the pin pockets 106 may be formed within a single layer.

[0025] Figure 2A is a front view of an exemplary RF or electron beam structure 100 according to several embodiments of the present invention. The RF or electron beam structure 100 exhibits exemplary alignment features including a square alignment feature 202, a rectangular alignment feature 204, a rotated rectangular (including square) alignment feature 212, a modified rectangular alignment feature 206 with relief, and a circular feature 208.

[0026] Each of the alignment features 202, 204, 206, 208, and 212 may define a pin pocket, such as a pin pocket 106, which helps align external features using alignment pins or male features, or it may define a multilayer alignment via that extends through two or more layers to align layers before joining. The circular alignment feature 208 may assist with positional alignment but not with rotational alignment. The square alignment feature 202, the rectangular alignment feature 204, the modified rectangular alignment feature 206 with relief, and the rotated rectangular alignment feature 212 may assist with both positional and rotational alignment. Two alignment features (whether circular or polygonal) may assist with rotational alignment even better than the rectangular alignment feature. The modified rectangular alignment feature 206 with relief may improve the insertion of alignment pins with sharp corners, in particular when the alignment pins are polished to the same dimensions as the pin pocket 106 with high precision. The rectangular alignment feature 212, rotated with respect to other alignment features, imposes constraints on the skew deviation between layers 118.

[0027] Figure 2B is a perspective view of an exemplary RF or electron beam structure 220, such as an RF or electron beam structure 100, according to several embodiments of the present invention, having exemplary aligned vias 222 formed across a multilayer 118, and similar aligned pins 224 configured to be inserted into the aligned vias 222 to help align the multilayer 118 before and / or during junction. By precisely positioning each via segment of the aligned vias 222 within each of the multilayer 118, similar aligned pins 224 may be inserted into the aligned vias 222 across the multilayer 118 before and / or during junction to ensure layer alignment after junction. Although the aligned vias 222 and aligned pins 224 are shown as having a rectangular cross-section, the cross-section may have different shapes, such as circular, elliptical, polygonal, or polygonal with relief modification. Furthermore, the exemplary waveguide 220 may include any number of aligned vias 222 spanning any set of layers at any location to help achieve layer alignment. In some embodiments, each via segment within each of the multilayers may have the same or different shape and / or dimensions as other via segments. Similar alignment pins 224 may have one or more similar shapes and / or one or more dimensions with via segments that precisely mat into the vias when the multilayer 118 is precisely positioned.

[0028] In some embodiments, the alignment pins 224 may be designed to have a length exactly equal to the via length, ensuring that when inserted, the end surfaces of the alignment pins 224 are coplanar with the end surfaces of the terminal layer 118. In some embodiments, the alignment pins 224 may be slightly shorter so that they are slightly recessed when inserted, to avoid interference with external components and / or to assist in bonding with additional layers or external components located on one or both of the end surfaces of the terminal layer 118. In some embodiments, the alignment pins 224 may be longer than the via length to achieve the desired alignment quality or other benefits. When inserted, one or both of the upper and lower surfaces of the alignment pins 224 may extend beyond the end surfaces of the terminal layer 118.

[0029] In some embodiments, the alignment pins 224 may be permanently fixed, or they may be removable after the multilayer 118 is joined. In some embodiments, one or more rectangular alignment pins may help ensure linearity within the manufacturing tolerance of the individual lengths of the rectangular feature edges. A straight line can be cut with a tolerance shift of a few microns. By utilizing one or more rectangular alignment pins polished to a tolerance of a few microns, the entire length of the feature edge can be kept straight across all layers.

[0030] In some embodiments, the alignment pin 224 shows an example of an alignment pin that can be used to extend into the interior of two pin pockets of two components. As noted above with respect to Figures 1A, 1D, and 2A, and below with respect to Figure 5, the cross-sectional shape of the pin can be circular, elliptical, polygonal, cruciate, rotated polygon, etc. Furthermore, different segments of the alignment pin may have different shapes based on the shape of the pin pocket into which the alignment pin is inserted.

[0031] Referring back to Figure 2A, the exemplary RF or electron beam structure 100 further illustrates exemplary concentric inspection features 210. The concentric inspection features 210 may be formed across multiple layers 118 (across three layers 118, as shown) by forming cutouts of gradually increasing or decreasing size in each layer 118 to enable inspection of positioning accuracy after joining. If the layers 118 are precisely positioned, the concentric inspection features 210 should be concentric around the same axis. Figures 3A and 3B further illustrate the details of the concentric circles. While the concentric inspection features include circular cutouts, other shapes such as elliptical or polygonal cutouts are also possible. Although the concentric inspection features 210 are described as including cutouts, those skilled in the art will recognize that the geometric features forming the concentric inspection features 210 do not need to be formed using a “cutting” process and can be formed by other means.

[0032] Figure 3A is a cross-sectional side view across the diameter of a concentric inspection feature 210 according to several embodiments of the present invention. The concentric inspection feature 210 can be formed across two or more layers 118. As shown, the concentric inspection feature 210 is formed across three layers 118 and includes gradually decreasing cylindrical cutouts 302, 304, and 306 in the uppermost layer 308, the middle layer 310, and the lowermost layer 312, respectively. As shown above, the concentric inspection feature may be formed with gradually decreasing cutouts of other shapes.

[0033] Figure 3B is a perspective view of an exemplary concentric inspection feature 320 formed across multiple layers of an RF structure according to several embodiments of the present invention.

[0034] Figure 4A is a top view of an RF or electron beam structure 400 having a stepped pattern inspection feature 402 according to several embodiments of the present invention. The stepped pattern inspection feature 402 includes cutouts within each of a plurality of layers 118 (not shown). Within adjacent layers 118, the cutouts may form “bridges” across the perimeter of a window. The bridges may be arranged in a predetermined relationship to one another, for example, spaced apart by a defined distance horizontally or vertically as shown. The stepped pattern inspection feature 402 may not only allow inspection of the lamination order and layer alignment (for example, measuring the amount of layer movement and skew after joining), but may also allow viewing inside the assembled RF structure 400. Although the bridges are described as being formed using cutouts, those skilled in the art will recognize that the bridges may be formed in other ways.

[0035] Figure 4B is an exploded cross-sectional side view of an RF or electron beam structure 400 including a stepped pattern inspection feature 402 according to several embodiments of the present invention. The cross-sectional position is shown in Figure 4A. The RF structure 400 includes a plurality of layers 118 comprising a first layer 404, a second layer 406, a third layer 408, and a fourth layer 410. Each layer 118 includes the same window perimeter 420, but includes and / or retains a bridge at a predetermined location across the window perimeter 420. The first layer 404 includes a first bridge 412 positioned at a predetermined distance from the left side of the window perimeter 420. The second layer 406 includes a second bridge 414 positioned at a predetermined distance from the right side of the first bridge 412. The third layer 408 includes a third bridge 416 positioned at a predetermined distance from the right side of the second bridge 414. The fourth layer 410 includes a fourth bridge 418 positioned at a specified distance from the right side of the third bridge 416 and at a specified distance from the right side of the outer perimeter 420 of the window. Accordingly, after assembly and joining, the stepped pattern window inspection feature 402 can be evaluated by looking down from the first layer 404 or looking up from the fourth layer 410. In particular, the first layer 404 may not be the top layer, and therefore the stepped pattern window inspection feature 402 may not be visible from the top. Alternatively, the fourth layer 410 may not be the bottom layer, and therefore the stepped pattern window inspection feature 402 may not be visible from the bottom. Although the bridges 412, 414, 416, and 418 are shown positioned at the same specified distance apart, they can be positioned at any distance apart. In some embodiments, bridges 412, 414, 416, and 418 may be formed to be positioned directly above each other, forming vertical walls, as well as windows, vias, and / or pockets on the left and right sides of the walls.

[0036] Figure 5 is a top view of exemplary (e.g., cruciform) alignment and / or inspection feature 500 according to some embodiments of the present invention. When the alignment and / or inspection feature 500 is formed in multiple layers 118, vias formed across the layers 118 can be inspected to confirm proper layer alignment (position and / or angle). In some embodiments, an inspection device can be used to ensure that multiple walls extend through the layers 118. In some embodiments, the inspection device may include human vision, computer vision, optical devices, laser devices, or similar cruciform pins having a similar cruciform cross-section.

[0037] Figure 6 is a perspective view of an RF or electron beam structure 600 with a stepped inspection feature 602 positioned on one edge of the RF structure 600, according to several embodiments of the present invention. The RF or electron beam structure 600 may be formed from a stack of layers 118, including a first layer 604, a second layer 606, a third layer 608, a fourth layer 610, and a fifth layer 612. Each of the layers 606, 608, 610, and 612 may include increasing cutouts that form steps along the same edge of the RF or electron beam structure 600. That is, the first layer 604 may have no cutouts on one edge. The second layer 606 may include a cutout 614 at a defined distance from one edge. The third layer 608 may include a cutout 616 at two defined distances from one edge. The fourth layer 610 may include cutouts 618 extending three times a defined distance from one edge. The fourth layer 612 may include cutouts 620 extending four times a defined distance from one edge. Accordingly, when the layers 118 are properly positioned during assembly and joining, the stepped inspection feature 602 should present steps within certain tolerance limits. In some embodiments, the enlargements of each cutout may, but do not have to be, the same enlargements. The cutouts may include the same or different enlargements.

[0038] Figure 7 is a flowchart illustrating a method 700 for forming an RF or electron beam structure by first forming a multilayer, e.g., multilayer 118, which has via segments formed inside that together form alignment pins, e.g., alignment vias 222, configured to accept alignment pins, e.g., alignment pins 224, which may help to position and / or rotationally align the multilayer 118 before and / or during bonding.

[0039] Method 700 begins with step 702, which involves forming each layer, for example, layers 118 of a multilayer 118. In step 704, via segments are formed within each layer 118 of the multilayer 118. In some embodiments, step 704 is integrated into step 702. In some embodiments, step 704 is a separate step from step 702. In step 706, the multilayer 118 is assembled and the via segments are aligned to form aligned vias, for example vias 222, and alignment pins, for example alignment pins 224, are inserted into the aligned vias before and / or after joining in step 708. In step 708, the multilayer 118 is joined together to form an RF or electron beam structure, for example RF or electron beam structure 220, as the alignment pins align the layers 118 in position and / or rotation.

[0040] In some embodiments, the present invention provides a method for manufacturing a radio frequency (RF) or electron beam structure, comprising the steps of forming each layer of a multilayer to be aligned, assembled together and joined, the first via segment having a first specific shape and dimensions in the layer at a first position in the layer, so that when the multilayer first via segments are aligned and assembled, the numerous first via segments are aligned to form a first via; and inserting a first similar pin into the first via, the first similar pin being formed based on the first specific shape and dimensions of each of the first via segments, the first similar pin being inserted into the first via, thereby assisting in the alignment and assembly of the multilayer.

[0041] The structure may include waveguides or interaction structures. The first particular shape may include a circular cross-section. The first particular shape may include a polygonal cross-section, and as a result, the step of inserting the first similar pin into the first via further helps to rotate and align to assemble the multilayer. Each via segment may include the same shape and dimensions, and the via may include a cross-section that does not change over its length. The first similar pin may include a top surface, a bottom surface, and a length, and the length of the first similar pin may be the same as the length of the first via, so that when the first similar pin is inserted into the first via, the top and bottom surfaces, respectively, are coplanar with the surface of the multilayer. The first similar pin may include a top surface, a bottom surface, and a length, and the length of the first similar pin may be shorter than the length of the first via, so that when the first similar pin is inserted into the first via, the top and bottom surfaces, respectively, are recessed from the surface of the multilayer. The method may further comprise the steps of joining the multilayers together and removing the first similar pins after joining the multilayers. The method may further comprise the steps of evaluating one or more walls of the first vias to check for alignment after removing the first similar pins. The step of forming each layer of the multilayer to be aligned and assembled together may comprise the step of forming a second via segment of a second specific shape and dimensions in the layer at a second position in the layer, so that when the second via segments of the multilayer are assembled in alignment, the multilayer aligns to form the second vias, and the method may further comprise the step of inserting a second similar pin into the second via, the second similar pin being formed based on the second specific shape and dimensions of each of the second via segments, so that the steps of inserting a first similar pin into the first via and inserting a second similar pin into the second via help to assemble the multilayer in alignment and rotation.

[0042] Additional steps and details are described above with respect to Figures 1A, 1B, 1C, 1D, 2A, 2B, 3A, 3B, 4A, 4B, 5, and 6.

[0043] Figure 8 is a flowchart illustrating a method 800 for forming an RF or electron beam structure, for example, an RF or electron beam structure 100, using a multilayer, for example, a multilayer 118, which has pin pockets, for example, pin pockets 106, 202, 204, 206, 208, or 212 formed inside for receiving alignment pins to assist in alignment to external components, according to some embodiments of the present invention. The pin pockets may be formed in a single layer 118 or in a multilayer 118.

[0044] Method 800 begins with step 802, which involves forming each layer, for example, layer 118 of a multilayer 118. In step 804, pin pockets 106, 202, 204, 206, 208, and 212 are formed in one or more of the layers 118. In some embodiments, step 804 is integrated into step 802. In some embodiments, step 804 is a separate step from step 802. In step 806, the multilayer 118 are joined together to form an RF structure, for example, an RF structure 100, so that the pin pockets 106, 202, 204, 206, 208, and 212, as well as the pin pockets of adjacent external components, can receive alignment pins in and between to align the RF structure 100 (or features of the RF structure) with the external components (or features of the external components). In some embodiments, the alignment pins may be partially or completely inserted in step 806, before, during, and / or after joining. The length of the alignment pins may be longer than the depth of pin pockets 106, 202, 204, 206, 208, or 212, and less than or equal to the sum of the depths of pin pockets 106, 202, 204, 206, 208, or 212 and the pin pockets of the external components.

[0045] Additional steps and details are described above with respect to Figures 1A, 1B, 1C, 1D, 2A, 2B, 3A, 3B, 4A, 4B, 5, and 6.

[0046] Figure 9 is a flowchart illustrating a method 900 of forming an RF or electron beam structure, for example, an RF or electron beam structure 100, using a multilayer 118 such that one or more layers have one or more geometric features that form pockets, for example, pocket 102, or bosses, for example, boss 104, to help align with external components.

[0047] Method 900 begins with step 902, which involves forming each layer, for example, layers 118 of a multilayer 118. In step 904, geometric features are formed in one or more of the layers 118. In some embodiments, step 904 is integrated into step 902. In some embodiments, step 904 is a separate step from step 902. In step 906, the multilayer 118 are joined together to form an RF or electron beam structure 100, wherein the geometric features in one or more layers form pockets 102 or bosses 104 configured to positionally and / or rotationally align the RF or electron beam structure 100 (or features of the RF or electron beam structure 100) with an external component (or features of the external component).

[0048] Additional steps and details are described above with respect to Figures 1A, 1B, 1C, 1D, 2A, 2B, 3A, 3B, 4A, 4B, 5, and 6.

[0049] Figure 10 is a flowchart illustrating a method 1000 of forming RF or electron beam structures, e.g., RF or electron beam structures 200, 300, 400, and / or 600, using a multilayer 118 having geometric features formed in two or more of the layers 118, configured to cooperate assist in post-join inspection of positional and / or rotational alignment, according to some embodiments of the present invention.

[0050] Method 1000 begins with step 1002, which involves forming each layer, for example, layers 118 of a multilayer 118. In step 1004, geometric features are formed in two or more of the multilayer 118. In some embodiments, step 1004 is integrated into step 1002. In some embodiments, step 1004 is a separate step from step 1002. In step 1006, the multilayer 118 are joined together to form an RF or electron beam structure, for example, RF or electron beam structures 200, 300, 400, and / or 600, and the geometric features in two or more layers 118 cooperate to form inspection features for checking the positional and / or rotational alignment of the layers or features after joining. Exemplary geometric features include geometric features that form a concentric inspection feature 210, geometric features that form a stepped pattern inspection feature 402, geometric features that form a cross alignment and / or inspection feature 500, and / or geometric features that form a stepped inspection feature 602.

[0051] Additional steps and details are described above with respect to Figures 1A, 1B, 1C, 1D, 2A, 2B, 3A, 3B, 4A, 4B, 5, and 6.

[0052] The foregoing description of preferred embodiments of the present invention is merely illustrative, and other variations and modifications of the embodiments and methods described above are possible in consideration of the foregoing teachings. The embodiments described herein are not intended to be exhaustive or limiting. The present invention is limited only to the following claims.

Claims

1. A method for manufacturing radio frequency (RF) or electron beam structures, A step of forming each layer of a multilayer to be aligned, assembled, and joined together, comprising the step of forming a first via segment of a first specific shape and size within the layer at a first location within the layer, wherein when the multilayer first via segments are aligned and assembled, a number of the first via segments align to form a first via, The step of inserting a first similar pin into the first via, wherein the first similar pin is formed based on the first specific shape and dimensions of each of the first via segments, and as a result, the step of inserting the first similar pin into the first via is a step that helps to align and assemble the multilayer. A method for providing this.

2. The method according to claim 1, wherein the structure includes a waveguide.

3. The method according to claim 1, wherein the structure includes an electron beam aperture.

4. The method according to claim 1, wherein the structure includes an interacting structure.

5. The method according to claim 1, wherein the first specific shape includes a circular cross-section.

6. The method according to claim 1, wherein the first particular shape includes a polygonal cross-section, and the step of inserting the first similar pin into the first via further helps to rotate and align the multilayer to assemble it.

7. The method according to claim 1, wherein each of the via segments has the same shape and dimensions, and the via has a cross-section that does not change over its length.

8. The method according to claim 1, wherein the first similar pin includes a top surface, a bottom surface, and a length, the length of the first similar pin being the same as the length of the first via, and as a result, when the first similar pin is inserted into the first via, the top surface and the bottom surface are each coplanar with the surface of the multilayer.

9. The method according to claim 1, wherein the first similar pin includes a top surface, a bottom surface, and a length, the length of the first similar pin being shorter than the length of the first via, and as a result, when the first similar pin is inserted into the first via, the top surface and the bottom surface are set back from the surface of the multilayer.

10. The method according to claim 1, wherein the first similar pin includes a top surface, a bottom surface, and a length, the length of the first similar pin being longer than the length of the first via, and as a result, when the first similar pin is inserted into the first via, at least one of the top surface and the bottom surface extends beyond the surface of the multilayer.

11. The method according to claim 1, further comprising the steps of joining the multilayers together and removing the first similar pin after joining the multilayers.

12. The method according to claim 11, further comprising the step of removing the first similar pins and then evaluating one or more walls of the first via to check for alignment.

13. The step of forming each of the layers of the multilayer to be aligned, assembled together and joined together includes the step of forming a second via segment of a second specific shape and size within the layer at a second location within the layer, so that when the second via segments of the multilayer are aligned and assembled, the multilayer aligns to form the second vias. The method comprises the step of inserting a second similar pin into the second via, wherein the second similar pin is formed based on the second specific shape and dimensions of each of the second via segments, and as a result the step of inserting a first similar pin into the first via and the step of inserting a second similar pin into the second via further comprises the step of aligning and rotating the pins to help assemble the multilayer. The method according to claim 1.

14. RF or electron beam structure, A multilayer that is aligned and assembled and joined together, wherein each layer includes a first via segment of a first specific shape and size in a first location within the layer, and as a result when the first via segments of the multilayer are assembled in alignment, the number of the first via segments align to form a first via in the multilayer, A first similar pin configured to be inserted into the first via, having a first specific shape and dimensions based on each of the first via segments, such that when the first similar pin is inserted into the first via, the first similar pin helps to align and assemble the multilayer with the first similar pin. An RF or electron beam structure comprising...

15. The RF or electron beam structure according to claim 14, comprising a waveguide.

16. The RF or electron beam structure according to claim 14, comprising an electron beam aperture.

17. The RF or electron beam structure according to claim 14, comprising an interaction structure.

18. The RF or electron beam structure according to claim 14, wherein the first specific shape includes a circular cross-section.

19. The RF or electron beam structure according to claim 14, wherein the first specific shape includes a polygonal cross-section, and the first similar pins are further configured to help assemble the multilayer by rotating and aligning them when inserted into the first vias.

20. The RF or electron beam structure according to claim 14, wherein each of the via segments has the same shape and dimensions, and the via has a cross-section that does not change over its length.

21. The RF or electron beam structure according to claim 14, wherein the first similar pin includes an upper surface, a lower surface, and a length, the length of the first similar pin being the same as the length of the first via, and the first similar pin is configured such that, when inserted into the first via, the upper surface and the lower surface of the first similar pin are coplanar with the surface of the multilayer.

22. The RF or electron beam structure according to claim 14, wherein the first similar pin includes a top surface, a bottom surface, and a length, the length of the first similar pin being shorter than the length of the first via, and the first similar pin being configured such that when inserted into the first via, the top surface and the bottom surface of the first similar pin are recessed from the surface of the multilayer layers.

23. The RF or electron beam structure according to claim 14, wherein the first similar pin includes a top surface, a bottom surface, and a length, the length of the first similar pin being longer than the length of the first via, and the first similar pin being configured such that, when inserted into the first via, at least one of the top surface and the bottom surface extends beyond the surface of the multilayer.

24. The RF or electron beam structure according to claim 14, wherein the first similar pin is configured to be removed after the multilayer is joined.

25. The RF or electron beam structure according to claim 24, wherein one or more walls of the first via are configured to help establish positional alignment during insertion.

26. Each of the layers of the multilayer, which are aligned and assembled together and joined, has a second via segment of a second specific shape and size in a second location within the layer, and as a result when the second via segments of the multilayer are assembled in alignment, the multilayer has a second via segment that aligns to form a second via. A second similar pin configured to be inserted into the second via, formed based on the second specific shape and dimensions of each of the second via segments, such that when the first similar pin is inserted into the first via, the first similar pin, and when the second similar pin is inserted into the second via, the second similar pin helps to align and rotate the multilayer. The RF or electron beam structure according to claim 14, including the above.

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