MANUFACTURING A MULTI-LAYER CONDUCTOR PLATE

Abstract

Process (700) for manufacturing a multilayer printed circuit board, wherein the process (700) comprises: Identifying (702) a region (310, 312, 314) of a circuit core layer (302, 304, 306), wherein the region (310, 312, 314) of the circuit core layer is associated with an increased dielectric resin requirement; selective application (704) of a dielectric resin (412, 512, 612) with glass spheres mixed therein onto the marked area (310, 312, 314) of the circuit core layer (302, 304, 306); and Partial curing (706) of the dielectric resin (412, 512, 612) prior to performing a layering cycle and forming the multilayer printed circuit board containing the circuit core layer (302, 304, 306).

Description

BACKGROUND

[0001] A printed circuit board (PCB) can have a multi-layered, stacked structure. For example, a PCB might be made of pre-impregnated glass fiber fabric, also known as a prepreg material. Due to the complexity of the fluid flow properties of thermosetting resins, designing PCB layering processes that utilize them can be challenging. The complexity of some multi-layered PCB designs can make it particularly difficult to precisely achieve a specific dielectric thickness and overall board thickness while maintaining a satisfactory impedance.For example, high-density interconnect (HDI) printed circuit boards can incorporate microvias, blind vias and buried vias, multiple controlled impedance and differential traces, fine-line technology and higher accuracy.

[0002] Document US 2015 / 0 294 754 A1 relates to a process for producing a resin multilayer substrate obtained by laminating a plurality of resin films, wherein the plurality of resin films includes at least one layer of a liquid crystal polymer film made of a liquid crystal polymer as the principal material, wherein the process comprises, in the following sequence: a paste application step of applying a paste containing a dispersion medium and a fibrillated liquid crystal polymer powder containing liquid crystal polymer particles dispersed in the dispersion medium, and containing substantially no binder resin component, to a portion of an area having insufficient thickness in a state in which at least the plurality of resin films are laminated, to a surface of at least one layer of the liquid crystal polymer film;a lamination step of laminating the multiple resin films to obtain a laminate; and a thermocompression bonding step of applying pressure and heat to the laminate to bond the laminate by thermocompression to obtain a laminate that includes a thickness-adjusting layer of paste.

[0003] Document CN 105 792 547 A describes a pre-lamination process for the inner layer core of a thick copper multilayer printed circuit board (PCB). After etching line diagrams on both sides of the PCB's inner layer core, a resin layer is applied to each side of the core using a coating device. Following resin drying, a brown oxidation or blackening process is performed, and the core is then laminated as usual. This pre-lamination process is simple and effective, successfully solving the problem of insufficient filler material after lamination of the thick copper multilayer PCB and preventing damage to the board materials from the screen-printing resin.

[0004] Document US 2002 / 0050405A1 relates to a method for manufacturing a multilayer printed circuit board by forming upper-layer circuit conductors over lower-layer circuit conductors using a layer of insulating resin containing fillers. The method comprises the following steps: applying a semi-cured insulating resin film, which contains no filler, to the lower-layer circuit conductors; applying a vacuum, heating, and curing the insulating resin film so that the spaces defined between adjacent lower-layer circuit conductors are filled with a semi-cured insulating resin, which contains no filler; removing excess insulating resin sections located over the lower-layer circuit conductors by grinding off the excess resin sections;Producing a height of each of the sublayer circuit conductors that is lower than that of the unfilled insulating resin, which resin fills each of the spaces between the adjacent sublayer circuit conductors, by using a soft etching technique; applying a further semi-cured insulating resin film containing fillers over the sublayer circuit conductors and on top of the unfilled insulating resin; and pressurizing, heating, and curing the further insulating resin film to form a layered insulating resin containing the fillers.

[0005] Patent application US 2009 / 0227719A1 relates to a curable ink composition comprising approximately 1-10 parts by weight of a curable epoxy resin system, approximately 1-30 parts by weight of ferroelectric ceramic powder, approximately 0.1-10 parts by weight of a polymeric dispersion agent, and approximately 50-96 parts by weight of a solvent. The ink composition is suitable for the formation of a high-dielectric film by inkjet printing for embedded capacitors.

[0006] US Patent 5,120,384 A describes a method for manufacturing a multilayer laminate. The method involves metal sheets forming a substrate with openings at the locations where through-holes are to be created. These openings are filled with a resin containing a first filler. Prepregs are then prepared and placed on either side of each substrate by impregnating a nonwoven fabric with a thermosetting resin containing a second filler. This allows the metal sheets forming the substrates to be thicker, enabling a power supply with greater capacity and improved heat dissipation.

[0007] Publication JP 2011 - 71 350 A concerns a process for manufacturing a multilayer printed circuit board. A gap between conductor patterns formed on the surface of a laminated board, with a thickness of 105 µm or more, is filled with a resin composition to make the surface of the conductor patterns flush with the surface of the resin composition. After a metal foil has been overlapped onto the surface over a prepreg, it is heated and pressurized, thus laminating it. SUMMARY

[0008] The invention relates to processes for manufacturing a multilayer printed circuit board, the features of which are specified in the independent claims. Embodiments are specified in the dependent claims.

[0009] An exemplary process for manufacturing a multilayer printed circuit board involves the selective application of a dielectric resin to a region of a circuit core layer. The process further includes partial curing of the dielectric resin prior to performing a layering cycle to form a multilayer printed circuit board containing the circuit core layer.

[0010] In one example, a multilayer printed circuit board (PCB) is provided. The PCB is formed according to a process that includes the selective deposition of a dielectric resin onto a region of a circuit core layer and partial curing of the dielectric resin. The process further includes the formation of a layer consisting of a pre-impregnated (prepreg) material adjacent to the partially cured dielectric resin of the circuit core layer. The process also includes performing a layering cycle to form the multilayer PCB.

[0011] In another example, a circuit core layer for manufacturing a multilayer printed circuit board is disclosed. The circuit core layer contains a partially cured dielectric resin located within an area of ​​increased resin demand.

[0012] In yet another example, a process for manufacturing a multilayer printed circuit board (PCB) is provided. The process involves the selective application of a dielectric resin mixture to a region of a circuit core layer. This dielectric resin mixture contains glass beads encapsulated in the resin. The process further includes partial curing of the dielectric resin prior to performing a layering cycle to form a multilayer PCB containing the circuit core layer.

[0013] In yet another example, a multilayer printed circuit board (PCB) is provided. The PCB contains a dielectric layer and a circuit core layer. The dielectric layer is made of a pre-impregnated (prepreg) material containing a partially cured dielectric resin in which a glass fiber fabric is encapsulated. The circuit core layer has an area adjacent to the dielectric layer. This area of ​​the circuit core layer comprises a region of dielectric material containing glass beads encapsulated in a cured dielectric resin.

[0014] The foregoing and other objectives, features and advantages of the invention will become apparent from the following more detailed descriptions of exemplary embodiments of the invention, as illustrated in the accompanying drawings, in which identical reference numerals generally represent identical parts of exemplary embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a diagram illustrating a process for manufacturing a multilayer printed circuit board in which a dielectric resin is selectively applied to one or more areas of a circuit core layer that are associated with an increased resin requirement, according to one embodiment. Fig. Figure 2 is a diagram illustrating a section of a multilayer printed circuit board containing areas with increased resin requirements, according to one embodiment. Fig. Figure 3A is a diagram illustrating areas with increased resin requirements belonging to several circuit core layers to be used to form a multilayer printed circuit board according to one embodiment. Fig. Figure 3B is a diagram illustrating the selective application of a dielectric resin to the surface in Fig. Figure 3A illustrates the areas of the circuit core layers and a partial hardening of the dielectric resin according to one embodiment. Fig. 3C is a diagram showing a layering that combines the circuit core layers with the partially cured dielectric resin of Fig. 3B contains, illustrated before a layering cycle according to one embodiment. Fig. 3D is a diagram that, according to one embodiment, illustrates that a layering of the layering of Fig. 3C for forming a multilayer printed circuit board leads to a hardening of the dielectric resin within the areas with an increased resin requirement. Fig. 4A to 4C are diagrams showing the stages of a process for developing the in Fig. 3B and Fig. 3C illustrates the first circuit core layer by selectively applying a dielectric resin to one or more areas with an increased resin requirement, followed by partial hardening of the dielectric resin before performing a layering cycle according to one embodiment. Fig. 5A to 5C are diagrams depicting the stages of a process for developing the skills in Fig. 3B and Fig. 3C illustrates the second circuit core layer by selectively applying a dielectric resin to one or more areas with an increased resin requirement, followed by partial hardening of the dielectric resin before performing a layering cycle according to one embodiment. Fig. 6A to 6C are diagrams showing the stages of a process for developing the skills in Fig. 3B and Fig. 3C illustrates the third circuit core layer by selectively applying a dielectric resin to one or more areas with an increased resin requirement, followed by partial hardening of the dielectric resin before performing a layering cycle according to one embodiment. Fig. Figure 7 is a flowchart illustrating a specific embodiment of a process for manufacturing a multilayer printed circuit board, which includes selective application and partial curing of a dielectric resin in one or more areas of the circuit core layer(s) with an increased resin requirement prior to a layering cycle. DETAILED DESCRIPTION

[0015] The present disclosure describes the selective application of a dielectric resin to areas of circuit core layers with increased resin demand prior to performing a layering cycle to form a multilayer printed circuit board. A dielectric resin can be applied to the areas with increased resin demand using inkjet printing techniques. Subsequently, the resin can be partially cured to form circuit core layers with a partially cured dielectric resin located within the areas with increased resin demand. During the layering cycle, the partially cured dielectric resin fills the areas with increased resin demand with a cured resin, thus preventing resin depletion. A dielectric resin mixture containing glass spheres encapsulated in a dielectric resin is selectively applied to the areas with increased resin demand.One possible advantage associated with the use of glass spheres is the ability to more accurately adjust the overall dielectric constant of adjacent dielectric layers.

[0016] Fig. Figure 1 is a diagram 100 illustrating a process for manufacturing a multilayer printed circuit board in which a dielectric resin is selectively applied to one or more regions of a circuit core layer that have an increased resin requirement, according to one embodiment. In the example of Fig. Figure 1 illustrates the selective application of a resin to areas of a single circuit core layer. As shown here, with regard to Fig. As illustrated and further described in sections 2, 3A to 3D, 4A to 4C, 5A to 5C and 6A to 6C, a dielectric resin can be selectively applied to several circuit core layers of a respective multilayer printed circuit board structure in one or more specified areas before performing a layering cycle.

[0017] The left side of Fig. Figure 1 represents a process for forming a circuit core layer containing areas with high resin requirements. The first stage corresponds to core layering, in which two epoxy glass layers (e.g., two layers of a prepreg material) are placed between two outer layers of copper foil and layered to form a raw core. In the example of Fig. 1. The outer copper layers on the raw core correspond to voltage and ground planes in a multilayer printed circuit board. The next one, on the left side of Fig. The first stage shown corresponds to structuring the copper layer of the raw core to form a circuit core. In the Fig. In the circuit core shown in Figure 1, areas with an increased resin requirement for a multilayer printed circuit board, which is formed from the circuit core, are indicated.

[0018] The right side of Fig. Figure 1 represents an example according to the present disclosure in which a dielectric resin is selectively applied and partially cured to the areas with increased resin requirements prior to performing a layering cycle to form a multilayer printed circuit board containing the circuit core. The right-hand side of Fig. Figure 1 illustrates that the dielectric resin (resin in the "A-state") can be selectively applied to the labeled areas of the circuit core and partially cured ("B-state") to form a resin-filled circuit core. As further described herein, the resin in the A-state can correspond to a dielectric resin mixture containing glass beads encapsulated in a dielectric resin. The next step in Fig. The first stage shown illustrates a selected section of a layering process that includes the circuit core with a resin and a layer of pre-impregnated (prepreg) material adjacent to the resin in the B state to form a circuit core and a prepreg. The next in Fig. The stage shown illustrates that a layering cycle leads to a multilayer printed circuit board, where the selectively applied resin prevents resin deficiency in areas with increased resin demand.

[0019] Consequently, it illustrates Fig. 1 An example of a process for selectively applying a dielectric resin to areas of a circuit core layer with high resin demand prior to a layering cycle to prevent resin depletion. As further described herein, the dielectric resin can be selectively applied using an inkjet printing process, followed by partial curing (“bringing to the B state”) of the resin. In some cases, the areas with increased resin demand can be identified by fabricating a multilayer printed circuit board from circuit core layers without the dielectric resin, followed by visual inspection to identify resin-depleted areas. In other cases, a reversal of the copper structure can be used to mark the areas for resin application via an inkjet printing process.For example, if a distance between adjacent copper strips meets a threshold distance that corresponds to an increased resin requirement, the area between the adjacent copper strips can be marked for resin dispensing.

[0020] Fig. Figure 200 illustrates a section of a multilayer printed circuit board containing areas with increased resin requirements, according to one embodiment. In the Fig. In the example shown, the multilayer printed circuit board can be formed from a single layer containing three circuit core layers with two prepreg layers in between. Examples of circuit core layers used to form the multilayer printed circuit board of Fig. 2 can be used, are discussed here with regard to Fig. 3A to 3D illustrated and further described. Fig. Figure 2 further illustrates examples of areas with an increased resin requirement in each of the circuit core layers.

[0021] Fig. Figures 3A to 3D illustrate an example of a process for preventing resin deficiency in a multilayer printed circuit board by selectively applying resin to one or more areas of individual circuit core layers, which are identified as areas with increased resin requirements. In the Fig. In the example shown in Figures 3A to 3D, three core circuit layers are used to form a multilayer printed circuit board. It can be seen that the processes described herein can be used for multilayer printed circuit boards containing a different number and / or arrangement of core circuit layers.

[0022] With reference to Fig. Figure 3A illustrates 300 areas with an increased resin requirement, belonging to several circuit core layers to be used to form a multilayer printed circuit board, according to one embodiment.

[0023] In the example of Fig. 3A contains several circuit core layers, a first circuit core 302, a second circuit core 304 and a third circuit core 306. Fig. Figure 3A illustrates that the first circuit core 302 contains an area 310 with an increased resin requirement, the second circuit core 304 contains an area 312 with an increased resin requirement, and the third circuit core 306 contains an area 314 with an increased resin requirement. In some cases, the areas 310 to 314 with an increased resin requirement can be identified by fabricating a multilayer printed circuit board from a layer containing the three circuit core layers 302 to 306 without the dielectric resin, followed by a visual inspection to identify resin-deficient areas. In other cases, a reversal of the copper structure for each of the circuit core layers 302 to 306 can be used to mark the areas for resin application via an inkjet printing process.

[0024] With reference to Fig. Figure 3B illustrates diagram 320, a selective application of a dielectric resin to the in Fig. 3A shows areas 310, 312, 314 of the circuit core layers and a partial hardening of the dielectric resin according to one embodiment. Fig. Figure 3B illustrates that following selective deposition and partial curing, the first circuit core 302 contains a resin 322 in the B-state in region 310, the second circuit core 304 contains a resin 322 in the B-state in region 312, and the third circuit core 306 contains a resin 322 in the B-state in region 314. In some cases, the resin 322 in the B-state may correspond to a dielectric resin mixture containing glass beads encapsulated in a partially cured dielectric resin.

[0025] The process for selectively applying a dielectric resin to the first circuit core 302 and for partially curing the dielectric resin to form the resin 322 in the B-state is described herein with regard to Fig. 4A to 4C are illustrated and further described. The process for selectively applying a dielectric resin to the second circuit core 304 and for partially curing the dielectric resin to form the resin 322 in the B-state is described here with regard to Fig. Sections 5A to 5C are illustrated and further described. The process for selectively applying a dielectric resin to the third circuit core 306 and for partially curing the dielectric resin to form the resin 322 in the B-state is described here with regard to Fig. Sections 6A to 6C are illustrated and further described.

[0026] With reference to Fig. 3C illustrates a diagram 330, a layering 332, which covers the circuit core layers 302 to 306 with the partially cured dielectric resin of Fig. 3B contains, prior to a stratification cycle according to one embodiment.

[0027] Fig. Figure 3C illustrates that the stack 332 contains a first prepreg layer 334, which is positioned between a lower surface of the first circuit core layer 302, which contains the resin 322 in the B state, and an upper surface of the second circuit core layer 304 (which does not contain the resin 322 in the B state). The stack 332 further contains a second prepreg layer 336, which is positioned between a lower surface of the second circuit core layer 304 (which contains the resin 322 in the B state) and an upper surface of the third circuit core layer 306 (which contains the resin 322 in the B state).

[0028] With reference to Fig. 3D illustrates a diagram 340 according to an embodiment showing a layering of the layering 332 of Fig. 3C for forming a multilayer printed circuit board leads to the hardening of resin 322 in the B state. The in Fig. The 3D depicted layering cycle involves arranging the layer 332 between an upper plate 342 and a lower plate 344 and applying pressure and heat. The layering cycle results in the resin 322 curing in the B-state to form a cured resin 346 in each of the regions 310 to 314 with an increased resin requirement, thus preventing resin deficiency in the multilayer printed circuit board. The cured resin 346 can correspond to a dielectric resin mixture containing glass beads encapsulated in a cured dielectric resin.

[0029] Fig. 4A to 4C are diagrams showing the stages of a process for developing the in Fig. 3B and Fig. 3C illustrates the first circuit core layer by selectively applying a dielectric resin to one or more areas with an increased resin requirement, followed by partial hardening of the dielectric resin before performing a layering cycle according to one embodiment.

[0030] With reference to Fig. Figure 4A illustrates a diagram 400, a cross-sectional view and a top view of the surface of the first circuit core 302 of Fig. 3A. Fig. Figure 4A illustrates that the area 310, with its increased resin requirement, can correspond to a relatively narrow gap between two copper traces on the first circuit core 302. The top view illustrates that the area 310 can be characterized by coordinates along an x-axis and a y-axis. As shown here, with regard to Fig. As illustrated and further described in Figure 4B, the coordinates along the x-axis and the y-axis can be used for resin dispensing by an inkjet printer.

[0031] With reference to Fig. Figure 4B illustrates a diagram 410, a cross-sectional view and a top view of the surface of the first circuit core 302 of Fig. 4A after resin discharge into area 310 with increased resin demand. During the in Fig. In the embodiment shown in 4B, the coordinates of the area 310 along the x-axis and the y-axis can be used to create a structure of individual “droplets” of a resin 412 (which is in Fig. 4B, designated as "inkjet-printed resin"), is dispensed in a manner similar to the dispensing of ink by an inkjet printer. The resin 412 dispensed within area 310 represents a resin in the "A state". The in Fig. Resin 412 shown in Figure 4B can correspond to a dielectric resin mixture containing glass spheres (e.g., hollow glass spheres) encapsulated in a dielectric resin. For example, the glass spheres can correspond to hollow glass spheres formed from a glass material (e.g., an "E-glass" material) that is essentially a glass fiber fabric of the adjacent prepreg layer 334 in the stack 332 (shown in Figure 4B). Fig. 3C). With reference to the in Fig. In a 3D representation of a multilayer printed circuit board, the hardened resin 346 within the area 310 of the first circuit core 302 can have a total dielectric constant that is essentially similar to a total dielectric constant of the adjacent dielectric layer formed from the first prepreg layer 334.

[0032] Fig. 4C is a diagram 420 that illustrates that the Harz 412 in the “A-state”, which has been delivered within area 310, as in Fig. 4B is shown, then partially cured (“brought into the B state”) to form resin 322 in the B state. The in Fig. The resin 322 shown in 4C in the B state can correspond to a dielectric resin mixture containing glass spheres (e.g. hollow glass spheres) encapsulated in a partially cured dielectric resin.

[0033] In some cases, the resin 412 dispensed within area 310 can be selected during a subsequent layering cycle to form a multilayer printed circuit board based on the resin belonging to an adjacent prepreg layer. Referring, for example, to the Fig. In the layering 332 shown in Figure 3C, the resin 412 released within the area 310 can be selected based on the resin belonging to the first prepreg layer 334, which borders the first circuit core layer 302. For illustration purposes, the resin 412 in the "A state" can be selected such that the resin 322 in the B state after "transition to the B state" corresponds to the resin in the B state within the first prepreg layer 334.

[0034] In other cases, the resin 412 delivered within area 310 can be selected so that, according to the in Fig. In the 3D depicted layering cycle, the cured resin 346 has a dielectric constant that is essentially similar to the dielectric constant of the adjacent dielectric layer formed from the first prepreg layer 334. That is, the resin 412 selected for dispensing within the area 310 can differ from the resin belonging to the first prepreg layer 334 in order to match an overall dielectric constant of the glass fiber fabric and the cured resin after the layering cycle.

[0035] Fig. 5A to 5C are diagrams depicting the stages of a process for developing the skills in Fig. 3B and Fig. 3C illustrates the second circuit core layer by selectively applying a dielectric resin to one or more areas with an increased resin requirement, followed by partial hardening of the dielectric resin before performing a layering cycle according to one embodiment.

[0036] With reference to Fig. Figure 5A illustrates a diagram 500, a cross-sectional view and a top view of the surface of the second circuit core 304 of Fig. 3A. Fig. Figure 5A illustrates that area 312, with its increased resin requirement, can correspond to a relatively narrow region between a plated through hole (PTH) and the copper of the ground plane (as in Fig. 2 shown). The top view illustrates that area 312 can be characterized by coordinates along an x-axis and a y-axis. As shown here with regard to Fig. As illustrated and further described in Figure 5B, the coordinates along the x-axis and the y-axis can be used for resin dispensing by an inkjet printer.

[0037] With reference to Fig. Figure 5B illustrates a diagram 510, a cross-sectional view and a top view of the surface of the second circuit core 304 of Fig. 5A after resin discharge into area 312 with increased resin demand. During the in Fig. In the embodiment shown in Figure 5B, the coordinates of the region 312 along the x-axis and the y-axis can be used to create a structure of individual “droplets” of a resin 512 (which is contained in Figure 5B). Fig. 5B, designated as "inkjet-printed resin"), is dispensed in a manner similar to the dispensing of ink by an inkjet printer. The resin 512 dispensed within area 312 represents a resin in the "A state". The in Fig. Resin 512 shown in Figure 5B can correspond to a dielectric resin mixture containing glass spheres (e.g., hollow glass spheres) encapsulated in a dielectric resin. For example, the glass spheres can correspond to hollow glass spheres formed from a glass material (e.g., an "E-glass" material) that is essentially a glass fiber fabric of the adjacent prepreg layer 336 in the stack 332 (shown in Figure 5B). Fig. 3C). With reference to the in Fig. In a 3D representation of a multilayer printed circuit board, the hardened resin 346 within the area 312 of the second circuit core 304 can have a total dielectric constant that is essentially similar to a total dielectric constant of the adjacent dielectric layer formed from the second prepreg layer 336.

[0038] Fig. 5C is a diagram 520 that illustrates that the resin 512 in the “A-state”, which has been discharged within area 312, as in Fig. 5B is shown, then partially cured ("brought into the B state") to form resin 322 in the B state. The in Fig. The resin 322 shown in 5C in the B state can correspond to a dielectric resin mixture containing glass spheres (e.g. hollow glass spheres) encapsulated in a partially cured dielectric resin.

[0039] In some cases, the resin 512 dispensed within area 312 can be selected during a subsequent layering cycle to form a multilayer printed circuit board based on the resin belonging to an adjacent prepreg layer. Referring, for example, to the Fig. In the layering 332 shown in Figure 3C, the resin 512 released within the area 312 can be selected based on the resin belonging to the second prepreg layer 336, which adjoins the second circuit core 304. For illustration purposes, the resin 512 in the "A state" can be selected such that the resin 322 in the B state after "transition to the B state" corresponds to the resin in the B state within the second prepreg layer 336.

[0040] In other cases, the resin 512 delivered within area 312 can be selected so that, according to the in Fig. In the 3D depicted layering cycle, the cured resin 346 has a dielectric constant that is essentially similar to the dielectric constant of the adjacent dielectric layer formed from the second prepreg layer 336. That is, the resin 512 selected for dispensing within the area 312 can differ from the resin belonging to the second prepreg layer 336 in order to match an overall dielectric constant of the glass fiber fabric and the cured resin after the layering cycle.

[0041] Fig. 6A to 6C are diagrams showing the stages of a process for developing the skills in Fig. 3B and Fig. 3C illustrates the third circuit core layer by selectively applying a dielectric resin to one or more areas 314 with an increased resin requirement, followed by partial hardening of the dielectric resin before performing a layering cycle according to an embodiment.

[0042] With reference to Fig. Figure 6A illustrates a diagram 600, a cross-sectional view and a top view of the surface of the third circuit core 306 of Fig. 3A. Fig. Figure 6A illustrates that the area 314, with its increased resin requirement, can correspond to a relatively narrow gap between two copper traces on the third circuit core 306. The top view illustrates that the area 314 can be characterized by coordinates along an x-axis and a y-axis. As shown here, with regard to Fig. As illustrated and further described in Figure 6B, the coordinates along the x-axis and the y-axis can be used for resin dispensing by an inkjet printer.

[0043] With reference to Fig. Figure 6B illustrates a diagram 610, a cross-sectional view and a top view of the surface of the third circuit core 306 of Fig. 6A after resin discharge into area 314 with increased resin demand. During the in Fig. In the embodiment shown in 6B, the coordinates of the area 314 along the x-axis and the y-axis can be used to create a structure of individual “droplets” of a resin 612 (which is in Fig. 6B, designated as "inkjet-printed resin"), is dispensed in a manner similar to the dispensing of ink by an inkjet printer. The resin 612 dispensed within area 314 represents a resin in the "A state". The in Fig. Resin 612 shown in Figure 6B can correspond to a dielectric resin mixture containing glass spheres (e.g., hollow glass spheres) encapsulated in a dielectric resin. For example, the glass spheres can correspond to hollow glass spheres formed from a glass material (e.g., an "E-glass" material) that is essentially a glass fiber fabric of the adjacent prepreg layer 336 in the stack 332 (shown in Figure 6B). Fig. 3C). With reference to the in Fig. In a 3D representation of a multilayer printed circuit board, the hardened resin 346 within the area 314 of the third circuit core 306 can have a total dielectric constant that is essentially similar to a total dielectric constant of the adjacent dielectric layer formed from the second prepreg layer 336.

[0044] Fig. 6C is a diagram 620 that illustrates that the resin 612 in "A-state", which was delivered within area 314, as in Fig. 6B is shown, then partially cured (“brought into the B state”) to form resin 322 in the B state. The in Fig. The resin 322 shown in Figure 6C in the B state can correspond to a dielectric resin mixture containing glass spheres (e.g. hollow glass spheres) encapsulated in a partially cured dielectric resin.

[0045] In some cases, the resin 612 dispensed within area 314 can be selected during a subsequent layering cycle to form a multilayer printed circuit board based on the resin belonging to an adjacent prepreg layer. Referring, for example, to the Fig. In the layering 332 shown in Figure 3C, the resin 612 released within the area 314 can be selected based on the resin belonging to the second prepreg layer 336, which borders the third circuit core 306. For illustration purposes, the resin 612 in the "A state" can be selected such that the resin 322 in the B state after "transition to the B state" corresponds to the resin in the B state within the second prepreg layer 336.

[0046] In other cases, the resin 612 delivered within area 314 can be selected so that, according to the in Fig. In the 3D depicted layering cycle, the cured resin 346 has a dielectric constant that is essentially similar to the dielectric constant of the adjacent dielectric layer formed from the second prepreg layer 336. That is, the resin 612 selected for dispensing within the area 314 can differ from the resin belonging to the second prepreg layer 336 in order to match an overall dielectric constant of the glass fiber fabric and the cured resin after the layering cycle.

[0047] Fig. Figure 7 is a flowchart illustrating a particular embodiment of Process 700 for manufacturing a multilayer printed circuit board, which includes the selective application and partial curing of a dielectric resin in one or more regions of the circuit core layer(s) with an increased resin requirement prior to a layering cycle. The dielectric resin may be a dielectric resin mixture containing glass spheres encapsulated in a dielectric resin. In a particular embodiment, the glass spheres may be hollow glass spheres formed from a glass material (e.g., an "E-glass" material) that is essentially a glass fiber woven material of a pre-impregnated material to be used for forming dielectric layers in a multilayer printed circuit board.This can allow the area of ​​the circuit core layer containing the glass beads and the cured dielectric resin to have a dielectric constant that is essentially similar to a dielectric constant belonging to an adjacent dielectric layer formed from the prepreg material.

[0048] In some embodiments, the Fig. The process 700 shown in Figure 7 is used to form a multilayer printed circuit board containing a dielectric layer and a circuit core layer. The dielectric layer is formed from a prepreg material containing a partially cured dielectric resin in which a glass fiber fabric is encapsulated. The circuit core layer has an area adjacent to the dielectric layer. This area of ​​the circuit core layer comprises a region of dielectric material containing glass beads encapsulated in a cured dielectric resin.

[0049] Process 700 includes a designation of one or more areas of a circuit core layer that are associated with an increased need for a dielectric resin, in 702. With reference to, for example, Fig. 3A and Fig. 4A, area 310 of the first circuit core 302 is associated with an increased need for a dielectric resin. As a further example, with reference to Fig. 3A and Fig. 5A, area 312 of the second circuit core 304, is associated with an increased need for a dielectric resin. As a further example, with reference to Fig. 3A and Fig. 6A, area 314 of the third circuit core 306, is associated with an increased need for a dielectric resin.

[0050] Process 700 involves the selective application of a dielectric resin to the area(s) of the circuit core layer in 704. Referring, for example, to Fig. 4B, the resin 412 can be printed into area 310 of the first circuit core 302 using inkjet printing (e.g., based on the xy coordinates of area 310, as shown in the top view). As a further example, with reference to Fig. 5B the resin 512 is printed into area 312 of the second circuit core 304 using inkjet technology (e.g., based on the xy coordinates of area 312, as shown in the top view). As a further example, with reference to Fig. 6B The resin 612 is printed in inkjet-jet into area 314 of the third circuit core 306 (e.g., based on the xy coordinates of area 314, as shown in the top view). The dielectric resin can correspond to a dielectric resin mixture containing glass spheres encapsulated in a dielectric resin.

[0051] Process 700 includes partial curing of the dielectric resin in 706. Referring, for example, to Fig. 4C forms a partial hardening of the resin 412, which is released within region 310, the resin 322 in the B state within region 310 of the first circuit core 302. As a further example, with reference to Fig. 5C partial hardening of the resin 512, which is released within region 312, the resin 322 in the B state within region 312 of the second circuit core 304. As a further example, with reference to Fig. 6C a partial hardening of the resin 612, which is released within area 314, the resin 322 in the B state within area 314 of the third circuit core 306. The in Fig. 4C, Fig. 5C and Fig. The resin 322 shown in Figure 6C in the B state can correspond to a dielectric resin mixture containing glass spheres encapsulated in a partially cured dielectric resin.

[0052] Process 700 includes the formation of a layer containing the circuit core layer, as described in 708. For example, with reference to Fig. Layer 3C contains the first circuit core 302 with the resin 322 in the B state within area 310, which has an increased resin requirement. Area 310 of the first circuit core 302 borders the first prepreg layer 334 in layer 332. As a further example, with reference to Fig. Layer 3C contains the second circuit core 304 with the resin 322 in the B state within area 312, which has an increased resin requirement. Area 312 of the second circuit core 304 borders the second prepreg layer 336 in layer 332. As a further example, with reference to Fig. Layer 3C contains the third circuit core 306 with resin 322 in the B state within area 314, which has an increased resin requirement. Area 314 of the third circuit core 306 borders the second prepreg layer 336 in layer 332.

[0053] Process 700 includes performing a layering cycle to form a multilayer printed circuit board in 710. For example, with reference to Fig. 3D can create the layering of 332 from Fig. 3C is arranged between the upper plate 342 and the lower plate 344, and the layering cycle may involve the application of pressure and heat. The resulting multilayer printed circuit board contains the cured resin 346 in the regions 310 to 314, with an increased resin requirement, thus preventing resin depletion. The cured resin 346 may correspond to a dielectric resin mixture containing glass spheres encapsulated in a cured dielectric resin. This may allow the region of the circuit core layer containing the cured resin 346 to have a first dielectric constant that is essentially similar to a second dielectric constant belonging to an adjacent dielectric layer formed from the prepreg material.

[0054] This illustrates Fig.Figure 7 is an example of a process for manufacturing a multilayer printed circuit board, which includes the selective application and partial curing of a dielectric resin in one or more areas of the circuit core layer(s) with increased resin demand prior to a layering cycle. The additional dielectric resin can fill the areas with increased resin demand during the layering cycle, thus preventing resin shortage.

[0055] The information in this description serves only for illustration and is not to be construed as limiting. The scope of the present invention is limited only by the wording of the following claims.

[0056] The invention can further be described, without limitation and only by way of example, by the following embodiments. The following embodiments may include preferred embodiments. Accordingly, the term "clause" used therein may refer to such a "preferred embodiment". Clause 1. Process for manufacturing a multilayer printed circuit board, wherein the process comprises: selective application of a dielectric resin to an area of ​​a circuit core layer; and Partial curing of the dielectric resin prior to performing a layering cycle to form a multilayer printed circuit board containing the circuit core layer. Clause 2. Process according to Clause 1, wherein the selective application of the dielectric resin includes the use of an inkjet printer to dispense the dielectric resin within the area. Clause 3. Clause following Clause 1, which further states: Forming a layer that includes a layer of pre-impregnated (prepreg) material adjacent to the circuit core layer area; and Performing the layering cycle to form the multilayer printed circuit board from the layered structure. Clause 4. Process according to Clause 3, wherein the partially cured dielectric resin is substantially similar to a partially cured resin within the layer of a pre-impregnated material. Clause 5. Process according to Clause 1, which further includes: selective application of the dielectric resin to a second area of ​​the circuit core layer; and Partial hardening of the dielectric resin before performing the layering cycle. Clause 6. Process according to Clause 5, wherein the dielectric resin is selectively applied to an area of ​​the circuit core layer adjacent to a via (PTH) position to be formed after the layering cycle. Clause 7. Process according to Clause 1, wherein the dielectric resin is applied between adjacent copper traces of the circuit core layer. Clause 8. Process according to Clause 7, wherein a distance between the adjacent copper tracks fulfills a threshold distance that is associated with an increased resin requirement. Clause 9. Layering for the manufacture of a multilayer printed circuit board, wherein the layering is formed according to a process which has: Selective application of a dielectric resin to an area of ​​a circuit core layer with a high resin requirement, without applying the dielectric resin to another area of ​​the circuit core layer; partial hardening of the dielectric resin within the area with high resin demand; and Forming a layer that includes a layer of pre-impregnated (prepreg) material adjacent to the partially cured dielectric resin within the area of ​​the circuit core layer with a high resin requirement. Clause 10. Layering according to Clause 9, wherein the selective application of the dielectric resin includes the use of an inkjet printer to dispense the dielectric resin within the area. Clause 11. Layering according to Clause 9, wherein the partially cured dielectric resin is substantially similar to a partially cured resin within the layer of a pre-impregnated material. Clause 12. Layering according to Clause 9, the process further comprising: selective application of the dielectric resin to a second area of ​​the circuit core layer with a high resin requirement; and Partial hardening of the dielectric resin within the second area with a high resin requirement before the formation of the layer. Clause 13. Layering according to Clause 9, wherein the dielectric resin is selectively applied to an area of ​​the circuit core layer adjacent to a via position (PTH) to be formed after a layering cycle to form a multilayer printed circuit board containing the circuit core layer. Clause 14. Layering according to Clause 9, wherein the dielectric resin is applied between adjacent copper traces of the circuit core layer. Clause 15. Stacking according to Clause 14, wherein a distance between the adjacent copper strips fulfills a threshold spacing that corresponds to an increased resin requirement. Clause 16. Circuit core layer for manufacturing a multilayer printed circuit board, wherein the circuit core layer has a high resin requirement area with a partially cured dielectric resin and another area without the partially cured dielectric resin. Clause 17. Circuit core layer according to Clause 16, wherein the partially cured dielectric resin is formed by: Using an inkjet printer to dispense a dielectric resin within the area with high resin demand; and Partial hardening of the dielectric resin within the area with high resin demand. Clause 18. Circuit core layer according to Clause 16, wherein the area with a high resin requirement corresponds to an area between adjacent copper traces. Clause 19. Circuit core layer according to Clause 16, wherein the area with a high resin requirement is adjacent to a via (PTH) position to be formed after performing a layering cycle to form a multilayer printed circuit board containing the circuit core layer. Clause 20. Circuit core layer according to Clause 16, wherein the partially cured dielectric resin is substantially similar to a partially cured resin within a layer of pre-impregnated (prepreg) material adjacent to the high resin requirement area of ​​the circuit core layer in a stacking that is stacked to form a multilayer printed circuit board containing the circuit core layer. Clause 21. Process for manufacturing a multilayer printed circuit board, wherein the process comprises: selective application of a dielectric resin mixture to an area of ​​a circuit core layer, wherein the dielectric resin mixture contains glass spheres encapsulated in a dielectric resin; and Partial curing of the dielectric resin prior to performing a layering cycle to form a multilayer printed circuit board containing the circuit core layer. Clause 22. Process according to Clause 21, which further specifies: Forming a layer that includes a layer of pre-impregnated (prepreg) material adjacent to the partially cured dielectric resin of the circuit core layer; and Performing a layering cycle to form the multilayer printed circuit board. Clause 23. Process according to Clause 22, wherein the area of ​​the circuit core layer of the multilayer printed circuit board containing the glass beads and the cured dielectric resin has a first dielectric constant that is substantially similar to a second dielectric constant that is associated with an adjacent dielectric layer formed from the prepreg material. Clause 24. Multilayer printed circuit board which features: a dielectric layer formed from a pre-impregnated (prepreg) material containing a partially cured dielectric resin in which a glass fiber fabric is encapsulated; and a circuit core layer having an area adjacent to the dielectric layer, wherein the area of ​​the circuit core layer has a region with a high resin requirement of a dielectric material with glass spheres encapsulated in a hardened dielectric resin and another region of a dielectric material without the glass spheres. Clause 25. Multilayer printed circuit board according to Clause 24, wherein the area of ​​a dielectric material with a high resin requirement has a first dielectric constant that is essentially similar to a second dielectric constant belonging to the dielectric layer adjacent to the surface of the circuit core layer. REFERENCE MARK LIST 302 first circuit core or circuit core layer 304 second circuit core or circuit core layer 306 third circuit core or circuit core layer 310, 312, 314 Area with increased resin requirements 322 Harz in “B-state” 334 first prepreg layer 336 second prepreg layer 332 layering 342 upper plate 344 lower plate 346 hardened resin 412, 512, 612 Harz in "A-condition"

Claims

[1] A process (700) for manufacturing a multilayer printed circuit board, the process (700) comprising: Marking (702) a region (310, 312, 314) of a circuit core layer (302, 304, 306), the region (310, 312, 314) of the circuit core layer being associated with an increased dielectric resin requirement; selectively applying (704) a dielectric resin (412, 512, 612) with glass beads mixed therein to the designated area (310, 312, 314) of the circuit core layer (302, 304, 306); and partially curing (706) the dielectric resin (412, 512, 612) before performing a lamination cycle and forming the multilayer printed circuit board containing the circuit core layer (302, 304, 306). [2] The process of claim 1, wherein selectively applying the dielectric resin (412, 512, 612) includes using an inkjet printer to dispense the dielectric resin (412, 512, 612) within the region (310, 312, 314) and / or wherein the glass spheres are hollow glass spheres. [3] The process of claim 1, further comprising: Forming (708) a stack (332) containing a layer (334, 336) of a pre-impregnated material adjacent to the region (310, 312, 314) of the circuit core layer (302, 304, 306); and Performing (710) the layering cycle to form the multilayer circuit board from the layering (332). [4] The process of claim 3, wherein the partially cured dielectric resin (322) substantially resembles a partially cured resin within the layer (334, 336) of pre-impregnated material. [5] The process of claim 1, further comprising: selectively applying the dielectric resin (412, 512, 612) to a second region of the circuit core layer (302, 304, 306); and partially curing the dielectric resin (412, 512, 612) before performing the layering cycle. [6] The process of claim 5, wherein the dielectric resin (412, 512, 612) is selectively applied to a surface of the circuit core layer (302, 304, 306) adjacent to a position of a via (PTH) (312) to be formed after the lamination cycle. [7] The process of claim 1, wherein the dielectric resin (412, 512, 612) is applied between adjacent copper traces of the circuit core layer (302, 304, 306). [8] The process of claim 7, wherein a distance between the adjacent copper traces satisfies a threshold distance associated with an increased dielectric resin requirement. [9] The process of claim 1, wherein the dielectric resin (412, 512, 612) is selectively applied between adjacent copper traces of the circuit core layer (302, 304, 306) separated by a threshold distance associated with increased resin demand. [10] A process (700) for manufacturing a multilayer printed circuit board, the process comprising: Marking (702) a region (310, 312, 314) of a circuit core layer (302, 304, 306), wherein the region (310, 312, 314) of the circuit core layer (302, 304, 306) is associated with an increased dielectric resin requirement; selectively applying (704) a dielectric resin (412, 512, 612) with glass beads mixed therein to the designated area (310, 312, 314) of the circuit core layer (302, 304, 306); selectively applying (704) the dielectric resin (412, 512, 612) to a second region of the circuit core layer (302, 304, 306); Partially curing (706) the dielectric resin (412, 512, 612) prior to performing a lay-up cycle and forming the multilayer printed circuit board including the circuit core layer (302, 304, 306), wherein the partially cured dielectric resin (322) substantially resembles a partially cured resin within the layer of prepreg material; Forming (708) a stack-up (332) including a layer (334, 336) of prepreg material adjacent to the region (310, 312, 314) of the circuit core layer (302, 304, 306); and Performing (710) the layering cycle to form the multilayer circuit board from the layering (332). [11] The process of claim 10, wherein the dielectric resin (412, 512, 612) is selectively applied to a surface of the circuit core layer (302, 304, 306) adjacent to a position of a via (PTH) to be formed after the lamination cycle, and / or wherein the glass beads are hollow glass beads. [12] The process of claim 10, wherein the dielectric resin (412, 512, 612) is applied between adjacent copper traces of the circuit core layer (302, 304, 306). [13] The process of claim 12, wherein a distance between the adjacent copper traces satisfies a threshold distance associated with increased resin demand. [14] The process of claim 10, wherein selectively applying the dielectric resin (412, 512, 612) includes using an inkjet printer to dispense the dielectric resin (412, 512, 612) within the region (310, 312, 314).

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