Method for forming resin substrate with conductive layer

Abstract

A method for forming a conductive layer-equipped resin substrate (1) includes a roughening step, a blasting step, a modification step, a first conductive layer forming step, and a second conductive layer forming step. In the roughening step, the surface (12A) of the insulating resin substrate (12) is roughened. In the sandblasting step, the roughened surface (12A) of the insulating resin substrate (12) is sandblasted by dry sandblasting. In the modification step, the surface (12A) of the insulating resin base material (12) that has been subjected to the sand blasting treatment is surface-modified. In the first conductive layer formation step, a first conductive layer (16) is formed on the surface-modified insulating resin substrate (12). The second conductive layer formation step forms a second conductive layer (18) on the first conductive layer (16) by a wet film formation process.

Description

Technical Field

[0001] An embodiment of the present invention relates to a method for forming a resin substrate with a conductive layer. Background Art

[0002] There are known techniques for forming a conductive layer on an insulating resin substrate. For example, the following method is disclosed: an opening such as a through hole is formed on an insulating resin substrate, and a filler or the like that is easily detached and exposed on the inner wall surface of the opening is removed to form a conductive layer (for example, refer to Patent Document 1).

[0003] Patent Document 1 discloses a method in which a filler or the like which is easily detached and exposed on the inner wall surface of the opening due to the formation of the opening is removed by sequentially performing a first alkali treatment, an ultrasonic cleaning treatment, and a second alkali treatment on an insulating resin layer having an opening. Patent Document 1 discloses that the adhesion between the insulating resin layer and the conductive layer is improved by forming a conductive layer after sequentially performing the above three steps.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2021-005624 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, in the prior art, in addition to the separation of filler, the adhesion strength between the insulating resin substrate and the conductive layer is reduced due to the influence of the resin part that is sparse and brittle due to the removal of smear. In addition, in the prior art, three steps must be performed to remove the filler that has separated or is about to separate, and the extension of the step becomes a problem. That is, in the prior art, it is difficult to seek to improve the adhesion strength between the insulating resin substrate and the conductive layer and shorten the step.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for forming a resin substrate with a conductive layer, which can improve the adhesion strength between the insulating resin substrate and the conductive layer and shorten the process.

[0010] Means used to solve problems

[0011] The method for forming a resin substrate with a conductive layer in an embodiment includes the following steps: a roughening step, roughening the surface of an insulating resin substrate; a sandblasting step, sandblasting the roughened surface of the insulating resin substrate by dry sandblasting; a modification step, surface modifying the sandblasted surface of the insulating resin substrate; a first conductive layer forming step, forming a first conductive layer on the surface-modified insulating resin substrate; and a second conductive layer forming step, forming a second conductive layer on the first conductive layer by a wet film forming process. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of an example of the resin substrate with a conductive layer according to the present embodiment.

[0013] Figure 2A This is a schematic diagram showing an example of a method for forming a resin substrate with a conductive layer according to the present embodiment.

[0014] Figure 2B This is a schematic diagram showing an example of a method for forming a resin substrate with a conductive layer according to the present embodiment.

[0015] Figure 2C This is a schematic diagram showing an example of a method for forming a resin substrate with a conductive layer according to the present embodiment.

[0016] Figure 2D This is a schematic diagram showing an example of a method for forming a resin substrate with a conductive layer according to the present embodiment.

[0017] Figure 2E This is a schematic diagram showing an example of a method for forming a resin substrate with a conductive layer according to the present embodiment.

[0018] Figure 2F This is a schematic diagram showing an example of a method for forming a resin substrate with a conductive layer according to the present embodiment.

[0019] Figure 3 This is a schematic structural diagram showing an example of the structure of a surface treatment device that performs single-side film formation.

[0020] Figure 4 Yes means Figure 3 A top view of an example of the structure of the interior of a chamber of a surface treatment device. DETAILED DESCRIPTION

[0021] Hereinafter, the details of the present embodiment will be described with reference to the drawings. It should be noted that in each of the drawings, the same components are denoted by the same reference numerals, and duplicate descriptions may be omitted.

[0022] Figure 1It is a schematic diagram of an example of the resin base material 1 with a conductive layer according to the present embodiment.

[0023] The resin base material with a conductive layer 1 is a laminated body in which an insulating resin base material 12 and a conductive layer 14 are sequentially laminated on a core base material 10 .

[0024] The core substrate 10 is a substrate that becomes the core of the resin substrate 1 with a conductive layer. For example, the core substrate 10 may be a so-called glass epoxy substrate in which an insulating resin such as an epoxy resin is impregnated in glass cloth. As the core substrate 10, a substrate in which an epoxy resin is impregnated in a woven or non-woven fabric such as glass fiber, carbon fiber, or aramid fiber can be used. In addition, the core substrate 10 may also be a laminate formed of a plurality of layers. For example, the core substrate 10 may also be a laminate in which a conductive layer, an insulating layer, a wiring layer, etc. are laminated.

[0025] The thickness of the core substrate 10 is not limited. The thickness of the core substrate 10 can be appropriately adjusted according to the application object of the resin substrate with a conductive layer 1. For example, when the resin substrate with a conductive layer 1 is used as a part of a wiring substrate, the thickness of the core substrate 10 is, for example, 60 μm or more and 1000 μm or less.

[0026] The insulating resin substrate 12 is provided on at least one surface in the thickness direction of the core substrate 10. In this embodiment, the insulating resin substrate 12 is provided on one surface in the thickness direction of the core substrate 10 as an example for description. In addition, the insulating resin substrate 12 may be provided on both surfaces in the thickness direction of the core substrate 10.

[0027] The insulating resin substrate 12 is an insulating resin substrate. The insulating resin substrate 12 may be in the form of a substrate, a layer, a film, or a block. In the present embodiment, the insulating resin substrate 12 is in the form of a layer as an example for explanation. Furthermore, the resin substrate 1 with a conductive layer may also be a structure without a core substrate 10. In this case, the resin substrate 1 with a conductive layer may function as the core substrate 10. For example, the core substrate 10 may be formed of an insulating resin substrate, and the resin substrate 1 with a conductive layer and the core substrate 10 may be formed into the same layer or the same substrate.

[0028] The constituent material of the insulating resin substrate 12 is not limited as long as it is an insulating resin material. As the constituent material of the insulating resin substrate 12, for example, in addition to epoxy resins widely used as insulating resins, imide resins, phenol-formaldehyde resins, novolac resins, melamine resins, polyphenylene ether resins, bismaleimide-triazine resins, siloxane resins, maleimide resins, polyetheretherketone resins, polyetherimide resins, polyethersulfones, etc. can be listed. In addition, as the constituent material of the insulating resin substrate 12, a resin obtained by mixing two or more resins selected from the above resins at an arbitrary ratio can also be used.

[0029] The thickness of the insulating resin substrate 12 is not limited. The thickness of the insulating resin substrate 12 may be appropriately adjusted according to the application of the resin substrate with a conductive layer 1. For example, when the resin substrate with a conductive layer 1 is used as a part of a wiring board, the thickness of the insulating resin substrate 12 is, for example, not less than 10 μm and not more than 40 μm.

[0030] The insulating resin base material 12 may contain a filler or may not contain a filler.

[0031] The material of the filler contained in the insulating resin base material 12 is not limited. As the filler, for example, silicon oxide, aluminum oxide, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate, etc. can be cited. Among them, silicon oxide is particularly preferred.

[0032] The particle size and content of the filler are not limited. The particle size of the filler is, for example, 0.3 μm to 4 μm. The content of the filler contained in the insulating resin substrate 12 is, for example, 30 wt % to 60 wt % relative to 100 wt % of the insulating resin substrate 12 .

[0033] Furthermore, through holes may be formed in the insulating resin base material 12 .

[0034] The conductive layer 14 is a layer having conductivity. The conductive layer 14 is a layer in which the second conductive layer 18 is stacked on the first conductive layer 16. The first conductive layer 16 functions as a seed layer for the second conductive layer 18. The second conductive layer 18 is a metal plating layer formed on the first conductive layer 16 as a seed layer.

[0035] The first conductive layer 16 and the second conductive layer 18 may be any conductive layer, and the materials constituting the first conductive layer 16 and the second conductive layer 18 are not limited. For example, the first conductive layer 16 and the second conductive layer 18 may be made of Cu, Al, Au, Pt, Ir, or alloys of two or more of the above. Furthermore, from the viewpoint of improving the adhesion of these layers, the first conductive layer 16 and the second conductive layer 18 are preferably made of the same metal. For example, the first conductive layer 16 and the second conductive layer 18 are preferably made of copper (Cu).

[0036] Next, a method for forming the resin substrate with a conductive layer 1 according to the present embodiment will be described in detail.

[0037] Figure 2A to Figure 2FThis is a schematic diagram showing an example of a method for forming the resin substrate 1 with a conductive layer according to the present embodiment.

[0038] The method for forming the resin substrate 1 with a conductive layer includes a roughening step, a sandblasting step, a modification step, a first conductive layer forming step, and a second conductive layer forming step.

[0039] Figure 2A 1 is a schematic diagram of a substrate in which an insulating resin substrate 12 is laminated on a core substrate 10. First, a substrate in which the insulating resin substrate 12 is laminated on the core substrate 10 is prepared. Furthermore, as described above, a substrate in which the insulating resin substrate 12 functions as the core substrate 10 and the insulating resin substrate 12 and the core substrate 10 are integrally formed may be prepared.

[0040] Figure 2B 1 is an explanatory diagram of an example of a roughening process. In the roughening process, the surface 12A of the insulating resin substrate 12 is roughened. The roughening process is performed so that the surface 12A of the insulating resin substrate 12 is roughened. The roughening process may be a process for roughening the surface 12A of the insulating resin substrate 12. The roughening process includes forming openings such as through holes on the surface 12A of the insulating resin substrate 12, forming fine concavo-convex shapes on the surface 12A, and the like.

[0041] The roughening treatment may be performed by either a wet method or a dry method.

[0042] As wet roughening treatment, chromic acid etching, permanganic acid etching, or organic solvent etching can be cited. The wet roughening treatment can be performed by immersing the surface 12A of the insulating resin substrate 12 in a solution such as a chromic acid solution, a permanganic acid solution, or an organic solvent heated to a predetermined temperature for a predetermined time. The predetermined temperature for the roughening treatment is, for example, 60°C to 80°C, but is not limited to this temperature range. In addition, the predetermined time for immersion is, for example, 10 minutes to 30 minutes, but is not limited to this range.

[0043] Examples of dry roughening treatment include plasma treatment, ultraviolet irradiation, etc. As the reactive gas used as plasma gas in the plasma treatment, for example, oxygen, argon, hydrogen, nitrogen, etc. may be used alone or in a mixed state.

[0044] As the roughening treatment using plasma, there are dry treatment using microwave plasma method and dry treatment using heat-assisted method. The microwave plasma method can reduce the heat load on the insulating resin substrate 12.

[0045] Figure 2C 1 is an explanatory diagram of an example of the sandblasting process. The sandblasting process is a process of sandblasting the surface 12A of the insulating resin base material 12 subjected to the roughening process by dry sandblasting.

[0046] Dry blasting is a non-wet blasting method, and examples thereof include dry ice blasting using dry ice particles D and air blasting using compressed air. Sandblasting using an abrasive material is not preferred because it will cause the abrasive material to remain on the surface. If dry ice blasting using dry ice particles D is used in the blasting process, no abrasive material will remain. In this way, the abrasive material that becomes gas after collision does not remain on the surface, which is preferred. Figure 2C 2 shows dry blasting using dry ice particles D as an example.

[0047] The particle size of the dry ice particles D is not limited, but is preferably in the range of 1 μm or more and 200 μm or less, for example. The particle size of the dry ice particles D can be measured by, for example, photographing with a high-speed camera or the like.

[0048] The flow velocity of the dry ice particles D is not limited, but is preferably in the range of 300 m / sec or more and 400 m / sec or less, for example. The flow velocity of the dry ice particles D can be measured using an anemometer.

[0049] The nozzle pressure of dry ice blasting is not limited, but is preferably in the range of 0.3 MPa to 0.7 MPa, for example.

[0050] As the blasting device for dry ice blasting or air blasting, any known device may be used.

[0051] The surface 12A of the insulating resin substrate 12 is roughened by the roughening process performed before the sandblasting process. The roughening of the surface 12A makes the resin on the surface 12A of the insulating resin substrate 12 fragile, so the adhesion strength is reduced. In addition, when the insulating resin substrate 12 contains fillers, in addition to the brittleness of the resin surface, a part of the filler is exposed on the surface 12A in a state of being about to be detached. The first conductive layer 16 formed on the resin layer that has become fragile due to the roughening becomes easy to peel off.

[0052] In the sandblasting step, the surface 12A of the insulating resin base material 12 is sandblasted by dry sandblasting. By performing the sandblasting, the fragile layer formed on the surface of the insulating resin base material 12 is removed from the surface 12A. Therefore, the first conductive layer 16 can be formed on the surface 12A firmly and not easily peeled off.

[0053] In addition, the inventor observed through SEM images that in a pure resin substrate containing no filler, the surface was roughened by the roughening process and became easy to peel off. If such a surface was sandblasted, it was also confirmed through SEM images that the surface became flat and difficult to peel off.

[0054] In the sandblasting step of the present embodiment, since the surface 12A of the insulating resin base material 12 is sandblasted by dry sandblasting, the surface 12A of the insulating resin base material 12 can be dry-cleaned without containing any infiltrated water.

[0055] In addition, when dry ice blasting using dry ice particles D is performed as the blasting process, it is estimated that the following effects can be obtained. Specifically, by blowing dry ice particles D onto the surface 12A of the insulating resin substrate 12, the fragile layer formed on the surface 12A can be removed. The fragile layer and the filler that is about to be separated are removed by the physical collision of the dry ice particles D and the volume expansion caused by the sublimation of the dry ice. Therefore, it is believed that by performing dry blasting using dry ice particles D, the fragile layer formed on the surface 12A of the insulating resin substrate 12 can be effectively removed in a short time.

[0056] Figure 2D 1 is an explanatory diagram of an example of the modification step. The modification step is a step of performing surface modification on the surface 12A of the insulating resin base material 12 subjected to the sandblasting treatment.

[0057] In the present embodiment, the so-called "surface modification" refers to a process of cutting the molecular chains present on the surface 12A of the insulating resin substrate 12 to generate functional groups such as hydroxyl, carboxyl, and formyl. As surface modification, there can be cited modification treatments using plasma treatment, ultraviolet irradiation treatment, UV (Ultra Violet) ozone treatment, small bubble ozone water treatment, or electrolytic sulfuric acid treatment. The so-called electrolytic sulfuric acid refers to a solution generated by electrolyzing sulfuric acid. The modification treatment may be performed by only one of these treatments, or by two or more treatments and performed in sequence.

[0058] When plasma treatment is used as the modification step, the modification step is preferably performed by first plasma treatment using an oxidizing gas containing 95% or more oxygen, and then, after the first plasma treatment, by using an oxidizing gas containing 1% or more H 2 The surface of the insulating resin base material 12 is surface-modified by the second plasma treatment using the reducing gas.

[0059] The treatment conditions of the modification treatment may be appropriately set according to the modification treatment method to be adopted, the type of the insulating resin base material 12 , and the like.

[0060] Figure 2E 1 is an explanatory diagram of an example of the first conductive layer forming step. The first conductive layer forming step is a step of forming the first conductive layer 16 on the surface 12A of the insulating resin substrate 12 that has been subjected to surface modification.

[0061] The first conductive layer 16 in the first conductive layer forming step can be formed by using either a wet film forming process or a dry film forming process.

[0062] As a dry film-forming process for forming the first conductive layer 16, i.e., a dry film-forming process, sputtering of a conductive material serving as a target can be cited. By forming the first conductive layer 16 on the insulating resin substrate 12 using a dry film-forming process, it is possible to omit a step of providing a catalyst such as Pd to the surface 12A before forming the first conductive layer 16. That is, the process can be shortened.

[0063] As a wet film-forming process for forming the first conductive layer 16 , that is, a wet film-forming process, there is mentioned electroless plating in which a film is formed by immersing the surface 12A in a plating solution.

[0064] Figure 2F 1 and 2 are diagrams for explaining an example of the second conductive layer forming step. The second conductive layer forming step is a step of forming the second conductive layer 18 on the first conductive layer 16 by a wet film forming process.

[0065] As a wet film-forming process for forming the second conductive layer 18 , there is exemplified a method of forming the second conductive layer 18 as a plated layer by electroplating.

[0066] By using Figure 2A to Figure 2F The resin substrate 1 with a conductive layer is formed through the roughening step, the sandblasting step, the modifying step, the first conductive layer forming step, and the second conductive layer forming step described above.

[0067] Furthermore, by further performing a firing step (annealing) on ​​the resin base material 1 with a conductive layer obtained through these steps, or removing a portion of the first conductive layer 16 , a wiring board or an IC (Integrated Circuit) chip can be constructed.

[0068] Specifically, a firing step may be further performed, that is, the laminate formed by sequentially undergoing the roughening step, the sandblasting step, the modification step, the first conductive layer forming step, and the second conductive layer forming step is heated at a temperature lower than the glass transition temperature of the insulating resin substrate 12 .

[0069] By further performing the firing step, the adhesion strength between the insulating resin base material 12 and the conductive layer 14 can be further improved.

[0070] The intervals (times) between the above-described roughening step, sandblasting step, modification step, first conductive layer forming step, second conductive layer forming step, and sintering step are not limited, but the intervals between these steps preferably satisfy the following conditions.

[0071] In detail, the sandblasting step is preferably started within 48 hours from the end of the roughening step. The modification step is preferably started within 48 hours from the end of the sandblasting step. The second conductive layer forming step is preferably started within 12 hours from the end of the first conductive layer forming step. The sintering step is preferably started within 6 hours from the end of the second conductive layer forming step.

[0072] When at least one of the intervals between the steps satisfies the above-mentioned conditions, it is possible to further improve the adhesion strength between the insulating resin base material 12 and the conductive layer 14 and shorten the steps.

[0073] As described above, the method for forming the resin substrate 1 with a conductive layer of the present embodiment includes a roughening process, a sandblasting process, a modification process, a first conductive layer forming process, and a second conductive layer forming process. The roughening process roughens the surface 12A of the insulating resin substrate 12. The sandblasting process sandblasts the surface 12A of the insulating resin substrate 12 that has been roughened by dry sandblasting. The modification process performs surface modification on the surface of the insulating resin substrate 12 that has been sandblasted. The first conductive layer forming process forms the first conductive layer 16 on the insulating resin substrate 12 that has been surface-modified. The second conductive layer forming process forms the second conductive layer 18 on the first conductive layer 16 by a wet film forming process.

[0074] Thus, in the method for forming the resin substrate 1 with a conductive layer of the present embodiment, the surface 12A of the insulating resin substrate 12 is roughened by the roughening step. By roughening the surface 12A, the resin powder of the insulating resin substrate 12 is attached to the surface 12A of the insulating resin substrate 12. In addition, when the insulating resin substrate 12 contains a filler, a part of the filler is attached to the surface 12A.

[0075] Therefore, in the sandblasting process, the surface 12A of the insulating resin base material 12 is sandblasted by dry sandblasting. By performing the sandblasting, the fragile layer or fine foreign matter such as filler generated by the sparseness of the insulating resin base material 12 is removed from the surface 12A. In addition, in the sandblasting process, since the surface 12A of the insulating resin base material 12 is sandblasted by dry sandblasting, it is possible to perform dry cleaning in a short time without impregnating the surface 12A of the insulating resin base material 12 with water.

[0076] Then, by forming the first conductive layer 16 and the second conductive layer 18 on the insulating resin substrate 12 subjected to the sandblasting treatment, it is possible to suppress the presence of a fragile layer or microscopic foreign matter such as fillers caused by sparseness between the insulating resin substrate 12 and the conductive layer 14. Therefore, in the method for forming the resin substrate 1 with a conductive layer of the present embodiment, it is possible to improve the adhesion strength between the insulating resin substrate 12 and the conductive layer 14.

[0077] Furthermore, since conductive layer 14 is formed on roughened surface 12A, the adhesion strength between insulating resin base material 12 and conductive layer 14 can be improved.

[0078] Here, in the prior art, fine foreign matter such as fillers is removed by three steps of the first alkali treatment, ultrasonic cleaning treatment, and the second alkali treatment. On the other hand, in the present embodiment, fine foreign matter on the surface 12A is removed by one step of the sandblasting step using dry sandblasting. Therefore, in the method for forming the resin substrate 1 with a conductive layer of the present embodiment, the steps can be shortened.

[0079] Therefore, the method for forming the resin substrate 1 with a conductive layer according to the present embodiment can improve the adhesion strength between the insulating resin substrate 12 and the conductive layer 14 and shorten the process.

[0080] When plasma treatment is used as the modification step, the modification step is preferably a first plasma treatment using an oxidizing gas containing 95% or more oxygen, and a second plasma treatment using an oxidizing gas containing 1% or more H 2 The second plasma treatment using the reducing gas performs surface modification on the surface of the insulating resin base material 12 .

[0081] By performing the second plasma treatment as a modification step after the first plasma treatment, it is possible to further improve the adhesion strength between the insulating resin substrate 12 and the conductive layer 14 .

[0082] In addition, as a modification process, by performing the second plasma treatment after the first plasma treatment, even when a completely cured (completely hardened) insulating resin substrate 12 is used, the surface of the insulating resin substrate 12 can be made to have reducing properties. Therefore, for example, by activating the resin substrate 1 with a conductive layer by annealing, a Cu-O bond is induced at the interface between the surface of the insulating resin substrate 12 and the conductive layer 14. Therefore, even when a completely cured insulating resin substrate 12 is used, the adhesion strength between the insulating resin substrate 12 and the conductive layer 14 can be further improved. In addition, by forming the conductive layer 14 using the completely cured insulating resin substrate 12, wiring patterning of several μm can be performed with high precision using the conductive layer 14.

[0083] In addition, as described above, through holes may be formed in the insulating resin substrate 12. The through hole formation region in the insulating resin substrate 12 is also subjected to the roughening process, the sandblasting process, and the modification process as described above to form the conductive layer 14. Therefore, in the case where electroplating is used as the conductive layer 14, the adhesion strength between the plated layer, i.e., the conductive layer 14 and the insulating resin substrate 12 can be improved and the process can be shortened.

[0084] Furthermore, it is preferred that two or more consecutive steps of the roughening step, the sandblasting step, the modification step, the first conductive layer forming step, and the second conductive layer forming step in the method for forming the resin substrate 1 with a conductive layer of this embodiment be performed as dry treatments under a vacuum environment.

[0085] For example, it is preferable to use dry treatment in the modification process and the first conductive layer forming process, and to perform these processes in a single vacuum environment. Specifically, plasma treatment is used for surface modification in the modification process, and sputtering, which is a dry film forming process, is used in the first conductive layer forming process. Then, the surface modification of the insulating resin substrate 12 and the formation of the first conductive layer 16 can be performed continuously by using an apparatus that performs the modification process and the first conductive layer forming process in a single chamber.

[0086] Figure 3 and Figure 4 1 is a schematic diagram of an example of a surface treatment apparatus 11. The surface treatment apparatus 11 is an example of an apparatus that performs a modification step and a first conductive layer forming step in one chamber.

[0087] Figure 3 An example of the configuration of a surface treatment device 11 that performs single-side film formation is shown. Figure 4 Yes means Figure 3 FIG. 1 is a plan view of an example of the structure inside the chamber of the surface treatment device 11.

[0088] The surface treatment apparatus 11 includes a workpiece placement unit 50 , a workpiece conveying unit 40 , a plasma electrode 210 , and a sputtering electrode 220 , which are contained in a chamber 20 .

[0089] The chamber 20 is a closed reaction container for performing surface treatment on the treated material W accommodated therein. Figure 3 The XYZ coordinate system shown has a rectangular parallelepiped shape with the X-axis direction as the longitudinal direction.

[0090] The processed material placement section 50 places the processed material W in a state of being substantially upright along the Y axis. The processed material placement section 50 includes a moving table 41 , a mounting table 47 , and a mounting shaft 48 .

[0091] The moving table 41 is a seat on which the material W is placed. The moving table 41 is transported along the X axis by the material transport unit 40. The mounting table 47 is a member provided on the moving table 41 and serving as a base on which the material W is mounted. The mounting shaft 48 supports the material W on the mounting table 47.

[0092] The processed material conveying section 40 conveys the processed material W placed on the processed material placing section 50 along the length direction (X axis) of the chamber 20. The processed material conveying section 40 is a single-axis movable stage driven by a conveying motor 43. Specifically, the processed material conveying section 40 conveys a movable stage 41 along the X axis by the rotational driving force of the conveying motor 43, and the movable stage 41 is fixed to a timing belt 42 mounted on two pulleys 44a and 44b. The processed material W is placed on the movable stage 41 via a mounting table 47 and a mounting shaft 48. Therefore, the processed material W is conveyed along the X axis by the processed material conveying section 40.

[0093] A plasma processing device 21 and a sputtering device 22 are provided on one side surface of the chamber 20 along the XY plane.

[0094] The plasma processing device 21 performs surface treatment on the workpiece W by irradiating the plasma generated in the plasma electrode 210 to the workpiece W. The plasma electrode 210 can move along an axis Z1 parallel to the Z axis, that is, in the direction of arrow A. By setting the interval between the workpiece W and the plasma electrode 210 to an optimal value, a more uniform film formation process can be achieved.

[0095] The sputtering device 22 ejects atoms for film formation from a target provided on a sputtering electrode 220 and causes the ejected atoms to adhere closely to the surface of the workpiece W, thereby performing sputtering. The sputtering electrode 220 can move along an axis Z2 parallel to the Z axis, that is, in the direction of arrow B. By setting the interval between the workpiece W and the sputtering electrode 220 to an optimal value, a more uniform film formation process can be achieved.

[0096] An exhaust device 51 is provided on the bottom surface of the chamber 20. The exhaust device 51 decompresses the interior of the chamber 20 to form a vacuum state. In addition, the exhaust device 51 exhausts the gas (reaction gas) filled in the interior of the chamber 20 by the surface treatment. The exhaust device 51 includes a pump unit 52 and a lift valve 53. The pump unit 52 is installed on the bottom surface of the chamber 20 to adjust the pressure inside the chamber 20 and to exhaust the gas filled in the interior of the chamber 20 due to the operation of the plasma processing device 21 or the sputtering device 22. The pump unit 52 is composed of, for example, a rotary pump or a turbomolecular pump. The lift valve 53 opens the opening 30 formed on the bottom surface of the chamber 20 to the atmosphere by moving between a state of abutting against the bottom surface of the chamber 20 and a state of moving toward the negative side of the Y axis.

[0097] The chamber 20 has opening and closing doors 23a and 23b on both sides along the YZ plane. The opening and closing doors 23a and 23b can be opened and closed by a hinge mechanism or a sliding mechanism. The operator of the surface treatment device 11 sets the material W to be treated and takes out the material W to be treated after the surface treatment by opening and closing the opening and closing doors 23a and 23b.

[0098] The surface treatment device 11 further includes a cooling device, a control device, a power supply device, a gas supply device, an operation panel, etc., but the illustration is omitted for the sake of simplicity. The cooling device generates cooling water for cooling the machine or the power supply. The control device controls the surface treatment device 11 as a whole. The power supply device accommodates the power supplied to each part of the surface treatment device 11. The gas supply device supplies film-forming gas and reaction gas to the chamber 20. The operation panel accepts operation instructions for the surface treatment device 11. In addition, the operation panel has the function of displaying the working status of the surface treatment device 11.

[0099] The chamber 20 has Figure 4 The shield plate 31 and the shield plate 32 are shown. The shield plate 31 moves along the arrow C. The shield plate 31 moves toward the positive side of the X axis to expose the plasma electrode 210 when the workpiece W is subjected to plasma treatment. In addition, the shield plate 31 moves toward the negative side of the X axis to store the plasma electrode 210 when the workpiece W is subjected to sputtering treatment. This prevents contamination of unused electrodes.

[0100] The shield plate 32 moves along the arrow E. The shield plate 32 moves toward the negative side of the X axis to expose the sputtering electrode 220 when the workpiece W is subjected to sputtering. In addition, the shield plate 32 moves toward the positive side of the X axis to store the sputtering electrode 220 when the workpiece W is subjected to plasma processing. This prevents contamination of unused electrodes.

[0101] Furthermore, during film formation, it is preferred that the plasma electrode 210 is not moved along the axis Z1, and the sputtering electrode 220 is not moved along the axis Z2, but the unwinding amount in the directions of the axis Z1 and the axis Z2 may be appropriately changed according to the vacuum degree inside the chamber 20, the gas flow rate, the conveying speed of the material W to be processed, the power, the voltage value, the current value, the discharge state, the temperature inside the chamber 20, etc. In this way, a more uniform film formation process can be achieved. In addition, the conveying speed of the material W to be processed may also be changed according to the values ​​of the above parameters.

[0102] In this embodiment, the insulating resin base material 12 subjected to the roughening treatment and the sandblasting treatment is used as the treated material W. Then, the insulating resin base material 12 as the treated material W is subjected to plasma treatment by the plasma treatment device 21, thereby modifying its surface. Then, the insulating resin base material 12 as the treated material W subjected to the surface modification is sputtered by the sputtering device 22, thereby forming the first conductive layer 16.

[0103] In this way, by using the surface treatment device 11 or the like, the modification process and the first conductive layer forming process are performed in a chamber 20 in a vacuum state. In this case, during the modification process and the first conductive layer forming process, the insulating resin substrate 12 can be prevented from being exposed to the atmosphere. Therefore, the adhesion strength between the insulating resin substrate 12 and the first conductive layer 16 can be further improved, and the process can be further shortened. That is, it is preferred that the modification process is set as plasma treatment, the first conductive layer forming process is set as sputtering, the insulating resin substrate 12 is arranged in the chamber, and the modification process and the first conductive layer forming process are continuously performed without exposing the insulating resin substrate 12 to the atmosphere.

[0104] Example

[0105] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples.

[0106] (Example 1, Example 2)

[0107] As the insulating resin substrate 12 laminated on the core substrate 10, a general semiconductor package substrate build-up film (epoxy resin containing SiO 2 The insulating resin substrate 12 has a size of 50 mm in length×50 mm in width×0.8 mm in thickness.

[0108] The surface 12A of the insulating resin substrate 12 is subjected to a wet roughening treatment (roughening step). The roughening step includes the following treatments: swelling treatment (60°C, 5 minutes), permanganate treatment (80°C, 20 minutes), reduction treatment (40°C, 5 minutes), and drying treatment (80°C, 15 minutes).

[0109] Next, using a sandblasting device manufactured by Air-Water, product name: QuickSnow (registered trademark), dry ice sandblasting is performed on the roughened surface 12A of the insulating resin substrate 12 (sandblasting process). The conditions for dry ice sandblasting are as follows: the particle diameter of the dry ice particles D is 10 μm, the nozzle pressure is about 0.1 to 0.5 MPa, and the insulating resin substrate is moved at a speed of 10 mm / sec.

[0110] Next, the surface 12A of the insulating resin substrate 12 subjected to the sandblasting treatment is subjected to surface modification by plasma treatment (modification step). The conditions for the plasma treatment for surface modification are set to an input power of 3.8 kW, a 2 The gas (gas flow rate: 3000 sccm), the transfer speed was 324 mm / min, and the processing time per unit area was 30 sec.

[0111] Next, the first conductive layer 16 is formed by sputtering on the surface 12A of the surface-modified insulating resin substrate 12 (first conductive layer forming step). As the sputtering conditions, after the chamber is evacuated, Ar gas is introduced until the gas pressure reaches 0.3 Pa, the power input is 45 kW, the film forming time is set to 10 seconds, and the first conductive layer 16 with a thickness of 300 μm is formed.

[0112] Next, the second conductive layer 18 is formed on the first conductive layer 16 by electroplating (second conductive layer forming step). As the plating solution used in the electroplating, a copper sulfate plating solution (manufactured by JCU, product name: CU-BRITE 21 (registered trademark)) is used, and the current density (ASD: Ampere per Square Decimeter: A / cm 2 ) After the 1ASD state is maintained for 1 minute, the 3ASD state is maintained for 3 minutes. Through these treatments, the second conductive layer 18 having a thickness of about 25 μm is formed on the first conductive layer 16 .

[0113] Then, the resin substrate 1 with a conductive layer, which is produced by forming a conductive layer 14 including a first conductive layer 16 and a second conductive layer 18 on an insulating resin substrate 12, is annealed (sintering process) at 200°C for 60 minutes using an air supply constant temperature thermostat (manufactured by Yamato Scientific), and then naturally cooled to obtain a resin substrate 1 with a conductive layer.

[0114] The sandblasting step starts 48 hours after the roughening step. The modification step starts 48 hours after the sandblasting step. The second conductive layer forming step starts 12 hours after the first conductive layer forming step. The sintering step starts 1 hour after the second conductive layer forming step.

[0115] The above-mentioned steps from the roughening step to the annealing step were performed on two insulating resin substrates 12 (general build-up films for semiconductor packaging) as samples to prepare two resin substrates 1 with conductive layers as resin substrates 1 with conductive layers of Examples 1 and 2.

[0116] The thickness of the conductive layer 14 in the resin substrate 1 with a conductive layer of Example 1 is 25 μm at the maximum and 22 μm at the minimum. The thickness of the conductive layer 14 in the resin substrate 1 with a conductive layer of Example 2 is 24 μm at the maximum and 20 μm at the minimum.

[0117] (Comparative Example 1, Comparative Example 2)

[0118] In the processes of Examples 1 and 2, except that the sandblasting process was not performed, the two insulating resin substrates 12 as samples were subjected to the same processes as in Examples 1 and 2, thereby producing comparative resin substrates with conductive layers of Comparative Examples 1 and 2.

[0119] The thickness of the conductive layer 14 in the comparative conductive layer-bearing resin substrate of Comparative Example 1 was 32 μm at maximum and 29 μm at minimum. The thickness of the conductive layer 14 in the comparative conductive layer-bearing resin substrate of Comparative Example 2 was 32 μm at maximum and 30 μm at minimum.

[0120] (Example 3)

[0121] A substrate A, which is a general semiconductor package build-up film, was prepared as the insulating resin substrate 12 to be laminated on the core substrate 10. The size of the insulating resin substrate 12 was 50 mm in length×50 mm in width×0.8 mm in thickness.

[0122] The surface 12A of the insulating resin substrate 12 was subjected to a dry roughening treatment (roughening process). Specifically, a plasma desmearing device (manufactured by NISSIN, product name: M120W-Y1) was used to perform the roughening treatment using micro plasma waves with an excitation frequency of 2.45 GHz. Then, pure water was used to perform ultrasonic cleaning at 33 kHz for 5 minutes. Furthermore, after cleaning with pure water running water, N 2 After air blowing, the film was dried at 80°C for 60 minutes.

[0123] Next, using the same sandblasting apparatus as in Example 1 and under the same sandblasting conditions as in Example 1, surface 12A of insulating resin base material 12 subjected to the roughening treatment is subjected to dry ice sandblasting (sandblasting step).

[0124] Next, the surface 12A of the insulating resin substrate 12 subjected to the sandblasting treatment is subjected to surface modification by plasma treatment (modification step). Then, the first conductive layer 16 is formed on the surface 12A of the insulating resin substrate 12 subjected to the surface modification by sputtering (first conductive layer forming step).

[0125] In Example 3, using Figure 3 and Figure 4 The surface treatment apparatus 11 for performing single-sided film formation shown is an improved surface treatment apparatus for performing double-sided film formation to perform the modification step and the first conductive layer forming step. Figure 3 and Figure 4The surface treatment device 11 shown is a single-sided film forming device in which a plasma treatment device 21 and a sputtering device 22 are provided only on one side of a direction (Z-axis direction) intersecting the conveying direction (X-axis direction) of the processed material W. The surface treatment device for double-sided film forming is a device in which a plasma treatment device 21 and a sputtering device 22 are provided on both sides of a direction (Z-axis direction) intersecting the conveying direction (X-axis direction) of the processed material W. Except for this aspect, the surface treatment device for double-sided film forming is Figure 3 and Figure 4 The surface treatment device 11 shown has the same structure.

[0126] The dimensions of the chamber 20 of the surface treatment apparatus for double-sided film formation used in Example 3 were 2,200 mm×1,045 mm×195 mm, and the volume of the chamber 20 was 450 L.

[0127] After the chamber 20 is evacuated, a plasma processing device 21 is provided on one side of a direction (Z-axis direction) intersecting a conveying direction (X-axis direction) of the workpiece W, and the input power is set to 2.5 kW, Ar / H 2 The surface 12A of the insulating resin substrate 12 as the material to be processed W was subjected to plasma treatment (first plasma treatment) with a gas (gas flow rate: 3000 sccm), a transport speed of 328 mm / min in the X-axis direction, and a treatment time of 30 seconds. In the first plasma treatment, the insulating resin substrate 12 as the material to be processed W was transported from one end side to the other end side in the X-axis direction in the chamber 20.

[0128] Then, the plasma processing device 21 provided on the other side of the direction (Z-axis direction) intersecting the conveying direction (X-axis direction) of the workpiece W is used to set the input power to 3.8 kW and 0. 2 The surface 12A of the insulating resin substrate 12 as the material to be processed W was subjected to plasma treatment (second plasma treatment) with Ar gas (gas flow rate: 180 sccm) and Ar gas (gas flow rate: 150 sccm) at a transport speed of 328 mm / min in the X-axis direction for a treatment time of 30 seconds. In the second plasma treatment, the insulating resin substrate 12 as the material to be processed W was transported in the opposite direction to that in the first plasma treatment, that is, from the other end side to the one end side in the X-axis direction in the chamber 20.

[0129] Furthermore, the insulating resin substrate 12 whose surface has been modified by the first plasma treatment and the second plasma treatment is transported to a position opposite to the sputtering device 22 in the chamber 20, and a first conductive layer 16 of copper with a film thickness of 300 nm is formed by the sputtering device 22 under the conditions of an input power of 55 kW and Ar gas (gas flow rate: 150 sccm) (first conductive layer forming process).

[0130] Then, similarly to the above-mentioned Example 1, the second conductive layer forming step and the annealing treatment were performed to obtain the resin base material 1 with a conductive layer of Example 3.

[0131] The thickness of the conductive layer 14 in the resin substrate with a conductive layer 1 of Example 3 was 24 μm at the maximum and 20 μm at the minimum.

[0132] (Comparative Example 3, Comparative Example 4)

[0133] The same steps as those in Example 3 were performed on each of the two insulating resin substrates 12 as samples, except that the sandblasting step was not performed in the steps of Example 3, thereby preparing comparative resin substrates with conductive layers of Comparative Examples 3 and 4.

[0134] The thickness of the conductive layer 14 in the comparative conductive layer-attached resin substrates of Comparative Examples 3 and 4 was 23 μm at the maximum and 20 μm at the minimum.

[0135] (Example 4 to Example 6)

[0136] As the insulating resin substrate 12 laminated on the core substrate 10, a general semiconductor package substrate build-up film (epoxy resin containing SiO 2 The insulating resin substrate 12 has a size of 50 mm in length×50 mm in width×0.8 mm in thickness.

[0137] Surface 12A of insulating resin base material 12 was subjected to a roughening treatment in the same manner as in Example 1 under the same conditions as in Example 1 (roughening step).

[0138] Next, the surface 12A of the roughened insulating resin substrate 12 is subjected to dry ice blasting (sandblasting process) using a sandblasting device manufactured by Air-Water and having the product name: QuickSnow (registered trademark). The dry ice blasting conditions are as follows: the particle size of the dry ice particles D is set to 10 μm, and the insulating resin substrate is moved at a speed of 10 mm / sec to perform dry ice blasting. The nozzle pressure is set to a nozzle pressure of 0.2 to 0.3 MPa (weak) in Example 4, a nozzle pressure of about 0.1 to 0.5 MPa (standard) in Example 5 as in Example 1, and a nozzle pressure of 0.3 to 0.4 MPa in Example 6.

[0139] Next, the surface 12A of the insulating resin base material 12 subjected to the sandblasting treatment is subjected to surface modification by plasma treatment (modification step). Specifically, the surface 12A of the insulating resin base material 12 is subjected to a first plasma treatment using an oxidizing gas containing 95% or more of oxygen, and after the first plasma treatment, a plasma treatment using an oxidizing gas containing 1% or more of H 2 The second plasma treatment using a reducing gas of the gas is performed to modify the surface of the insulating resin substrate 12. The conditions of the first plasma treatment are set to an input power of 2.5 kW, O 2 The conditions for the second plasma treatment were: input power 3.8 kW, Ar 2 The ratio of gas to hydrogen is set as gas flow rate: Ar / H 2 =800sccm, the transport speed is set to 490mm / min, H 2 The gas concentration was set to 5%, and the treatment time per unit area was set to 40 seconds.

[0140] Next, on the surface 12A of the surface-modified insulating resin substrate 12, a first conductive layer 16 having a thickness of 300 μm was formed by sputtering under the same conditions as in Example 1 (first conductive layer forming step). Then, on the first conductive layer 16, a second conductive layer 18 having a thickness of about 25 μm was formed under the same conditions as in Example 1 (second conductive layer forming step). Then, the resin substrate 1 with a conductive layer, which was prepared by forming the conductive layer 14 including the first conductive layer 16 and the second conductive layer 18 on the insulating resin substrate 12, was subjected to an annealing treatment (sintering step) at 200° C. for 60 minutes using an air supply constant temperature thermostat (manufactured by Yamato Scientific Co., Ltd.), and then naturally cooled, thereby obtaining the resin substrate 1 with a conductive layer.

[0141] Furthermore, in Examples 4 to 6, the sandblasting process starts 48 hours after the roughening process is completed. The modification process starts 48 hours after the sandblasting process is completed. The second conductive layer forming process starts 12 hours after the first conductive layer forming process is completed. The sintering process starts 1 hour after the second conductive layer forming process is completed.

[0142] The thickness of the conductive layer 14 in each of the resin substrates with a conductive layer 1 of Examples 4 to 6 was 26.5 μm, 24.4 μm, and 22.2 μm, respectively.

[0143] (Example 7)

[0144] The resin substrate 1 with a conductive layer was obtained in the same manner as in Example 4 under the same conditions as in Example 4 except that the following roughening step was performed instead of the roughening step in Example 4.

[0145] In Example 7, the surface 12A of the insulating resin base material 12 was roughened by dry treatment using microwave plasma. The conditions of the dry treatment using microwave plasma were as follows: the CF4 flow rate ratio was set to 13% and the etching amount was set to 1.0 μm.

[0146] The thickness of the conductive layer 14 in the resin substrate with a conductive layer 1 of Example 7 was 26.5 μm.

[0147] (evaluate)

[0148] The adhesive strength between the insulating resin substrate 12 and the conductive layer 14 was evaluated for each of the resin substrates 1 with conductive layers of Examples 1 to 7 and the comparative resin substrates with conductive layers of Comparative Examples 1 to 4 produced through the above-described steps.

[0149] The evaluation of the adhesion strength uses a 90° peel test. In the 90° peel test, a adhesion tester (manufactured by Toyo Seiki Co., Ltd.: Strograph, E2-L05) based on JIS C6481 (1996, Test method for copper-clad laminates for printed wiring boards) is used, and the tensile speed is set to 50 mm / min to measure the 90° peel strength (N / cm). Furthermore, in the 90° peel test, the resin substrate 1 with a conductive layer of Examples 1 to 7 and the comparative resin substrate with a conductive layer of Comparative Examples 1 to 4 are used. The samples are cut out with a width of 10 mm and a length of 100 mm. In addition, during the 90° peel test, a 5 mm incision is cut into the boundary between the conductive layer 14 and the insulating resin substrate 12 from the end of each sample using a single blade, and the peeling angle of the conductive layer 14 relative to the insulating resin substrate 12 is set to 90°, and the peelability (adhesion strength) of the conductive layer 14 from the insulating resin substrate 12 is evaluated. The evaluation results are shown in Table 1.

[0150] Table 1

[0151]

[0152] As shown in Table 1, the resin substrate 1 with a conductive layer of Example 1 and Example 2 manufactured by a process including a sandblasting process can be improved in adhesion strength compared with the resin substrate with a conductive layer of Comparative Example 1 and Comparative Example 2 manufactured under the same conditions except that the sandblasting process is not performed. In addition, the resin substrate 1 with a conductive layer of Example 3 manufactured by a process including a sandblasting process can be improved in adhesion strength compared with the resin substrate with a conductive layer of Comparative Example 3 and Comparative Example 4 manufactured under the same conditions except that the sandblasting process is not performed. In addition, the resin substrate 1 with a conductive layer of Examples 4 to 7 manufactured by a process including a sandblasting process can be improved in adhesion strength compared with the resin substrate with a conductive layer of Comparative Example 1 to Comparative Example 4 without the sandblasting process.

[0153] The nozzle pressure of dry ice blasting is 0.3 MPa or more and 0.7 MPa or less, and the peel strength is high.

[0154] In addition, in the resin substrate with a conductive layer 1 of Examples 1 to 7, since the sandblasting step is a single step, the steps can be shortened compared to the conventional technique of removing fine foreign matter through multiple steps.

[0155] Therefore, it was confirmed that in this embodiment, the adhesion strength between the insulating resin base material 12 and the conductive layer 14 can be improved and the process can be shortened as compared with the comparative example and the conventional technology.

[0156] Explanation of symbols

[0157] 1Resin substrate with conductive layer

[0158] 12Insulating resin substrate

[0159] 14 Conductive layer

[0160] 161st conductive layer

[0161] 18 2nd conductive layer

Claims

1. A method for forming a resin substrate with a conductive layer, comprising the following steps: A roughening process is to roughen the surface of the insulating resin substrate; a sandblasting step of sandblasting the roughened surface of the insulating resin substrate by dry sandblasting; A modification step of modifying the surface of the insulating resin substrate after sandblasting; A first conductive layer forming step of forming a first conductive layer on the surface-modified insulating resin substrate; and The second conductive layer forming step forms the second conductive layer on the first conductive layer by a wet film forming process.

2. The method for forming a resin substrate with a conductive layer according to claim 1, wherein: The roughening step is a step of roughening the surface of the insulating resin base material by plasma treatment, ultraviolet irradiation, chromic acid etching, permanganate etching, or organic solvent etching.

3. The method for forming a resin substrate with a conductive layer according to claim 2, wherein: The plasma treatment is a dry treatment using a microwave plasma method or a dry treatment using a heat-assisted method.

4. The method for forming a resin substrate with a conductive layer according to claim 1, wherein: The sandblasting step sandblasts the roughened surface of the insulating resin base material by dry sandblasting such as dry ice sandblasting.

5. The method for forming a resin substrate with a conductive layer according to claim 4, wherein: The nozzle pressure of the dry ice blasting is 0.3 MPa or more and 0.7 MPa or less.

6. The method for forming a resin substrate with a conductive layer according to claim 1, wherein: The insulating resin base material contains a filler.

7. The method for forming a resin substrate with a conductive layer according to claim 1, wherein: The modification step modifies the surface of the insulating resin substrate by plasma treatment, ultraviolet irradiation treatment, UV ozone treatment, or electrolytic sulfuric acid treatment.

8. The method for forming a resin substrate with a conductive layer according to claim 1, wherein: The modification step modifies the surface of the insulating resin substrate by a first plasma treatment using an oxidizing gas containing 95% or more oxygen and a second plasma treatment using a reducing gas containing 1% or more H 2 gas after the first plasma treatment.

9. The method for forming a resin substrate with a conductive layer according to claim 1, wherein: The first conductive layer forming step forms the first conductive layer on the surface of the insulating resin substrate that has been surface-modified by a dry film forming process.

10. The method for forming a resin substrate with a conductive layer according to claim 1, wherein: The first conductive layer and the second conductive layer are made of the same metal.

11. The method for forming a resin substrate with a conductive layer according to claim 1, wherein: The modifying step is plasma treatment, the first conductive layer forming step is sputtering, the insulating resin substrate is arranged in a chamber, and the modifying step and the first conductive layer forming step are continuously performed without exposing the insulating resin substrate to the atmosphere.

12. The method for forming a resin substrate with a conductive layer according to claim 1 includes a firing step, wherein the firing step heats the stacked body formed by sequentially undergoing the roughening step, the sandblasting step, the modification step, the first conductive layer forming step, and the second conductive layer forming step at a temperature lower than the glass transition temperature of the insulating resin substrate.

Images