Wiring board, method for manufacturing same, and device for removing resin from wiring board

Abstract

Provided is a method for manufacturing a wiring board, wherein a resin removal step for removing a portion of a resin layer 6 formed on a surface of a core board 2 is executed, and, prior to executing the resin removal step, executed is a laser irradiation step for making the resin fragile by irradiating, with a laser 16, all or a portion of a region of the surface of the resin layer 6 where the resin is to be removed in the resin removal step.

Description

Wiring board, its manufacturing method, and wiring board resin removal device

[0001] The technology disclosed in this specification relates to a wiring board in which at least a portion of a resin layer formed on the surface of the board is removed, a manufacturing method thereof, and a resin removal device for a wiring board.

[0002] Build-up wiring boards are used as high-density wiring boards on which electronic components of electronic devices are mounted. They are constructed by stacking insulating layers and circuit layers on both sides of a core substrate (an example of a substrate) with through holes. The through holes in the core substrate are filled with a resin filler. The through holes are filled with the resin filler, for example, by screen printing. The resin is printed so that it protrudes from the surface of the substrate to completely fill the through holes, even taking into account shrinkage during hardening. After the resin hardens, the protruding resin is removed, the entire surface is flattened, and circuits are then formed on top of it.

[0003] As described above, the core substrate is formed into a multilayer substrate by sequentially stacking layers, and poor flatness of the core substrate adversely affects the flatness of the overlying layers, and ultimately the accuracy of the circuit pattern. For this reason, a high degree of flatness is required for the core substrate. Furthermore, not only the core substrate of this type of build-up wiring board, but also the wiring substrate of an IC package on which a semiconductor chip is mounted is similarly manufactured by polishing the resin layer formed on the surface, and poor flatness of the wiring substrate can cause a decrease in the reliability of the connection with the semiconductor chip, so a high degree of flatness is also required.

[0004] As described above, various methods and devices are available for removing at least a portion of the resin layer that has risen from the substrate and planarizing the substrate, such as a buff polishing device in which several buff rolls that rotate around a rotation axis that runs parallel to the surface of the substrate are arranged; a CMP polishing device in which a polishing pad is rotated around a rotation axis that is perpendicular to the wiring substrate surface, and pressed against the surface of the resin layer, and an abrasive and chemical solution are supplied to mechanically and chemically polish the surface; and a wet blasting method in which a slurry in which an abrasive is dispersed in a liquid is sprayed onto the substrate surface together with compressed air from a blast gun.

[0005] However, the resin layer filled into the through-holes and cured has a high hardness and a relatively smooth surface after curing. Therefore, the resin layer surface does not get caught, and even when an abrasive tool such as a buff roll comes into contact with it, polishing tends not to proceed quickly. Although the resin layer often contains functional filler particles (filler particles), such as silica powder, most of these filler particles are located below the surface of the resin layer, and only a small proportion are exposed to the surface of the resin layer, so the surface of the resin layer is generally smooth. Therefore, even if the resin layer contains filler, the situation of the resin layer surface not getting caught remains the same, and it is difficult to say that resin removal proceeds quickly regardless of the polishing method used.

[0006] In mechanical polishing, in which an abrasive tool such as a buff roll directly contacts the surface of a resin layer, filler particles in the resin layer come into contact with the abrasive surface of the abrasive tool such as a buff roll as the resin layer is polished. However, because filler particles are generally harder than the resin layer, they actually place a strain on the abrasive tool. This results in excessive wear on the abrasive tool or adhesion to the surface of the abrasive tool, significantly reducing polishing performance. This necessitates repeated regeneration processes to regenerate the abrasive tool's abrasive surface during polishing operations, and the abrasive tool must be frequently replaced, ultimately reducing polishing productivity and increasing costs. Furthermore, in this type of polishing device, increasing the contact pressure of the abrasive tool against the resin layer generally increases the resin removal efficiency, but this also leads to the problem of deformation or damage to the wiring board substrate.

[0007] JP 2013-254760 A JP 2009-182284 A JP 2004-95582 A

[0008] An object of one aspect of the present invention is to improve productivity, prevent damage to the substrate, or reduce costs in a resin removal step of removing at least a part of a resin layer formed on the surface of a substrate.

[0009] A method for manufacturing a wiring board according to an aspect of the present invention is a method for manufacturing a wiring board that performs a resin removal step of removing at least a part of a resin layer formed on the surface of a substrate. Before performing the resin removal step, a laser irradiation step of irradiating a laser to all or part of an area on the surface of the resin layer where resin is scheduled to be removed in the resin removal step is performed.

[0010] According to the above configuration, it is possible to improve the productivity of the resin removal step of removing at least a part of the resin layer formed on the substrate, prevent damage to the substrate, or reduce costs.

[0011] Cross-sectional view of the through-hole portion of the printed wiring board before performing the laser irradiation step according to the embodiment Cross-sectional view of the through-hole portion of the printed wiring board after performing the laser irradiation step Cross-sectional view of the through-hole portion of the printed wiring board after performing the resin removal step Top view showing the state before the resin is filled in the printed wiring board according to Embodiment 1 Top view showing the printed wiring board before the resin is filled and the laser irradiation step is performed Top view showing the printed wiring board after the laser irradiation step Cross-sectional view of the printed wiring board shown in FIG. 2A Cross-sectional view of the printed wiring board shown in FIG. 2B Cross-sectional view showing the printed wiring board during the laser irradiation step Cross-sectional view showing the printed wiring board during the resin removal step Cross-sectional view showing the printed wiring board after the resin removal step Block diagram of the laser irradiation device Top view of the printed wiring board according to Embodiment 2 after the resin is filled (before the laser irradiation step) Schematic diagram for explaining the main scanning and sub-scanning of the laser Schematic diagram showing the starting point, ending point of starting the laser irradiation, and the movement locus of the laser irradiation spot Cross-sectional view showing the state of irradiating the laser to the component-mounted substrate according to Embodiment 4 Perspective view of the semiconductor device according to Embodiment 5 Perspective view of the lead frame, IC chip, and die pad Cross-sectional view showing the state where the IC chip is mounted on the die pad and connected by bonding wires Cross-sectional view showing the lead frame, etc. before being housed in the mold and before the mold is closed Cross-sectional view showing the state where the mold resin is filled in the mold Cross-sectional view of the semiconductor device taken out of the mold Cross-sectional view showing the state of irradiating the laser to the semiconductor device Cross-sectional view of the semiconductor device after the laser is irradiated Block diagram of the resin removal device according to Embodiment 6

[0012] [Outline of the embodiment of the present disclosure] First, an outline of the embodiment of the present disclosure will be listed and described.

[0013] (1) A method for manufacturing a wiring board according to an embodiment is characterized in that, in a method for manufacturing a wiring board that performs a resin removal process to remove at least a portion of a resin layer formed on the surface of a substrate, before performing the resin removal process, a laser irradiation process is performed in which a laser is irradiated onto all or part of the area on the surface of the resin layer from which resin is to be removed in the resin removal process.

[0014] For example, in the field of manufacturing general printed wiring boards, in which a core substrate (an example of a substrate) is made of a material that combines glass fiber and epoxy resin, laser irradiation is sometimes used for so-called trepanning, in which a laser is focused on an extremely small area of ​​the core substrate for a short time of less than one second to vaporize the substrate material and create a hole, or for trimming metal layers.

[0015] However, in the laser irradiation step of this embodiment, the region where the resin is to be removed in the resin removal step is irradiated with a laser planarly or discretely at an energy density per area of ​​the region that is significantly lower than that of the above-mentioned trepanning process, etc. The energy density of the irradiation spot of the irradiated laser varies depending on various conditions such as the wavelength and output of the laser oscillation unit, irradiation time, and the type and shape of the resin that makes up the resin layer, and can be set appropriately depending on these conditions.

[0016] As an example, an RF excitation pulse CO ２ The laser has an energy density of 0.7 J / cm to 700 J / cm ２Examples of suitable methods include adjusting the laser output, irradiation spot diameter, and irradiation time so that the laser beam reaches a desired level. By irradiating the laser beam at this energy density over a surface area, only the surface of the resin layer is evaporated, leaving a portion of the resin layer on the core substrate, preventing damage to the core substrate or the resin in the through-holes. Even when irradiating with a high-energy laser, the energy density relative to the total area can be kept within the above-mentioned range by irradiating the area to be polished discretely. Furthermore, because the heat absorption efficiency of the laser is relatively high in the resin layer, a portion of the resin layer is immediately thermally decomposed and evaporated, or becomes brittle due to thermal degradation. Even when inorganic filler particles are included, the remaining resin layer that has not completely evaporated will have the filler particles released from the resin layer due to thermal decomposition of the resin, resulting in a porous surface.

[0017] 1A is a diagram, drawn with reference to an electron microscope photograph, of a cross section of a through-hole 3 portion of a printed wiring board 1. The diagram shows a state in which a resin 4 (containing filler particles 5) is filled into the through-hole 3 of a core substrate 2 made of a so-called glass epoxy resin, which is a material made by combining glass fiber and epoxy resin, and the resin layer 6 is cured in a state where it protrudes from the surface of the core substrate 2.

[0018] The resin layer 6 protruding from the core substrate 2 is polished by a polishing device to be flattened as shown in Fig. 1C. As shown in Fig. 1A, the surface of the resin layer 6 is relatively smooth. In conventional methods, the state shown in Fig. 1A is immediately followed by a resin removal process using a polishing device to remove the protruding portion and flatten it to the state shown in Fig. 1C.

[0019] 1B shows the state after the laser irradiation step of the present invention is performed. In the laser irradiation step, the CO 2 laser is applied from above to the area of ​​the resin layer 6 that is to be polished, as shown by the arrow in FIG. ２The laser is irradiated over the entire surface. It can be seen that the thermal energy of the laser vaporizes the resin layer 6 from the surface to a predetermined depth, thinning the resin layer 6 and roughening the surface of the remaining resin layer 6, weakening its structure. It can also be seen that many filler particles 5 have fallen off the resin layer 6, leaving numerous pits 7 where the filler particles 5 had left on the surface of the resin layer 6. If the resin removal process is carried out in this state, a polishing tool such as a buff roll will catch on the roughened surface of the resin layer 6, allowing for easy polishing. The fact that part of the resin layer 6 in the area to be polished has been vaporized by the laser irradiation also allows for rapid polishing.

[0020] The resin removal process can be performed not only by mechanical polishing, in which an abrasive such as a buff roll is brought into direct contact with the surface of the resin layer of the substrate, but also by non-contact methods such as the following. For example, wet blasting, in which a slurry of abrasive material dispersed in a liquid such as water is sprayed onto the surface of the substrate together with compressed air from a blast gun, or dry etching, in which no liquid is used, can be used. Examples of dry etching methods include gas etching, in which a gas such as hydrogen fluoride (HF) reactive with resin is supplied to remove the surface of the resin layer without using an abrasive; sputter etching, in which the substrate is placed in a vacuum chamber and ions of an inert gas such as argon (Ar) are accelerated by an electric field and collided with the surface of the resin layer to remove the surface of the resin; and reactive ion etching, in which a reactive gas capable of forming radicals reactive with the resin and argon ions are collided with the surface of the resin layer in a vacuum chamber to remove the resin by combining physical collisions of the ions with chemical reactions of the radicals.

[0021] In the laser irradiation process, it is beneficial to shorten the takt time of the laser irradiation process by making the laser irradiation spot as large as possible within the range in which the required energy density can be obtained. It is also desirable to scan the laser in two directions, X and Y, using, for example, a well-known X and Y two-axis galvanometer scanner mechanism so that the irradiation spot moves relative to the wiring board.

[0022] Furthermore, since the laser irradiation step described above allows the subsequent resin removal step to be carried out extremely efficiently, the pressure of the abrasive tool on the resin layer side can be reduced compared to conventional methods in the mechanical resin removal step using an abrasive tool. As a result, cracking of the substrate during the resin removal step can be prevented. This means that the substrate thickness can be made thinner than conventional methods, and that the method can also be applied to the manufacture of wiring substrates using glass substrates, which are more easily broken than organic material substrates because the substrate material itself is brittle. Thus, the wiring substrate manufacturing method described in (1) above can improve productivity in the resin removal step of removing at least a portion of the resin layer formed on the surface of the substrate, prevent damage to the substrate, and reduce costs.

[0023] In the laser irradiation step, the energy density of the laser irradiation spot on the resin layer should be set according to the materials of the resin layer and the filler. For example, in the case of a resin containing fillers such as silica or calcium carbonate, which is generally used in printed wiring boards using glass epoxy resin substrates, when a resin layer having a thickness of 1 mm is polished by successive treatments of the laser irradiation step and the resin removal step, the energy density is set to 0.7 J / cm. ２ ~700 J / cm ２ The numerical value is 0.7 J / cm ２ If the treatment efficiency is below 700 J / cm, the treatment efficiency will drop significantly and become unrealistic. ２ However, if the energy density exceeds this, the equipment cost and energy cost will become too high. According to experiments by the present inventors, an industrially reasonable range is 0.7 J / cm. ２ ~300 J / cm ２ is recommended, but a better range would be 0.7 J / cm ２ ~120 J / cm ２ The laser irradiation pattern can be, for example, a stripe-like irradiation with a width of 500 μm to 3000 μm.

[0024] (2) In the method for manufacturing a wiring board described in (1) above, the laser irradiation step may be characterized in that the laser is main-scanned so that the movement locus of the laser irradiation spot on the resin layer forms a band, and after the movement of the irradiation spot by the main scanning is completed, the laser is sub-scanned so that the movement locus of the irradiation spot by the next main scanning is shifted in a direction perpendicular to the movement locus of the irradiation spot by the previous main scanning, thereby repeating the main scanning, and the sub-scan is performed so that the movement locus of the irradiation spot in the main scanning direction partially overlaps or is lined up without any gaps with the movement locus of the irradiation spot by the previous main scanning.

[0025] As described above, when the movement locus of the irradiation spot in the main scanning direction overlaps with the movement locus of the irradiation spot from the previous main scanning, the laser is irradiated twice at the overlapping portion, and the second laser irradiation is performed while residual heat from the first laser irradiation remains, thereby increasing the utilization rate of thermal energy and making the laser irradiation process more efficient.

[0026] (3) In the method for manufacturing a wiring board described in (1) or (2) above, the board may include a recess for accommodating an electronic component, the electronic component accommodated in the recess, and a resin layer that fills the recess and covers the electronic component, and the laser irradiation step may involve irradiating a laser onto all or part of a region of the resin layer that protrudes from the recess.

[0027] In wiring boards in which electronic components are embedded in recesses, resins containing a large amount of filler are often used to fill the recesses. Therefore, such wiring boards are characterized by a hard resin layer. Therefore, conventional manufacturing methods have had the problem of making it difficult to remove the resin. According to the manufacturing method described in (3) above, a laser is irradiated from above onto all or part of the region of the resin layer that protrudes from the recess. Therefore, even for wiring boards with a hard resin layer, it is possible to improve productivity in the resin removal process, prevent damage to the substrate, and reduce costs in the resin removal process that removes at least a portion of the resin layer formed on the surface of the substrate.

[0028] (4) In the method for manufacturing a wiring board according to any one of (1) to (3) above, the substrate may be made of glass, and a protective layer may be formed on the substrate before the laser irradiation step to protect the substrate from laser irradiation.

[0029] As described above, any one of the wiring board manufacturing methods (1) to (3) can be applied to the manufacture of wiring boards using substrates that are prone to breakage due to the nature of the substrate material itself, such as glass, or to the manufacture of wiring boards using substrates made of well-known glass fiber-reinforced epoxy resin, which are prone to breakage due to their thinner thickness than conventional substrates. Experiments conducted by the present inventors have shown that the resin layer can be polished efficiently even with a lower polishing pressure than conventional mechanical polishing, thereby reducing the polishing pressure and reducing the stress acting on the substrate. The glass substrate may be made of not only a material primarily composed of inorganic glass, but also a material containing a ceramic powder or a substrate made by sintering glass powder and ceramic powder.

[0030] Furthermore, when a glass substrate is used, if a protective layer such as a platinum thin film is formed on the substrate by sputtering or the like before the resin layer is formed, the protective layer will reflect the laser, thereby preventing the glass substrate from being microcracked by the laser during the laser irradiation process. Note that the protective layer is not limited to platinum, and various metal thin films can be selected depending on the wavelength of the laser used, and examples thereof include gold and copper.

[0031] (5) In the method for manufacturing a wiring board described in any one of (1) to (4) above, after the laser irradiation step and the resin removal step are performed in sequence, the laser irradiation step and the resin removal step may be repeated again.

[0032] If the surface of the resin layer is roughened in the first laser irradiation step, a hard resin layer will appear when the surface layer of the resin layer is removed in the subsequent resin removal step, making it difficult for abrasive tools such as buff rolls to catch, and this can make it difficult to remove the resin efficiently. However, according to the manufacturing method described in (5) above, the laser irradiation step and the resin removal step are repeated, so even if a hard resin layer appears in the resin removal step, it can be roughened again in the next laser irradiation step. Therefore, the resin layer can be removed more efficiently than when the laser irradiation step and the resin removal step are each performed only once.

[0033] (6) The wiring board according to the embodiment is a wiring board having a resin layer on its surface, and at least a portion of the resin layer is to be removed, and the surface of the resin layer is roughened by irradiating a laser onto all or part of the area of ​​the resin layer from which the resin is to be removed.

[0034] According to the wiring board described in (6) above, since the surface is roughened, it is possible to provide a wiring board from which the resin can be easily removed to the recipient of the wiring board.

[0035] (7) A resin removal device for a wiring board according to an embodiment is a resin removal device that removes resin from a predetermined region of a resin layer of a wiring board having a resin layer on its surface, and includes a laser oscillator unit, a galvanometer scanner mechanism that reflects a laser output from the laser oscillator unit in a predetermined direction and moves the laser irradiation spot while irradiating it onto a predetermined surface region of the resin layer of the wiring board, and a resin removal function unit that removes at least a portion of the resin layer in the region where the laser irradiation has been completed.

[0036] According to the resin removal device described in (7) above, the surface of the resin layer is roughened by laser irradiation, so that the resin can be removed efficiently.

[0037] [Details of the embodiments of the present disclosure] Details of the embodiments of the present disclosure will be described. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. The embodiments of the present disclosure can be realized in various forms, such as an apparatus, a method, a computer program for implementing the functions of these apparatuses or methods, and a recording medium on which the computer program is recorded.

[0038] First Embodiment A first embodiment will be described with reference to Figures 1 to 4. In the following description, the reference numerals of the drawings may be omitted for the same components, with some exceptions.

[0039] [1] Wiring Board With reference to Fig. 2A, a printed wiring board 1 as a wiring board according to the first embodiment will be described. Fig. 2A shows the printed wiring board 1 in the middle of manufacture. The printed wiring board 1 is a printed wiring board for an integrated circuit package having a ball grid array. A semiconductor chip is mounted on the top surface of the printed wiring board 1, and electrical connection is made to lands (not shown) formed on the top surface of the printed wiring board 1 by a large number of solder balls. The semiconductor chip is further fixed onto the printed wiring board 1 with an adhesive, and a heat sink is adhered to the top surface of the semiconductor chip with an adhesive.

[0040] The core substrate 2 serving as the substrate of the printed wiring board 1 is made of glass epoxy resin. The core substrate 2 has through holes 3 formed at high density in a rectangular region indicated by dotted line 13. In the following description, the rectangular region indicated by dotted line 13 will be referred to as the high-density region 13. The multiple through holes 3 are arranged in a staggered pattern. The arrangement of the through holes 3 is not limited to a staggered pattern, and they may also be arranged in a matrix or randomly.

[0041] 2A will be described with reference to FIG. 3A. A double-sided copper-clad board with a thickness of approximately 0.1 mm to 8.0 mm is recommended as the printed wiring board 1. Through holes are formed in the core substrate 2 using a laser or drill, and inner surface plating 12 that is conductive to the copper foil 11 on both sides is applied to the inner wall surfaces of the through holes, thereby forming through holes 3 that electrically connect the copper foil 11 on both sides. The inner diameter of the through holes 3 is, for example, 150 μm.

[0042] [2] Filling Step The filling step of filling the through-holes 3 with the filler 4 will be described with reference to FIGS. 2B and 3B. Here, a resin-based filler (so-called resin-based ink) will be used as the filler 4. In the following description, the resin-based filler 4 will be simply referred to as resin 4. The resin 4 contains silica powder, but other fillers such as calcium carbonate, copper, and silver may also be used. The filler is not limited to resin-based. For example, the filler may be magnetic (so-called magnetic ink).

[0043] In the filling process, the resin 4 is filled using a vacuum printing machine. The vacuum printing machine is equipped with a screen plate and a squeegee that slides over the screen plate, inside a vacuum chamber maintained at a pressure sufficiently lower than atmospheric pressure. In the filling process, the printed wiring board 1 with the sealing film attached is placed on a flat jig. The printed wiring board 1 with the sealing film attached is positioned so that the sealing film side is in contact with the flat jig and the other surface on the opposite side (hereinafter referred to as the "front surface") is located below the screen plate.

[0044] The screen plate has large openings formed in a shape corresponding to the high-density regions 13. With the resin 4 supplied onto the screen plate, the vacuum printing machine lowers a squeegee to slide over the screen plate. This forces the resin 4 into the through-holes 3 through the screen plate, and the entire high-density regions 13 are covered with the resin 4. The sealing film has many pores formed therein. Therefore, when screen printing is performed on the printed wiring board 1 in the vacuum printing machine, as the resin 4 is forced into the through-holes 3, the small amount of gas remaining in the through-holes 3 is discharged into the vacuum chamber through the pores. This allows the resin 4 to smoothly fill the through-holes 3 until it reaches the sealing film. The printed wiring board 1 is then removed from the vacuum printing machine, and the sealing film is peeled off from the printed wiring board 1.

[0045] [3] Filler Hardening Process Next, the printed wiring board 1 after the auxiliary filling process is removed from the vacuum printer and heated or irradiated with ultraviolet light. This completely hardens the resin 4. As shown in FIG. 3B, the filler hardening process forms hard resin layers 6 on both sides of the core substrate 2. The formed resin layers 6 are polished in their entirety in the planarization process described below. The entire resin layer 6 is an example of the area of ​​the surface of the resin layer that will be polished in the resin removal process.

[0046] As shown in FIG. 3B, the resin layer 6 is raised at the positions where the through holes 3 are located, so the surface of the resin layer 6 is uneven, but because the surface is formed by hardening the fluid resin 4, it can be said to be a smooth surface when viewed microscopically.

[0047] [4] Laser Irradiation Step The laser irradiation step will be described with reference to Figures 2C and 3C. In the laser irradiation step according to embodiment 1, a laser is irradiated onto a portion of the high-density region 13 (the region where the resin is to be removed). The circle 15 shown by a solid line in Figure 2C indicates the irradiation spot where the laser is irradiated. In the laser irradiation step according to embodiment 1, the laser is irradiated onto the periphery of the region where the portion protrudes from the through-hole 3 (protruding portion). In other words, the laser is irradiated onto the region where the portion does not protrude from the through-hole 3. The diameter of the laser irradiation spot is, for example, 340 µm, which is smaller than the distance between two adjacent through-holes 3.

[0048] If a position where a laser is spot-irradiated is defined as one laser irradiation position, the laser may be irradiated discretely so that two laser irradiation positions do not overlap, or may be irradiated so that two laser irradiation positions overlap.

[0049] As shown in FIG. 3C , when the laser 16 is irradiated, the surface of the resin layer 6 evaporates. The laser 16 is set to a required energy density by adjusting the laser output and irradiation time so that the entire thickness of the resin layer 6 does not evaporate. Therefore, a certain thickness of the resin layer 6 remains at the position irradiated by the laser 16. The position irradiated by the laser 16 is not limited to the example described above and can be appropriately determined so that the resin layer 6 is suitably polished in the planarization process described below. The same applies to the output conditions of the laser 16. The reason for setting the laser irradiation position away from the through-hole 3 is to reduce the risk of excessive laser irradiation adversely affecting the resin 4 filling the through-hole 3. In areas other than the through-hole 3, copper foil that reflects the laser is present under the resin layer 6, so no adverse effects on the board occur.

[0050] [5] Planarization Step: Referring to FIG. 3D , the planarization step performed after the laser irradiation step will be described. The planarization step is an example of a resin removal step in which the surface of the resin layer is mechanically polished. In the planarization step, after the laser irradiation step, both surfaces of the printed wiring board 1 are polished, for example, by a buffing machine using buff rolls 20. The protruding portions of the through-holes 3 on both surfaces of the printed wiring board 1 are removed, resulting in the entire surfaces of the printed wiring board 1 being planarized, as shown in FIG. 3E .

[0051] Although not shown, the buffing machine transports the printed wiring board 1 in a predetermined direction on rollers, and includes multiple buff rolls 20 having rotation axes that extend along the surface of the printed wiring board 1 and in a direction perpendicular to the transport direction. The buff rolls 20 are arranged on both the top and bottom sides of the printed wiring board 1, with multiple buff rolls (e.g., two on each side) spaced apart in the transport direction of the printed wiring board 1. The printed wiring board 1 is transported from left to right on the page by a transport device (not shown) and polished by the multiple buff rolls 20. When polished by each buff roll 20, an abrasive is supplied, and the printed wiring board 1 is supported by a backup roll provided on the opposite side of the buff roll 20.

[0052] [6] Laser Irradiation Device The laser irradiation device 30 will be described with reference to Fig. 4. The laser irradiation device 30 is a scanning type laser irradiation device having a galvano scanner mechanism. The laser irradiation device 30 includes a control unit 31, a laser oscillation unit 32, a galvano scanner mechanism 33, and a galvano scanner control unit 35.

[0053] The laser oscillator 32 is a type of gas laser, CO ２ This is a device that outputs a laser. The laser that is output is CO ２ The laser is not limited to a laser, and may be another gas laser, a solid-state laser, a fiber laser, a semiconductor laser, or the like.

[0054] The galvanometer scanner mechanism 33 is a two-axis galvanometer scanner mechanism that reflects the laser output from the laser oscillator 32 in a predetermined direction and moves the laser irradiation spot while irradiating it onto a predetermined surface area of ​​the resin layer 6 of the printed wiring board 1. The galvanometer scanner mechanism 33 includes an X-axis galvanometer mirror 33A rotatably supported about an X-axis (e.g., a horizontal axis), an X-axis motor 33B that rotates the X-axis galvanometer mirror 33A, a Y-axis galvanometer mirror 33C rotatably supported about a Y-axis (e.g., a vertical axis) perpendicular to the X-axis, a Y-axis motor 33D that rotates the Y-axis galvanometer mirror 33C, and an fθ lens 33E. The fθ lens 33E is a lens that focuses the laser reflected by the galvanometer mirror to create an irradiation spot.

[0055] The control unit 31 includes a CPU, RAM, a storage unit, etc. The CPU executes a control program stored in the storage unit to control each unit of the laser irradiation device 30. The galvanometer scanner control unit 35 is a control unit that controls the rotation of the X-axis motor 33B and the Y-axis motor 33D under the control of the control unit 31. The laser irradiation device 30 can scan a laser irradiation spot in two directions, X and Y, over a required area on the printed wiring board 1 by changing the angles of the X-axis galvanometer mirror 33A and the Y-axis galvanometer mirror 33C.

[0056] Although the galvanometer scanner mechanism 33 is a two-axis type here, it is not limited to this, and a three-axis type galvanometer scanner mechanism that can move the irradiation spot in the direction along the optical axis of the laser may also be used. In particular, when the printed wiring board 1 is large in size, adjustment in the direction along the optical axis of the laser is effective, so a three-axis type galvanometer scanner mechanism is preferable.

[0057] [7] Effects of the Embodiments According to the wiring board manufacturing method of the first embodiment, the resin layer 6 is irradiated with a laser, and the surface of the resin layer 6 in the irradiated portion evaporates and becomes thinner. Furthermore, the remaining surface of the resin layer 6 is weakened and roughened by thermal energy. Therefore, when the rotating buff roll 20 comes into contact with the resin during the planarization process (resin removal process), the buff roll 20 catches on the resin layer 6 more, resulting in efficient polishing of the resin layer 6. This reduces the number of times the buff roll 20 needs to be replaced or the number of times the buff roll 20 needs to be regenerated during the planarization process, thereby improving polishing productivity and reducing costs. Furthermore, the ease of polishing improves polishing efficiency without increasing the contact pressure of the buff roll 20 against the resin layer 6. This also reduces deformation and damage to the core substrate 2. Therefore, the wiring board manufacturing method of the first embodiment improves productivity in the planarization process of polishing the resin layer 6 formed on the surface of the core substrate 2, prevents damage to the core substrate 2, and reduces costs.

[0058] The printed wiring board 1 according to the first embodiment may be a printed wiring board that is provided to another business (receiver) as an intermediate product after being irradiated with a laser, and that is scheduled to undergo a planarization process (mechanical polishing of the surface of the resin layer 6) by the other business. Even in this case, the printed wiring board 1 provided as an intermediate product has the resin layer 6 on its surface, and the surface of the high-density region 13 (the region of the resin layer 6 that is scheduled to be polished) is roughened by being irradiated with a laser, so that the recipient of the printed wiring board 1 can be provided with a printed wiring board 1 that is easy to polish.

[0059] 5 and 6, a laser irradiation step according to embodiment 2 will be described. The printed wiring board 1, laser irradiation device, and buffing machine according to embodiment 2 are substantially the same as those of embodiment 1. In the laser irradiation step according to embodiment 2, the laser is continuously (planarly) irradiated onto the entire high-density region 13 (the region from which the resin is to be removed).

[0060] 5 is a top view of the printed wiring board 1. In FIG. 5, a rectangular area 40 indicated by a dashed line indicates a laser irradiation area according to the second embodiment. The laser irradiation area 40 surrounds the high-density area 13 and is slightly larger than the high-density area 13. In the laser irradiation step according to the second embodiment, the laser is irradiated planarly onto the laser irradiation area 40. Therefore, the laser is irradiated onto the entire high-density area 13 as well as the outside of the high-density area 13.

[0061] 6A, each of the multiple straight lines 41 represents one main scan of the laser. In the laser irradiation process according to the second embodiment, the laser is main-scanned so that the movement locus (main-scanning region) of the laser irradiation spot on the resin layer 6 forms a band, and after the movement of the irradiation spot by the main scan is completed, the laser is sub-scanned so that the movement locus of the irradiation spot by the next main scan is shifted in a direction perpendicular to the movement locus of the irradiation spot by the previous main scan, thereby repeating the main scan, and the sub-scan is performed so that the movement locus of the irradiation spot in the main scanning direction partially (for example, 30 to 70%) overlaps with the movement locus of the irradiation spot by the previous main scan.

[0062] Each main scan has a starting point where laser irradiation starts and an ending point where laser irradiation ends. In the laser irradiation process according to the second embodiment, the starting point is aligned on the opposite side of the ending point in each main scan. In other words, the main laser scan is always performed in the same direction (forward in this case). The reason for this will be explained later.

[0063] A more specific explanation will be given with reference to Figure 6B. Here, an example will be explained in which the overlap of the movement trajectories described above is 50%. The circle 42 shown in Figure 6B indicates the irradiation spot at the starting point of the first main scanning pass. The entire irradiation spot at the starting point is located behind the high-density region 13. In this case, the center of the irradiation spot is located on an extension of the right side of the high-density region 13. Therefore, during the first main scanning pass, the left half of the irradiation spot moves over the high-density region 13.

[0064] 6B indicates the irradiation spot at the first end point. The entire irradiation spot at the end point is located in front of the high-density region 13. When the irradiation spot reaches the end point, laser irradiation is stopped, and the irradiation spot is directed toward the starting point of the second main scan.

[0065] Circle 44 indicates the irradiation spot at the starting point of the second main scan. The starting point of the second main scan is a position moved to the left from the starting point of the first main scan by the radius of the irradiation spot. Therefore, the left half of the movement trajectory of the first irradiation spot is also irradiated with the laser in the second main scan. For this reason, the overlap is 50%. The same is true for the third and subsequent main scans. Because the overlap of the movement trajectories is 50%, the entire high-density region 13 is irradiated with the laser twice in the laser irradiation process according to embodiment 2.

[0066] Although the main scanning direction is illustrated as the front-to-rear direction here, the main scanning direction is not limited to this. For example, the main scanning direction may be left-to-right or diagonal. The center of the irradiation spot at the starting point of the first main scanning pass does not have to be located on an extension of the right side of the high-density region 13. For example, the center of the irradiation spot may be located to the right of the extension of the right side. Even in this case, the entire high-density region 13 is irradiated with the laser twice. If the left and right edges of the high-density region 13 need only be irradiated with the laser once, or if they do not need to be irradiated at all, the center of the irradiation spot at the starting point of the first main scanning pass may be located to the left of the extension of the right side. The starting point or end point of the main scanning pass may be partially or entirely located on the high-density region 13.

[0067] The reason why the starting point of each main scan is aligned on the opposite side of the end point (here, the rear side) is explained below. For example, it is possible to reverse the direction for each main scan, such as performing the first main scan from rear to front and the second main scan from front to rear. However, if this is done, heat from the first main scan is trapped at the front end of the second main scan, resulting in a temperature difference between the front and rear ends of the movement trajectory when the second main scan is performed, and this results in a difference in the amount of resin 4 that evaporates and becomes weak. In contrast, if the main scan of the laser is always performed in the same direction, the temperature when the second laser irradiation is performed is approximately constant at any position on the movement trajectory. This makes it possible to suppress differences in the amount of resin 4 that evaporates and becomes weak.

[0068] According to the method for manufacturing a wiring board of the second embodiment, there is an overlapping portion in the main scanning movement trajectory, so the laser is irradiated twice at that overlapping portion, and the second laser irradiation is performed while residual heat from the first laser irradiation remains, which increases the utilization rate of thermal energy and makes the laser irradiation process more efficient.

[0069] According to the method for manufacturing a wiring board of the second embodiment, the starting point is aligned on the opposite side of the end point in each main scan, so that differences in the amount of resin 4 that evaporates and becomes weak can be suppressed.

[0070] The printed wiring board 1 according to the second embodiment may also be a printed wiring board that is provided to another business (recipient) as an intermediate product after being irradiated with a laser, and for which a planarization process (mechanical removal of resin from the surface of the resin layer 6) is planned to be performed by the other business.

[0071] In particular, with carbon dioxide lasers, laser output tends to overshoot immediately after irradiation begins and then stabilize. In such cases, the amount of resin evaporated and weakened near the starting point of the main scan is slightly greater than when the laser output is stable. Maintaining this amount of resin evaporation and weakening as uniform as possible across the entire laser irradiation area increases the efficiency of the subsequent resin removal process. Therefore, if such a laser output tendency exists, it is desirable to alternately reverse the starting and ending points of laser irradiation for each main scan. That is, for example, after the first main scan is performed in one direction from the starting point to the ending point, the second main scan is performed from the end point of the first scan toward the starting point of the first main scan. This ensures that the areas with high amounts of resin evaporated and weakened are evenly distributed across the entire substrate, allowing for an efficient resin removal process.

[0072] <Embodiment 3> A printed wiring board according to embodiment 3 has a core substrate made of glass. In recent years, there has been a demand for using glass as the material for core substrates. When attempting to manufacture a wiring board using a glass core substrate (hereinafter simply referred to as a glass substrate) having through holes 3 by a conventional manufacturing method (i.e., a manufacturing method that does not include a laser irradiation step), there has been a problem in that the glass substrate is prone to cracking during the planarization step.

[0073] For this reason, the inventors of the present application conducted a test in which the manufacturing method described in Embodiment 2 was applied to a glass substrate. In this test, a thin platinum film was formed as a protective layer on the glass substrate by sputtering, and then a resin layer was printed and cured. The test conditions are as follows:

[0074] Glass substrate size = 75 x 52 mm, thickness 1.27 mm Coating resin size = 57 x 33 mm, thickness 0.1 mm (100 μm) Laser type = RF excitation pulse CO ２ Laser Laser wavelength = 9.4 μm Laser spot diameter = 500 μm Filler = Resin (so-called resin-based ink)

[0075] The test results can be summarized as follows: - By making the resin layer thinner in the laser irradiation process, it was possible to reduce the pressure applied to the glass substrate in the planarization process. This prevented damage to the glass substrate. - Because the surface of the glass substrate diffuses the laser, the laser did not affect the glass substrate. - The thickness of the resin layer was reduced from 100 μm to less than 4 μm after the laser irradiation process. - Because the platinum protective layer reflects the laser and protects the glass substrate, it was possible to prevent microcracks from occurring on the glass substrate due to laser irradiation.

[0076] From the above results, it was found that the manufacturing method described in embodiment 2 can also be suitably applied to glass substrates. Here, the case where the manufacturing method in embodiment 2 is applied to a glass substrate has been exemplified, but the manufacturing method in embodiment 1 can also be applied to a glass substrate.

[0077] Fourth Embodiment A printed wiring board 50 according to a fourth embodiment will be described with reference to Fig. 7 . The printed wiring board 50 is a component-embedded substrate (hereinafter referred to as component-embedded substrate 50) including a recess 52 for accommodating an electronic component 51, the electronic component 51 accommodated in the recess 52, and a resin layer 6 filled in the recess 52 and covering the electronic component 51. In manufacturing the component-embedded substrate 50, a resin adhesive film 53 is attached to the lower surface of the core substrate 2 to close the lower opening of the through hole 3, thereby forming a bottomed recess 52. Then, the electronic component 51, such as a resistor or a capacitor, is accommodated in the recess 52, and in this state, the recess 52 is filled with resin 4, thereby covering the electronic component 51 with the resin layer 6.

[0078] In the laser irradiation step according to the fourth embodiment, a laser is irradiated from above the region of the resin layer 6 that protrudes from the recesses 52. The laser irradiation may be performed planarly (continuously) on the region that includes a plurality of recesses 52 (for example, the high-density region 13 in the second embodiment), or may be performed in a scattered manner on all or part of the region that protrudes from the recesses 52.

[0079] According to the method for manufacturing a wiring board of embodiment 4, a laser is irradiated from above onto all or part of the area of ​​the resin layer 6 that protrudes from the recess 52. Therefore, even in the case of a component-embedded substrate 50 that is characterized by a hard resin layer 6, it is possible to improve productivity in the planarization process, prevent damage to the substrate, and reduce costs.

[0080] 8 to 10 , a method for manufacturing a wiring board according to a fifth embodiment will be described. As shown in Fig. 8A , a wiring board 60 according to the fifth embodiment is a QFP (Quad Flat Package) type semiconductor device (hereinafter referred to as semiconductor device 60). As shown in Fig. 8B , semiconductor device 60 has a well-known configuration in which an IC chip 64 is fixed on a die pad 63 of a lead frame 62 (an example of a substrate), bonding pads (not shown) on IC chip 64 are connected to the chip side of lead terminals 61 with bonding wires 65 (see Fig. 9A ), and then IC chip 64 and bonding wires 65 are resin-molded.

[0081] In manufacturing the semiconductor device 60, a lead frame 62 (see FIG. 9A ) having an IC chip 64 mounted on a die pad 63 and connected with bonding wires 65 is placed in a mold 66 as shown in FIG. 9B , and mold resin 67 is filled into the mold 66 as shown in FIG. 9C . As shown in FIG. 9D , the semiconductor device 60 removed from the mold 66 has a resin layer (hereinafter referred to as the resin layer 67) made of the mold resin 67 formed on both the top and bottom surfaces of the lead frame 62 serving as a substrate. The resin layer 67 on the bottom side (the surface opposite the surface on which the IC chip 64 is mounted) is polished and removed to the extent that it reaches the surface of the lead frame 62 in order to thin the semiconductor device 60.

[0082] In the method for manufacturing a wiring board according to the fifth embodiment, a laser irradiation step is performed in which the laser irradiation device 30 performs a planar (continuous) irradiation by scanning a laser irradiation spot in the X-Y directions over the entire surface of the lower resin layer 67 (see FIG. 10A). By performing laser irradiation with an appropriate energy density, the resin layer 67 evaporates from the surface and becomes thinner, and the surface of the remaining resin layer 67 becomes rough (weakened) (see FIG. 10B). For example, the resin layer 67, which has a thickness of about 100 μm, can be thinned to 10 μm to several μm.

[0083] Thereafter, the roughened surface of resin layer 67 can be polished quickly by buffing. Furthermore, since the pressure of the buff roll on resin layer 67 can be reduced, adverse effects of buffing pressure on lead frame 62 and IC chip 64 can be suppressed. Note that while a QFP-type semiconductor device 60 is exemplified as the wiring substrate here, the semiconductor device as the wiring substrate is not limited to this and may be a small outline package (SOP)-type semiconductor device, or a small outline non-leaded package (SON) or quad flat non-leaded package (QFN), which are so-called leadless types in which the leads of the lead frame are removed and exposed as electrodes on the package surface.

[0084] Sixth Embodiment A sixth embodiment will be described with reference to FIG. 11 . A resin removal apparatus 80 according to the sixth embodiment is a resin removal apparatus that mechanically polishes a predetermined region of a resin layer of a wiring board having a resin layer on its surface, and is suitable for implementing a wiring board manufacturing method that involves a laser irradiation process. A well-known conveying device 84 that conveys a work table 83 from left to right in the figure is provided within a housing 82 supported by a frame 81. A wiring board (not shown) serving as a processing object can be fixed to the work table 83. A supply stage 85 that conveys the work table 83 toward the conveying device 84 is provided on the left side of the housing 82, and an unloading stage 86 that unloads the polished printed wiring board 1 using the conveying device 84 is provided on the right side of the housing 82.

[0085] A laser irradiation device 87 similar to the laser irradiation device 30 described above is disposed in the left side area (upstream area of ​​the conveying device 84) within the housing 82. The laser irradiation device 87 is a CO ２ The laser irradiation device 87 is equipped with a laser oscillator 32 that outputs a laser, a well-known galvanometer scanner mechanism 33 that reflects the laser, and the laser irradiation spot can be scanned in two directions, X and Y, over a desired area on the wiring board. The configuration of the laser irradiation device 87 is substantially the same as that of the laser irradiation device 30 described above, so a detailed description will be omitted.

[0086] A buffing device 90 of well-known construction is provided in the right-hand region of the housing 82 (the region downstream of the conveying device). This device polishes the surface of a wiring board by sandwiching it between a lower backup roll 91 and an upper buff roll 92 (an example of a polishing tool). In this embodiment, two pairs of buff rolls 92 and backup rolls 91 are provided, forming a biaxial configuration. The buffing device 90, which serves as a resin removal function, mechanically polishes the resin layer in the region where laser irradiation has been completed. Note that the resin removal function is not limited to a device that performs mechanical polishing, and dry etching methods such as the wet blasting method already exemplified, gas etching method, sputter etching method, and reactive ion etching method can also be used.

[0087] Dust collection hoods 94 are provided within the housing 82 above the laser irradiation device 87 and above the buffing device 90, and the dust collection hoods 94 are provided with dust collection ducts 95 and dust collection fans 96 connected thereto. By activating the dust collection fans 96, air currents are generated above the laser irradiation device 87 and above the buffing device 90, and dust generated during the laser irradiation process and / or the planarization process by the buffing device 90 can be collected in a dust collection filter (not shown). It is also effective to provide a blower that blows air or gas to remove dust and gas generated from the laser-irradiated substrate from the laser irradiation optical path.

[0088] Although shown simply in FIG. 11, an airtight wall 100 equipped with an airlock door that allows the work table 83 to pass from left to right as needed is provided between the laser irradiation device 87 and the buffing device 90, so that the desired temperature and humidity can be maintained on the side of the laser irradiation device 87 during the laser irradiation process.

[0089] According to the resin removal device 80 of the sixth embodiment, the surface of the resin layer 6 is roughened by laser irradiation, which makes it easier to polish the surface with the buffing device 90 .

[0090] Seventh Embodiment A wiring board manufacturing method according to a seventh embodiment is a method of manufacturing a wiring board according to any one of the first to fifth embodiments, in which the laser irradiation step and the planarization step (resin removal step) are sequentially performed, and then the laser irradiation step and the planarization step are repeated again. Specifically, for example, in the seventh embodiment, a plurality of resin removal devices 80 described in the sixth embodiment are arranged along the direction in which the wiring board is transported, and the laser irradiation step and the planarization step are repeated by these resin removal devices 80. The steps may be repeated by repeatedly passing one wiring board through one resin removal device 80.

[0091] According to the method for manufacturing a wiring board of the seventh embodiment, the laser irradiation step and the planarization step are repeated, so that the surface of the resin layer 6 (or the resin layer 67), which has been polished in the planarization step until it is difficult for the buff roll to catch on it, can be roughened again in the laser irradiation step. Therefore, compared to when the laser irradiation step and the planarization step are each performed only once, the resin can be removed more efficiently, or adverse effects on the substrate can be suppressed by keeping the energy density of the laser irradiation low in one laser irradiation step.

[0092] <Other Embodiments> The technology disclosed in this specification is not limited to the embodiments described above and in the drawings, and for example, the following embodiments are also included in the technical scope disclosed in this specification.

[0093] (1) In the above embodiment, an example was given of a case where a sub-scan is performed so that the movement trajectory of the irradiation spot in the main scanning direction partially overlaps with the movement trajectory of the irradiation spot in the previous main scanning. However, the movement trajectories of the main scanning do not necessarily have to overlap, and the two movement trajectories may be adjacent to each other with no gaps between them, or may be parallel with a specified gap between them.

[0094] (2) In the above embodiment, the starting point of each main scan is aligned on the opposite side of the end point, but the starting points do not have to be aligned. For example, the direction of each main scan may be reversed, such as performing the first main scan from back to front and the second main scan from front to back.

[0095] (3) In the above embodiment, the buffing resin removal method was exemplified as a method for removing at least a portion of the resin layer, but this is not limited to this. It may also be a CMP resin removal method in which a removal pad is rotated on a rotation axis perpendicular to the workpiece and pressed against the workpiece, and a remover and chemical solution are supplied to mechanically and chemically remove the resin, or a lap resin removal method in which a slurry containing abrasive grains is poured between a rotating flat surface plate and the workpiece to remove the resin. According to the present invention, since the resin is weakened by the laser irradiation process, it is easy to remove the resin. Therefore, not only the above-mentioned method of mechanically polishing the resin layer by bringing an abrasive tool into contact with the resin layer, but also the wet blasting method already exemplified can be used to polish a resin layer of 20 μm or more.

[0096] (4) In the seventh embodiment, the combination of the laser irradiation step and the resin removal step is repeated twice, but this is not limiting. The resin removal step may be performed first, and then the laser irradiation step and the resin removal step may be performed. In short, if the laser irradiation step is performed before the resin removal step, the load of the resin removal step is significantly reduced.

[0097] (5) In the above embodiment, typical steps other than the laser irradiation step and the resin removal step were given as examples of various steps in manufacturing a wiring board. However, there are no particular restrictions on the implementation of the present invention. For example, the method of forming the resin layer is not limited to the so-called vacuum printing method, and it may be general printing under atmospheric pressure. The method of filling the through-holes with resin may be a method in which resin filling is completed in a single printing step without performing the auxiliary filling step exemplified in embodiment 1.

[0098] (6) In the third embodiment, when the present invention is applied to a method for manufacturing a wiring board using a glass substrate, a protective layer is formed on the glass substrate and then a resin layer is formed on the glass substrate. However, the formation of a protective layer is not essential. This is because the glass substrate is not necessarily adversely affected by laser irradiation, depending on various conditions such as the laser frequency and the material of the glass substrate.

[0099] 1: Printed wiring board (an example of a wiring board) 2: Core board (an example of a board) 3: Through hole 6: Resin layer 13: High-density area (an example of an area from which resin is to be removed) 16: Laser 20: Buff roll (an example of a polishing tool) 32: Laser oscillator 33: Galvano scanner mechanism 50: Component-embedded board (an example of a wiring board) 51: Electronic component 52: Recess 60: Semiconductor device (an example of a wiring board) 62: Lead frame (an example of a board) 67: Resin layer 80: Resin removal device 90: Buff polishing device (an example of a resin removal function part) 92: Buff roll (an example of a polishing tool)

Claims

1. A method for manufacturing a wiring board that includes a resin removal process for removing at least a portion of a resin layer formed on the surface of a substrate, and a laser irradiation process for irradiating with a laser all or part of the area on the surface of the resin layer from which resin is to be removed in the resin removal process, before the resin removal process is performed.

2. A method for manufacturing a wiring board as claimed in claim 1, wherein the laser irradiation step comprises main scanning the laser so that the movement locus of the laser irradiation spot on the resin layer forms a band, and after the movement of the irradiation spot by the main scanning is completed, sub-scanning is carried out so that the movement locus of the irradiation spot by the next main scanning is shifted perpendicularly to the movement locus of the irradiation spot by the previous main scanning, thereby repeating the main scanning, and the sub-scanning is carried out so that the movement locus of the irradiation spot in the main scanning direction partially overlaps or is lined up without any gaps with the movement locus of the irradiation spot by the previous main scanning.

3. A method for manufacturing a wiring board according to claim 1 or 2, wherein the board comprises a recess for accommodating an electronic component, the electronic component accommodated in the recess, and a resin layer filling the recess and covering the electronic component, and the laser irradiation step irradiates a laser onto all or part of the area of ​​the resin layer that protrudes from the recess.

4. A method for manufacturing a wiring board according to claim 1 or claim 2, wherein the substrate is made of glass, and a protective layer is formed on the substrate before the laser irradiation step to protect the substrate from laser irradiation.

5. A method for manufacturing a wiring board according to claim 1 or 2, wherein the laser irradiation step and the resin removal step are carried out in order, and then the laser irradiation step and the resin removal step are repeated again.

6. A wiring board having a resin layer on its surface, at least a portion of which is to be removed, in which the surface of the resin layer is roughened by irradiating all or part of the area of ​​the resin layer from which the resin is to be removed with a laser.

7. A resin removal device for removing resin from a predetermined region of a resin layer of a wiring board having a resin layer on its surface, comprising: a laser oscillator; a galvanometer scanner mechanism that reflects a laser output from the laser oscillator in a predetermined direction and moves the laser irradiation spot while irradiating the predetermined surface region of the resin layer of the wiring board; and a resin removal function unit that removes at least a portion of the resin layer in the region where the laser irradiation has been completed.