TWI394505B - Method for manufacturing multilayer wiring board - Google Patents

Description

Method for manufacturing multilayer wiring board

The present invention relates to a method of manufacturing a multilayer wiring substrate, and more particularly to an annealing step of a material for a substrate.

In recent years, with the miniaturization of electrical equipment, electronic equipment, and the like, miniaturization and high density have been demanded in wiring boards mounted on these apparatuses. In order to meet the needs of the market, the multilayer technology of wiring boards is being studied. As a method of multilayering the wiring substrate, a so-called build-up method is generally employed in which a resin 'insulating layer and a conductor layer are alternately laminated on the front and back surfaces of the core substrate.

In the case of manufacturing such a multilayer wiring board, a copper-clad laminate having a structure in which a copper foil is attached to both surfaces of a resin substrate as a core substrate is generally used. In the multilayer wiring board, in order to alleviate the internal stress generated when the copper foil is attached to the resin substrate, an annealing treatment (heat treatment) for heating the copper clad laminate is performed (for example, see Patent Document 1). Thereafter, the copper foil of the copper clad laminate is etched and patterned to form a conductor layer.

[Patent Document 1] JP-A-2003-324260

However, in the conventional annealing treatment, for example, in the hot air drying device 51, a plurality of copper clad laminates 48 are arranged to be laid flat (horizontal) so as to constitute the glass of the resin material of the copper clad laminate 48. The temperature above the transfer point is heated for a predetermined time (see, for example, Fig. 19). When this is heated, each of the copper clad laminates 48 is prevented from being bent by its own weight, so that there is no gap. Configured in a state of coincidence. In this case, heat is not uniformly transferred to all of the substrates, and the substrate on the outer side and the substrate on the inner side differ in temperature retention time (holding time of temperature above the glass transition point). This high-temperature holding time is different, and the shrinkage amount of the core substrate in the subsequent step (layering step of the build-up layer, etc.) is different, and the uneven shrinkage of the substrate is enlarged. As a result, when the exposure mask is provided, it is difficult to accurately align the wiring pattern of the lower layer, and it is not possible to make the wiring pattern fine.

The present invention has been made in view of the above problems, and an object of the invention is to provide a method for manufacturing a multilayer wiring board, which can uniformly transfer heat to a plurality of core substrates in an annealing step, thereby reducing shrinkage unevenness of the substrate.

As a means for solving the above-described problems (method 1), there is a method of manufacturing a multilayer wiring board in which a conductor layer of a laminated wiring portion is disposed on a core substrate having a core substrate conductor layer A laminated wiring portion in which an interlayer insulating layer is laminated, the manufacturing method characterized by comprising: a preparation step of preparing a plurality of cores by attaching a metal foil to a main surface of an insulating substrate including a resin material a material for a core substrate; an annealing step of heating a plurality of materials for the core substrate in a state in which a gap is provided between the plurality of core substrate materials; and a core substrate conductor layer forming step After the annealing step, the metal foil is patterned to form the core substrate conductor layer.

Therefore, in the manufacturing method of the multilayer wiring board of the means 1, in the preparation step, a metal foil is attached to the main surface of the insulating substrate including the resin material, thereby preparing a plurality of materials for the core substrate. Then, in the annealing step, a state in which a space is provided between a plurality of materials for the core substrate Heating of a plurality of materials for the core substrate is performed. In this manner, since voids are provided between the respective core substrate materials, heat is uniformly transferred to the respective core substrate materials, so that uneven shrinkage of the insulating substrate can be reduced.

In the annealing step of the method for manufacturing a multilayer wiring board of the means 1, the gap between the plurality of core substrate materials can be arranged in any state, but it is preferably in a state of being erected, for example. This is because in the case of such a configuration, it becomes easy to provide a space between a plurality of materials for the core substrate. Further, a plurality of materials for the core substrate are preferably placed in the longitudinal direction in a state in which a space is provided between the plurality of core substrates. In this case, unlike the case where the gap is provided in the lateral direction, it is possible to prevent the insulating substrate from being bent. Therefore, in the core substrate conductor layer forming step, when the metal foil is patterned, the exposure mask can be accurately placed, and the alignment of the wiring pattern can be performed with high precision. As a result, the wiring pattern of the core substrate conductor layer can be made fine. Further, it is also possible to hang a plurality of materials for the core substrate in an upright state, but it can be stably arranged in an upright state supported on any of the supports (that is, in the longitudinal direction).

Further, in the annealing step, it is preferable that the material main faces of the plurality of core substrate materials face each other and are arranged in parallel. According to this configuration, since the flow direction of the hot air becomes fixed and the hot air can smoothly pass through the gap, heat can be uniformly transferred to the material for each core substrate. In this case, by fixing the gap, it is possible to surely reduce the heating unevenness of each of the plurality of core substrate materials.

In the annealing step, it is preferable that the plurality of core substrate materials are heated to a temperature equal to or higher than a glass transition point of the resin material, and it is preferred to heat at a temperature equal to or higher than the glass transition point for 240 minutes or longer. In the foregoing When the metal foil is attached in the preparation step, internal stress remains in the material for the core substrate, but the internal stress can be surely released by heating to a temperature higher than the glass transition point of the resin material. Further, the glass transition point of the resin material refers to a temperature at which a resin material having a glassy hard and fragile property in a low temperature region changes to a rubbery state as the temperature rises.

In the annealing step, it is preferable to use a substrate supporting tool which is composed of a heat-resistant material which can withstand the temperature above the glass transition point of the resin material, and which is supported in the longitudinal direction to support the plurality of materials for the core substrate. Heat up. As the substrate supporting tool, for example, a scaffold or the like including a frame (frame) composed of a heat-resistant material such as stainless steel or ceramics can be cited. In the annealing step, it is preferable not to cover as much as possible. A structure for heating hot air for a material for a core substrate.

It is preferable that the substrate supporting device has a space holding portion for securing the gap between the plurality of core substrate materials. Examples of the space-retaining portion include a guide member formed of a wire portion formed in a frame body of the substrate supporting device and a wire member fixed to the frame body.

In the annealing step, it is preferable that the plurality of core substrate materials are disposed in the hot air drying device, and the materials for the core substrates are heated by blowing hot air. Preferably, in the hot air drying device, the plurality of the core substrates are used. The core substrate material is configured to be heated parallel to the hot air direction. When the materials for the core substrates are arranged in this manner, the hot air can pass through the gaps between the materials, and at this time, heat can be uniformly transferred to the materials for the core substrates, and the unevenness of shrinkage of the insulating substrates can be further reduced.

The resin material forming the core substrate can be appropriately selected in consideration of cost, workability, insulation properties, machine strength, and the like. Specific examples of the core substrate include an EP resin (epoxy resin) substrate, a PI resin (polyimine resin) substrate, and a BT resin (Bismaleimide-III) Resin) substrate, PPE resin (polyphenylene ether resin) substrate, and the like. In addition to this, a substrate composed of a composite material of these resins and organic fibers such as glass fibers (glass woven fabric and glass nonwoven fabric) or polyamide fibers may also be used. Alternatively, a substrate composed of a resin-resin composite material in which a thermosetting resin such as an epoxy resin is impregnated into a three-dimensional mesh fluororesin base material of continuous porous PTFE may be used. Further, a plurality of plated through holes penetrating the upper surface and the lower surface of the core substrate may be formed, or a filling material may be filled in the plurality of plated through holes. Further, the core substrate may be a substrate in which a wiring layer is formed, or may be a substrate in which electronic components such as a wafer capacitor and a wafer impedance are embedded.

The formation method of the core substrate conductor layer and the laminated wiring portion conductor layer can be appropriately selected in consideration of conductivity, tightness with the resin insulating layer, and the like. Examples of the material of each conductor layer include copper, a copper alloy, nickel, a nickel alloy, tin, a tin alloy, and the like. Further, the conductor layer can be formed by a conventional method such as a subtractive method, a semi-additive method, or a full-additive method. Specifically, for example, etching of copper foil, electroless copper plating or electrolytic copper plating, electroless nickel plating, or electrolytic nickel plating can be employed. Further, the metal layer may be formed by sputtering or CVD or the like to be etched to form a conductor layer, or a conductive layer may be formed by printing a conductive paste or the like.

The interlayer insulating layer is formed, for example, by using a resin having thermosetting properties. Suitable examples of the thermosetting resin include EP resin (epoxy resin), PI resin (polyimine resin), and BT resin (bismaleimide-three Resin), phenol resin, xylene resin, polyester resin, enamel resin, and the like. Even among these, it is preferred to select EP resin (epoxy resin), PI resin (polyimine resin), BT resin (bismaleimide-three Resin). For example, as the epoxy resin, a so-called BP (bisphenol) type, PN (phenol novolak) type, or CN (cresol novolac) type may be used. In particular, the BP (bisphenol) type is preferred, and the BPA (bisphenol A) type and the BPF (bisphenol F) type are preferred.

An embodiment of a multilayer wiring board in which the present invention is embodied will be described in detail based on the drawings. 1 is a schematic plan view of a multilayer wiring board, and FIG. 2 is a cross-sectional view of a multilayer wiring board.

As shown in Fig. 1, the multilayer wiring substrate 11 has a rectangular shape as viewed in plan, and has a plurality of (here, 4 × 4) product regions 100, and a frame region 101 surrounding those product regions 100. Since the frame portion 101 does not become an article, it is cut off at the end by a cutting step.

As shown in Fig. 2, the core substrate 12 constituting the multilayer wiring board 11 is a substantially rectangular plate-shaped member (thickness: 0.8 mm) composed of glass epoxy, and has an upper surface 13 and a lower surface 14 as main surfaces. A first build-up layer 15 (laminated wiring portion) is formed on the upper surface 13 of the core substrate 12, and a second build-up layer 16 (laminated wiring portion) is formed on the lower surface 14 of the core substrate 12. At a predetermined portion of the product region 100 of the core substrate 12, a plurality of plated through holes 17 that connect the upper surface 13 and the lower surface 14 are formed. In the cavity portion located in the plated through hole 17, a filling material 18 composed of an epoxy resin to which a copper filler is added is filled. Further, a pattern of a conductor layer 19 (core substrate conductor layer) composed of copper is formed on the upper surface 13 and the lower surface 14 of the core substrate 12, and each conductor layer 19 is electrically connected to the plated through hole 17.

The first build-up layer 15 formed on the upper surface 13 of the core substrate 12 has a resin insulating layer 20, 21 (interlayer insulating layer) composed of an epoxy resin, and conductor layers 22 and 23 composed of copper (layered wiring) The partial conductor layer) has a structure in which two layers are laminated. In the present embodiment, the thickness of each of the resin insulating layers 20 and 21 is about 40 μm, and the thickness of each of the conductor layers 22 and 23 is about 20 μm.

The terminal pads 230 constituting the conductor layer 23 are formed in an array form at a plurality of points on the surface of the second-layer resin insulating layer 21. A plurality of via holes 25 and via conductors 26 are provided in the first resin insulating layer 20, and a plurality of via holes 27 and via conductors 28 are provided in the second resin insulating layer 21. The via conductors 26, 28, the conductor layers 19, 22 and the terminal pads 230 are electrically connected to each other. Further, the surface of the second resin insulating layer 21 is covered substantially by the solder resist portion 29. An opening 30 for exposing the terminal pad 230 is formed at a predetermined portion of the solder resist portion 29. Each of the terminal pads 230 is electrically connected to a connection terminal of an IC chip (semiconductor integrated circuit element) via a solder bump (not shown).

The second build-up layer 16 formed on the lower surface 14 of the core substrate 12 has substantially the same structure as the first build-up layer 15 described above. In other words, the second build-up layer 16 has a structure in which the resin insulating layers 31 and 32 made of an epoxy resin and the conductor layers 33 and 34 made of copper are laminated in two layers. The BGA spacers 340 constituting the conductor layer 34 are formed in an array in a plurality of places on the lower surface of the second resin insulating layer 32. A plurality of via holes 25 and via conductors 26 are provided in the first resin insulating layer 31, and a plurality of via holes 27 and via conductors 28 are provided in the second resin insulating layer 32. The via-hole conductors 26, 28, the conductor layers 19, 33, and the BGA pad 340 are electrically connected to each other. In addition, the underside of the second resin insulating layer 32 is protected by a solder mask 36 is covered almost entirely. An opening 37 for exposing the BGA spacer 340 is formed at a predetermined portion of the solder resist portion 36. A plurality of solder bumps 38 are disposed on the surface of the BGA pad 340 for electrical connection with a mother board (not shown). By the solder bumps 38, the multilayer wiring substrate 11 is It is assembled on a motherboard not shown.

Next, the manufacturing procedure of the multilayer wiring board 11 configured as described above will be described.

First, in the preparation step, a plurality of double-sided copper-clad laminates 48 (for the core substrate) prepared by attaching a copper foil 47 (metal foil) to the upper surface and the lower surface of the insulating substrate 46 made of glass epoxy are prepared. Material) (Refer to Figure 3).

Then, in the annealing step, heating of each of the double-sided copper clad laminates 48 as a material for the core substrate is performed. Specifically, as shown in FIG. 4, a plurality of (for example, 24) double-sided copper clad laminates 48 are placed in the longitudinal direction in a state in which a space is provided in the storage rack 50 (substrate support tool). The main faces 12A (material main faces) of the respective double-sided copper clad laminates 48 are arranged to face each other in parallel, and the voids of the respective two-sided copper clad laminates 48 are fixed. The storage rack 50 in this state was placed in the hot air drying device 51, and heated at 200 ° C for 240 minutes. In the hot air drying device 51 of the present embodiment, the air blowing fan 52 is provided in the upper portion of the device, and the hot air W1 heated by the heating portion 53 is blown downward from above.

As shown in Fig. 5 and Fig. 6, the storage rack 50 includes a frame (frame) 55 which is formed in a box shape using a heat resistant material (for example, stainless steel), and a plurality of holding guides 56 (intervals) The holding portion) is fixed to the frame 55 at a predetermined pitch and is used to secure a gap between the copper clad laminates 48. For each of the holding guide portions 56, for example, a wire made of stainless steel having a diameter of about 2 mm is used. Further, it is formed at a position facing the side portion of the frame 55 so as to be along the insertion direction of the double-sided copper clad laminate 48 (in the present embodiment, the vertical direction). Then, the edge portion (frame portion 101) of the double-sided copper clad laminate 48 is inserted and held between the slits of the adjacent two holding guides 56.

After the annealing step, the two-sided copper clad laminate 48 taken out from the storage rack 50 is subjected to laser drilling using a YAG laser or a carbon dioxide gas laser, and a through-face copper clad laminate 48 is formed at a predetermined position. Through hole. Then, electroless copper plating and electrolytic copper plating are performed in accordance with a conventional method to form plated through holes 17, and the filling material 17 is filled with the filling material 18 and thermally hardened.

Thereafter, in the core substrate conductor layer forming step, the copper foil 47 on both sides of the substrate is etched, whereby the conductor layer 19 is patterned on the core substrate 12. Specifically, after electroless copper plating, an exposure glass mask is placed on the surface of the substrate, exposed, and further developed to form a plating resist having a predetermined pattern. In this state, after electrolytic copper plating is performed using the electroless copper plating layer as a common electrode, the plating resist is first dissolved and removed, and the unnecessary electroless copper plating layer is further removed by etching. As a result, a conductor layer 19 having a predetermined pattern is formed on the surface of the core substrate 12 (see FIG. 7).

In the insulating layer forming step, the upper surface 13 and the lower surface 14 of the core substrate 12 are disposed so as to overlap the film-shaped insulating resin materials containing epoxy resin as a main component. Then, the laminate is subjected to pressure heating under vacuum by a vacuum pressure bonding heat press (not shown) to harden the film-shaped insulating resin material, and a first layer of resin is formed on each of the upper surface 13 and the lower surface 14 Insulating layers 20, 31 (see Fig. 8).

Formed by irradiating a laser to a predetermined position of the resin insulating layers 20, 31 Via hole 25 (refer to Fig. 9). Then, by performing electroless copper plating, the via hole conductor 26 is formed in the via hole 25, and an electroless copper plating layer is formed on the entire upper surface of the resin insulating layer 20. Thereafter, exposure and development are performed to form a plating resist of a predetermined pattern. Then, after electrolytic copper plating is performed, the plating resist is first dissolved and removed, and the unnecessary electroless copper plating layer is further removed by etching. As a result, the conductor layers 22 and 33 having a predetermined pattern are formed on the resin insulating layers 20 and 31 (see FIG. 10).

Next, in the case of the same as the first resin insulating layers 20 and 31 described above, the insulating layer forming step is performed to form the second resin insulating layers 21 and 32. Further, a laser beam is irradiated to a predetermined position of the resin insulating layers 21 and 32 to form a via hole 27 (see FIG. 11). Then, electroless copper plating is performed to form the via-hole conductor 28 in the via hole 27, and an electroless copper plating layer is formed on the entire resin insulating layers 21 and 32. Thereafter, exposure and development are performed to form a plating resist of a predetermined pattern, and electrolytic copper plating is performed. Then, after the plating resist is dissolved and removed, the unnecessary electroless copper plating layer is further removed by etching. As a result, a plurality of terminal pads 230 are formed on the resin insulating layer 21, and a plurality of BGA pads 340 are formed on the resin insulating layer 32 (see Fig. 12).

In the solder resist forming step, a photosensitive liquid resin material is applied onto the upper surface and the lower surface of the core substrate 12 and cured to form solder resist portions 29 and 36 (see Fig. 13). Further, in the present embodiment, a halogen-free photosensitive liquid solder resist (for example, SR-7200 manufactured by Hitachi Chemical Co., Ltd.) can be used.

Next, in the opening step, the exposure glass mask 58 is placed so as to overlap the surface of the solder resist 29 (see FIG. 14). In this case In the state, exposure is performed through the glass cover 58 for exposure, and further development is performed, whereby the opening portion 30 is patterned on the solder resist portion 29 (see Fig. 15).

Further, in the same manner as the solder resist portion 36 on the lower surface side of the core substrate 12, the exposure glass mask 58 is placed on the surface of the solder resist portion 36, exposure and development are performed, and the opening portion is patterned on the solder resist portion 36. 37 (refer to Figure 15).

Then, the terminal pad 230 exposed from each of the openings 30 or the BGA pad 340 exposed from each of the openings 37 is subjected to surface roughening treatment and nickel-gold plating treatment. Thereafter, the solder bump forming step is performed by a conventional method, and solder bumps 38 are formed on the surface of the BGA pad 340 (see FIG. 2). Specifically, a mask of a predetermined pattern is placed on the solder resist 36, and after the solder paste is printed on the BGA pad 340, the solder paste is reflowed. Then, the intermediate product integrated in a large state is cut and separated into individual pieces by using a cutting tool such as a cutting blade, thereby completing the multilayer wiring board.

In order to confirm the effect of the manufacturing method of the present embodiment, in the above-described annealing step, a plurality of positions (the measurement points shown in FIG. 16) are placed in each of the copper-clad laminates 48 housed in the storage rack 50 in the longitudinal direction. A temperature sensor is placed on the temperature to measure the temperature at each measurement point. The result is shown in Fig. 17. Here, as a setting condition of the hot air drying device 51, the temperature was 200 ° C and the time was 240 minutes. Further, in Fig. 17, the measurement point (Max), the lowest measurement point (Min), and the measurement point (Ave) of the average temperature at which the measured temperature is the highest are shown in the list at each measurement point. The maximum temperature (Max. temp) and the hold time (Keep time) maintained by the temperature higher than the glass transition point Tg (for example, 180 ° C). In addition, in this list, it is also indicated by The highest temperature measured by the measurement point (Max) and the measurement point (Min) and the unevenness R (error) of the retention time.

Further, the inventors of the present invention arranged a plurality of copper clad laminates 48 in a lateral direction as in the prior art, and measured a plurality of positions when heated under the same conditions (200 ° C, 240 minutes) as described above (refer to The temperature of Figure 18 and Figure 19). Further, in the case of Fig. 18 (Comparative Example 1), in the hot air drying device 51, 50 sheets of copper-clad laminates 48 stacked in a flat state are arranged in one set, and are arranged in three portions (three components). ). Further, in the case of Fig. 19 (Comparative Example 2), in the hot air drying device 51, 50 copper clad laminates 48 were placed in a flat stack (one component amount). The measurement results in the case of Comparative Example 1 are shown in Fig. 20, and the measurement results in the case of Comparative Example 2 are shown in Fig. 21.

As shown in Fig. 20 and Fig. 21, in the case of Comparative Examples 1 and 2, heat was not uniformly transferred to each of the copper clad laminates 48 at the temperatures of the respective measurement points. Further, the retention time (Keep time) of the glass transition point Tg or more also causes unevenness R at each measurement point.

On the other hand, as shown in Fig. 17, in the case of the present embodiment, the temperatures of the respective measurement points are substantially the same, and it is confirmed that heat can be uniformly transferred to each of the copper clad laminates 48. Further, in terms of the retention time (Keep time) of the glass transition point Tg or more, the unevenness R is smaller than that of the comparative examples 1 and 2, and a sufficiently long time can be secured.

Further, the inventors of the present invention confirmed the shrinkage unevenness of the substrate in the manufacturing method of the present embodiment. As a specific confirmation method, as shown in FIG. 22, in the two-side copper clad laminate 48 prepared in the preparation step, guide holes are formed in advance at positions corresponding to the four corners of the frame portion 101. 60, straight In each manufacturing step before the opening step of performing the exposure of the solder resist portions 29 and 36, the interval between the respective guide holes 60 is measured as the plate pitch P. Then, the error ΔP of the plate pitch P of each manufacturing step after the annealing step is measured with the plate pitch P of the guide hole 60 (before the annealing step) as a reference. The result is shown in Fig. 23. Here, the error ΔP of the plate pitch P was measured for the three samples 1 to 3 in which the material of the insulating substrate 46 of the copper clad laminate 48 and the thickness of the copper foil 47 were changed. In addition, in each of the samples 1 to 3, the error ΔP of the plate pitch P when the copper clad laminate 48 was flatly stacked and heated in parallel (see FIG. 18) was measured, and the measurement results were shown as comparative examples. The left side of Figure 23. As shown in Fig. 23, in the production method of the present embodiment, it is confirmed that the value of the standard deviation Std is small and the unevenness of the plate pitch P is small as compared with the case of the comparative example.

Further, the inventors of the present invention measured the positions of the openings 30, 37 of the solder resist portions 29, 36 with respect to the conductor layers 23, 34 (the terminal pads 230, the pads 340 for BGA) located under the solder resist portions 29, 36. Precision. The result is shown in Fig. 24. Here, the positional accuracy was also measured for the three samples 1 to 3 in which the material of the insulating substrate 46 of the copper clad laminate 48 and the thickness of the copper foil 47 were changed. In addition, the positional accuracy when the copper clad laminate 48 is flatly stacked and heated (see FIG. 18) is also shown as a comparative example on the left side of FIG. As shown in Fig. 24, in the manufacturing method of the present embodiment, it is confirmed that the positional deviation of the openings 30 and 37 is small as compared with the case of the comparative example, and the respective openings 30 and 37 can be formed with high precision.

Therefore, the following effects can be obtained by the present embodiment.

(1) In the method of manufacturing the multilayer wiring board 11 of the present embodiment, in the annealing step, by using the storage rack 50, it is possible to set the gap in the plural In the state between the materials for the core substrate, a plurality of copper clad laminates 48 are placed in the longitudinal direction, and the copper clad laminates 48 can be heated in this state. As described above, a gap is provided between each of the copper clad laminates 48, whereby the hot air W1 is blown to the entirety of each of the copper clad laminates 48 in the hot air drying device 51, and the copper clad laminates 48 are uniformly transferred. Heat. Thereby, the unevenness of shrinkage of the insulating substrate 46 can be reduced. In addition, since each of the copper clad laminates 48 is placed in the vertical direction with the gap provided, it is possible to prevent the insulating substrate 46 from being deflected unlike the case where the gap is provided in the lateral direction. Therefore, when the copper foil 47 of the copper clad laminate 48 is patterned, the alignment of the pattern can be performed with high precision. Further, since the substrate shrinkage unevenness in each step after the annealing step can be suppressed, the opening portions 30, 37 of the conductor layers 22, 23, 33, 34 of the build-up layers 15, 16 or the solder resist portions 29, 36 can be suppressed. In the formation step, the exposure glass mask 58 or the like can be accurately placed on the wiring pattern of the lower layer, and the wiring pattern can be made fine.

(2) In the case of the present embodiment, in the annealing step, since the plurality of copper clad laminates 48 are heated at a temperature equal to or higher than the glass transition point Tg of the resin material for 240 minutes or more, the copper can be surely released. The internal stress of the laminated plate 48.

(3) Since the storage rack 50 of the present embodiment is composed of a heat-resistant material (specifically, stainless steel) capable of withstanding a temperature equal to or higher than the glass transition point Tg, annealing of the copper clad laminate 48 can be surely performed. Further, the storage rack 50 is composed of a box-shaped frame 55, and since the hot air W1 is not shielded, the copper clad laminates 48 can be reliably heated.

(4) In the storage rack 50 of the present embodiment, a plurality of holding guides 56 (interval holding portions) are provided in order to secure the gap between the copper-clad laminates 48. This insurance The holding portion 56 is formed by a wire made of stainless steel, and is disposed in the vertical direction along the direction in which the hot air W1 is blown. Then, by inserting the edge portion (frame portion region 101) of the double-sided copper clad laminate 48 between the gaps of the adjacent two holding guide portions 56, the copper clad laminates can be held in the longitudinal direction. 48. In this manner, it is possible to prevent the hot air W1 from being blown to the product region 100 of each of the copper clad laminates 48 by the fact that the hot air W1 is shielded by the holding of the guide portion 56.

(5) In the hot air drying device 51 of the present embodiment, the air blowing fan 52 is provided in the upper portion thereof, and the hot air W1 heated by the heating unit 53 is configured to blow air from the upper side toward the lower side. In this case, the hot-air W1 is blown in parallel with respect to each of the copper-clad laminates 48 placed in the longitudinal direction by using the storage rack 50. Therefore, the hot air W1 can pass through the gap between the copper clad laminates 48, and at this time, heat can be uniformly transferred to the copper clad laminates 48, and the unevenness of shrinkage of the insulating substrate 46 can be further reduced.

Further, the embodiment of the present invention may be modified as follows.

In the hot air drying device 51 of the above-described embodiment, the air blowing fan 52 is provided in the upper portion thereof, and the hot air W1 is blown downward from the upper side. However, as shown in Fig. 25, the air blowing device may be provided on the side surface of the device. The fan blows the hot air W1 in the lateral direction (horizontal direction). Further, in this case, the storage rack 50 is placed and heated so that the copper clad laminates 48 are parallel to the direction of the hot air W1. In other words, if the voids can be ensured, the copper clad laminates 48 can be placed laterally and subjected to an annealing step.

In the storage rack 50 of the above-described embodiment, the gap holding portion of the double-sided copper-clad laminate 48 is a holding guide portion 56 composed of a wire material, but is not limited thereto. Specifically, it can also be in a part of the frame 55. The recesses (for example, the positioning grooves) into which the edge portions of the substrate are insertable are formed at equal intervals, and those recesses are used as the spacers. Further, a plurality of convex portions (for example, small projections for fixing) for sandwiching the edge portion of the substrate may be provided in a part of the frame 55, and those convex portions may be used as the spacing holding portions.

In the above embodiment, the package pattern of the multilayer wiring substrate 11 is a BGA (Ball Gate Array Package), but it is not limited to the BGA, and may be, for example, a PGA (Pin Grid Array) or an LGA (Plane Gate Array). .

In the above-described embodiment, the annealing step is performed by placing each of the copper clad laminates 48 in a longitudinal direction in a state of standing at 90 degrees. However, the present invention is not limited thereto, and other embodiments such as those shown in Fig. 26 may be employed. . That is, in Fig. 26, a plurality of materials for the core substrate are held in the storage rack 50B obliquely.

In the above embodiment, each of the copper clad laminates 48 is supported by the storage rack. Alternatively, the copper clad laminates 48 may be suspended by using the slinging device 50A as shown in Fig. 27, for example. And keep it. In this case, each of the copper clad laminates 48 may be held at a constant interval by holding the guide portion 58 (interval holding portion).

Next, in addition to the technical ideas described in the patent application, the technical ideas grasped by the above embodiments will be listed below.

(1) A method of manufacturing a multilayer wiring board in which a multilayer wiring board is laminated on a core substrate having a core substrate conductor layer, and a laminated layer of a laminated wiring portion conductor layer and an interlayer insulating layer is disposed. In the wiring unit, the manufacturing method includes a preparation step of preparing a plurality of materials for a core substrate obtained by attaching a metal foil to a main surface of an insulating substrate including a resin material, and an annealing step. The foregoing plurality of core bases a plurality of core substrate materials are longitudinally placed and heated in a state in which a space is provided between the plate materials; and a core substrate conductor layer forming step of patterning the metal foil to form the foregoing after the annealing step In the core substrate conductor layer, in the annealing step, the plurality of core substrate materials are heated at a temperature equal to or higher than a glass transition point of the resin material for 240 minutes or longer.

(2) The method of manufacturing a multilayer wiring board according to (1) above, characterized in that in the annealing step, the plurality of core substrate materials are placed in a hot air drying device and heated.

11‧‧‧Multilayer wiring board

12‧‧‧core substrate

15, 16‧‧‧ as a layered layer of the laminated wiring

19‧‧‧Conductor layer as conductor layer of core substrate

20, 21, 31, 32‧‧‧ resin insulating layer as interlayer insulating layer

22, 23, 33, 34‧‧‧ as the conductor layer of the conductor layer of the laminated wiring portion

46‧‧‧Insert substrate

47‧‧‧ Copper foil as metal foil

48‧‧‧Two-sided copper-clad laminate as a material for core substrates

50, 50B‧‧‧ storage rack as a substrate support device

50A‧‧‧ hanging device as a substrate support device

51‧‧‧Hot air drying device

52‧‧‧Air supply fan

53‧‧‧ heating department

56, 58‧‧‧ as the holding guide of the interval holding portion

W1‧‧‧ hot air

Fig. 1 is a schematic plan view showing a multilayer wiring board according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing the main part of a multilayer wiring board according to an embodiment of the present invention.

Fig. 3 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 4 is a front view showing the hot air drying device.

Fig. 5 is a front view showing the storage rack (longitudinal state).

Fig. 6 is a side view showing the storage rack (longitudinal state).

Fig. 7 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 8 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 9 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 10 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 11 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 12 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 13 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 14 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 15 is a cross-sectional view for explaining a method of manufacturing a multilayer wiring board according to an embodiment.

Fig. 16 is an explanatory view showing measurement points of temperatures of the respective copper-clad laminates placed in the longitudinal direction in the embodiment.

Fig. 17 is an explanatory view showing changes in temperature at respective measurement points in the embodiment.

Fig. 18 is an explanatory view showing measurement points of temperatures of the respective copper-clad laminates placed horizontally in Comparative Example 1.

Fig. 19 is an explanatory view showing measurement points of temperatures of the respective copper-clad laminates placed horizontally in Comparative Example 2.

Fig. 20 is an explanatory view showing changes in temperature at each measurement point of Comparative Example 1.

Fig. 21 is an explanatory view showing changes in temperature at each measurement point of Comparative Example 2.

Figure 22 is a plan view showing the guide holes and the pitch of the plates.

Fig. 23 is an explanatory view showing unevenness of substrate shrinkage.

Fig. 24 is an explanatory view showing the positional accuracy of the opening of the solder resist portion.

Fig. 25 is a front elevational view showing a storage rack (horizontal state) of another embodiment.

Fig. 26 is a front elevational view showing the storage rack (slanted state) of another embodiment.

Fig. 27 is a front elevational view showing the hanging device (suspended state) of another embodiment.

48‧‧‧Two-sided copper-clad laminate as a material for core substrates

50‧‧‧Storage rack as a substrate support

51‧‧‧Hot air drying device

52‧‧‧Air supply fan

53‧‧‧ heating department

W1‧‧‧ hot air

Claims (10)

A method of manufacturing a multilayer wiring substrate comprising a laminated wiring portion (15, 16) having a structure in which a plurality of laminated core substrates (12) having a core substrate conductor layer (19) are laminated a laminated wiring portion conductor layer (22, 23, 33, 34) and a plurality of interlayer insulating layers (20, 21, 31, 32), the method comprising the following steps: a preparation step prepared by insulating the resin material a plurality of core material (48) formed by attaching a metal foil (47) to a main surface of the substrate (46); and an annealing step of providing a gap between the plurality of core substrate materials and being parallel to each other The plurality of core substrate materials (48) are heated in an upright state; and a core substrate conductor layer forming step is formed by patterning the metal foil (47) after the annealing step to form the core Core substrate conductor layer (19). A method of producing a multilayer wiring board according to the first aspect of the invention, wherein in the annealing step, the plurality of core substrate materials (48) are erected on the substrate supporting devices (50, 50A, 50B). The method for manufacturing a multilayer wiring substrate according to the first or second aspect of the invention, wherein in the annealing step, the plurality of core substrates are The materials (48) are arranged in parallel such that their major faces (12A) face each other. The method for producing a multilayer wiring board according to the first or second aspect of the invention, wherein in the annealing step, the plurality of core substrate materials (48) are arranged in parallel and are used in the core substrate. The materials have a predetermined interval therebetween such that the aforementioned main faces (12A) face each other. The method for producing a multilayer wiring board according to the first or second aspect of the invention, wherein in the annealing step, the plurality of core substrates are heated at a temperature equal to or higher than a glass transition point of the resin material Material (48). The method for producing a multilayer wiring board according to the first or second aspect of the invention, wherein in the annealing step, the plurality of core substrate materials (48) are heated for 240 minutes or longer. The method for producing a multilayer wiring board according to the first or second aspect of the invention, wherein the plurality of core substrate materials (48) are disposed in a hot air drying device (51) and heated in the annealing step. . A method of manufacturing a multilayer wiring board according to the first or second aspect of the invention, wherein the substrate supporting device made of a heat resistant material capable of withstanding a temperature equal to or higher than a glass transition point of the resin material is used. (50, 50A, 50B) for supporting the plurality of core substrate materials (48), wherein the plurality of core substrate materials are erected on the substrate supporting device when heated in the annealing step. , 50A, 50B) in the state. The method of manufacturing a multilayer wiring board according to the eighth aspect of the invention, wherein the substrate supporting tool (50, 50A, 50B) includes a space holding portion (56, 58) for securing a material for the plurality of core substrates The interval between. The method for producing a multilayer wiring board according to the first or second aspect of the invention, wherein the plurality of core substrate materials (48) are used when the core substrate material (48) is heated in the annealing step. It is configured to be parallel to the direction of hot air (W1).