Multilayer resin substrate and electronic device

Abstract

To provide a resin multilayer substrate that ensures adhesion between a mounting portion and a multilayer substrate portion and that suppresses deformation of a rigid portion constituted by the multilayer substrate portion and the mounting portion and generation of cracks at a boundary between a flexible portion and the rigid portion, and an electronic device including the resin multilayer substrate.SOLUTION: A resin multilayer substrate includes a multilayer substrate portion 101 and a mounting portion 201. Both a resin layer of the multilayer substrate portion 101 and a resin layer of the mounting portion 201 are layers made of, as a first component, a crystalline thermoplastic resin that is identical. The resin layer of the multilayer substrate portion 101 and the resin layer of the mounting portion 201 have a difference in endothermic peak temperature that appears first during temperature raising in a 1st-up chart when differential scanning calorimetry (DSC) is performed at a temperature raising rate of 10°C / min, the endothermic peak temperature of the resin layer of the multilayer substrate portion 101 is lower as compared to the endothermic peak temperature of the resin layer of the mounting portion 201, and the resin layer of the multilayer substrate portion 101 and the resin layer of the mounting portion 201 are directly bonded to each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin multilayer board having a multilayer board portion formed by stacking resin layers and a mounting portion mounted on the multilayer board portion or having a shape that is mounted on the multilayer board portion, and an electronic device having the resin multilayer board. [Background technology]

[0002] Patent Document 1 shows a resin multilayer substrate having a plurality of resin layers, conductor layers attached to one side of the resin layers, and interlayer connection conductors formed inside predetermined resin layers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 051649 Summary of the Invention [Problem to be solved by the invention]

[0004] If the structure is such that the number of stacked insulator layers with conductor layers attached to them varies, and thereby areas with different thicknesses in the stacking direction are formed, the thicker parts can be given the function of a specified electronic component.

[0005] However, when joining dissimilar materials, it is difficult to ensure adhesion between the multilayer substrate and the mounted components. Furthermore, the multilayer substrate and the mounted components on the multilayer substrate constitute the rigid portion, while the remaining portion of the multilayer substrate itself is the flexible portion. While the flexible portion can be deformed, there is a risk that the rigid portion will also be deformed. Furthermore, stress tends to concentrate at the boundary between the flexible and rigid portions (the base of the rigid portion), so cracks are likely to occur at this boundary when the flexible portion is bent, for example.

[0006] Therefore, the object of the present invention is to provide a resin multilayer substrate that ensures adhesion between a mounting portion mounted on a multilayer substrate portion or having a shape mounted on a multilayer substrate portion and the multilayer substrate portion, and also suppresses deformation of the rigid portion composed of the multilayer substrate portion and the mounting portion, and the occurrence of cracks at the boundary between the flexible portion and the rigid portion, and an electronic device equipped with the same. [Means for solving the problem]

[0007] (1) An example of a resin multilayer substrate according to the present disclosure includes: a multilayer substrate portion having a plurality of resin layers and a conductor layer attached to a predetermined resin layer among the plurality of resin layers; a mounting portion having a resin layer and a conductor layer formed on the resin layer, the mounting portion being mounted on the multilayer substrate portion or having a shape to be mounted on the multilayer substrate portion; Equipped with the resin layer of the multilayer substrate section and the resin layer of the mounting section are both layers made of the same crystalline thermoplastic resin as a first component, a difference in endothermic peak temperature that first appears during temperature rise in a first-up chart when differential scanning calorimetry is performed between the resin layer of the multilayer substrate section and the resin layer of the mounting section at a temperature rise rate of 10°C / min, and the endothermic peak temperature of the resin layer of the multilayer substrate section is lower than the endothermic peak temperature of the resin layer of the mounting section; The resin layer of the multilayer substrate portion and the resin layer of the mounting portion are directly bonded to each other.

[0008] (2) An electronic device as an example of the present disclosure includes: The device is characterized by comprising the resin multilayer substrate and another substrate on which the resin multilayer substrate is mounted.

[0009] (3) An electronic device as an example of the present disclosure includes: The device is characterized by comprising the resin multilayer substrate and a housing that houses the resin multilayer substrate. [Effects of the Invention]

[0010] According to the present invention, a resin multilayer substrate is obtained that ensures adhesion between a multilayer substrate portion and a mounting portion for the multilayer substrate portion, and also suppresses deformation of the rigid portion composed of the multilayer substrate portion and the mounting portion, and the occurrence of cracks at the boundary between the flexible portion and the rigid portion, and an electronic device equipped with the same. [Brief explanation of the drawings]

[0011] [Figure 1] The lower part of FIG. 1 is a cross-sectional view of a resin multilayer substrate 301 according to the first embodiment, and the upper part of FIG. 1 is a cross-sectional view of a state before mounting portion 201 onto multilayer substrate portion 101. [Figure 2] FIG. 2 is a typical example of a chart showing the temperature and DSC variations over time when differential scanning calorimetry (DSC) is performed. [Figure 3] The lower part of FIG. 3 is a cross-sectional view of a resin multilayer substrate 302 according to the second embodiment, and the upper part of FIG. 3 is a cross-sectional view of the resin multilayer substrate 302 during its manufacture. [Figure 4] The lower part of FIG. 4 is a cross-sectional view of a resin multilayer substrate 303 according to the third embodiment, and the upper part of FIG. [Figure 5] FIG. 5 is a cross-sectional view of a resin multilayer substrate 304 according to the fourth embodiment. [Figure 6] FIG. 6 is a cross-sectional view of a resin multilayer substrate 305 according to the fifth preferred embodiment. [Figure 7] FIG. 7 is a cross-sectional view of a resin multilayer substrate 306 according to the sixth preferred embodiment. [Figure 8] FIG. 8 is a cross-sectional view of a resin multilayer substrate 307 according to the seventh preferred embodiment. [Figure 9] FIG. 9 is a cross-sectional view of a resin multilayer substrate 308 according to the eighth embodiment. [Figure 10] FIG. 10 is a cross-sectional view of an electronic device 409 according to the ninth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several specific examples will be given with reference to the drawings to illustrate multiple modes for carrying out the present invention. The same symbols are used for the same parts in each drawing. To facilitate explanation and understanding of the main points, the modes for carrying out the invention are shown divided into multiple embodiments, but partial omission, substitution, or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, descriptions of matters common to the first embodiment will be omitted, and only the differences will be described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment.

[0013] First Embodiment In the first embodiment, an example of a resin multilayer substrate will be described.

[0014] The lower part of Fig. 1 is a cross-sectional view of resin multilayer substrate 301 according to the first embodiment, and the upper part of Fig. 1 is a cross-sectional view of the state before mounting portion 201 on multilayer substrate portion 101. In the cross-sectional view, lines that appear in the cross section (appearing due to cutting) are drawn, and lines that exist behind the cross section are not shown. This also applies to each embodiment described later.

[0015] The resin multilayer substrate 301 includes a multilayer substrate portion 101 and a mounting portion 201 .

[0016] The multilayer substrate section 101 includes a plurality of resin layers 11, 12, 13, 14, and 15, and conductor layers and interlayer connection conductors attached to predetermined resin layers among the plurality of resin layers 11, 12, 13, 14, and 15. The conductor layers and interlayer connection conductors are conductors whose main component is, for example, Cu or Ag.

[0017] The mounting portion 201 has a resin layer and a resin layer 21 formed on the resin layer. In Fig. 1, the resin layer 21 is illustrated as a single layer, but the resin layer 21 is composed of a single layer or multiple layers.

[0018] A connecting conductor BM is applied to the opening of the resin layer 15. The connecting conductor BM is, for example, a heat-melting metal such as solder. Multilayer substrate side pad electrodes 2a and 2b are formed below the connecting conductor BM. In this example, the resin layers 11, 12, 13, 14, and 15 are laminates of thermoplastic resin sheets with Cu foil attached to one side.

[0019] A conductor layer 7 is formed on or near the top surface of the mounting portion 201 so that the mounting portion 201 acts as a circuit having predetermined electrical characteristics.

[0020] Terminal electrodes 6a and 6b are formed on the mounting surface (lower surface) of mounting portion 201. These terminal electrodes 6a and 6b are electrically connected to pad electrodes 2a and 2b formed on multilayer substrate portion 101.

[0021] A plurality of external electrodes 1 are formed on the underside of the multilayer substrate part 101. These external electrodes 1 are connected to pad electrodes formed on another substrate as will be described later, thereby mounting the resin multilayer substrate 301 on the other substrate. Alternatively, as will be described later, electronic components are mounted on these external electrodes 1 to form a resin multilayer substrate on which electronic components are mounted.

[0022] Signal line conductor patterns SL1, SL2 and a ground conductor layer GL are formed inside the multilayer substrate unit 101. Two microstrip type transmission lines are configured by the signal line conductor patterns SL1, SL2, the ground conductor layer GL, and the resin layer between the signal line conductor patterns SL1, SL2 and the ground conductor layer GL.

[0023] The mounting portion 201 is subjected to a temperature increase / decrease process before being mounted on the multilayer substrate portion 101. As will be described later, this increases the crystallinity of the mounting portion 201, thereby increasing the modulus of elasticity. In other words, the modulus of elasticity of the multilayer substrate portion 101 is relatively reduced compared to that of the mounting portion 201.

[0024] The elastic modulus is measured by the following method: A TriboIndenter TI980 (manufactured by Bruker Japan) is used as the measuring device to measure the elastic modulus of the first component crystalline thermoplastic resin in resin layers 11, 12, 13, 14, and 15 of multilayer substrate portion 101 and resin layer 21 of mounting portion 201 by nanoindentation. The measurement mode is (load-hold-unload): 5-2-5 seconds, load (indenter): 10 mN (Berkovich), number of measurement points: 5.

[0025] For example, when the crystalline thermoplastic resin is a liquid crystal polymer resin (LCP), the modulus of elasticity of multilayer substrate section 101 is lower than that of mounting section 201 by 0.44 GPa.

[0026] 1, the mounting portion 201 is placed at a predetermined position on the multilayer substrate portion 101, and the entire assembly is heated to a predetermined temperature and pressurized with a predetermined pressure, thereby melting the connection conductor BM and electrically connecting the pad electrodes 2a and 2b on the multilayer substrate portion side to the terminal electrodes 6a and 6b on the mounting portion 201 side.

[0027] Resin layers 11, 12, 13, 14, and 15 of multilayer substrate section 101 and resin layer 21 of mounting section 201 are all layers whose first component is the same crystalline thermoplastic resin. By applying heat and pressure as described above, resin layers 11, 12, 13, 14, and 15 of multilayer substrate section 101 and resin layer 21 of mounting section 201 are directly bonded together. This makes it possible to obtain high adhesion between mounting section 201 and multilayer substrate section 101.

[0028] In this way, resin layers 11, 12, 13, 14, and 15 of multilayer substrate section 101 and resin layer 21 of mounting section 201 are all made of the same crystalline thermoplastic resin, which makes it possible to obtain a stronger adhesive force between mounting section 201 and multilayer substrate section 101. Furthermore, because the resin layer of multilayer substrate section 101 is made of a crystalline thermoplastic resin, the resin layers can be easily laminated together and a separate bonding process is not required, which reduces the overall number of processes and enables low-cost manufacturing.

[0029] Here, the "first component" refers to the main component excluding any accompanying layers, such as adhesive layers that bond the resin layers together. For example, resin layers 11, 12, 13, 14, and 15 of multilayer substrate portion 101 and resin layer 21 of mounting portion 201 are all layers made of a crystalline thermoplastic resin, such as a wholly aromatic polyester resin or a thermoplastic polyimide resin.

[0030] The resin layers 11, 12, 13, 14, and 15 of the multilayer substrate section 101 and the resin layer 21 of the mounting section 201 have the following relationship: When differential scanning calorimetry (DSC) is performed on the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate section 101 and the resin layer 21 of the mounting section 201 at a temperature rise rate of 10°C / min, there is a difference in the endothermic peak temperature that appears first during temperature rise in the 1st-up chart, and the endothermic peak temperature of the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate section 101 is lower than the endothermic peak temperature of the resin layer 21 of the mounting section 201.

[0031] FIG. 2 is a typical example of a graph (chart) showing the temperature and DSC change over time when the above-mentioned differential scanning calorimetry (DSC) was performed. First, using a Rigaku DSC8230, the temperature was raised from room temperature at a rate of 10°C / min to the temperature at which the crystalline thermoplastic resin completely melts, and the resin was completely melted. Among the endothermic peaks that appeared during this process, the first endothermic peak temperature T1 was measured. However, peaks that were small and broad (area value: 0.8 mJ / mg or less) at the glass transition temperature were excluded. In other words, the temperature of such small and broad peaks (shallow peaks) at the glass transition temperature were not considered to be endothermic peak temperatures.

[0032] For example, if the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate section 101 and the resin layer 21 of the mounting section 201 all have the same first component, which is a liquid crystal polymer resin (LCP), the endothermic peak temperature T1 of the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate section 101 is approximately 2.2°C lower than the endothermic peak temperature T1 of the resin layer 21 of the mounting section 201.

[0033] In Figure 2, Tm1 is the first melting point in the 1st-up chart. After the temperature rises above this first melting point Tm1, the temperature drops below the endothermic peak temperature T1 and then rises again. The melting point (second melting point) during this temperature rise is Tm2.

[0034] As stated above, "The resin layers 11, 12, 13, 14, and 15 of the multilayer substrate portion 101 and the resin layer 21 of the mounting portion 201 are all layers whose first component is the same crystalline thermoplastic resin." This "same crystalline thermoplastic resin" is identified in the following manner.

[0035] First, the spectra of the first component crystalline thermoplastic resins of the mounting section 201 and the multilayer substrate section 101 are obtained using a Fourier transform infrared spectrophotometer (FT-IR). Then, it is confirmed that the peaks of the spectra are the same for the mounting section 201 and the multilayer substrate section 101, and that they are the same crystalline thermoplastic resin. Thereafter, the first component crystalline thermoplastic resins of the mounting section 201 and the multilayer substrate section 101 are each scraped off to obtain samples, and differential scanning calorimetry (DSC) is performed to measure the second melting points Tm2 of each.

[0036] The second melting point Tm2 is measured as follows. As shown in Figure 2, first, each crystalline thermoplastic resin is heated at a rate of 10°C / min from room temperature to a temperature at which the crystalline thermoplastic resin completely melts, thereby completely melting it. Then, the melt of each crystalline thermoplastic resin is cooled to room temperature at a rate of 10°C / min, and then heated at a rate of 10°C / min. During this heating, the temperature at the endothermic peak that appears at the temperature at which the crystalline thermoplastic resin completely melts is taken as the second melting point Tm2 of that crystalline thermoplastic resin.

[0037] If the temperature difference between the second melting point Tm2 of the mounting portion 201 and the second melting point Tm2 of the multilayer substrate portion 101 is within 5°C, the crystalline thermoplastic resin of the mounting portion 201 and the crystalline thermoplastic resin of the multilayer substrate portion 101 are considered to be the same crystalline thermoplastic resin.

[0038] According to this embodiment, the following effects are achieved.

[0039] (a) If the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate portion 101 and the resin layer 21 of the mounting portion 201 were made of different materials, it would be difficult to ensure adhesion between the multilayer substrate portion 101 and the mounting portion 201. However, since the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate portion 101 and the resin layer 21 of the mounting portion 201 are made of the same crystalline thermoplastic resin, it is easy to ensure adhesion between the two.

[0040] (b) Since the elastic modulus of the multilayer substrate portion 101 is lower than that of the mounting portion 201, when the multilayer substrate portion 101 is bent while being heated to near its softening point temperature, the bendability of only the multilayer substrate portion 101 can be improved without deforming the mounting portion 201.

[0041] Second Embodiment In the second embodiment, a resin multilayer substrate in which the mounting structure of the mounting portion relative to the multilayer substrate portion is different from that in the first embodiment will be exemplified.

[0042] The lower part of FIG. 3 is a cross-sectional view of a resin multilayer substrate 302 according to the second embodiment, and the upper part of FIG. 3 is a cross-sectional view of the resin multilayer substrate 302 during its manufacture.

[0043] This resin multilayer substrate 302 comprises a multilayer substrate portion 102 and a mounting portion 202 .

[0044] As shown in the upper part of Fig. 3, initially, the multilayer substrate section 102 and the mounting section 202 are in an integrated laminated substrate state. In the range shown in the upper part of Fig. 3, a predetermined amount is cut out with a router on the left and right sides of the range indicated by the dashed line, resulting in a shape in which the mounting section 202 is mounted on the multilayer substrate section 102.

[0045] Thereafter, the mounting portion 202 is subjected to a temperature increase / decrease process by partial heat treatment, without substantially increasing the temperature of the multilayer substrate portion 101. The heating temperature of the mounting portion 202 is set to a temperature that provides the characteristic that the endothermic peak temperature (T1) of the resin layer 21 of the mounting portion 202 is higher than the endothermic peak temperature (T1) of the resin layers 11, 12, 13, 14, and 15 of the multilayer substrate portion 101.

[0046] According to this embodiment, the step of mounting the mounting portion on the multilayer substrate portion is not required, and electrical connection and integral joining of resin portions are facilitated.

[0047] Third Embodiment In the third embodiment, a resin multilayer substrate having a mounting portion with a structure different from that of the examples shown in the first and second embodiments will be illustrated.

[0048] The lower part of Fig. 4 is a cross-sectional view of resin multilayer substrate 303 according to the third embodiment, and the upper part of Fig. 4 is a plan view of mounting section 203. In the upper part of Fig. 4, the dashed dotted line indicates the cross-sectional position of the cross-sectional view shown in the lower part of Fig. 4. However, the plan view of multilayer substrate section 101 is omitted from the illustration.

[0049] Resin multilayer substrate 303 includes multilayer substrate section 101 and mounting section 203. Multilayer substrate section 101 has the same structure as multilayer substrate section 101 shown in FIG.

[0050] A rectangular radiation electrode 7A is formed on or near the top surface of the mounting portion 203. A ground electrode 7G is formed around this radiation electrode 7A. In other words, the mounting portion 203 is used as a patch antenna or as a component that functions as part of a patch antenna.

[0051] The mounting portion 203 is a laminate of resin layers 21 with Cu foil attached to one side. Terminal electrodes 6A and 6G are formed on the mounting surface (lower surface) of the mounting portion 203. A laminate of multiple conductor foils 5 and multiple interlayer connection conductors 4 is formed between the terminal electrode 6A and the radiation electrode 7A. Similarly, a laminate of multiple conductor foils 5 and multiple interlayer connection conductors 4 is formed between the terminal electrode 6G and the ground electrode 7G. The interlayer connection conductors 4 electrically connect the conductor layers formed by the conductor foils 5. In this way, a stacking direction conductor path is formed in the mounting portion 203 by laminating the interlayer connection conductors 4 and the resin layers having the conductor foils 5 in contact with these interlayer connection conductors 4.

[0052] According to this embodiment, unlike a structure in which interlayer connections are made by penetrating through holes, a structure without openings (holes) can be realized, and the strength of the mounting portion 203 can be improved.

[0053] In the third embodiment, the mounting portion 203 is also subjected to a temperature increase / decrease process before being mounted on the multilayer substrate portion 101. This increases the crystallinity of the mounting portion 203, thereby increasing the modulus of elasticity. In other words, the modulus of elasticity of the multilayer substrate portion 101 is relatively reduced compared to that of the mounting portion 203.

[0054] Fourth Embodiment In the fourth embodiment, a resin multilayer substrate will be illustrated in which the structure of the interlayer connection conductors of the mounting portion is different from that of the example shown in the third embodiment.

[0055] 5 is a cross-sectional view of a resin multilayer substrate 304 according to the fourth embodiment. The resin multilayer substrate 304 includes a multilayer substrate section 101 and a mounting section 204. The structure of the multilayer substrate section 101 is similar to that of the multilayer substrate section 101 shown in FIG.

[0056] A rectangular radiation electrode 7A is formed on or near the top surface of the mounting portion 204. A ground electrode 7G is formed around this radiation electrode 7A. The mounting portion 204 is used as a patch antenna or as a component that functions as part of a patch antenna, similar to the mounting portion 203 shown in the third embodiment.

[0057] The mounting portion 204 is a laminate of resin layers 21 with Cu foil attached to one side. Terminal electrodes 6A and 6G are formed on the mounting surface (lower surface) of the mounting portion 204. A laminate of multiple conductor foils 5 and multiple interlayer connection conductors 4 is formed between the terminal electrode 6A and the radiation electrode 7A. Similarly, a laminate of multiple conductor foils 5 and multiple interlayer connection conductors 4 is formed between the terminal electrode 6G and the ground electrode 7G. The interlayer connection conductors 4 are arranged at positions shifted in the X direction for each adjacent layer. In this way, the mounting portion 204 may be configured with stacking direction conductor paths in which the interlayer connection conductors 4 are arranged at positions where they do not overlap in the Z direction.

[0058] According to this embodiment, unlike a structure in which interlayer connections are made by penetrating through holes, a structure without openings (holes) can be realized, improving the strength of the entire mounting section 204. Also, unlike filled vias that are formed by plating the inside of through holes, vias can be arranged at different positions in the inner layers of the mounting section 204, providing a high degree of freedom in design.

[0059] Fifth Embodiment In the fifth embodiment, a resin multilayer substrate will be illustrated in which the structure of the interlayer connection conductors of the mounting portion is different from that of the example shown in the fourth embodiment.

[0060] 6 is a cross-sectional view of a resin multilayer substrate 305 according to the fifth embodiment. The resin multilayer substrate 305 includes a multilayer substrate section 105 and a mounting section 205. The structure of the multilayer substrate section 105 is similar to that of the multilayer substrate section 105 shown in FIG. 1. However, the resin layers 11, 12, 13, 14, and 15 are bonded together by adhesive layers indicated by dashed lines.

[0061] A rectangular radiation electrode 7A is formed on or near the top surface of the mounting portion 205. A ground electrode 7G is formed around this radiation electrode 7A. The mounting portion 205 is used as a patch antenna or as a component that functions as part of a patch antenna, similar to the mounting portion 203 shown in the third embodiment.

[0062] The mounting section 205 is a laminate in which a resin layer 21 having a Cu foil attached on one side is bonded by an adhesive layer 20 indicated by a dashed line. Terminal electrodes 6A and 6G are formed on the mounting surface (lower surface) of the mounting section 205. A laminate of a plurality of conductor foils 5 and a plurality of interlayer connection conductors 4 is formed between the terminal electrode 6A and the radiating electrode 7A. Similarly, a laminate of a plurality of conductor foils 5 and a plurality of interlayer connection conductors 4 is formed between the terminal electrode 6G and the ground electrode 7G. Interlayer connection conductors 4 aligned in the Z direction are arranged between the terminal electrode 6G and the ground electrode 7G, and interlayer connection conductors 4 alternately shifted in the X direction are arranged between the terminal electrode 6A and the radiating electrode 7A.

[0063] Furthermore, the radiating electrode 7A and the ground electrode 7G made of Cu foil are formed on the upper surface of the uppermost resin layer among the plurality of resin layers 21. In this manner, the radiating electrode 7A and the ground electrode 7G may be exposed on the outer surface of the mounting portion 205.

[0064] Sixth Embodiment In the sixth embodiment, a resin multilayer substrate provided with electronic components will be exemplified.

[0065] 7 is a cross-sectional view of a resin multilayer substrate 306 according to the sixth embodiment. This resin multilayer substrate 306 includes a multilayer substrate portion 106, a mounting portion 203, and an electronic component 24. Hatching of the electronic component 24 is omitted.

[0066] The multilayer substrate section 106 includes a plurality of resin layers 11, 12, 13, 14, and 15, and conductor layers and interlayer connection conductors attached to predetermined resin layers among the plurality of resin layers.

[0067] The mounting portion 203 is the same as the mounting portion 203 shown in the third embodiment.

[0068] The component-side pad electrodes 42 are connected to the external electrodes 1 of the multilayer substrate section 106 via connection conductors BM. The connection conductors BM are, for example, a heat-melting metal such as solder.

[0069] The electronic component 24 is, for example, an IC that amplifies the power of a transmission signal and supplies the power to an antenna, or an IC that amplifies a signal received by an antenna.

[0070] According to this embodiment, the electronic components 24 can be easily mounted on the multilayer substrate section 106 because the electronic components 24 can be easily mounted on the multilayer substrate section 106 .

[0071] Seventh Embodiment In the seventh embodiment, a resin multilayer substrate having a curved multilayer substrate portion will be exemplified.

[0072] 8 is a cross-sectional view of a resin multilayer substrate 307 according to the seventh embodiment. This resin multilayer substrate 307 includes a multilayer substrate portion 107 and a connector 25 mounted thereon. Hatching of the connector 25 is omitted in the illustration.

[0073] The mounting portion 207 has a radiation electrode 7A formed on or near the upper surface thereof so that the mounting portion 207 functions as a patch antenna or as a part of the patch antenna.

[0074] A terminal electrode 6 is formed on the mounting surface (lower surface) of the mounting portion 207. A laminate of a plurality of conductor foils 5 and a plurality of interlayer connection conductors 4 is formed between this terminal electrode 6 and the radiation electrode 7A. In this way, in the mounting portion 207, a laminate of resin layers having the interlayer connection conductors 4 and the conductor foils 5 in contact with these interlayer connection conductors 4 forms a stacking direction conductor path.

[0075] Signal line conductor patterns SLa, SLb and a ground conductor layer GL are formed inside the multilayer substrate section 107. A microstrip transmission line is formed by the signal line conductor patterns SLa, SLb, the ground conductor layer GL, and a resin layer between the signal line conductor patterns SLa, SLb and the ground conductor layer GL.

[0076] A plurality of external electrodes 1 are exposed on a first surface S1 of the multilayer substrate section 107. A pad electrode 2 is formed on a second surface S2 of the multilayer substrate section 107. A terminal electrode 6 of the mounting section 207 is joined to this pad electrode 2 via a connecting conductor BM. In addition, the lower surface of the bottommost resin layer 21 of the mounting section 207 is joined to the resin layer 15 of the multilayer substrate section 107.

[0077] Component-side pad electrodes 42 are connected via connecting conductors BM to external electrodes 1 of multilayer substrate section 107. Connecting conductors BM are, for example, a heat-melting metal such as solder.

[0078] 8, multilayer substrate unit 107 is curved (bent) by 90° along the XZ plane toward the mounting surface of mounting unit 207. In other words, multilayer substrate unit 107 has a bent portion.

[0079] The connector 25 is connected to a patch antenna configured by mounting the mounting portion 207 .

[0080] According to this embodiment, multilayer substrate section 107 having such bent portions formed by heating can be arranged in any space, so that resin multilayer substrate 307 having a predetermined overall shape can be formed.

[0081] Eighth Embodiment In the eighth embodiment, an example will be shown in which the structure of the boundary between the multilayer substrate portion and the mounting portion is different from the resin multilayer substrates shown so far.

[0082] 9 is a cross-sectional view of a resin multilayer substrate 308 according to an eighth embodiment. The resin multilayer substrate 308 includes a multilayer substrate portion 108 and a mounting portion 208. The multilayer substrate portion 108 includes a plurality of resin layers 11, 12, 13, 14, and 15, and conductor layers and interlayer connection conductors attached to predetermined resin layers among the plurality of resin layers. A connection conductor BM is applied to an opening in the resin layer 15. The connection conductor BM is, for example, a heat-melting metal such as solder. A multilayer substrate portion-side pad electrode 2 is formed below the connection conductor BM.

[0083] The mounting portion 208 has a radiation electrode 7A formed on or near the upper surface thereof so that the mounting portion 208 functions as a patch antenna or as a part of the patch antenna.

[0084] Inside the resin layer 21, a plated filled through hole 9 is formed, which is electrically connected to the radiation electrode 7A.

[0085] The boundary between the mounting portion 208 and the multilayer substrate portion 108 (the base of the mounting portion 208) is covered with a resin material 10. This resin material 10 is structured to cover the second surface S2 of the multilayer substrate portion 108, so that the base of the mounting portion 208 is pressed down by the multilayer substrate portion 108.

[0086] The resin material 10 is, for example, an epoxy resin, and is applied to the multilayer substrate section 108 in the state where the mounting section 208 is mounted. It is desirable that the resin material 10 has a higher Young's modulus than the material that constitutes the resin layer of the multilayer substrate section 108. The Young's modulus can be determined by performing a nanoindenter test in accordance with the standards JIS Z 2255 and ISO 14577. For example, it can be determined from load-displacement data using a Micro Nanoindenter device manufactured by KLA.

[0087] Since the mounting portion of mounting portion 208 is rigid and the other portions are flexible, when an external force is applied to resin multilayer substrate 308 that tends to bend it, stress tends to concentrate at the base of mounting portion 208 .

[0088] In the resin multilayer substrate 308 of this embodiment, the bonding strength between the multilayer substrate section 108 and the mounting section 208 is strong, preventing cracks and chips at the interface between the multilayer substrate section 108 and the mounting section 208. In addition, the rigidity of the mounting section 208 relative to the multilayer substrate section 108 is high, suppressing deformation such as tilting of the mounting section 208. This suppresses deviations in the radiation direction (directivity) of the antenna.

[0089] 9 shows an example in which the resin material 10 is a separate member from the multilayer substrate section 108 and the mounting section 208, but the shape of the resin material 10 may be formed from the multilayer substrate section 108 or the mounting section 208. That is, after the mounting section 208 is placed on the multilayer substrate section 108, pressure is applied to press the mounting section 208 into the multilayer substrate section 108, and heat is applied. This causes the mounting section 208 to sink into the multilayer substrate section 108, and the resin layer on the upper layer of the multilayer substrate section 108 is raised toward the base of the mounting section 208, and this raised portion is formed as the resin material 10. Alternatively, the resin material 10 is formed by melting the base of the mounting section 208 using the pressure and heat.

[0090] Ninth Embodiment In the ninth embodiment, an electronic device including a resin multilayer substrate and another substrate will be exemplified.

[0091] 10 is a cross-sectional view of an electronic device 409 according to the ninth embodiment. This electronic device 409 includes another substrate 27, and a multilayer substrate section 101 and a mounting section 203 mounted thereon. Hatching is omitted from the illustration of the other substrate 27.

[0092] The structure of the resin multilayer substrate 303 including the multilayer substrate section 101 and the mounting section 203 is the same as the resin multilayer substrate 303 shown in FIG. 4 in the third embodiment.

[0093] An external electrode 1 is formed on the mounting surface (lower surface) of the resin multilayer substrate 303. An other-substrate-side pad electrode 41 is formed on the mounting surface (upper surface) of the other substrate 27.

[0094] The external electrodes 1 of the multilayer substrate section 101 are connected to the pad electrodes 41 on the other substrate side via connection conductors BM. The connection conductors BM are, for example, a heat-melting metal such as solder.

[0095] The other substrate 27 is, for example, a rigid glass epoxy resin substrate.

[0096] Tenth Embodiment In the eighth embodiment, an electronic device including a housing will be exemplified.

[0097] The electronic device according to this embodiment includes a resin multilayer substrate according to any one of the first to ninth embodiments, and a housing that houses the resin multilayer substrate.

[0098] The housing that houses the resin multilayer board has a size and shape that allows the resin multilayer board to be housed (built-in).

[0099] Various embodiments of the present invention have been presented so far, but these are all examples and are not intended to limit the scope of the present invention. Various omissions, substitutions, and modifications can be made to the embodiments of the present invention without departing from the spirit of the invention. Embodiments with such omissions, substitutions, and modifications are included within the scope and spirit of the present invention, and are also included in the scope of the invention and its equivalents as set forth in the claims of this application.

[0100] For example, although the embodiments do not show examples in which a protective film is formed on the multilayer substrate portion, mounting portion, etc., a protective film may be formed on a predetermined portion of the outer surface or on the entire surface.

[0101] In addition, in each embodiment, a microstrip line is configured by forming a signal line conductor pattern SL and a ground conductor layer GL, but the configuration of the resin multilayer substrate is not limited to one in which a transmission line is connected to a mounting portion.

[0102] The resin multilayer substrate and electronic device of the present invention may be provided in the following embodiments.

[0103] <1> a multilayer substrate portion having a plurality of resin layers and a conductor layer attached to a predetermined resin layer among the plurality of resin layers; a mounting portion having a resin layer and a conductor layer formed on the resin layer, the mounting portion being mounted on the multilayer substrate portion or having a shape to be mounted on the multilayer substrate portion; Equipped with the resin layer of the multilayer substrate section and the resin layer of the mounting section are both layers made of the same crystalline thermoplastic resin as a first component, a difference in endothermic peak temperature that first appears during temperature rise in a first-up chart when differential scanning calorimetry is performed between the resin layer of the multilayer substrate section and the resin layer of the mounting section at a temperature rise rate of 10°C / min, and the endothermic peak temperature of the resin layer of the multilayer substrate section is lower than the endothermic peak temperature of the resin layer of the mounting section; the resin layer of the multilayer substrate portion and the resin layer of the mounting portion are directly bonded to each other; Resin multilayer board.

[0104] <2> The crystalline thermoplastic resin is a wholly aromatic polyester resin. <1> The resin multilayer substrate according to claim 1.

[0105] <3> the mounting portion has a higher crystallinity than the multilayer substrate portion due to a temperature increase / decrease treatment performed on the mounting portion; <1> or <2> The resin multilayer substrate according to claim 1.

[0106] <4> the modulus of elasticity of the multilayer substrate portion is lower than the modulus of elasticity of the mounting portion; <1> from <3> 1. The resin multilayer substrate according to claim 1 ,

[0107] <5> the mounting portion includes a plurality of resin layers, conductor layers formed on the resin layers, and interlayer connection conductors that electrically connect the conductor layers to each other; <1> from <4> 1. The resin multilayer substrate according to claim 1 ,

[0108] <6> the conductor layer formed on the mounting portion includes a radiation electrode and the interlayer connection conductor that is electrically connected to the radiation electrode; <5> The resin multilayer substrate according to claim 1.

[0109] <7> the multilayer substrate section has interlayer connection conductors on an upper surface of the multilayer substrate section; the mounting portion has terminal electrodes on a lower surface of the mounting portion, the terminal electrodes of the mounting portion are electrically connected to the interlayer connection conductors of the multilayer substrate portion; <1> from <6> 1. The resin multilayer substrate according to claim 1 ,

[0110] <8> a transmission line is formed in the multilayer substrate portion; <1> from <7> 1. The resin multilayer substrate according to claim 1 ,

[0111] <9> The multilayer substrate portion has a bent portion. <1> from <8> 1. The resin multilayer substrate according to claim 1 ,

[0112] <10> the multilayer substrate unit has external electrodes, and a component is connected to the external electrodes and mounted on the multilayer substrate unit. <1> from <9> 1. The resin multilayer substrate according to claim 1 ,

[0113] <11> a resin material covering the boundary between the mounting portion and the multilayer substrate portion; <1> from <10> 1. The resin multilayer substrate according to claim 1 ,

[0114] <12> <1> from <11> a resin multilayer substrate according to any one of the preceding claims, and another substrate on which the resin multilayer substrate is mounted. electronic equipment.

[0115] <13> <1> from <11> and a housing that houses the resin multilayer substrate. [Explanation of symbols]

[0116] BM...connecting conductor GL: Ground conductor layer S1...Side 1 S2...Side 2 SL, SL1, SL2, SLa, SLb...Signal line conductor patterns 1...External electrode 2, 2a, 2b... Multilayer board side pad electrodes 4...Interlayer connecting conductor 5...Conductor foil 6,6A,6a,6b…Terminal electrode 7...Conductor layer 7A…Radiation electrode 7G: Ground electrode 9...Plated through-hole filling 10...Resin material 11,12,13,14,15...Multilayer board side resin layer 20...adhesive layer 21... Mounting portion side resin layer 24...Electronic components 25...Connector 27...Other boards 41...Pad electrode on other substrate 42...Component side pad electrode 101,102,105,106,107,108...Multilayer board part 201, 202, 203, 204, 205, 207, 208...Mounting section 301,302,303,304,305,306,307,308...Resin multilayer board 409...Electronic equipment

Claims

1. a multilayer substrate portion having a plurality of resin layers and a conductor layer attached to a predetermined resin layer among the plurality of resin layers; a mounting portion having a resin layer and a conductor layer formed on the resin layer, the mounting portion being mounted on the multilayer substrate portion or having a shape to be mounted on the multilayer substrate portion; Equipped with the resin layer of the multilayer substrate section and the resin layer of the mounting section are both layers made of the same crystalline thermoplastic resin as a first component, a difference in endothermic peak temperature that first appears during temperature rise in a first-up chart when differential scanning calorimetry is performed between the resin layer of the multilayer substrate portion and the resin layer of the mounting portion at a temperature rise rate of 10°C / min, and the endothermic peak temperature of the resin layer of the multilayer substrate portion is lower than the endothermic peak temperature of the resin layer of the mounting portion; the resin layer of the multilayer substrate portion and the resin layer of the mounting portion are directly bonded to each other; Resin multilayer board.

2. The crystalline thermoplastic resin is a wholly aromatic polyester resin. The resin multilayer substrate according to claim 1 .

3. the mounting portion has a higher crystallinity than the multilayer substrate portion due to a temperature increase / decrease treatment performed on the mounting portion; The resin multilayer substrate according to claim 1 or 2.

4. the modulus of elasticity of the multilayer substrate portion is lower than the modulus of elasticity of the mounting portion; The resin multilayer substrate according to claim 1 or 2.

5. the mounting portion includes a plurality of resin layers, conductor layers formed on the resin layers, and interlayer connection conductors that electrically connect the conductor layers to each other; The resin multilayer substrate according to claim 1 or 2.

6. the conductor layer formed on the mounting portion includes a radiation electrode and the interlayer connection conductor that is electrically connected to the radiation electrode; The resin multilayer substrate according to claim 5 .

7. the multilayer substrate section has interlayer connection conductors on an upper surface of the multilayer substrate section; the mounting portion has terminal electrodes on a lower surface of the mounting portion, the terminal electrodes of the mounting portion are electrically connected to the interlayer connection conductors of the multilayer substrate portion; The resin multilayer substrate according to claim 1 or 2.

8. a transmission line is formed in the multilayer substrate portion; The resin multilayer substrate according to claim 1 or 2.

9. The multilayer substrate portion has a bent portion. The resin multilayer substrate according to claim 1 or 2.

10. the multilayer substrate unit has external electrodes, and a component is connected to the external electrodes and mounted on the multilayer substrate unit. The resin multilayer substrate according to claim 1 or 2.

11. a resin material covering the boundary between the mounting portion and the multilayer substrate portion; The resin multilayer substrate according to claim 1 or 2.

12. A resin multilayer substrate according to claim 1 or 2; and another substrate on which the resin multilayer substrate is mounted. electronic equipment.

13. 3. An electronic device comprising: the resin multilayer board according to claim 1; and a housing that houses the resin multilayer board.

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