Manufacturing method of wiring boards
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- IBIDEN CO LTD
- Filing Date
- 2022-03-24
- Publication Date
- 2026-08-04
Smart Images
Figure 0007900168000001 
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Abstract
Description
Technical Field
[0001] The present invention relates to a method for manufacturing a wiring board.
Background Art
[0002] Patent Document 1 discloses a method for manufacturing a wiring board. In Patent Document 1, a second wiring board having a first electrode and a second electrode formed via a seed layer on a support is connected with the surface on the side opposite to the support facing the first wiring board side. The first electrode of the second wiring board is in contact with the seed layer, and the second electrode is connected to the first wiring board. After the second wiring board and the first wiring board are joined, the support is peeled off from the second wiring board with the seed layer attached to the second wiring board, and then the seed layer is removed by etching.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the method for manufacturing a wiring board disclosed in Patent Document 1, the second wiring board is joined to the first wiring board without performing a conduction inspection on the second wiring board. There is a case where a good first wiring board is selected as a defective product and discarded in a later inspection together with a defective second wiring board.
Means for Solving the Problems
[0005] The present invention provides a method for manufacturing a wiring board, comprising: preparing a first support plate and forming a metal film on the first support plate; forming a first wiring structure on the metal film having an insulating layer and a conductive layer, and having a first surface in contact with the metal film and a second surface opposite to the first surface; attaching a second support plate to the second surface; removing the first support plate and the metal film from the first wiring structure after attaching the second support plate to expose the first surface; preparing a second wiring structure and connecting the first surface to the outermost surface of the second wiring structure; and removing the second support plate from the first wiring structure to expose the second surface. The first surface includes a plurality of first-surface-side conductor pads connected to the second wiring structure, and the second surface includes a plurality of second-surface-side conductor pads constituting a component mounting area. A first continuity test is performed between the plurality of second-surface-side conductor pads before the first support plate and the metal film are removed, and a second continuity test is performed between the exposed plurality of first-surface-side conductor pads after the removal of the first support plate and the metal film, and before the second support plate is removed from the first wiring structure.
[0006] According to the manufacturing method of a wiring board, which is an embodiment of the present invention, before connecting the first wiring structure to the second wiring structure, a first continuity test is performed between the second-side conductor pads on the second surface of the first wiring structure, and a second continuity test is performed between the first-side conductor pads on the first surface. This is expected to improve the yield in the manufacturing of the wiring board. [Brief explanation of the drawing]
[0007] [Figure 1] A cross-sectional view showing an example of a wiring board manufactured by a manufacturing method according to one embodiment of the present invention. [Figure 2] An enlarged view of the first wiring structure in Figure 1, which shows an example of a wiring board manufactured by a manufacturing method according to one embodiment of the present invention. [Figure 3A] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 3B] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 3C]A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 3D] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4A] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4B] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4C] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4D] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4E] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4F] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4G] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4H] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Figure 4I] A cross-sectional view showing a manufacturing method for a wiring board according to one embodiment. [Modes for carrying out the invention]
[0008] A wiring board manufactured by the wiring board manufacturing method of one embodiment of the present invention will be described with reference to the drawings. Note that the drawings referenced below are not intended to show the exact proportions of each component, but are drawn in a way that facilitates understanding of the features of the present invention. Figure 1 shows a cross-sectional view of a wiring board 1 as an example of a structure that the manufactured wiring board may have.
[0009] As shown in Figure 1, the wiring board 1 has a core substrate 100 which includes an insulating layer (core insulating layer) 101 and conductive layers (core conductive layers) 102 formed on both sides of the core insulating layer 101. The insulating layer and conductive layer are alternately laminated on both sides of the core substrate 100. In the illustrated example, a first build-up section 10 is formed on one side F1 of the core substrate 100, in which the insulating layer 11 and conductive layer 12 are laminated. A second build-up section 20 is formed on the other side F2 of the core substrate 100, in which the insulating layer 21 and conductive layer 22 are laminated.
[0010] In the description of the wiring board of this embodiment, the side furthest from the core insulating layer 101 is referred to as "top," "upper side," "outside," or "outer," and the side closer to the core insulating layer 101 is referred to as "bottom," "lower side," "inside," or "inner." Furthermore, in each component, the surface facing away from the core substrate 100 is also referred to as the "top surface," and the surface facing the core substrate 100 is also referred to as the "bottom surface." Accordingly, in the description of each element constituting the wiring board 1, the side furthest from the core substrate 100 is referred to as "top," "upper side," "upper layer side," "outside," or simply "top" or "outer," and the side closer to the core substrate 100 is referred to as "bottom," "downward," "lower layer side," "inside," or simply "bottom" or "inner."
[0011] On the first build-up section 10, a covering layer 110 is formed that covers the conductor layer 12 and the insulating layer 11 exposed from the conductor pattern of the conductor layer 12. On the second build-up section 20, a covering layer 210 is formed that covers the conductor layer 22 and the insulating layer 21 exposed from the conductor pattern of the conductor layer 22. The covering layers 110 and 210 may be, for example, solder resist layers that constitute the outermost insulating layer of the wiring board 1.
[0012] The coating layer 110 has openings 110a and 110b formed therein. The openings 110a and 110b are through holes penetrating the coating layer 110 in the thickness direction. The opening 110a is filled with a conductor, and a wiring structure WS1 is disposed within the opening 110b. The wiring structure WS1 includes relatively fine wirings and may have a circuit wiring with a relatively high density. The conductor filling the opening 110a constitutes the outermost surface of the wiring board 1 and forms a connection element MP that can be used for connecting the wiring board 1 to an external electronic component. The connection element MP can be, for example, a post (metal post) formed of a metal.
[0013] Note that the wiring structure WS1 constitutes the wiring board 1 together with the wiring structure composed of the core substrate 100, the first and second build-up portions 10 and 20, the coating layers 110 and 210, and the connection element MP. The wiring structure WS1 is also referred to as the first wiring structure WS1. The wiring structure composed of the core substrate 100, the first and second build-up portions 10 and 20, the coating layers 110 and 210, and the connection element MP, other than the first wiring structure WS1 that constitutes the wiring board 1, is also referred to as the second wiring structure WS2.
[0014] The upper surface of the first wiring structure WS1 disposed within the opening 110b, similar to the connection element MP, constitutes the outermost surface of the wiring board 1 and has a conductor pad OP for connection that can be used for connecting the wiring board 1 to an external electronic component. An opening 210a is formed in the coating layer 210, and a conductor pad 22p of the outermost conductor layer 22 in the second build-up portion 20 is exposed from the opening 210a. The conductor pad OP constituting the outermost surface of the first wiring structure WS forms a component mounting surface on the wiring board 1 to which an external electronic component can be connected. In the illustrated example, the upper surface of the conductor pad OP and the upper surface of the connection element MP form a substantially flush component mounting surface.
[0015] The insulating layers 101, 11, and 21 that constitute the second wiring structure WS2 can each be formed using an insulating resin such as, for example, an epoxy resin, a bismaleimide triazine resin (BT resin), or a phenolic resin. Each of the insulating layers 101, 11, and 21 may contain a reinforcing material (core material) such as glass fiber and / or an inorganic filler such as silica or alumina. The coating layers 110 and 210 that can be solder resist layers can be formed using, for example, a photosensitive epoxy resin or a polyimide resin. [[ID=D1]] [[ID=D2]]
[0016] [[ID=D3]] The conductor layers 102, 12, 22, via conductors 13, 23, through-hole conductors 103, and connection elements MP are formed using any metal such as copper or nickel. The conductor layers 102, 12, 22, via conductors 13, 23, through-hole conductors 103, and connection elements MP can be constituted by, for example, a metal foil such as a copper foil and / or a metal film formed by plating or sputtering. The conductor layers 102, 12, 22, via conductors 13, 23, through-hole conductors 103, and connection elements MP are shown as a single-layer structure in FIG. 1, but may have a multilayer structure having two or more metal layers. [[ID=D5]] [[ID=D6]]
[0017] [[ID=D7]] [[ID=D8]]Each of the conductor layers 102, 12, 22 included in the wiring substrate 1 is patterned so as to have a predetermined conductor pattern. In the illustrated example, the outermost conductor layer 12 of the first build-up portion 10 is formed in a pattern having a plurality of conductor pads P1, P2. A connection element MP is connected to the conductor pad P1. The conductor pad P2 is exposed at the bottom of the opening 110b and is electrically connected to the conductor pad IP included in the first wiring structure WS1. [[ID=D9]] [[ID=D10]]
[0018] [[ID=D11]] The component mounting surface, including the upper surface of the connection pad OP and the upper surface of the connection element MP, has multiple component mounting areas, and in the illustrated example, it has component mounting areas EA1, EA2, and EA3. Component mounting areas EA1, EA2, and EA3 correspond to areas where electronic components E1, E2, and E3 are to be mounted, respectively. The upper surface of the connection element MP and the upper surface of the conductor pad OP can be electrically and mechanically connected to external electronic components via a conductive bonding material (not shown), such as solder, between them and the connection pads of external electronic components.
[0019] In the illustrated example, a plurality of conductor pads OP formed on the upper surface of the first wiring structure WS1 are located in three component mounting areas EA1, EA2, and EA3, respectively. The first wiring structure WS1 may have wiring that can electrically connect electronic components that can be connected to the first wiring structure WS1. Conductor pads OP located in the first component mounting area EA1 and conductor pads OP located in the adjacent second and third component mounting areas EA2 and EA3 can be electrically connected via wiring within the first wiring structure WS1.
[0020] Furthermore, the first wiring structure WS1 is positioned within the opening 110b so that its entire side and top surfaces are exposed, in order to suppress the influence of its thermal expansion on the components of the second wiring structure WS2 that constitute the wiring board 1 (particularly the connecting element MP and the conductor pad P1).
[0021] Next, the configuration of the first wiring structure WS1 will be described with reference to Figure 2. Figure 2 is an enlarged view of region II enclosed by the dashed line in Figure 1. The first wiring structure WS1, which is placed within the opening 110b of the covering layer 110, has alternatingly stacked insulating layers 31 and conductor layers 32. Conductor layers 32 facing each other with a single insulating layer 31 in between are connected by via conductors 33.
[0022] The first wiring structure WS1 has a first surface A and a second surface B opposite to the first surface A. In the illustrated example, the first surface A is composed of the surface (bottom surface) of the insulating layer 31 and the surface (bottom surface) of the conductor layer 32. In the illustrated example, the conductor layer 32 constituting the first surface A includes a conductor pad IP, and the conductor pad IP is connected to a conductor pad P2 via a bump BP, which is a conductive bonding material (e.g., solder). The conductor pad P2 has a protective film (not shown) on its surface, composed of, for example, three layers of Ni, Pd, and Au, and the bump BP can be bonded to, for example, the Au layer constituting the outermost surface of the protective film. The conductor pad IP constituting the first surface A is also referred to as the first surface side conductor pad IP.
[0023] The second surface B is composed of the surface (top surface) of the conductor layer 32 and the surface (top surface) of the insulating layer 31 exposed from the pattern of the conductor layer 32. The conductor layer 32 constituting the second surface B has a conductor pad OP. On the surface of the conductor pad OP, for example, a plating layer P including a nickel layer N and a tin layer S may be formed, as shown in the figure. The conductor pad OP provided on the second surface B of the first wiring structure WS1 is also referred to as the second surface side conductor pad OP.
[0024] The insulating layer 31 can be formed using an insulating resin such as epoxy resin or phenolic resin. Examples of conductors constituting the conductor layer 32 and via conductor 33 include copper and nickel, with copper being preferred. In the illustrated example, the conductor layer 32 constituting the first surface A is composed of a single layer of plating film layer (preferably electrolytic copper plating film) ep, while the other conductor layers 32 and via conductor 33 have a two-layer structure including a metal film layer (preferably electroless copper plating film layer) np and a plating film layer (preferably electrolytic copper plating film) ep.
[0025] The conductor pads OP located in the first component mounting area EA1 and the conductor pads OP located in the second and third component mounting areas EA2 and EA3 can be electrically connected via wiring (bridge wiring) BW. With this configuration, the wiring board 1 can electrically connect multiple external electronic components to each other via the wiring structure WS1 during its use. The first wiring structure WS1 can be installed between the first surface A and the bottom surface of the opening 110b via an underfill insulating film UF when placed within the opening 110b.
[0026] Next, referring to Figures 3A to 4I, a method for manufacturing a wiring board according to one embodiment will be described, using the case where the wiring board 1 shown in Figure 1 is manufactured as an example. The wiring board 1 can be formed by preparing a second wiring structure WS2 and connecting the manufactured first wiring structure WS1 to the second wiring structure WS2 (see Figure 1). First, referring to Figures 3A to 3D, an overview of preparing the second wiring structure WS2 and connecting the first wiring structure WS1 to the second wiring structure WS2 will be described.
[0027] First, as shown in Figure 3A, a core substrate 100 is prepared. For example, a double-sided copper-clad laminate is prepared, in which a metal foil is provided on the surface of the core insulating layer 101. Through holes 103a are formed in this double-sided copper-clad laminate, for example, by drilling. An electroless plating film is formed on the inner wall of the through holes 103a and the upper surface of the metal foil, and an electrolytic plating film is formed on top of this electroless plating film, using this electroless plating film as a power supply layer. As a result, although it is shown as a single layer in the figure, a through-hole conductor 103 is formed that has a two-layer structure of an electroless plating film and an electrolytic plating film and covers the inner wall of the through holes 103a.
[0028] The inside of the through-hole conductor 103 formed on the inner wall of the through-hole 103a is filled with resin body 103b, for example by injecting epoxy resin. After the filled resin body 103b has solidified, an electroless plating film and an electrolytic plating film are further formed on the upper surface of the resin body 103b and the electrolytic plating film. As a result, although shown as a single layer in the figure, a conductor layer 102 having a five-layer structure of metal foil, electroless plating film, electrolytic plating film, electroless plating film, and electrolytic plating film is formed on both sides of the insulating layer 101. Then, by patterning the conductor layer 102 using a subtractive method, a core substrate 100 having a predetermined conductor pattern is obtained.
[0029] Next, as shown in Figure 3B, a first build-up section 10 is formed on one side F1 of the core substrate 100 by laminating a desired number of insulating layers 11 and conductive layers 12. On the other side F2 of the core substrate 100, a second build-up section 20 is formed by laminating a desired number of insulating layers 21 and conductive layers 22. For example, each insulating layer 11, 21 is formed by thermocompressing a film-like insulating resin onto the core substrate 100. The conductive layers 12, 22 can be formed simultaneously with via conductors 13, 23 that fill openings 13a, 23a, which can be formed in the insulating layers 11, 21, for example by laser light, using any conductive pattern formation method such as a semi-additive method. The outermost conductive layer 12 in the first build-up section 10 is formed in a pattern including a plurality of conductive pads P1, P2. The outermost conductive layer 22 in the second build-up section 20 is formed in a pattern including conductive pads 22p.
[0030] Next, as shown in Figure 3C, a coating layer 110 is formed on the first build-up section 10, and a coating layer 210 is formed on the second build-up section 20. The coating layer 110 has an opening 110a that exposes the conductor pad P1, and an opening 110b that exposes the conductor pad P2. The coating layer 210 has an opening 210a that exposes the conductor pad 22p. For example, the coating layers 110 and 210 can be formed by spray coating, curtain coating, or film application to create a photosensitive epoxy resin film, and the openings 110a, 110b, and 210a can be formed by exposure and development.
[0031] Next, the opening 110a is filled with a conductor to form the connecting element MP. The connecting element MP can be formed, for example, by a semi-additive method, similar to the formation of the via conductors 13 and 23 and the conductor layers 12 and 22 described above. The connecting element MP may also be formed solely by electroless plating on the conductor pad P1. During the formation of the connecting element MP, the opening 110b may be closed with a protective film or the like as appropriate. The preparation of the second connecting structure WS2 is then complete.
[0032] Next, as shown in Figure 3D, the first wiring structure WS1 is installed in the opening 110b. The first wiring structure WS1 can be installed with its first surface A facing the first build-up section 10, and with an underfill insulating film UF interposed between the insulating layer 11 and the first surface A.
[0033] Next, with reference to Figures 4A to 4I, the manufacturing of the first wiring structure WS1 shown in Figure 2, and the specific connection between the first wiring structure WS1 and the second wiring structure WS2 will be explained. Regarding the manufacturing of the first wiring structure WS1, first, as shown in Figure 4A, a first support plate GS1 is prepared, which is a substrate made of an inorganic material such as glass and has good surface flatness. A metal film mf is formed (adhered) to one surface of the first support plate GS1 via a first adhesive layer AL1. The first adhesive layer AL1 may use an adhesive that adheres relatively strongly to the first support plate GS1, which is a glass substrate, but adheres to the metal film mf with a weaker adhesive strength than the adhesive strength to the first support plate GS1.
[0034] In the description of the manufacturing of the first wiring structure, the side closer to the first support plate GS1 is referred to as "bottom" or "lower side," and the side further from the first support plate GS1 is referred to as "top" or "upper side." Therefore, the side of each element constituting the wiring structure that faces the first support plate GS1 is referred to as the "bottom surface," and the side that faces away from the first support plate GS1 is also referred to as the "top surface."
[0035] Next, as shown in Figure 4B, a conductive layer 32 including conductive pads IP as its conductive pattern is formed on the metal film mf. In forming the conductive layer 32, for example, a plating resist is formed on the metal film mf, and openings corresponding to the formation area of the conductive pad IP pattern are formed in the plating resist, for example, by photolithography. Next, an electroplated film is formed in the openings by electroplating with the metal film mf as a seed layer. After the formation of the electroplated film, the plating resist is removed. Subsequently, an insulating layer 31 covering the conductive layer 32 with conductive pads IP is laminated. As the insulating layer 31, for example, a film-like insulating resin containing epoxy resin, phenolic resin, etc., and not containing a core material such as glass fiber may be used.
[0036] Next, as shown in Figure 4C, the required number of insulating layers 31 and conductor layers 32 are laminated on the upper side of the first support plate GS1, forming the first wiring structure WS1 up to the second surface B. The laminated structure of the first wiring structure WS1 having the first surface A and the second surface B is completed. In the illustrated example, all insulating layers 31 constituting the first wiring structure WS1 are formed from a film-like insulating resin that does not contain a core material. Furthermore, in forming the conductor layers 32 on the insulating layers 31, any conductor layer 32 can be formed to have the form of embedded wiring, embedded in the insulating layer 31 below.
[0037] Specifically, in forming the conductor layer 32 having the form of embedded wiring, a metal film layer and an electroplated film layer formed with the metal film layer as a seed layer are formed on the inside of grooves formed by laser processing using an excimer laser, for example, and on the upper surface of the insulating layer 31. A portion of the electroplated film layer and the metal film layer are removed, for example, by chemical mechanical polishing (CMP) until the upper surface of the insulating layer 31 is exposed, thereby forming the conductor layer 32 having the form of embedded wiring.
[0038] In the illustrated example, the uppermost conductor layer 32 of the first wiring structure WS1 is formed, for example, by a semi-additive method, into a pattern including multiple conductor pads (second-side conductor pads) OP. A plating layer P including, for example, a nickel layer N and a tin layer S may be formed on the upper surface of the conductor pads OP. Furthermore, the multiple conductor pads (second-side conductor pads) OP may be formed to be electrically connected to each other by wiring included in the conductor layer 32 that constitutes the first wiring structure WS1. Specifically, in the use of a wiring board, the conductor layer 32 may be formed to have wiring (bridge wiring) BW that interposes the connection between the conductor pads OP so that conductor pads OP that can be connected to different electronic components can be electrically connected to each other.
[0039] Next, in the state shown in Figure 4C, a continuity test of the first wiring structure WS1 is performed. Specifically, a continuity test is performed on the conductor paths (conductor circuits) formed by the conductors (conductor layers 32 and via conductors 33) that constitute the first wiring structure WS1, via the multiple exposed second-side conductor pads OP. In this specification, "continuity test" means checking for open faults and / or short faults in the conductor circuits that electrically connect the conductor pads exposed on the surface of the first wiring structure WS1.
[0040] For continuity testing, a testing device commonly called an open-short checker may be used. An open-short checker has multiple contact terminals and can measure the continuity resistance value of a conductor circuit connected via a pair of these terminals. By comparing the detected continuity resistance value with a predetermined resistance value, the presence or absence of an open-circuit or short-circuit defect can be checked. Each of the multiple contact terminals en of the testing device contacts the exposed surface of the second-side conductor pad OP, and the resistance value between any two second-side conductor pads OP is measured. By checking whether the measured resistance value between the second-side conductor pads OP falls within a predetermined range, the presence or absence of a defect in the conductor circuit between the second-side conductor pads OP can be determined.
[0041] In the state shown in Figure 4C, all of the multiple first-side conductor pads IP constituting the first surface A are connected to a conductive metal film mf. That is, the multiple first-side conductor pads IP are short-circuited by the metal film mf. Therefore, an open check is possible between the second-side conductor pads OP, each electrically connected to a different first-side conductor pad IP via a different conductive path.
[0042] Specifically, of the multiple (15) second-side conductor pads OP shown in the diagram, the two second-side conductor pads OP located at both ends of the first wiring structure WS1 are connected to different first-side conductor pads IP by different conductor paths. If the conductor circuit connecting these two second-side conductor pads OP and the first-side conductor pad IP at both ends is open, such as being broken, the resistance value between the second-side conductor pads OP will be significantly larger than when it is not open. Therefore, it is possible to inspect for open-circuit defects in the conductor circuit (open-circuit inspection) based on the resistance value obtained by measurement. Thus, in the manufacturing method of the wiring board of this embodiment, open-circuit inspection is possible in the conductor circuit connecting the second-side conductor pad OP and the first-side conductor pad IP, which would otherwise be impossible to perform an open-circuit inspection on unless they were short-circuited by a metal film mf.
[0043] The continuity test performed between multiple second-side conductor pads OP in the state shown in Figure 4C is referred to as the first continuity test. The first continuity test is performed when the first wiring structure WS1 is supported by the first support plate GS1. Therefore, the first continuity test can be performed when the flatness of the wiring board 1 is maintained in a relatively good state. It is thought that contact between the contact terminal en and the second-side conductor pad OP can be made more reliable, and a more reliable continuity test can be performed. In addition, if an open fault or short fault is detected in the first continuity test, the first wiring structure WS1 will be recalled as a defective product.
[0044] The first continuity test may include a short circuit test between multiple second-side conductor pads OP that should be electrically insulated in the first wiring structure WS1. Specifically, a short circuit test may be performed between second-side conductor pads OP that are electrically connected to different bridge wirings BWs, among multiple bridge wirings BWs that connect second-side conductor pads OP located in different component mounting areas. In other words, a short circuit test may be performed between bridge wirings. For example, a short circuit test may be performed between the second second-side conductor pad OP and the third second-side conductor pad OP from the end of the illustrated first wiring structure WS1. The first continuity test may also include an open circuit test between second-side conductor pads OP that are electrically connected by a common bridge wiring BW. In other words, an open circuit test may be performed between bridge wirings. For example, an open circuit test may be performed between the third second-side conductor pad OP and the fourth second-side conductor pad OP from the end of the illustrated first wiring structure WS1.
[0045] If the first wiring structure WS1 is determined to be a good product in the first continuity test, the following subsequent steps are performed. As shown in Figure 4D, the second support plate GS2 is attached to the second surface B side of the first wiring structure WS1. As shown in the figure, the second support plate GS2 may be, for example, a double-sided copper-clad laminate in which copper foil cf is laminated on both sides of an organic layer OR in which an insulating resin is impregnated into a core material such as glass fiber or aramid fiber. The second support plate GS2 is attached, for example, with a second adhesive layer AL2 interposed between the copper foil cf and the second surface B side of the first wiring structure WS1.
[0046] Next, as shown in Figure 4E, the first support plate GS1 is removed from the first wiring structure WS1. At the time of removal of the first support plate GS1, the adhesive strength between the first adhesive layer AL1 and the metal film mf is weaker than the adhesive strength between the first adhesive layer AL1 and the first support plate GS1. Therefore, when removing the first support plate GS1, the first support plate GS1 and the first adhesive layer AL1 are peeled off from the metal film mf as a single unit. Furthermore, the adhesive strength between the first adhesive layer AL1 and the metal film mf is weaker than the adhesive strength between the second adhesive layer AL2 and the second surface B of the first wiring structure WS1, as well as the adhesive strength between the second adhesive layer AL2 and the second support plate GS2 (specifically, the copper foil cf). Therefore, the first support plate GS1 and the first adhesive layer AL1 can be removed from the first wiring structure WS1 (specifically, the metal film mf) while the first wiring structure WS1 is stably held by the second support plate GS2.
[0047] Next, as shown in Figure 4F, the metal film mf exposed on the lower surface of the first wiring structure WS1 is removed by etching. Removal of the metal film mf exposes the first surface A of the first wiring structure WS1, which consists of the conductor pad IP and the insulating layer 31.
[0048] Next, in the state shown in Figure 4F, a continuity test is performed on the conductor circuits constituting the first wiring structure WS1. Similar to the first continuity test described above, a test device generally called an open-short checker may be used. The continuity test performed in the state shown in Figure 4F is referred to as the second continuity test.
[0049] In the second continuity test, the presence or absence of open-circuit defects and / or short-circuit defects can be checked by measuring the continuity resistance between multiple first-side conductor pads IP that constitute the first surface A. The contact terminal en of the testing device is connected to the exposed surfaces of the multiple first-side conductor pads IP, and the resistance value between any pair of first-side conductor pads IP is measured, for example. If the measured resistance value does not fall within a predetermined range, it can be determined that a defect exists.
[0050] In the illustrated example, the multiple first-side conductor pads IP are electrically isolated from each other by separating the first support plate GS1 and removing the metal film mf. Each of the multiple (five) first-side conductor pads IP shown in Figure 4F is completely electrically isolated from each other without being connected by the conductor paths that constitute the first wiring structure WS1. In the second continuity test, the presence or absence of short circuits between these first-side conductor pads IP that should be completely electrically isolated from each other can be checked (short circuit test).
[0051] Specifically, for example, a contact terminal en is connected to each of a pair of first-side conductor pads IP that should be electrically isolated from each other, and the resistance between the pair of first-side conductor pads IP is measured. If the pair of first-side conductor pads IP are short-circuited, the resistance between the corresponding contact terminals en will be very low. This allows for the detection of a short-circuit defect between first-side conductor pads IP that should be completely electrically isolated from each other.
[0052] In the state shown in Figure 4F, the second continuity test between multiple first-side conductor pads IP is performed while the first wiring structure WS1 is supported by the second support plate GS2. Therefore, the second continuity test can be performed while the flatness of the first wiring structure WS1 is well maintained. It is thought that contact between the contact terminal en and the first-side conductor pad IP can be made more reliable, and a more reliable continuity test can be performed. Note that any first wiring structure WS1 in which a defect is detected by the second continuity test will be collected as a defective product. By performing the aforementioned first and second continuity tests before the first wiring structure WS1 is connected to the second wiring structure WS2, it is possible to avoid a situation where a good second wiring structure WS2 is collected together with a defective wiring structure WS1.
[0053] Next, as shown in Figure 4G, a bump BP, which is a bonding material made of solder, for example, is formed on the surface (bottom surface) of the exposed first-sided conductor pad IP. After the bump BP is formed, an underfill insulating film UF is provided so as to cover the bump BP and the bottom surface of the insulating layer 31. The underfill insulating film UF is attached to the bottom surface of the bump BP and the insulating layer 31, for example, under vacuum.
[0054] Next, the first wiring structure WS1 is installed in the opening 110b of the second wiring structure WS2, supported by the second support plate GS2, as shown in the figure. The dimensions of the opening 110b in the planar direction are larger than the dimensions of the first wiring structure WS1 in the planar direction, so that the first wiring structure WS1 can be positioned relatively easily in the desired location within the opening 110b so that its entire side and top surfaces are exposed. When installing the first wiring structure WS1 into the opening 110b, the bump BP and the conductor pad P2 are aligned. The underfill insulating film UF is heated to a temperature that is fluid but does not significantly harden (for example, about 60-150°C), and then pressed downwards until the bump BP and the conductor pad P2 come into contact. After that, it is heated to the melting temperature of the bump BP, and the bonding between the bump BP and the second conductor pad P2 is completed.
[0055] Next, as shown in Figure 4H, the second support plate GS2 is removed from the first wiring structure WS1. For example, at the time the second support plate GS2 is removed, the adhesive strength between the second adhesive layer AL2 interposed between the second support plate GS2 and the second surface B of the first wiring structure WS1 and the second surface B of the first wiring structure WS1 is weaker than the adhesive strength between the second support plate GS2 (specifically, the copper foil cf). Therefore, in this case, the second support plate GS2 and the second adhesive layer AL2 can be removed together from the second surface B of the first wiring structure WS1.
[0056] Next, as shown in Figure 4I, a third continuity test of the first wiring structure WS1 can be performed via a plurality of second-side conductor pads OP that are exposed by removing the second support plate GS2. The third continuity test may include a short-circuit test between a plurality of second-side conductor pads OP that should be electrically insulated from each other. Specifically, the third continuity test may include a short-circuit test between second-side conductor pads OP that are connected to different first-side conductor pads IP by different conductive paths. The third continuity test can be performed by having each of a plurality of contact terminals en provided by the testing device contact the exposed surface of the second-side conductor pads OP and measuring the resistance between any two second-side conductor pads OP.
[0057] The manufacturing method of the wiring board of the embodiment is not limited to the method described with reference to the drawings. In the manufacturing method of the wiring board of the embodiment, the first continuity test for the first wiring structure is performed between a plurality of second-face conductor pads constituting the component mounting area with the first support plate attached to the first wiring structure, and the second continuity test is performed after the metal film is removed and before it is connected to the second wiring structure. Any additional steps may be added in addition to the steps described above. Furthermore, any part of the steps described above may be omitted. Also, the wiring board manufactured by the manufacturing method of the wiring board of the embodiment is not limited to the structure of the illustrated wiring board, or to the structures, shapes, and materials exemplified herein. The second wiring structure is not limited to a form having a core substrate and may have any number of conductor layers and insulating layers. Also, the first wiring structure constituting the wiring board may have any number of conductor layers and insulating layers. The conductor pattern of each conductor layer may be formed into any pattern. [Explanation of symbols]
[0058] 1 Wiring board 10. First Build-up Department 20. Second Build-up Department 13, 23, 33 via conductors 101, 11, 21, 31 Insulating layer 102, 12, 22, 32 Conductor layers 100 core boards 103 Through-hole conductor 110a, 110b, 210a aperture WS1 wiring structure (1st wiring structure) WS2 wiring structure (second wiring structure) P1, P2 Conductor Pads OP conductor pad (second side conductor pad) IP conductor pad (first-side conductor pad) MP Connection Element UF Underfill Insulating Film BP Bump EA1, EA2, EA3 component mounting areas E1, E2, E3 electronic components GS1 1st support plate GS2 2nd support plate mf metal film
Claims
1. A first support plate is prepared, and a metal film is formed on the first support plate, A first wiring structure is formed on the metal film, having an insulating layer and a conductive layer, and comprising a first surface in contact with the metal film and a second surface opposite to the first surface. The second support plate is attached to the second surface, After the second support plate is attached, the first support plate and the metal film are removed from the first wiring structure to expose the first surface. A second wiring structure is prepared, and the first surface is connected to the outermost surface of the second wiring structure, The second support plate is removed from the first wiring structure to expose the second surface, A method for manufacturing a wiring board, including, The first surface includes a plurality of first surface-side conductor pads connected to the second wiring structure, The second surface includes a plurality of second-surface-side conductor pads that constitute a component mounting area. Before the first support plate and the metal film are removed, a first continuity test is performed between the plurality of second-side conductor pads. After the removal of the first support plate and the metal film, and before removing the second support plate from the first wiring structure, a second continuity test is performed between the exposed plurality of first-face conductor pads. After removing the second support plate from the first wiring structure, a third continuity test is performed between the plurality of second-side conductor pads. The first continuity test includes an open test between the plurality of second-side conductor pads, The second continuity test includes a short circuit test between the plurality of first-side conductor pads, The third continuity test includes a short-circuit test between the plurality of second-side conductor pads, each electrically connected to the plurality of first-side conductor pads by a different conductor path.
2. A method for manufacturing a wiring board according to claim 1, wherein forming the first wiring structure includes forming a plurality of bridge wirings in the conductor layer that connect the second-side conductor pads that constitute different component mounting areas among the plurality of second-side conductor pads, and the first continuity test includes a short-circuit test between the plurality of second-side conductor pads that are electrically connected to each of the plurality of different bridge wirings.
3. A method for manufacturing a wiring board according to claim 1, wherein the first continuity test further includes an open test between the plurality of second-side conductor pads that are electrically connected to a plurality of common bridge wirings.