JP2006278991A - Manufacturing method of multilayer wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a multilayer wiring board that can laminate layers with a high location accuracy in laminating a number of multilayer wiring boards at once. <P>SOLUTION: This method manufactures a multilayer wiring board through the thermocompression of a connection board 107 with a junction for preventing inter-layer position misalignment and another board 110 subject to connection with a junction for preventing an inter-layer position misalignment formed at the location opposite to the junction for preventing the inter-layer position misalignment of the above connection board. It joins a junction 112 of an inter-layer position misalignment and the above junction 112 to constitute prevention fixture for an inter-layer position misalignment through thermocompression. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a multilayer wiring board.

  As a method of manufacturing a multilayer wiring board, there is a method of manufacturing a plurality of multilayer wiring board manufacturing substrates by collectively thermocompression bonding. When stacking together, improvement in positional accuracy between circuit boards has become a major issue as miniaturization and higher density of recent wiring.

  As a conventional technique, there is a method in which a plurality of circuit boards are aligned by a pin lamination method in which alignment is performed by pins in order to suppress misalignment at the time of thermocompression bonding, and then thermocompression bonding is performed with the pins inserted (for example, , See Patent Document 1). Furthermore, after aligning a plurality of circuit boards, a method of caulking with eyelet pins or the like, a method of partial thermal welding using an adhesive member such as a prepreg, or a simultaneous thermocompression bonding after performing these simultaneously (For example, refer to Patent Document 2). By these methods, the positional deviation of the inner circuit board during thermocompression bonding can be suppressed to some extent.

However, when using a pin, eyelet pin, or the like, a positional deviation occurs by the clearance of the pin insertion hole during thermocompression bonding. In addition, when the molten resin enters the clearance portion of the pin at the time of thermocompression bonding, it becomes difficult to remove the pin, and the process of removing the pin becomes troublesome. Furthermore, in the method of caulking with a pin for temporary fixing such as eyelet pins, the temporary fixing pin is disposable, which is expensive. In a method of using an adhesive member such as a prepreg to suppress misalignment between the layers by thermal welding, misalignment between the respective layers occurs due to remelting of the thermally welded portion by heating during thermocompression bonding.
JP 2002-101253 A (2nd term) Japanese Patent Application Laid-Open No. 2002-198644 (second item)

  In order to solve the above-described problems, an object of the present invention is to provide a method for manufacturing a multilayer wiring board that can be laminated with high precision in a method for collectively laminating multilayer wiring boards.

That is, the present invention
(1) A connection substrate on which an interlayer misalignment prevention joint is formed, and a connection in which an interlayer misalignment prevention joint is formed at a position facing the interlayer misalignment prevention joint of the connection substrate. A method of manufacturing a multilayer wiring board by thermocompression bonding with a circuit board, wherein the interlayer misalignment prevention joining portion and the interlayer misalignment prevention joined portion are joined, and an interlayer misalignment prevention fixing portion A method of manufacturing a multilayer wiring board, characterized by forming a thermocompression bonding,
(2) The multilayer wiring according to (1), wherein the fixing portion for preventing misalignment is made of an alloy formed of a metal constituting the joining portion and a metal constituting the joined portion. Board manufacturing method,
(3) The method for producing a multilayer wiring board according to (2), wherein the alloy has a higher melting point than the metal constituting the joining portion or the metal constituting the joined portion,
(4) The multilayer wiring board according to (2) or (3), wherein the alloy includes Sn and at least one selected from Ag, Cu, Au, and Ni.
(5) The method for producing a multilayer wiring board according to any one of (1) to (4), wherein the formation of the fixing portion for preventing misalignment is performed during temporary lamination.
(6) The formation of the fixing portion for preventing interlayer misalignment is less than the melting point of the fixing member material, the melting point of the higher melting point of the melting point of the metal constituting the joining portion and the melting point of the metal constituting the non-joining portion, The method for producing a multilayer wiring board according to any one of items (1) to (5), which is performed by heating at a temperature,
(7) The multilayer wiring board according to any one of (1) to (6), wherein the thermocompression bonding is performed by laminating a plurality of the connection substrates and the connection substrates. Manufacturing method,
(8) Items (1) to (7), wherein a distance between the center portion of the interlayer displacement prevention joint after thermocompression bonding and the center portion of the interlayer displacement prevention joint portion is 50 μm or less. A method for producing a multilayer wiring board according to any one of the items,
Is to provide.
Is to provide.

  ADVANTAGE OF THE INVENTION According to this invention, the position shift between the layers of the multilayer wiring board at the time of thermocompression bonding is suppressed, and the multilayer wiring board positioned with high precision can be obtained.

  The present invention provides a connection board on which an interlayer displacement prevention joint is formed, and a substrate on which an interlayer position prevention joint is formed at a position facing the interlayer displacement prevention joint of the connection board. A method of manufacturing a multilayer wiring board by thermocompression bonding with a connecting substrate, wherein the interlayer misalignment prevention joint and the interlayer misalignment prevention joint are joined, and interlayer misalignment prevention fixing This is a method for manufacturing a multilayer wiring board characterized by forming a portion and thermocompression bonding. In the thermocompression bonding process of the multilayer wiring board, the positional displacement between inner circuit boards can be suppressed and thermocompression bonding can be performed with high positional accuracy. is there.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings, but the present invention is not limited thereto.

First, so that one surface is exposed from the insulating layer 101, the conductor circuit 102 and the land 103 embedded in the insulating layer pass through the insulating layer on the surface opposite to the exposed surface, and the tip is convex. The conductor post 104 is formed so that the tip portion protrudes from the insulating layer, and the solder 105 is formed on at least one of the conductor circuit, the land, and the conductor post tip, and the tip of the conductor post protrudes. A multilayer wiring board manufacturing substrate (connection substrate) 107 whose surface of the insulating layer and the tip of the conductor post are covered with an adhesive layer 106 is formed, and a conductor circuit 108 and a land 109 are formed on the base copper foil. The connected substrates 110 to be connected are arranged so as to face each other (FIG. 1A).
Here, what constitutes the fixing portion for preventing the misalignment between the layers can use the conductor post 104 and the solder 105 as the joining portion for preventing the misalignment between the layers in the connecting substrate. As an inter-layer misalignment prevention bonded portion, a land 109 provided at a position opposite to the inter-layer misalignment prevention junction can be used, and a misalignment prevention fixing portion is previously formed in the multilayer wiring board. It is preferable to design the land, the conductor post, and the solder that are not related to the electrical connection between the layers.
Examples of the solder constituting the junction include Sn and In, or Sn and one or more selected from Ag, Cu, Zn, Bi, Pd, Sb, Pb, In, and Au. . In addition, examples of the conductor post include those made of copper or conductive paste, but if the conductor post is made of the same material as the solder layer, a solder layer is provided at the end of the conductor post. There is no need to form.

  Although the manufacturing method of the wiring board 107 for manufacturing the multilayer wiring board and the substrate for connection 110 is not described in detail, for example, a patterned plating resist is formed on a metal plate, and the metal plate is subjected to an electrolytic plating lead ( As the power supply electrode), a resist metal layer and a conductor circuit are sequentially formed by electrolytic plating. Next, when the plating resist is removed, a substrate for connection is obtained. Subsequently, an insulating layer is formed on the formed conductor circuit, and a via is formed in the formed insulating layer. Next, the metal plate is used as an electroplating lead (feeding electrode), and the conductor post is formed by electroplating. By this electroplating, a conductor post is formed in the portion of the insulating layer where the via is formed, and solder is formed on the tip surface thereof. Next, an adhesive layer is formed so as to cover the tip surface of the bonding metal material layer and the insulating layer, and the metal plate is removed by etching so that one surface is exposed from the insulating layer of the present invention. A wiring board for producing a multilayer wiring board having a conductor circuit embedded in an insulating layer can be obtained.

  Next, the multilayer wiring board manufacturing substrate 107 and the substrate to be connected 110 are aligned, and thermocompression bonding is performed at a temperature at which the solder does not melt and the adhesive melts and the substrates adhere to each other through the adhesive. A laminated multilayer wiring board 111 is obtained (FIG. 1B). Although not shown in the figure as an alignment method, when using the pin lamination method, a pin insertion hole is previously formed in a predetermined portion of the multilayer wiring board and the substrate to be connected, and the pin is installed at a predetermined position. The pin is inserted into the pin insertion hole and installed. In the case of using the image recognition device, the connection substrate and the connection target substrate are respectively placed on a bonding stage having a suction mechanism. As an adsorption mechanism, vacuum adsorption, adsorption by an electrostatic chuck, or the like can be used. Further, the stage preferably has a driving mechanism capable of fine adjustment for positioning and a mechanism for pressing and bonding.

Next, the interlayer misalignment prevention junction (land 103, conductor post 104, solder 105) at the location where the temporarily misaligned multilayer wiring board 111 is to be formed with the misalignment prevention fixing portion is connected to the multilayer wiring board manufacturing substrate 107 side. Then, the bonding mechanism 113 is partially subjected to thermocompression bonding at a temperature equal to or higher than the solder melting point to form a misalignment prevention fixing portion 112 to obtain a temporary laminate 114 (FIG. 1C).
As the bonding mechanism used in the present invention, a mechanism capable of locally heating and pressurizing the misalignment prevention fixing portion to a temperature equal to or higher than the solder melting point is preferable. For example, using a soldering iron, the misalignment prevention fixing portion is provided. The method of pressing the place to form from the board | substrate side for multilayer wiring board manufacture is mentioned.
The fixing portion for preventing the interlayer displacement is heated at a temperature lower than the melting point of the fixing member material, the higher melting point of the melting point of the metal constituting the joining portion and the melting point of the metal constituting the non-joining portion. It is preferable to do so.

  The positional misalignment prevention fixing portion obtained in this manner is preferably composed of an alloy formed of a metal constituting the joint and a metal constituting the joined portion, and constitutes the joint. It is more preferable that the metal has a higher melting point than the metal constituting the bonded portion. By alloying, the melting point becomes high, the heating temperature in the pressure bonding can be adjusted, the metal can be prevented from melting and flowing, and displacement can be prevented. As a specific example of such a misalignment-preventing fixing part, the material constituting the solder fixing part is preferably an alloy containing Sn and at least one selected from Ag, Cu, Au and Ni. An alloy composition including Sn—Cu alloy, Sn—Ag—Ni alloy, and Sn—Au alloy, which are alloyed at the time of soldering and increase in melting point, is more preferable. In order to configure the above system at the joint, for example, Sn-Ag solder is used for the solder formed on the conductor post, and Au is formed on the portion in contact with the land solder. When the temporary laminate is thermocompression bonded, if there is no solder fixing part, when thermocompression bonding is performed, shearing stress or adhesion is caused by the pressure of the multilayer wiring board manufacturing substrate and the connected substrate simultaneously with melting of the solder. The force that moves between the layers in the material flow direction works, and the position of the layers is greatly displaced. Although the center portion is displaced, the force of shifting the layers can be greatly suppressed, so that the positional deviation between the layers can be significantly suppressed. Furthermore, by keeping the melting point of the alloy formed on the solder fixing part higher than that of the solder, the solder fixing part is solid at the temperature at which the solder melts, and the interlayer displacement due to shear stress and adhesive flow is further reduced. I can do it. Thus, batch thermocompression bonding can be performed in the production of the multilayer wiring board.

  Further, when it is desired to increase the number of layers of the multilayer wiring board, the above-described temporary stacking process may be repeated a predetermined number of times. However, as an example, the case where another layer is temporarily stacked will be described with reference to the drawings. The multilayer wiring board manufacturing substrate 115 is opposed to the temporary laminate 114 (FIG. 1 (d)) and aligned and bonded to obtain a temporarily laminated multilayer wiring board 116 (FIG. 2 (e)). At this time, the place where the fixing part for preventing misalignment between layers is locally thermocompression bonded, so a dent is generated, but the adhesive layer is melted by thermocompression during temporary lamination, and the dent is filled with an adhesive. It becomes. Here, thermocompression bonding in a vacuum atmosphere is preferable because the dent is surely filled with an adhesive, so that it is difficult for voids to be contained in the multilayered wiring board laminated in a lump. Furthermore, the multilayer wiring board manufacturing substrate 115 is known at a place where the fixing portion for preventing misalignment of the temporarily laminated multilayer wiring board 116 is to be formed, and the bonding mechanism 113 performs thermocompression bonding at a temperature equal to or higher than the solder melting point to prevent misalignment. The fixing part 118 is formed, and the temporary laminate 117 is obtained.

  Next, the temporary laminated body 117 is thermocompression-bonded at a time to obtain a multilayer wiring board 119 (FIG. 2 (g)). At this time, since each inner layer is a fixing portion for preventing displacement, the displacement between layers is greatly suppressed, and a multilayer wiring board having excellent positional accuracy can be obtained. At this time, since the multilayer wiring board manufacturing substrate formed to form the misalignment prevention fixing portion is crimped so as to correct the dent on the alligator, the center of the conductor post and the misalignment prevention fixing portion are The distance of the center of the soldered portion formed when formed is shifted within 50 μm. However, when the fixing portion for preventing misalignment is not formed, the distance is further shifted, so that the yield is deteriorated.

  Next, the multilayer copper wiring board 120 is obtained by removing the base copper foil by etching (FIG. 2G). At this time, although not shown, it is preferable that a resist metal layer as an etching barrier is formed on the conductor circuit 108 and the land 109. As a method for forming the conductive circuit 108 and the land 109, the conductor circuit 108 and the land are electroplated on the base copper foil. By forming a resist metal layer by electrolytic plating before forming 109, the resist metal layer can be formed.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

  First, a method for manufacturing a wiring board for manufacturing a multilayer wiring board and a substrate for connection will be described in detail.

<Manufacture of wiring boards for manufacturing multilayer wiring boards and connected boards>
A dry film resist (AQ-2058, manufactured by Asahi Kasei, AQ-2058) is roll-laminated on a rolled copper plate (metal plate 101, manufactured by Furukawa Electric Co., Ltd., EFTEC-64T) with a roughened surface, and a predetermined negative film is used. Exposure and development were performed to form a plating resist necessary for the formation of conductor circuits and lands.
Next, a rolled copper plate was used as a lead for electrolytic plating, gold as a resist metal was formed by electrolytic plating, and further a conductive circuit and a land were formed by electrolytic copper plating. The conductor circuit had a line width / interline / thickness = 40 μm / 40 μm / 10 μm.
Next, the dry film resist was peeled off. Here, in order to increase the wettability with the solder only on the substrate to be connected, gold is formed by electrolytic plating on the conductor circuit and the land, and is separated into a size of 50 mm × 50 mm to obtain the substrate to be connected. It was.
Next, an insulating layer (manufactured by Sumitomo Bakelite) with a PET film as a supporting base material formed on the substrate after peeling is molded while embedding the irregularities of the conductor circuit by vacuum laminating, and the PET film is peeled off to insulate 25 μm thick A layer was formed.
Next, vias having a diameter of 50 μm were formed by a UV-YAG laser, and processing residues inside and around the vias were removed by wet desmearing using ultrasonic waves.
Subsequently, the rolled copper plate was used as an electrolytic plating lead, and electrolytic copper plating was performed to fill the via with copper, thereby forming a conductive post and a conductive post for forming a solder fixing portion.
Next, Sn-Ag solder was formed on the conductor post so as to have a thickness of 5 μm by electrolytic plating using the rolled copper plate as a lead for electrolytic plating. Next, it separated into pieces of 50 mm × 50 mm.
Next, the adhesive is applied to a PET film, dried at 80 ° C. for 20 minutes to form a dry film, and the adhesive layer is formed on the surface of the insulating layer, that is, the surface on which the solder is formed, by a dry film laminator (manufactured by Taisei Laminator Co., Ltd.). ). Finally, the entire surface of the rolled copper foil was etched with a ferric chloride solution to obtain a wiring board for producing a multilayer wiring board.

  Then, the manufacturing method of a multilayer wiring board using said wiring board for multilayer wiring board manufacture is demonstrated in detail.

<Manufacture of multilayer wiring boards>
The wiring board for manufacturing the multilayer wiring board obtained by the above process and the positioning mark formed in advance on the substrate to be connected are read with an image recognition bonding apparatus (manufactured by System Development Co., Ltd.), and both are aligned. And superimposed. After the overlapping, the solder fixing part was formed by pressing the soldering iron heated to 280 ° C. from the multilayer wiring board manufacturing substrate to the part where the solder fixing part provided in advance was formed. At this time, a dent was formed in the substrate for manufacturing the multilayer wiring board, centering on the solder fixing portion.
Further, the process of forming the solder fixing portion by repeating the process of aligning and bonding the mark exposed on the surface of the multilayer wiring board manufacturing substrate and the next multilayer wiring board manufacturing substrate by image recognition to form the solder fixing portion is repeated. A multilayer wiring board in which a multilayer wiring board manufacturing substrate was formed on only three layers on the connection substrate was obtained.
Next, the temperature is raised to 250 ° C. in 10 seconds by a thermocompression press using a pulse heat heating method, and then pressure is applied at a pressure of 0.1 MPa to connect all the points between the conductor posts and the lands, and the layers are adhesive layers. Glued by.
Next, the rolled copper foil was removed by etching using a ferric chloride solution to obtain a multilayer wiring board in which three layers of wiring boards for manufacturing a multilayer wiring board were laminated.
Next, as a result of measuring the alignment mark displacement amount for each layer with an X-ray inspection apparatus (manufactured by Toshiba IT Control System Co., Ltd.), the alignment marks arranged in advance at the four corners of the substrate are as follows. It was 46 μm. The distance between the center of the bump of the solder joint and the center of the wetness remaining on the land when observed by X-ray transmission from the substrate surface was within 50 μm.
As a comparative example, in the manufacturing method of the multilayer wiring board of the above example, the substrate of the comparative example was formed except for the step of forming the solder fixing portion, and the deviation amount of the obtained substrate was 68 μm on average. Finally, the entire surface of the rolled copper foil of the substrate to be connected was etched with a ferric chloride solution. As described above, a multilayer wiring board having excellent positional accuracy between layers was obtained by forming solder joints.

  The multilayer wiring board obtained by the present invention is suitable for a substrate for mounting a semiconductor chip, and can be applied to fine wiring, high-density wiring, and electronic components that are required to be thin.

It is sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which is embodiment of this invention. It is sectional drawing for demonstrating an example of the manufacturing method of the multilayer wiring board which is embodiment of this invention (continuation of FIG. 1).

Explanation of symbols

DESCRIPTION OF SYMBOLS 101: Insulating layer 102: Conductor circuit 103: Land 104: Conductor post 105: Solder 106: Adhesive layer 107: Board | substrate for multilayer wiring board manufacture 108: Conductor circuit 109: Land 110: Substrate for connection 111: Multilayer wiring board 112 : Positioning prevention fixing portion 113: Joining mechanism 114: Temporary laminated body 115: Multilayer wiring board manufacturing substrate 116: Temporarily laminated multilayer wiring board 117: Temporary laminated body 118: Positional deviation preventing fixing portion 119: Multilayer wiring Board 120: Multilayer wiring board

Claims (8)

A connection substrate on which an interlayer displacement prevention joint is formed, and a connection substrate on which an interlayer displacement prevention joined portion is formed at a position facing the interlayer displacement prevention joint of the connection substrate; A multilayer wiring board is manufactured by thermocompression bonding, wherein the interlayer misalignment prevention joint and the interlayer misalignment prevention joint are joined to form an interlayer misalignment prevention fixing portion. A method of manufacturing a multilayer wiring board, characterized by thermocompression bonding. 2. The method of manufacturing a multilayer wiring board according to claim 1, wherein the fixing portion for preventing misalignment is made of an alloy formed of a metal constituting the joining portion and a metal constituting the joined portion. The method for producing a multilayer wiring board according to claim 2, wherein the alloy has a melting point higher than that of the metal constituting the joining portion or the metal constituting the joined portion. 4. The multilayer wiring board according to claim 2, wherein the alloy includes Sn and at least one selected from Ag, Cu, Au, and Ni. 5. The method of manufacturing a multilayer wiring board according to claim 1, wherein the formation of the misalignment prevention fixing portion is performed during temporary lamination. The fixing portion for preventing the interlayer displacement is heated at a temperature lower than the melting point of the fixing member material, the higher melting point of the melting point of the metal constituting the joining portion and the melting point of the metal constituting the non-joining portion. The method for producing a multilayer wiring board according to claim 1, wherein the method is carried out as follows. The method for manufacturing a multilayer wiring board according to claim 1, wherein the thermocompression bonding is performed by laminating a plurality of the connection substrates and the connection substrates. The multilayer wiring according to any one of claims 1 to 7, wherein a distance between a center portion of the interlayer misalignment preventing joined portion after thermocompression bonding and a center portion of the interlayer misalignment preventing joined portion is 50 µm or less. A manufacturing method of a board.

Images