JP4433771B2 - Circuit board member and circuit board manufacturing method - Google Patents

Description

The present invention relates to a manufacturing method excellent circuits member and the circuit board substrate in productivity and has a high precision circuit pattern.

  With the reduction in weight and size of electronic products, there is a need for higher precision in patterning of printed circuit boards. Among them, the demand for flexible film substrates is increasing because three-dimensional wiring is possible due to its flexibility and it is suitable for downsizing of electronic products. For example, TAB (Tape Automated Bonding) technology used for IC connection to a liquid crystal display panel can obtain a fine pattern of the highest level as a resin substrate by processing a relatively narrow wide polyimide film substrate. However, the progress of miniaturization is approaching the limit. Pattern miniaturization includes an index expressed by a line width and a space width between lines, and an index expressed by a position of a pattern on a substrate. The latter index, so-called positional accuracy, is related to the alignment of the electrode pad and the circuit board pattern when connecting the circuit board and the electronic component such as an IC, and the required accuracy is severe as the number of pins of the IC increases. It has become to.

  In view of the above positional accuracy, it is becoming difficult to improve the processing of the flexible film substrate in particular. Circuit board processing includes heat treatment processes such as drying and curing, and wet processes such as etching and development, and the flexible film repeatedly expands and contracts in the course of these processes. The hysteresis at this time causes displacement of the circuit pattern on the substrate. In addition, when there are a plurality of processes that need alignment, if there is expansion and contraction between these processes, positional deviation occurs between the formed patterns. The deformation due to the expansion and contraction of the flexible film has a greater influence in the case of an FPC (Flexible Printing Circuit) that performs processing with a relatively large substrate size. Further, the positional shift is caused by an external force such as pulling or twisting, and special attention is required when a thin substrate is used to increase flexibility.

On the other hand, a flexible film is bonded to a reinforcing plate via an organic material layer, and by maintaining dimensional accuracy, a very fine circuit pattern is formed and adjusted to a work size suitable for the subsequent process. There is a proposal of cutting and dividing a circuit board member (see, for example, Patent Document 1). However, when the reinforcing plate, the organic material layer, and the flexible film are divided at the same time, the flexible film may be peeled off at the divided end.
International Publication No. 03/009657 Pamphlet

Therefore, an object of the present invention is to attach a flexible film to a reinforcing plate through an organic material layer, and maintain a dimensional accuracy, thereby providing a circuit board member having a highly accurate circuit pattern with excellent dimensional stability. It is an object of the present invention to provide a method for manufacturing a circuit board member that enables the end of a flexible film to be divided without peeling.

  Another object of the present invention is to provide a method for dividing a circuit board member obtained by bonding a flexible film to a reinforcing plate via an organic material layer without peeling off the end of the flexible film. There is to do.

  Another object of the present invention is to provide a method of manufacturing a circuit board on which a highly accurate circuit pattern having excellent dimensional stability is formed.

In order to achieve the above object of the present invention, the present invention comprises the following constitution.
(1) A flexible film is bonded to a reinforcing plate through an organic layer, and a circuit pattern made of a metal film is formed on the surface opposite to the reinforcing plate bonding surface of the flexible film, and then the flexible film is formed. A method for producing a circuit board member, characterized in that a conductive film is divided into two or more by providing a gap , and then a reinforcing plate is divided within the gap of the divided flexible film.
(2) The method for producing a circuit board member according to (1), wherein the flexible film is divided by providing a gap of 0.2 mm or more and 20 mm or less, and then the reinforcing plate is divided in the gap. .
(3) The method for producing a member for a circuit board according to (1), wherein the flexible film is divided at a portion where the metal film is not formed on the flexible film.
(4) A flexible film is bonded to a reinforcing plate through an organic layer, and a circuit pattern made of a metal film is formed on the surface opposite to the reinforcing plate bonding surface of the flexible film, and then the flexible film is formed. The conductive film is divided into two or more by providing a gap , and then the reinforcing plate is divided in the gap of the divided flexible film, and then the circuit pattern made of a metal film on the divided flexible film has an electron. A method of manufacturing a circuit board, comprising: connecting components; and further separating the divided flexible film from the reinforcing plate.
(5) A flexible film is bonded to a reinforcing plate through an organic layer, and a circuit pattern made of a metal film is formed on the surface opposite to the reinforcing plate bonding surface of the flexible film, and then the flexible film is formed. The conductive film is divided into two or more with a gap , and then an electronic component is connected to a circuit pattern made of a metal film on the divided flexible film, and then reinforced in the gap of the divided flexible film. A method of manufacturing a circuit board, comprising: dividing a board; and further peeling the divided flexible film from the reinforcing board.
(6) The above-mentioned (4) or (5), wherein the divided flexible film is peeled off from the reinforcing plate before the electronic component is connected to the circuit pattern made of a metal film on the flexible film. The manufacturing method of the circuit board of description.

  According to the present invention, a flexible film is bonded to a reinforcing plate through an organic material layer, and a circuit board member having an excellent dimensional accuracy and a high-precision circuit pattern is formed, and an end of the flexible film is peeled off. It is possible to divide without letting.

  In addition, by using the circuit board member of the present invention, a circuit board on which a highly accurate circuit pattern is formed with excellent dimensional accuracy can be obtained with high productivity.

The circuit board member produced by the present invention is basically constituted by bonding a flexible film to a reinforcing plate via an organic material layer.

  The flexible film used in the present invention is a plastic film, and it is important that the film has a heat resistance sufficient to withstand a thermal process in a circuit pattern manufacturing process and electronic component mounting. For example, polycarbonate, Examples thereof include plastic films made of polyether sulfide, polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polyimide, polyamide, liquid crystal polymer, and the like. Among these, a polyimide film is preferably used because it is excellent in heat resistance and chemical resistance. In addition, a liquid crystal polymer is preferably used because it has excellent electrical characteristics such as low dielectric loss. Furthermore, it is also possible to employ a flexible glass fiber reinforced resin plate. Examples of the resin for the glass fiber reinforced resin plate include epoxy, polyphenylene sulfide, polyphenylene ether, maleimide, polyamide, and polyimide.

  The thickness of the flexible film is preferable to reduce the weight and size of electronic equipment, or to form fine via holes. On the other hand, to ensure mechanical strength and maintain flatness. From the viewpoint that a thicker one is preferable, it is preferably in the range of 4 μm to 125 μm.

  In the present invention, the flexible film is preferably conditioned. Since a flexible film expands thermally and humidity, when the flexible film expanded at temperature and humidity is bonded to a reinforcing plate to form a highly accurate circuit pattern, the flexible film is peeled off from the reinforcing plate. Due to the shrinkage, the position accuracy of the circuit pattern on the flexible film is lowered. Alternatively, when a flexible film that has shrunk due to temperature or humidity is attached to a reinforcing plate to form a highly accurate circuit pattern, the flexible film expands after peeling from the reinforcing plate, so the circuit on the flexible film The pattern position accuracy decreases. It is preferable that the humidity adjustment timing is before the bonding with the reinforcing plate.

  In the present invention, the flexible film is preferably heat-treated prior to bonding with the reinforcing plate. By heat-treating the flexible film, it is possible to mitigate the accumulation of heat shrinkage strain in the flexible film due to the thermal history of the circuit board manufacturing process. The heat treatment temperature is preferably 100 ° C. or higher, and more preferably the highest temperature in the circuit board manufacturing process. It is preferable that the timing of heat processing is performed before humidity control.

  In the present invention, the flexible film is bonded to the reinforcing plate prior to bonding with the reinforcing plate, and an underlayer for improving adhesion comprising at least one of chromium, nickel, titanium, tungsten, and alloys thereof, and the underlayer The copper layer is preferably formed. The base layer and the copper layer thereon are used together as a conductive layer for subsequent electrolytic plating. Prior to manufacturing the circuit board member of the present invention by the single wafer method, the fact that the long flexible film is provided with the electroconductive layer for electrolytic plating is effective in improving productivity, but reinforcing The conductive layer may be formed in the form of a single sheet in which a plate and a flexible film are bonded together. The electroplating conductive layer is preferably formed by sputtering because of its high adhesive strength.

  In the present invention, when the circuit board member is cut and divided after the circuit pattern is formed, it is important that the flexible film is divided in advance before the reinforcing plate is divided. That is, by dividing the flexible film in advance, it is possible to prevent force from being applied to the end of the flexible film when the reinforcing plate is divided, and to suppress peeling of the flexible film. .

As a method of dividing the flexible film, a method of dividing after bonding the flexible film to the reinforcing plate and the like. In particular, as a method of dividing the flexible film after bonding, a method of dividing and removing a part of the bonded flexible film is preferable. If the gap between the divided flexible films is too narrow, it is difficult to divide the reinforcing plate within the gap. In addition, there is a risk of peeling due to the force applied to the end of the flexible film during processing such as chamfering to prevent generation of particles from the divided cross section. Furthermore, since the flexible film is bonded to the reinforcing plate via the slightly adhesive pressure-sensitive adhesive, if a part of the divided part of the flexible film is peeled off, there is a risk that the peeled part will be a major peeling. . On the other hand, if the gap between the divided flexible films is too wide, the productivity is lowered. Therefore, the gap between the divided flexible films is preferably 0.2 mm or more and 20 mm or less, and more preferably 0.5 mm. It is preferable to set it to 10 mm or less. The flexible film bonded onto the circuit board member after the reinforcing plate is divided may be one sheet or a plurality of sheets.

  Examples of the reinforcing plate used in the present invention include glass such as soda lime glass, borosilicate glass, and quartz glass, metals such as invar alloy, stainless steel, and titanium, or ceramics such as alumina, zirconia, and silicon nitride. And a glass fiber reinforced resin plate. All of these are preferable because of their low thermal expansion coefficient and hygroscopic expansion coefficient, but they are excellent in heat resistance and chemical resistance in the circuit pattern manufacturing process, and a substrate having a large area and high surface smoothness is easily available at low cost. A glass plate is particularly preferably used in that it is difficult to be plastically deformed.

  Further, when the reinforcing plate is bonded to the flexible film via the organic layer, it is preferable to use an ultraviolet curable organic layer as the organic layer. Therefore, it is desirable that the reinforcing plate transmits ultraviolet rays, and a glass plate is also preferable in this respect. Among them, a borosilicate glass plate represented by aluminoborosilicate glass is particularly preferably used because it has a high elastic modulus and a small thermal expansion coefficient.

  When a metal plate or a glass fiber reinforced resin plate is used for the reinforcing plate, it can be manufactured in a long continuous body, but the method for manufacturing a circuit board of the present invention is a single wafer type because it is easy to ensure positional accuracy. Preferably it is done. A sheet means a state where it is handled as an individual sheet, not a long continuous body.

  If the glass substrate used for the reinforcing plate has a small Young's modulus or a small thickness, warping and twisting will increase due to the expansion and contraction of the flexible film, and the glass substrate will be It may break. Further, the flexible film is deformed in the vacuum adsorption / desorption process, and it tends to be difficult to ensure the positional accuracy. On the other hand, when the glass substrate is thick, the flatness may deteriorate due to uneven thickness, and the exposure accuracy tends to deteriorate. In addition, the load increases during handling by a robot or the like, which makes it difficult to handle quickly and causes a decrease in productivity, and also tends to increase the transportation cost. From these points, the thickness of the glass substrate is preferably in the range of 0.3 mm to 2.0 mm.

  When a metal plate is used for the reinforcing plate, if the Young's modulus of the metal substrate is small or the thickness is thin, the warp or twist of the metal substrate increases due to the expansion force or contraction force of the flexible film, and a vacuum is formed on a flat stage. Since the flexible film is deformed by the amount of warp or twist of the metal substrate, it becomes difficult to maintain the positional accuracy. Further, if the metal substrate is bent, it becomes a defective product at that time. On the other hand, when the metal substrate is thick, the flatness may be deteriorated due to uneven thickness, and the exposure accuracy is deteriorated. In addition, the load is increased during handling by a robot or the like, which makes it difficult to handle quickly and causes a decrease in productivity, and also increases the transportation cost. From these points, the thickness of the metal substrate is preferably in the range of 0.1 mm to 0.7 mm.

  In the present invention, an adhesive or a pressure-sensitive adhesive is used for the organic layer used for bonding the flexible film and the reinforcing plate. Examples of the adhesive or pressure-sensitive adhesive include pressure-sensitive adhesives called acrylic or urethane re-peeling agents. There is sufficient adhesive strength during flexible film processing, and it can be easily peeled off at the time of peeling, and in order not to cause distortion in the flexible film, the adhesive strength in a region called weak to medium adhesive is used. preferable. As the adhesive or pressure-sensitive adhesive, a silicone resin having tackiness can be used, and an epoxy resin having tackiness can also be used.

  In addition, as the organic material layer, those whose adhesive strength and adhesive strength are reduced in a low temperature region, those whose adhesive strength and adhesive strength are reduced by ultraviolet irradiation, and those whose adhesive strength and adhesive strength are reduced by heat treatment are suitably used. . Among these, those that are irradiated with ultraviolet rays are preferably used because of large changes in adhesive strength and adhesive strength. As an example of the adhesive strength and adhesive strength that are reduced by ultraviolet irradiation, a two-component cross-linking acrylic pressure-sensitive adhesive can be mentioned. Moreover, as an example of what adhesive strength and adhesive force reduce in a low temperature area | region, the acrylic adhesive which changes reversibly between a crystalline state and an amorphous state is mentioned, It uses preferably.

  In the present invention, the peel force is measured by the 180 ° peel strength when peeling a 1 cm wide flexible film bonded to a reinforcing plate via an organic layer. The peeling speed when measuring the peeling force is 300 mm / min. In the present invention, the peel force is preferably in the range of 0.098 N / m to 98 N / m.

  If the peeling force when peeling the flexible film from the reinforcing plate is too low, the flexible film may peel from the organic layer during circuit pattern formation. On the other hand, if the peeling force is too high, the flexible film after peeling may be deformed or curled.

  The peeling interface may be either the interface between the reinforcing plate and the organic material layer or the interface between the organic material layer and the flexible film, but the step of removing the organic material layer from the flexible film can be omitted. It is preferable to peel at the interface with the flexible film.

  In order to improve the adhesive force between the reinforcing plate and the organic layer, the reinforcing plate may be subjected to a primer treatment such as application of a silane coupling agent. In addition to the primer treatment, cleaning by ultraviolet treatment, ultraviolet ozone treatment, etc., surface roughening treatment such as chemical etching treatment, sand blast treatment or fine particle dispersion layer formation is also preferably used.

  In the present invention, the thickness of the organic layer is preferably in the range of 0.1 μm to 20 μm, and more preferably in the range of 0.3 μm to 10 μm.

  The flexible film used in the present invention may have a circuit pattern formed on the reinforcing plate bonding surface prior to bonding with the reinforcing plate. In this case, it is preferable to form an alignment mark with the circuit pattern formed on the other surface simultaneously with the pattern formation. In order to make use of the high definition of the high definition pattern formed on the surface opposite to the reinforcing plate bonding surface, it is very effective for the production of the high definition pattern to provide the alignment mark. The alignment mark reading method is not particularly limited, and for example, an optical method or an electrical method can be used. The alignment mark can also be used for alignment when the flexible film is bonded to the reinforcing plate. The shape of the alignment mark is not particularly limited, and a shape generally used in an exposure machine or the like can be suitably employed. The advantage of double-sided wiring is that crossing through through holes is possible, increasing the degree of freedom in wiring design, and LSI that operates at high speed by propagating the ground potential to the vicinity of the necessary place with thick wiring In addition, the power supply potential can be propagated to the vicinity of the necessary location with thick wiring as well, so that the potential drop can be prevented even at high-speed switching, the operation of the LSI can be stabilized, and external noise can be blocked as an electromagnetic wave shield. This is very important as the LSI speeds up and the number of pins is increased due to the increased functionality.

  Furthermore, in the present invention, it is possible to use a reinforcing plate when processing both sides of a flexible film, and to form a pattern with particularly high precision on both sides. For example, the first reinforcing plate and the second surface of the flexible film are bonded together via an ultraviolet curable organic material layer to form a circuit pattern on the first surface of the flexible film. After the first surface and the second reinforcing plate are bonded together via an ultraviolet curable organic material layer, the flexible film is peeled off from the first reinforcing plate, and then the circuit is formed on the second surface of the flexible film. There is a method of peeling the flexible film from the second reinforcing plate after forming the pattern, and high-precision circuit pattern processing can be realized on both sides.

  In the present invention, the circuit board member is cut and divided after the circuit pattern is formed, but it is important that the flexible film is divided prior to the division of the circuit board member. When the flexible film and the reinforcing plate are divided at the same time, or when the reinforcing plate is divided in a state where the flexible film is not divided, the flexible film at the divided end of the circuit board member may be peeled off. In addition to causing troubles such as taking out the chemical solution and transporting in the subsequent process, the chemical solution enters between the reinforcing plate and the peeled flexible film, and is sandwiched in the subsequent process to become impurities.

Method as a method of dividing the flexible film, after the flexible film that is not split bonded to a reinforcing plate, which prior to dividing the entire circuit board member, performs the division of flexible film door is Ru and the like. The tool body case, and a method of dividing the flexible film by using a knife or a laser such as a cutter. At this time, the entire thickness of the flexible film is cut, and at the same time, scratches and distortions for dividing the reinforcing plate can be given to the reinforcing plate, and the number of steps can be reduced.

  In this invention, it is preferable that the place which divides | segments the member for circuit boards is the part which is not equipped with the flexible film, or the part into which the flexible film is divided | segmented. If the gap between the divided flexible films is too narrow, it is difficult to divide the reinforcing plate within the gap. In addition, there is a risk of peeling due to the force applied to the end of the flexible film during processing such as chamfering to prevent generation of particles from the divided cross section. Furthermore, since the flexible film is bonded to the reinforcing plate via the slightly adhesive pressure-sensitive adhesive, if a part of the divided part of the flexible film is peeled off, there is a risk that the peeled part will be a major peeling. . On the other hand, when the gap between the divided flexible films is too wide, the productivity is lowered. Therefore, the gap between the divided flexible films is preferably set to 0.2 mm or more and 20 mm or less. It is preferable to be 5 mm or more and 10 mm or less.

  A preferable form of the divided flexible film is a substantially square piece or a rectangular strip. In the case of a rectangular strip, the long side direction of the rectangle is set so as to be orthogonal to the long side direction of the electronic component because the electronic component described later is easy to peel off from the reinforcing plate. It is preferable.

  When the flexible film portion of the circuit board member after the circuit pattern is formed is divided, if a circuit pattern made of a metal layer is formed at the divided end portion, the shear stress at the time of dividing the metal layer and the flexible film As a result, the flexible film may peel off from the reinforcing plate. Therefore, it is preferable that the circuit pattern which consists of a metal layer is not formed in the division part of the divided flexible film.

  As a method for dividing the reinforcing plate, a diamond cutter, a laser cutter, or the like can be suitably used, but it is not particularly limited. In addition, the flexible film and / or the reinforcing plate may be divided while pressing the end of the flexible film against the reinforcing plate in order to prevent the flexible film from peeling off from the reinforcing plate at the time of dividing. preferable. After dividing the reinforcing plate, it is preferable to chamfer the divided end portion of the reinforcing plate.

  In the present invention, before or after dividing the circuit board member, or after being divided, an electronic component such as an IC is mounted on the circuit board member and connected to the circuit board. For example, a method of thermally bonding a metal layer such as tin, gold, or solder formed on a connection portion of a circuit board and a metal layer such as gold or solder formed on a connection portion of an electronic component to perform metal bonding, An anisotropic conductive adhesive disposed between a circuit board and an electronic component while crimping a metal layer such as tin, gold or solder at the connection portion and a metal layer such as gold or solder formed at the connection portion of the electronic component, or There is a method in which a non-conductive adhesive is cured and mechanically joined. The electronic component is preferably mounted before the flexible film is peeled from the reinforcing plate in order to keep the electronic component mounting with high accuracy.

Next, although an example of the manufacturing method of the circuit board using the member for circuit boards manufactured by the present invention is explained below, the present invention is not limited to this.

  A silane coupling agent is applied to an aluminoborosilicate glass plate having a thickness of 0.7 mm using a spin coater, blade coater, roll coater, bar coater, die coater, screen printer, or the like. In order to uniformly apply a thin film of a silane coupling agent having a relatively low viscosity to a single substrate that is intermittently sent, it is preferable to use a spin coater. After application of the silane coupling agent, drying is performed by heat drying or vacuum drying to obtain a silane coupling agent layer having a thickness of 20 nm.

  Next, an ultraviolet curable organic material is applied onto the silane coupling agent layer by a spin coater, a blade coater, a roll coater, a bar coater, a die coater, a screen printer, or the like. In order to uniformly apply an organic substance having a relatively high viscosity to a single-wafer substrate sent intermittently, it is preferable to use a die coater. After applying the organic material, the organic material layer is dried by heat drying or vacuum drying to obtain an organic material layer having a thickness of 2 μm. An air blocking film in which a silicone resin layer is provided on a polyester film is bonded to the organic material layer and aged for one week. Instead of laminating an air blocking film, it can be stored in a nitrogen atmosphere or in a vacuum. It is also possible to apply the organic layer to a long film substrate, transfer it to a single substrate after drying.

  In the present invention, the organic material layer may be initially formed on the flexible film side, may be formed on the reinforcing plate side, or may be formed on both. In order to control the ease of formation and the peeling interface so as to be a flexible film and an organic layer, it is preferably formed on the reinforcing plate side.

  Next, the air blocking film is peeled off, and a polyimide film is bonded thereto. The thickness of the polyimide film is preferably in the range of 4 μm to 125 μm. As described above, a metal layer may be formed in advance on one side or both sides of the polyimide film. If a metal layer is provided on the reinforcing film bonding surface side of the polyimide film, it can be used as a ground layer for shielding electromagnetic waves. The polyimide film may be bonded together in a predetermined size cut sheet, or may be bonded and divided while being unwound from a long roll. In the present invention, it is important that the flexible film is divided into two or more. Therefore, the cut sheet having a size suitable for the division is bonded, or the width suitable for the division is obtained. Unwinding from a long roll, pasting, and division are preferred. A roll laminator or a vacuum laminator can be used for such a bonding operation. After the polyimide film is bonded to the glass substrate, the ultraviolet curable organic material layer is irradiated with ultraviolet rays to allow crosslinking to proceed.

  In the case where a metal film is not provided in advance on the surface opposite to the bonded surface of the polyimide film, a circuit pattern can be formed by a full additive method or a semi-additive method. The full additive method is, for example, the following process. The surface on which the circuit pattern is to be formed is treated with a catalyst such as palladium, nickel or chromium, and dried. The catalyst referred to here does not act as a nucleus for plating growth as it is, but it becomes a nucleus for plating growth by activation treatment. Next, the photoresist is applied by a spin coater, a blade coater, a roll coater, a bar coater, a die coater, a screen printing machine or the like and dried. The photoresist is exposed and developed through a photomask having a predetermined pattern to form a resist layer in a portion where a plating film is unnecessary. Thereafter, after activating the catalyst, the polyimide film is immersed in an electroless plating solution composed of a combination of copper sulfate and formaldehyde to form a copper plating film having a thickness of 2 μm to 20 μm. Get.

  The semi-additive method is, for example, the following process. An underlayer for improving adhesion made of at least one of chromium, nickel, titanium, tungsten, and alloys thereof is formed on the surface on which the circuit pattern is to be formed. The thickness of the underlayer is usually in the range of 1 nm to 1000 nm. Further laminating a copper sputtered film on the underlayer from 50 nm to 3000 nm is effective for ensuring sufficient conduction for subsequent electrolytic plating, improving the adhesion of the metal layer, and preventing pinhole defects. Prior to the formation of the underlayer, it is appropriately used that plasma treatment, reverse sputtering treatment, primer layer application, or adhesive layer application is performed on the polyimide film surface in order to improve the adhesion. Among them, the adhesive layer application such as epoxy resin system, acrylic resin system, polyamide resin system, polyimide resin system and NBR system has a great effect of improving the adhesive strength. These treatments and application may be performed before the glass substrate is bonded, or may be performed after the glass substrate is bonded. Productivity can be improved by performing continuous roll-to-roll processing on a long polyimide film before bonding the glass substrates. On the conductive layer thus formed, a photoresist is applied by a spin coater, a blade coater, a roll coater, a die coater, a screen printing machine or the like, and dried. The photoresist is exposed and developed through a photomask having a predetermined pattern to form a resist layer in a portion where a plating film is unnecessary. Next, electrolytic plating is performed using the base layer as an electrode. As the electrolytic plating solution, a copper sulfate plating solution, a copper cyanide plating solution, a copper pyrophosphate plating solution, or the like is used. After forming a copper plating film with a thickness of 2 μm to 20 μm, the photoresist is peeled off, and then the underlying layer is removed by a light etching, and further, gold, nickel, tin, etc. are plated if necessary, and a circuit pattern Get.

  If necessary, a solder resist film is formed on the circuit pattern. For fine circuit patterns, it is preferable to use a photosensitive solder resist. A photosensitive solder resist is applied onto the circuit pattern with a spin coater, blade coater, roll coater, bar coater, die coater, screen printing machine, etc., dried, and then exposed to ultraviolet rays through a predetermined photomask and developed. Thus, a solder resist pattern is obtained. Next, curing is performed at 100 ° C. to 200 ° C.

  When forming a high-definition circuit pattern on both sides of a flexible film, the flexible film is bonded to the glass substrate, and the subtractive method, semi-additive method or full additive method is opposite to the glass substrate bonding surface. A circuit pattern is formed on the surface of the flexible film, and then the circuit forming surface side of the flexible film is bonded to another glass substrate, then the first glass substrate is peeled off, and the other surface is subjected to a subtractive method. A method of forming a circuit pattern by a semi-additive method or a full additive method and then peeling the glass substrate is preferably used.

  An electronic component such as an IC or LSI is bonded to a high-precision circuit pattern that has been bonded to a glass substrate. As the electronic component mounting apparatus, an apparatus having an optical position detection function and a positioning function such as a movable stage, which can ensure mounting accuracy is preferably used. The present invention is particularly effective in ensuring the mounting accuracy of a large-scale LSI with a small joining pitch and a large number of pins. In addition, as a method for joining the electronic component and the circuit board, there is a method in which a metal layer formed at the joint portion of the circuit board and a metal layer formed at the joint portion of the semiconductor component are subjected to thermocompression bonding and metal joining is performed. In addition, the anisotropic conductive adhesive or non-conductive adhesive placed between the circuit board and the semiconductor component is cured while the metal layer formed at the junction of the circuit board and the metal layer formed at the joint of the semiconductor component are crimped. And a method of mechanically joining them.

  Next, the circuit board member is divided before or after mounting the electronic component. In order to divide, it is important to first divide the flexible film and then divide the reinforcing plate. In the method of dividing the flexible film and the reinforcing plate at the same time or the method of dividing the reinforcing plate before dividing the flexible film, the flexible film may be peeled off from the reinforcing plate at the divided end. The method of dividing the reinforcing plate is preferably a method of dividing with a diamond cutter or a laser cutter, but is not particularly limited. In addition, it is preferable to divide the flexible film and / or the reinforcing plate while pressing the end of the flexible film against the reinforcing plate in order to prevent the flexible film from peeling off from the reinforcing plate at the time of dividing. . After dividing the reinforcing plate, it is preferable to chamfer the divided portion of the reinforcing plate.

  In the present invention, the circuit board can be obtained by peeling the flexible film from the reinforcing plate. The peeling method includes a method of peeling while gripping the end of the flexible film, a method of peeling by pressing an adhesive tape on the surface of the flexible film, and an angle formed by the reinforcing plate and the flexible film. A method of peeling by turning the flexible film from the end while keeping a certain peeling angle, or transferring the flexible film to a peeling roller having an appropriate adhesive force, and then transferring from the peeling roller. A method of re-peeling the flexible film, a method of vacuum-sucking the flexible film and gradually peeling it from the end, a method of peeling a part of the flexible film along a curved support, etc. Can be mentioned. In the present invention, the state before peeling the flexible film from the reinforcing plate is called a circuit board member, and the state where the flexible film is peeled from the reinforcing plate is called a circuit board.

  In order to prevent electrostatic charge when peeling flexible film, a method of blowing air ionized by an ionizer, etc., a method of performing the peeling process in a partitioned space, and constantly setting the humidity to 60% RH or more, a reinforcing plate A method in which a liquid is present between the flexible film and the flexible film is preferably used. The timing of peeling is preferably performed after the electronic component is mounted in order to keep the electronic component mounting with high accuracy.

Circuit board member prepared in the present invention are, for example, the wiring board of the electronic device is preferably used in an IC package interposer and wafer level burn-in socket wiring board.

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

Comparative Example 1
As a flexible film, a polyimide film having a thickness of 25 μm and a width of 290 mm (“Kapton” (registered trademark) 100EN manufactured by Toray Du Pont Co., Ltd.) was prepared. A long polyimide film is mounted on a reel-to-reel sputtering apparatus, and a 6 nm thick chromium: nickel = 20: 80 (weight ratio) alloy film and a 100 nm thick copper film are arranged in this order on the polyimide film. Laminated. A 0.7 mm thick, 300 mm square aluminoborosilicate glass plate prepared as a reinforcing plate was coated with an ultraviolet curable adhesive “SK Dyne” (registered trademark) SW-22 (manufactured by Soken Chemical Co., Ltd.) using a die coater. And a curing agent L45 (manufactured by Soken Chemical Co., Ltd.) mixed at 100: 3 (weight ratio) were applied and dried at 80 ° C. for 2 minutes to provide an organic layer. The organic layer thickness after drying was set to 2 μm. Next, an air blocking film made of a film in which a silicone resin layer that is easy to release was provided on a polyester film was bonded to the organic layer, and left for one week. The air blocking film was peeled off, and a polyimide film on which a copper film was formed was bonded to the organic layer side of the aluminoborosilicate glass plate using a roll laminator with a cutter. The surface opposite to the bonding surface of the polyimide film to the aluminoborosilicate glass plate was the copper film surface. Next, a positive photoresist was applied onto the copper film with a spin coater and dried at 90 ° C. for 30 minutes. The photoresist was exposed through a photomask and developed to form a photoresist having a thickness of 10 μm in a portion where a plating film was unnecessary.

  The test photomask pattern was as follows. As the inner lead (IL) portion, 400 connection pads (width 20 μm, length 200 μm) were provided in two rows in parallel at a pitch of 40 μm. The two connection pad rows were arranged so that the centers of the opposite connection pads were 1.5 mm apart. Further, as the outer lead (OL) portion, the parallel connection pads are separated from the 400 connection pad rows by 14 mm, and the lengths of the connection pad rows are aligned in the center in the length direction, so that the 400 connection pads (width 30 μm, length 500 μm). ). The connection pad row of the IL part and the connection pad row of the OL part and the wiring having a width of 17 μm connecting the corresponding connection pads are regarded as one unit, and this is arranged in 6 rows × 6 columns at a pitch of 40 mm on a 300 mm square substrate. Evenly arranged. Next, a copper film having a thickness of 5 μm was formed by electrolytic plating in a copper sulfate plating solution using the copper film as an electrode. The photoresist was stripped with a photoresist stripping solution, and then the copper film and the chromium-nickel alloy film that were under the resist layer were removed by soft etching with a hydrogen peroxide-sulfuric acid aqueous solution. Subsequently, a 0.4 μm thick tin film was formed on the copper plating film by electroless plating. The solder resist was screen printed except for the IL and OL portions of the circuit board, dried at 60 ° C. for 30 minutes, and then cured at 120 ° C. for 90 minutes. The solder resist thickness after drying was 20 μm. Thus, a circuit board member was obtained.

  Next, the obtained circuit board member was cut into strip-shaped members of 6 units each corresponding to one row. First, divide the polyimide film with a single-edged razor, and then apply a scribe line to the aluminoborosilicate glass plate on the opposite side of the polyimide film dividing surface with a diamond cutter, and then apply force to the area between the scribe lines. The aluminoborosilicate glass plate was divided. At this time, the aluminoborosilicate glass plate was divided according to the line into which the polyimide film was divided, that is, the dividing line. In this way, when 36 units of circuit patterns on one substrate were cut into 6 mm-long strip-shaped members each having a length of 40 mm and a length of 300 mm, 3 strip-shaped members among the 6 strip-shaped members were cut out. A part of the end of the flexible film of the member was peeled off by several millimeters, but it was able to be cut into a strip-shaped member with almost no problem. Subsequently, an IC chip was mounted and joined using an IC bonder device. A model IC chip, in which 400 gold-plated bumps with 50 μm pitch in a row and two rows in parallel with a gap of 1.5 mm are provided on the IL portion of the circuit pattern, is heated to 300 ° C. from the IC chip side by a flip chip bonder. Meanwhile, the connection pad on the polyimide film was metal-bonded. The conveyance failure and the IC bonding position failure in the process after the member division did not occur and were good.

Example 1
A circuit board member was obtained in the same manner as in Comparative Example 1 . Next, the obtained circuit board member was cut into strip-shaped members of 6 units each corresponding to one row. First, divide the polyimide film with a single-edged razor, then apply a scribe line to the aluminoborosilicate glass plate on the opposite side of the polyimide film dividing surface with a diamond cutter, and then apply force to the area between the scribe lines. The aluminoborosilicate glass plate was divided. At this time, the polyimide film was peeled off between the dividing lines by providing two dividing lines at a position 1 mm in parallel from the boundary line between two adjacent unit rows to the both unit rows. Next, the aluminoborosilicate glass plate was divided at a gap position of 2 mm width between the two dividing lines. In this way, when 36 units of circuit patterns on one substrate were cut into 6 units of 40 mm wide × 300 mm long strip-shaped members, no peeling occurred at the ends of the 6 strip-shaped members. As can be seen, the strip-shaped member was successfully cut out. Subsequently, an IC chip was mounted and joined using an IC bonder device. A model IC chip, in which 400 gold-plated bumps at 50 μm pitch in a row and two rows in parallel with a gap of 1.5 mm are provided on the IL portion of the circuit pattern, is heated to 300 ° C. from the IC chip side by a flip chip bonder. Meanwhile, the connection pad on the polyimide film was metal-bonded. No conveyance failure or IC bonding failure occurred in the IC bonder device, which was good.

Example 2
Example except that two dividing lines were provided on polyimide at a position 0.3 mm parallel moved from the boundary line between two adjacent unit rows to both unit rows, and the polyimide film between the dividing lines was peeled off. In the same manner as in Example 1 , a strip-shaped member was obtained. Among the six strip-shaped members, the end portion of the flexible film of one strip-shaped member was partially peeled off by about several mm, but it was able to be cut out into the strip-shaped member with almost no problem. Subsequently, an IC chip was mounted and joined using an IC bonder device. A model IC chip, in which 400 gold-plated bumps with 50 μm pitch in a row and two rows in parallel with a gap of 1.5 mm are provided on the IL portion of the circuit pattern, is heated to 300 ° C. from the IC chip side by a flip chip bonder. Meanwhile, the connection pad on the polyimide film was metal-bonded. The conveyance failure and the IC bonding position failure in the process after the member division did not occur and were good.

Comparative Example 2
A circuit board member was obtained in the same manner as in Comparative Example 1 . Next, without dividing the polyimide film, a scribe line was attached to the aluminoborosilicate glass plate with a diamond cutter, and then a force was applied to a region sandwiching the scribe line to divide the glass. Next, when the polyimide film was divided with a single-edged razor, almost all of the end portions of the polyimide film peeled inwardly about 5 to 10 mm along the dividing line of the glass. For this reason, inadequate conveyance in the process after dividing the member, and in the subsequent IC chip mounting and bonding process, the flexible film is peeled off to the IC mounting scheduled position, so that the alignment for IC bonding cannot be performed. Reduced the process yield.

The circuit board member using the flexible film substrate manufactured according to the present invention can cope with higher precision of patterning of the printed circuit board as the electronic product is reduced in weight and size. It is suitably used for equipment wiring boards, IC package interposers, wafer level burn-in socket wiring boards, and the like.

Claims (6)

A flexible film is bonded to a reinforcing plate through an organic layer, and a circuit pattern made of a metal film is formed on the surface opposite to the reinforcing plate bonding surface of the flexible film, and then the flexible film is attached to the reinforcing film. A method for producing a circuit board member, characterized in that a gap is provided and divided into two or more, and then the reinforcing plate is divided within the gap of the divided flexible film.   2. The method for manufacturing a circuit board member according to claim 1, wherein the flexible film is divided by providing a gap of 0.2 mm or more and 20 mm or less, and then the reinforcing plate is divided in the gap.   2. The method for producing a circuit board member according to claim 1, wherein the flexible film is divided at a portion where the metal film is not formed on the flexible film. A flexible film is bonded to a reinforcing plate through an organic layer, and a circuit pattern made of a metal film is formed on the surface opposite to the reinforcing plate bonding surface of the flexible film, and then the flexible film is attached to the reinforcing film. Dividing into two or more by providing a gap, and then dividing the reinforcing plate in the gap of the divided flexible film, and then connecting the electronic component to the circuit pattern made of a metal film on the divided flexible film Furthermore, the circuit board manufacturing method characterized by peeling the divided flexible film from the reinforcing plate. A flexible film is bonded to a reinforcing plate through an organic layer, and a circuit pattern made of a metal film is formed on the surface opposite to the reinforcing plate bonding surface of the flexible film, and then the flexible film is attached to the reinforcing film. Divide into two or more by providing a gap , then connect the electronic components to the circuit pattern consisting of the metal film on the divided flexible film, and then divide the reinforcing plate in the gap of the divided flexible film Furthermore, the circuit board manufacturing method characterized by peeling the divided flexible film from the reinforcing plate.   6. The circuit board according to claim 4, wherein the divided flexible film is peeled off from the reinforcing plate before the electronic component is connected to the circuit pattern made of a metal film on the flexible film. Method.