JP4082415B2 - Circuit module division method - Google Patents

Description

  The present invention relates to a circuit board dividing method for circuit boards. More specifically, the present invention relates to a method of dividing a circuit module in which a plurality of small circuit modules are formed on a single circuit board into each small circuit module.

A conventional circuit board dividing method will be described with reference to FIG. Reference numeral 1 denotes a circuit board including a plurality of small circuit modules 7 on which components are mounted. As shown in 51, the circuit board 1 is placed on the cut stage 3 and is vacuum-sucked through the suction holes 4 to fix the circuit board 1 on the cut stage 3. The suction hole 4 provided in the cut stage 3 is provided corresponding to the position of the small circuit module 7 on the circuit board 1. 53, when the circuit board 1 is divided into the small circuit modules 7 by using the cut blade 5, the small circuit module 7 can be securely fixed by using the cut stage 3, so that the accuracy is high. The circuit board 1 can be divided (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-168074

  However, such a conventional circuit board dividing method has the following problems. The first problem is that a dedicated cut stage is required for the circuit board. That is, since the suction hole 4 on the cut stage 3 is created corresponding to the small circuit module on the circuit board, a dedicated cut stage must be created on the circuit board each time.

  The second problem is a crack in the substrate that occurs during division. This becomes a big problem when the circuit board mounted on both sides is divided. In this case, in order to securely fix the circuit board to the cut stage, the front surface of the cut stage 3 is recessed according to the component mounted on the back surface of the circuit board, and the escape portion for preventing the component from hitting the air inlet 4 Must be provided. However, since a slight gap is generated between the circuit board and the cut stage due to the mounting variation of components mounted on the circuit board, air flows from the cut portion 6 and a sufficient suction force cannot be obtained. For this reason, when the circuit board is divided, the fixing with the cut stage becomes weak and the circuit board moves, so that cracks are generated in the divided portions as shown in FIG. Furthermore, since the circuit board moves from the original cutting position, the board outline of the divided small circuit module is deformed, resulting in a defective product. Further, when the small circuit module moves during cutting, unnecessary force is applied to the cutting blade, and the cutting blade is damaged.

  In order to solve the conventional problem, the circuit module dividing method according to the present invention includes a heat-resistant film disposed on a flat surface of a flat plate having at least one flat surface, and a predetermined thickness on the heat-resistant film. An application step of applying a resin paste to form a resin layer, an arrangement step of placing a circuit board module on the resin layer, and arranging the back surface of the circuit board module to be buried in the resin layer; and Then, by heating and curing the resin layer, a curing process for integrating the flat plate to the circuit board module as a laminated body, and removing the flat plate and the heat-resistant film from the laminated body are performed. A removal step of forming a laminate, and fixing the resin paste surface of the second laminate on the stage, and cutting the substrate at a desired position of the circuit module with a cutting means A substrate dividing step to remove leaving serial resin paste layer is obtained by, comprising the.

  As described above, according to the circuit module dividing method of the present invention, the circuit board is divided in the dividing step by forming the resin layer by applying the resin paste to the circuit board composed of a plurality of small circuit modules and curing the resin paste. In this case, the resin layer is left to be cut, so that a satisfactory division can be performed without defects such as a substrate external shape defect, a substrate burr, and a substrate chip of the small circuit module in the dividing step. In addition, since the circuit board can be firmly fixed in the dividing step, the movement of the circuit board at the time of dividing can be suppressed, and the production efficiency is improved without breakage of the cutting blade.

  Hereinafter, embodiments of a circuit module of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram for explaining each step of the circuit board dividing method according to the first embodiment of the present invention. In FIG. 1, (a) shows an application pallet and (b) shows an application process. The coating pallet includes a flat plate 9 having a flat surface, a heat-resistant film 10 for facilitating peeling, and a coating frame 11. The flat plate 9 is a glass plate mainly composed of lead glass or borosilicate glass, and the flatness of the surface thereof is suppressed to 0.05 mm or less. However, it is not necessary to stick to the glass plate, and any material that does not deform at the resin curing temperature (130 to 150 degrees in this embodiment) of the resin paste used in the next step may be used. Moreover, the heat-resistant temperature of a heat-resistant film should just be what can endure this resin curing temperature. In this example, PEI (polyetherimide) and PES (polyethersulfone) were used. However, the heat resistant film is not limited to this, and may be PET (polyester) as long as it can withstand the resin curing temperature.

  As shown in FIG. 1B, a resin paste 17 is applied with a squeegee 12 on an application pallet to form a resin layer 13. The thickness of the coating frame 11 needs to be greater than the height of the component mounted on the circuit board. In this example, since the component height was 0.9 mm, the coating thickness was 1.2 mm. The resin paste 17 is made of a resin whose main components are a vinyl resin derivative, a fatty acid ester, and an epoxy ester, and the content of the vinyl resin derivative is 55 to 65% by weight.

  The hardness and peel strength of the resin after thermosetting are important. That is, if the resin hardness is high, the resin layer cannot be bent when the small circuit module is removed from the resin layer, so that it is difficult to remove the small circuit module from the resin layer. If the peel strength is low, the small circuit module cannot be reliably fixed when the small circuit module is divided by the dicing blade, and cracks are likely to occur in the divided portion. In addition, since the small circuit module deviates from the original cutting position, a defective outer shape in which the outer shape of the small circuit module is different from the target shape occurs.

  That is, when the hardness of the resin layer after curing exceeds 70 ° (vulcanized rubber and thermoplastic rubber hardness test method JIS K6253), there is a problem that the small circuit module cannot be removed from the resin layer. If the peel strength is less than 0.3 N / mm, there arises a problem that the circuit module and the resin layer are displaced or peeled at the time of cutting. Therefore, the resin paste to be used must have a physical property that the hardness after curing is 70 ° or less and the peel strength is 0.3 N / mm or more. By using the resin paste having such physical characteristics, the resin layer is easily deformed after being cured, so that the circuit module can be removed from the resin layer. Therefore, the resin paste that can be used in the present invention only needs to satisfy this physical characteristic.

  In this embodiment, a glass epoxy material is used for the coating frame 11. The coating frame 11 needs to have a uniform thickness, and if it satisfies the requirement, a desired material such as metal or resin may be selected as appropriate. The squeegee 12 may be any material that has a flat resin-coated surface and does not deform during coating. FIG. 3C is a process showing application frame removal. After applying the resin paste, the application frame 11 is removed.

FIG. 1D shows a process of placing the circuit board module 1 on a pallet coated with resin. The circuit board 1 on which components are mounted is superposed on the coating layer 13 to which the resin paste is applied, and the state is maintained and heated to be cured. In this example, the heating temperature was 150 degrees higher than the resin curing temperature of 130 degrees. If the curing temperature is too low, insufficient curing occurs and the adhesion strength between the circuit module and the resin layer decreases. Also, an excessively high curing temperature is not preferable because it causes decomposition of the resin or damages the mounted components of the circuit board module.
FIG.1 (e) shows the process of removing a flat plate and a heat-resistant film. The glass flat plate 9 and the heat-resistant film 10 are removed from the laminate in which the circuit board module 1, the cured resin 14 in which the resin layer 13 is cured, and the film 10 are integrated.

  FIG. 1 (f) shows the dividing step. 15 is a cross-sectional view of the cut stage 15. Reference numeral 16 denotes a porous plate made of ceramic, which can be fixed by vacuum-sucking a member placed on the surface by a vacuum pump (not shown) in the direction of the arrow in the figure. The porous plate is not limited to ceramic but may be a metal porous plate. The circuit board module 1 integrated with the cured resin 14 is placed on the cut stage 15, and the circuit board is divided by the cut blade 5 while being vacuum-sucked. At this time, the cutting is performed until the cutting blade 5 reaches the cured resin 14. Accordingly, since only the circuit board is cut, the circuit board can be firmly fixed without lowering the degree of adsorption on the cut stage 15.

  FIG. 1G shows a process of removing the circuit module 1. Since the cured resin 14 is an elastic resin, it can be easily and easily deformed, and can be peeled off without adhesion of the resin to the small circuit module 7, so that the small circuit module 7 can be easily removed. Further, there is no adhesion of resin to the small circuit module 7.

  Further, the post-process using the small circuit module 7 is usually far from the dividing process. At that time, the separated circuit modules 7 need to be packed. However, in the present invention, the divided small circuit modules 7 are connected to each other through the cured resin 14, so there is no need for packing. After the dividing step, the small circuit module 7 that is necessary in the step can be easily detached from the resin layer by being transported to a distant removal step as it is.

  Note that it is more effective to mix conductive particles having good electrical conductivity with the resin paste 17. This is because the resin layer 13 having good electrical conductivity can be formed from the conductive particles. When this resin layer 14 is heat-cured, a cured resin 14 that can prevent the small circuit module 7 from being destroyed by static electricity can be produced. Therefore, it leads to an improvement in reliability when the cured resin 14 is transported to a distant removal process with the small circuit module 7 attached.

  The circuit board dividing method according to the present invention can remarkably reduce defects at the time of division, and is therefore optimal for dividing a circuit board on which components are mounted on both sides. Further, it has an advantage that it can be used as it is for conveyance after the dividing step.

(A) Sectional view of resin pallet in Embodiment 1 of the present invention (b) Diagram showing resin paste application step (c) Diagram showing coating frame removal step (d) Diagram showing circuit board placement step on resin paste (E) The figure which shows the pallet removal after resin hardening (f) The figure which shows the division | segmentation process of a circuit board (g) The figure which shows the removal process The figure which shows the conventional circuit board dividing method The figure which shows the crack by the conventional circuit board dividing method

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit board module 2 Parts 3 Cut stage 4 Suction hole 5 Cut blade 6 Cut part 7 Small circuit module 8 Crack 9 Glass board 10 Film 11 Coating frame 12 Squeegee 13 Resin layer 14 Cured resin 15 Cut stage 16 Porous board 17 Resin paste

Claims (12)

An application step of disposing a heat-resistant film on a flat surface of a flat plate having at least one flat surface, applying a resin paste at a predetermined thickness on the heat-resistant film, and forming a resin layer;
Placing the circuit board module on the resin layer, and placing the circuit board module so that the back surface of the circuit board module is buried in the resin layer; and
After the placing step, by curing the resin layer by heating, a curing step for integrating the flat plate to the circuit board module as a laminate, and
From the laminate, a removing step of removing the flat plate and the heat-resistant film to form a second laminate,
A substrate splitting step of fixing the resin paste surface of the second laminate to the stage and removing the substrate at a desired position of the circuit module leaving the resin paste layer by a cutting means;
A circuit module dividing method comprising: The circuit module dividing method according to claim 1, wherein the flat plate has a heat resistant temperature higher than a thermosetting temperature of the resin. The circuit module dividing method according to claim 2, wherein the flat plate is made of lead glass or borosilicate glass. The circuit module dividing method according to claim 1, wherein the heat resistant film has a heat resistant temperature equal to or higher than a curing temperature of the resin paste. The circuit module dividing method according to claim 4, wherein the heat-resistant film is PEI (polyetherimide) or PES (polyethersulfone). The circuit module dividing method according to claim 1, wherein an electronic component is mounted on at least one surface of the circuit board module. The circuit module dividing method according to claim 1, wherein the cured resin layer has a hardness of 70 ° or less and a peel strength of 0.3 N / mm or more. The circuit module dividing method according to claim 1, wherein the resin paste contains conductive particles. 2. The circuit module dividing method according to claim 1, wherein the resin paste is mainly composed of a vinyl resin derivative, a fatty acid ester, and an epoxy ester, and the content of the vinyl resin derivative is 55 to 65 wt% of the whole. 2. The circuit module dividing method according to claim 1, wherein in the coating step, the predetermined thickness is larger than a maximum thickness of a component mounted on the circuit board module. The circuit module dividing method according to claim 1, wherein in the substrate dividing step, the third stacked body is fixed to the stage by being sucked through the stage. The circuit module dividing method according to claim 1, wherein in the substrate dividing step, the cutting means is a dicer.

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