JP2009164350A - Method for manufacturing wired circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing wired circuit boards which dehydrates the surface of a wired circuit board surely while preventing the disconnection of the wired circuit board. <P>SOLUTION: With respect to the method for manufacturing wired circuit boards, a sheet 3 having a plurality of wired circuit boards 21 is water-washed in a water-washing process S1. Thereafter, the sheet 3 is so dehydrated in an immersing and bubbling process S3 included in a dehydrating process S2 as to bubble a processing liquid 10 while immersing the sheet 3 in the processing liquid 10 containing a water-soluble solvent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a printed circuit board.

Conventionally, in a method of manufacturing a printed circuit board, it is known that the surface of the plating or solder is washed with water after plating or soldering at the terminal portion. For example, the printed wiring board after plating is washed with water. (For example, refer to Patent Document 1).
JP-A-8-32205

However, in the printed wiring board after washing with water proposed in Patent Document 1, a method of removing water remaining on the surface of the printed wiring board by ultrasonic cleaning while immersing the printed wiring board in a water-soluble solvent such as isopropanol. Can be considered. However, in this method, there is a problem that a disconnection occurs in the terminal portion of the printed wiring board due to the stress caused by the ultrasonic waves.
An object of the present invention is to provide a method of manufacturing a printed circuit board that can reliably dehydrate the surface of the printed circuit board while preventing disconnection of the printed circuit board.

In order to achieve the above object, a method for manufacturing a printed circuit board according to the present invention includes a water washing step of washing the printed circuit board, and the water soluble step after the water washing step while immersing the wiring circuit board in at least a water soluble solvent. A dehydration step of dehydrating the printed circuit board by bubbling a solvent.
According to this method, after the wiring circuit board is washed in the water washing step, the wiring circuit board is dehydrated by bubbling a water-soluble solvent in the dehydration step, so that relatively large bubbles are brought into contact with the surface of the wiring circuit board. Thus, the wiring circuit board can be reliably dehydrated while preventing disconnection in the wiring circuit board.

As a result, it is possible to obtain a wired circuit board with high connection reliability while reliably dehydrating the wired circuit board.
In the wired circuit board manufacturing method of the present invention, the dehydration step adds the water-soluble solvent to the surface of the wired circuit board by adding a layer separation solvent that can be separated into the water-soluble solvent. It is preferable to provide a solvent replacement step of replacing with the layer separation solvent.

In this method, in the solvent replacement step, the water-soluble solvent is replaced with the layer separation solvent on the surface of the wiring circuit board. Therefore, the water-soluble solvent containing water dehydrated from the wiring circuit board is removed by the layer separation solvent. Can be reliably removed from the surface of the surface. Therefore, the printed circuit board can be dehydrated more reliably.
In the method for manufacturing a printed circuit board according to the present invention, it is preferable that the specific gravity of the layer separation solvent is larger than the specific gravity of the water-soluble solvent.

  In this method, since the specific gravity of the layer separation solvent is larger than that of the water-soluble solvent, the layer separation solvent forms the lower layer and the water-soluble solvent forms the upper layer. Therefore, if the water-soluble solvent is replaced with a layer separation solvent, the water-soluble solvent containing water dehydrated from the wiring circuit board can be removed by overflow. As a result, the printed circuit board can be dehydrated easily and reliably.

  According to the method for manufacturing a wiring board of the present invention, it is possible to obtain a wiring circuit board with high connection reliability while reliably dehydrating the wiring circuit board.

FIG. 1 is a perspective view of a dehydrating apparatus used in an embodiment of a method for manufacturing a printed circuit board according to the present invention, FIG. 2 is a plan view of the dehydrating apparatus shown in FIG. 1, and FIG. 3 is a dehydrating apparatus shown in FIG. FIG. 4 is a flow chart of each process for dehydrating the sheet, and FIG. 5 is a longitudinal direction of the printed circuit board to be dehydrated by the dehydrating apparatus shown in FIG. FIG.
First, a dehydrating apparatus used in an embodiment of a method for manufacturing a printed circuit board according to the present invention will be described with reference to FIGS. 1, 2, and 3 (a). In FIG. 1, the processing tank 2 is omitted in order to clarify the relative arrangement of the sheet 3 and the bubble generating unit 4.

1 and 2, the dehydrating apparatus 1 is provided for dehydrating a printed circuit board assembly sheet (hereinafter simply referred to as “sheet”) 3 in which a plurality of printed circuit boards 21 to be described later are arranged. . The dehydrating apparatus 1 includes a processing tank 2, a bubble generating unit 4, and a processing liquid supply unit (not shown).
As shown in FIG. 3A, the processing tank 2 is a container for storing a processing liquid 10 to be described later, and has a bottomed box shape, for example. The internal capacity of the processing tank 2 is, for example, 10 to 70 L, preferably 30 to 50 L, depending on the capacity of the processing liquid 10 to be accommodated and the size and number of sheets 3 to be dehydrated.

As shown in FIG. 1 and FIG. 3A, the bubble generating unit 4 is provided in the lower part in the processing tank 2 and is disposed along the horizontal direction (the direction along the bottom wall of the processing tank 2). Moreover, the bubble generation part 4 is integrally provided with the gas distribution pipe 6 and the bubble generation pipe 7, as shown in FIG.
The gas distribution pipe 6 is disposed at one end of the processing tank 2 in the width direction (the left-right direction on the paper surface, the same shall apply hereinafter). Further, the gas distribution pipe 6 is disposed so as to extend in the depth direction (direction orthogonal to the width direction) in the processing tank 2. The gas distribution pipe 6 is provided with a gas inlet 5 at one end in the depth direction and the other end in the depth direction. Moreover, the gas distribution pipe 6 is formed, for example, in a cylindrical shape, and has an inner diameter of, for example, 3 to 10 mm, preferably 4 to 6 mm.

  A plurality of bubble generating pipes 7 are provided so as to branch from the gas distribution pipe 6. Each bubble generation pipe 7 is arranged to be opposed to each other with an interval in the depth direction, and is formed to extend from the gas distribution pipe 6 toward the other side in the width direction. Moreover, the bubble generation tube 7 is formed in a cylindrical shape, for example, and a bubble generation port 8 that is opened in a circular shape in a plan view is formed on the upper peripheral wall of the bubble generation tube 7 with an interval in the extending direction (width direction) of the bubble generation tube 7. Are provided.

  More specifically, the bubble generating tube 7 includes a plurality of (five) first bubble generating tubes 7A in which the bubble generating ports 8 are arranged only on one side (base end side) half in the width direction, and the bubble generating ports. 8 includes a plurality (five) of second bubble generation tubes 7B arranged only on the other half (free end side) in the width direction. In the processing tank 2, the first bubble generating tubes 7A and the second bubble generating tubes 7B are alternately arranged in the depth direction.

The space | interval between each adjacent bubble generation tube 7 is 10-100 mm, for example, Preferably, it is 20-50 mm. Each bubble generating tube 7 has an inner diameter of, for example, 1 to 10 mm, preferably 3 to 7 mm. Each bubble generating port 8 has an inner diameter of, for example, 0.1 to 1 mm, preferably 0.2 to 0.5 mm.
A treatment liquid supply unit (not shown) is connected to the treatment tank 2 and is configured to supply a treatment liquid described later into the treatment tank 2.

The dehydrating apparatus 1 is provided with a transport mechanism (not shown) for carrying the sheet 3 before the dehydration process into the processing tank 2 and then unloading the sheet 3 after the dehydration process from the processing tank 2. The transport mechanism includes a suspending portion (not shown) that moves up and down, and is configured to suspend the sheet 3 by the suspending portion.
Next, an embodiment of a method for manufacturing a printed circuit board according to the present invention using the above dehydrating apparatus 1 will be described with reference to FIGS.

In this method, first, a sheet 3 is prepared as shown in FIG.
As shown in FIG. 1, the sheet 3 includes a plurality of wiring circuit boards 21 such as suspension boards with circuits, and the wiring circuit boards 21 are spaced apart from each other within a substantially rectangular sheet-shaped metal support board 19. Are arranged in an aligned state.
Each printed circuit board 21 is formed in a substantially rectangular shape extending in the longitudinal direction. As shown in FIG. 5, each printed circuit board 21 includes a metal support layer 22, a base insulating layer 23 formed on the metal support layer 22, and a conductor layer 24 formed on the base insulating layer 23. The insulating cover layer 25 is formed on the insulating base layer 23 so as to cover the conductor layer 24.

The metal support layer 22 is formed from the metal support substrate 19. The metal support substrate 19 is formed of stainless steel or the like, and the thickness thereof is, for example, 10 to 100 μm, preferably 18 to 50 μm. Moreover, the magnitude | size of the metal support substrate 19 is 200-300 mm, for example, Preferably, it is 250-300 mm.
The base insulating layer 23 is made of polyimide or the like, and has a thickness of, for example, 3 to 30 μm, or preferably 5 to 15 μm.

The conductor layer 24 is integrally provided with a plurality of wirings 26 that are spaced apart from each other and extend along the longitudinal direction, and terminal portions 27 that are continuous with both ends of the wirings 26 in the longitudinal direction. The conductor layer 24 is made of copper or the like, and has a thickness of, for example, 3 to 20 μm, or preferably 7 to 15 μm.
The insulating cover layer 25 is formed on the insulating base layer 23 as a pattern that covers the wiring 26 and exposes the terminal portion 27. The insulating cover layer 25 is made of polyimide or the like, and has a thickness of, for example, 2 to 20 μm, preferably 4 to 15 μm.

The wired circuit board 21 is provided with a metal plating layer 28 made of gold or nickel on the surface of the terminal portion 27. The thickness of the metal plating layer 28 is, for example, 0.2 to 5 μm, or preferably 0.5 to 3 μm.
Next, in this method, as shown in FIG. 4, the sheet 3 is washed with water (water washing step S1).
In order to wash the sheet 3 with water, for example, a known method such as dipping or spraying is used.

Next, in this method, the sheet 3 is dehydrated (dehydration step S2).
To dehydrate the sheet 3, first, as shown in FIG. 3A and FIG. 4, the processing liquid 10 is bubbled while the sheet 3 after the water washing step S1 is immersed in the processing liquid 10 containing a water-soluble solvent. (Immersion bubbling step S3).
The treatment liquid 10 contains a water-soluble solvent, and preferably comprises a mixed liquid of a water-soluble solvent and a layer separation solvent. When the treatment liquid 10 contains a layer separation solvent, the water-soluble solvent remaining on the surface of the sheet 3 (more specifically, the water and the water-soluble solvent remaining on the surface of the sheet 3) Can be repelled from the surface of the sheet 3, and the remaining water-soluble solvent on the surface of the sheet 3 can be prevented.

  The water-soluble solvent is a solvent that can dissolve water remaining on the surface of the sheet 3 after the water washing step S1. Moreover, the specific gravity at 20 degreeC of a water soluble solvent is 0.7-1.5, for example, Preferably, it is 0.7-1.0, More preferably, it is 0.7-0.8. The water-soluble solvent has a boiling point of, for example, 200 ° C. or less, preferably 100 ° C. or less, and usually 80 ° C. or more.

  Examples of such water-soluble solvents include alcohols having 1 to 4 carbon atoms such as methanol, ethanol, propanol, isopropanol (isopropyl alcohol: IPA), butanol, and isobutanol, such as ethylene glycol and ethylene glycol monomethyl ether ( For example, glycols such as methyl cellosolve) and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone are used. Preferably, C1-C4 alcohol is used, More preferably, IPA is used.

  The layer separation solvent is a solvent capable of layer separation from the water-soluble solvent in the layer separation step S4 described later. Further, the layer separation solvent has a specific gravity at 20 ° C. larger than the specific gravity at 20 ° C. of the water-soluble solvent. Specifically, the specific gravity (20 ° C.) of the layer separation solvent is, for example, 120% or more, preferably 150% or more, more preferably, when the specific gravity (20 ° C.) of the water-soluble solvent is 100%. It is 180% or more, and is usually 300% or less. More specifically, the specific gravity (20 ° C.) of the layer separation solvent is, for example, 1.0 or more, preferably 1.3 or more, more preferably 1.5 or more, and usually 2.0 or less. is there. Moreover, the boiling point of a layer separation solvent is 50-100 degreeC, for example, Preferably, it is 50-70 degreeC. Such a layer separation solvent is flame retardant, and therefore can impart explosion-proof properties to the treatment liquid 10.

As such a layer separation solvent, for example, a fluorine-based solvent is used.
Examples of the fluorine-based solvent include hydrocarbons such as C ₄ F ₉ OCH ₃ , C ₄ F ₉ OCH ₂ CH ₃ , CF ₃ CF ₂ CF ₂ OCH ₃ , (CF ₃ ) ₂ CFOCH ₃ , and CF ₃ CFHCF ₂ OCH _3. Fluoroether (HFE), for example perfluorocarbon (PFC) such as C ₆ F ₁₄ , C ₈ F ₁₈ , (C ₄ F ₉ ) ₃ N, perfluorodimethylcyclobutane, perfluoro (2-butyltetrahydrofuran), for example C ₄ F ₉ CH ₂ CH ₃ , C ₆ F ₁₃ CH ₂ CH ₃ , (CF ₃ ) ₂ CFCFHCHFCF ₃ , CF ₃ CFHCCFHCF ₂ CF ₃ , C ₆ F ₁₃ H, HC ₆ F ₁₂ H, HC ₄ F ₈ H Hydrofluorocarbon (HFC) such as is used.

Of these, hydrofluoroether (HFE) is preferably used, and C ₄ F ₉ OCH ₃ is more preferably used.
The mixing ratio of the water-soluble solvent and the layer separation solvent in the treatment liquid 10 is, for example, 1/99 to 50/50, preferably 3/97 to 7/93, by weight ratio of the water-soluble solvent / layer separation solvent. Preferably, it is 4/96 to 6/94. When the blending ratio of the water-soluble solvent is less than the above range, water droplets (or traces) may remain on the surface of the sheet 3 after the dehydration step S2. On the other hand, when the blending ratio of the water-soluble solvent exceeds the above-described range, water-soluble solvent droplets (or traces) may remain on the surface of the sheet 3 after the dehydration step S2, and a solvent described later. In the substitution step S5, the amount of the layer separation solvent to be substituted may increase excessively, resulting in an increase in manufacturing cost.

The temperature of the treatment liquid 10 in the treatment tank 2 is adjusted to, for example, more than 50 ° C. and 54 ° C. or less, preferably 52 to 54 ° C. When the treatment liquid 10 is at the temperature or lower, water droplets (or traces) may remain on the surface of the sheet 3 after the dehydration step S2.
In order to immerse the sheet 3 in the processing liquid 10, the sheet 3 is put into the processing tank 2 by a transport mechanism.

As shown in FIGS. 1 and 3, the sheet 3 is suspended so that the sheet 3 is suspended by a suspended portion of a conveyance mechanism (not shown). Specifically, as shown in FIG. 1, a plurality of (eight) sheets 3 are arranged in a suspended portion in the processing tank 2 so as to be opposed to each other with an interval in the depth direction, as shown in FIG. 1. It is suspended.
Then, the sheet 3 is lowered by the lowering of the suspension, the sheet 3 is put into the processing tank 2, and the sheet 3 is immersed in the processing liquid 10 in the processing tank 2.

In addition, as shown in FIG. 3, the lower end part of the sheet | seat 3 is opposingly arranged by the bubble generating part 4 at intervals in the up-down direction in the front view. Moreover, as shown in FIG. 2, each sheet | seat 3 is arrange | positioned between each bubble generation tube 7 in a depth direction in planar view.
Simultaneously with the above immersion, the treatment liquid 10 is bubbled by the bubble generating unit 4.
In order to bubble the processing liquid 10 by the bubble generating unit 4, gas is supplied to the gas inlet 5, and gas is discharged from each bubble generating port 8 through the gas distribution pipe 6 and each bubble generating pipe 7.

The gas discharged from the bubble generating port 8 is not limited to forming bubbles in the processing liquid 10, that is, not dissolved in the processing liquid 10. For example, an inert gas such as nitrogen or argon, for example, air (Atmosphere) etc. are used.
The discharge amount (that is, bubbling flow rate) of the gas discharged from each bubble generating port 8 is, for example, 30 to 40 L / min, preferably 35 to 40 L / min.

Further, bubbles generated in the treatment liquid 10 are very large compared to micron-sized bubbles (for example, 0.1 to 0.3 μm) generated by ultrasonic cleaning, and the average diameter thereof is, for example, 0.3 to It is 10 mm, preferably 0.3 to 5 mm.
The bubbling time is, for example, 20 to 150 seconds, preferably 60 to 120 seconds, and more preferably 60 to 90 seconds.

Accordingly, the processing liquid 10 is bubbled, and the generated bubbles come into contact with the entire surface of the sheet 3 and the processing liquid 10 on the surface of the sheet 3 is sufficiently stirred, whereby the sheet 3 can be dehydrated.
In addition, in this immersion bubbling process S3, since the process liquid 10 is stirred by the bubbling of the bubble generation part 4, the water-soluble solvent is disperse | distributed (suspended) in the layer separation solvent. ) Forming a state.

Next, in this method, as shown in FIGS. 3B and 4, the processing liquid 10 is allowed to stand and the processing liquid 10 is separated into layers (layer separation step S <b> 4).
In order to separate the treatment liquid 10 into layers, bubbling is interrupted, and then the treatment liquid 10 is allowed to stand. The standing time is, for example, 60 seconds or longer, preferably 90 seconds or longer, and usually 150 seconds or shorter.

By allowing the treatment liquid 10 to stand, the water-soluble solvent forms the upper layer 11, and the layer separation solvent forms the lower layer 12, whereby an interface is formed between the upper layer 11 and the lower layer 12 in the treatment liquid 10. Thereby, the process liquid 10 can be separated into layers.
Next, in this method, as shown in FIGS. 3 (c) and 4, a layer-separating solvent is further added to the treatment liquid 10 from a treatment liquid supply unit (not shown), so that a water-soluble solvent is layered on the surface of the sheet 3. Substitution with a separation solvent (solvent substitution step S5).

Further, the layer separation solvent to be added may be the same as or different from the layer separation solvent contained in the treatment liquid 10, and is preferably the same.
Furthermore, the volume of the added layer separation solvent is set to a capacity that causes all the water-soluble solvents forming the upper layer 11 to overflow from the upper end of the treatment tank 2, for example. Moreover, the speed | rate which adds such a layer separation solvent is 10-20 L / min, for example, Preferably, it sets to 12-15 L / min.

As a result, the interface between the upper layer 11 and the lower layer 12 rises as shown by the arrow in FIG. 3B, and then the water-soluble solvent that forms the upper layer 11 as shown by the thick arrow in FIG. Overflows from the upper end of the treatment tank 2, and the water-soluble solvent can be replaced with a layer separation solvent.
Thereafter, in this method, as indicated by an arrow in FIG. 3C, the sheet 3 is pulled up from the processing liquid 10 by raising the hanging portion.

Then, as shown in FIG. 4, the sheet 3 can be dehydrated by sequentially performing the immersion bubbling step S3, the layer separation step S4, and the solvent replacement step S5 (dehydration step S2).
Although not shown in FIG. 4, after the dehydration step S2, the sheet 3 is dried by a drying step using hot air if necessary.

  According to this method, the sheet 3, that is, the sheet 3 on which the metal plating layer 28 is formed is washed with water in the washing step S 1, and then the processing liquid 10 is bubbled in the immersion bubbling step S 3 of the dehydration step 2. 3 can be dehydrated while relatively large bubbles are in contact with the surface of the sheet 3, and the sheet 3 can be reliably dehydrated while preventing disconnection in the sheet 3, particularly disconnection in the terminal portion 27. Can do.

As a result, it is possible to obtain the printed circuit board 21 with high connection reliability while reliably dehydrating the sheet 3.
In this method, in the solvent replacement step S5, the water-soluble solvent is replaced with the layer separation solvent on the surface of the sheet 3, so that the water-soluble solvent containing water dehydrated from the sheet 3 is replaced with the layer 3 by the layer separation solvent. Can be reliably removed from the surface of the surface. Therefore, the sheet 3 can be dehydrated more reliably.

  Further, in this method, since the specific gravity of the layer separation solvent is larger than that of the water-soluble solvent, the layer separation solvent forms the lower layer 12 and the water-soluble solvent forms the upper layer 11. Therefore, if the water-soluble solvent is replaced with a layer separation solvent, the water-soluble solvent containing water dehydrated from the sheet 3 can be removed by overflow. As a result, the sheet 3 can be dehydrated easily and reliably.

In the above description, the water washing step S1 and the dehydration step S2 were performed after the formation of the metal plating layer 28. Furthermore, as shown by the broken lines in FIG. After the formation, the water washing step S1 and the dehydration step S2 can be further performed.
In the above description, as shown in FIG. 4, both the layer separation step S4 and the solvent replacement step S5 are performed. For example, both the layer separation step S4 and the solvent replacement step S5 are not performed, and after the immersion bubbling step. The sheet 3 can be pulled up as it is. In addition, the sheet 3 after the layer separation step S4 can be pulled out from a lower sheet outlet (not shown) provided in the lower portion of the processing tank 2 without performing only the solvent replacement step S5.

  In the above description, the specific gravity of the layer separation solvent is larger than the specific gravity of the water-soluble solvent. However, for example, the specific gravity of the layer separation solvent can be smaller than the specific gravity of the water-soluble solvent. In this case, although not shown, the water-soluble solvent forms the lower layer 12 and the layer separation solvent forms the upper layer 11. In the solvent replacement step S5, the layer-soluble solvent is further added to cause the water-soluble solvent forming the lower layer 12 to flow out from a lower solvent outlet (not shown) provided at the lower portion of the processing tank 2.

Example 1
(Washing process)
A sheet provided with a plurality of printed circuit boards was prepared. That is, first, a metal support substrate made of stainless steel (SUS304) having a thickness of 20 μm and a size of 100 × 100 mm is prepared, and then a base insulating layer made of polyimide having a thickness of 12 μm is formed on the metal support substrate. And a conductor layer made of copper having a thickness of 10 μm, and then covering the wiring and forming a cover insulating layer made of polyimide having a thickness of 5 μm in a pattern that exposes the terminal portion, and then having a thickness of 2 μm A plurality of printed circuit boards were formed by forming a metal plating layer made of gold on the surface of the terminal portion (see FIGS. 1 and 5). In addition, each wiring and each terminal part width | variety were 30 micrometers.

By immersing this sheet in water for 20 seconds, the sheet was washed with water (see FIG. 4, water washing step (S2)).
(Dehydration process)
Next, the sheet was dehydrated using a dehydrator (dehydration step (S2)).
In the dehydrating apparatus, the length of the gas distribution pipe was 349 mm, the length of each bubble generation pipe was 270 mm, and the distance between the bubble generation pipes arranged to face each other was 40 mm. Moreover, the space | interval between each bubble generation opening was 5 mm, and the diameter of the bubble generation opening was 0.3 mm.

In the dehydration step (S2), first, the sheet is divided into 3 parts by weight of IPA (specific gravity 0.78 (20 ° C.), boiling point 82 ° C.) and C ₄ F ₉ OCH ₃ (specific gravity 1.52 (20 ° C.), boiling point 61 ° C. ) While being immersed in a treatment liquid containing 97 parts by weight and having a temperature adjusted to 52 ° C., the treatment liquid was bubbled with nitrogen using a bubble generating part (see FIG. 3A and FIG. 4, immersion bubbling). Step (S3)). In the immersion bubbling step (S3), the bubbling time was 75 seconds, and the bubbling flow rate was 30 L / min. The average bubble diameter was 3 mm.

Next, the bubbling was interrupted, and the treatment liquid was allowed to stand for 75 seconds to separate the treatment liquid into layers (see FIG. 3B and FIG. 4, the layer separation step (S4)). Thereby, in the processing liquid, an upper layer was formed by IPA, and a lower layer was formed by C ₄ F ₉ OCH ₃ .
Then, by adding the processing liquid supply unit in the C ₄ F ₉ OCH ₃ The treatment solution further rate 12L / min, the surface of the sheet, and replace all of IPA (aqueous solution containing IPA) in C ₄ F ₉ OCH ₃ (Refer FIG.3 (c) and FIG. 4, a solvent substitution process (S5)). In the solvent replacement step (S5), the interface between the upper layer and the lower layer rose, and then the water-soluble solvent forming the upper layer overflowed from the upper end of the treatment tank.

Thereafter, the sheet was pulled up, thereby dehydrating the sheet.
Examples 2-10
Except that the IPA concentration and temperature of the treatment liquid, the bubbling flow rate and bubbling time of the immersion bubbling step (S3), and the standing time of the layer separation step (S4) were changed according to Table 1, the same as in Example 1 The sheet | seat was dehydrated by the process and the wiring circuit board of Examples 2-10 was obtained, respectively.

Example 11
Both the layer separation step (S4) and the solvent replacement step (S5) were not performed, and the sheet 3 after the immersion bubbling step (S3) was dehydrated by the same treatment as in Example 8 except that the sheet 3 was pulled up as it was. Thus, printed circuit boards of Example 11 were obtained.
Comparative Example 1
The same treatment as in Example 1 except that IPA was used as the treatment liquid, and the immersion ultrasonic wave process was performed instead of the immersion bubbling process (S3), and then the sheet was pulled up from the treatment liquid as it was. The sheet was dehydrated.

  In the immersion ultrasonic process, the sheet was immersed for 150 seconds using 40 kHz ultrasonic waves.

(Evaluation)
1) Disconnection in the terminal part About the wiring circuit board of the sheet | seat manufactured by Examples 1-11 and the comparative example 1, the presence or absence of the disconnection in a terminal part was confirmed by ultrasonic cleaning.

As a result, in Examples 1-11, the disconnection in the terminal part was not confirmed.
On the other hand, in the comparative example 1, the disconnection in the terminal part was confirmed.
2) Trace of water washing process The presence or absence of the trace of the water washing process (S1) in the printed circuit board of the sheet | seat manufactured by Examples 1-11 and Comparative Example 1 was confirmed.

  The results are shown in Table 1.

なお、表１の「水洗工程の痕」欄における評価の略号を下記に示す。
○：水洗工程の痕が確認されなかった。
△：水洗工程の痕がわずかに確認された。

The abbreviations for evaluation in the column “Trace of washing step” in Table 1 are shown below.
○: No trace of the washing process was confirmed.
(Triangle | delta): The trace of the water washing process was confirmed slightly.

  X: The trace of the washing process was confirmed.

The perspective view of the spin-drying | dehydration apparatus used for one Embodiment of the manufacturing method of the wired circuit board of this invention is shown. The top view of the spin-drying | dehydration apparatus shown in FIG. 1 is shown. It is front sectional drawing of the dehydrating apparatus shown in FIG. 1, and is each process drawing which dehydrates a sheet | seat, (a) is an immersion bubbling process, (b) is a layer separation process, (c) is a solvent substitution process. Indicates. The flowchart of each process which spin-dry | dehydrates a sheet | seat is shown. Sectional drawing along the longitudinal direction of the printed circuit board dehydrated by the dehydrating apparatus shown in FIG. 1 is shown.

Explanation of symbols

21 printed circuit board S1 water washing process S2 dehydration process

Claims (3)

A water washing process for washing the printed circuit board;
A dehydrating step of dehydrating the wiring circuit board by bubbling the water-soluble solvent while immersing the wiring circuit board in at least a water-soluble solvent after the rinsing step. Method.   The dehydration step includes a solvent replacement step of replacing the water-soluble solvent with the layer separation solvent on the surface of the wiring circuit board by adding a layer separation solvent that can be separated into the water-soluble solvent. The method for manufacturing a printed circuit board according to claim 1, wherein:   The method for manufacturing a printed circuit board according to claim 2, wherein the specific gravity of the layer separation solvent is larger than the specific gravity of the water-soluble solvent.

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