JPS63261787A - Printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to printed wiring boards.

[Prior Art] Generally, a printed wiring board is constructed by forming a required circuit pattern on an insulating substrate via a conductor, and incorporating required electronic components into this circuit pattern.

In order to assemble the electronic components onto the printed wiring board, the circuit pattern surface of the printed wiring board is immersed in a molten solder tank or jet solder tank while the electronic components are mounted on the printed wiring board. This is accomplished by attaching solder to the leads of the electronic component and the circuit pattern, and then mechanically and mechanically connecting them.

Furthermore, when soldering the circuit pattern and the lead of the electronic component, for example, a solder resist is applied to the entire surface of the circuit pattern except for the land portion to be soldered so that the solder adheres only to the connected parts of the two. is applied, but
With the miniaturization of circuit patterns, the spacing between adjacent circuits and the spacing between connecting lands with the leads of electronic components are also becoming narrower, which impairs the original function of the solder resist and causes problems between the lands due to soldering. There were cases where a bridging phenomenon occurred and correction work was required.

Therefore, in order to prevent such solder bridging, especially in areas where the land spacing is narrow, a conductive pattern is printed on the insulating substrate when manufacturing the printed wiring board. Then, a first layer of soldering resistance layer is formed on the entire surface of the conductor pattern formation surface, leaving lands to be soldered, and a bridging prevention layer is used to prevent +m bridging at least in areas where the land spacing is narrow. A method of forming a soldering resistor layer on the first layer of soldering resistor layer is adopted,
Such a method has also been disclosed in Japanese Patent Publication No. 54-41162.

However, the method of forming the first layer of soldering resistance layer and then forming a soldering resistance layer for preventing bridging on the first layer of soldering resistance layer is difficult. Since the soldering resistor layer is formed on the entire surface of the conductor pattern formation surface, leaving a land to be soldered, high alignment precision is required to leave the land to be soldered, and this first layer In soldering, a soldering resistive layer for preventing bridging is formed on the first soldering resistive layer after formation on the resistive layer, so in addition to alignment precision to leave the land to be soldered. However, when forming a soldering resistance layer on the land portion to be soldered, the solder resist ink caused by screen printing bleeds out.

Therefore, in view of the above-mentioned drawbacks of the conventional printed wiring board, the applicant has previously proposed an invention related to Japanese Patent Application No. 62-37647 to implement the conventional solder resist without requiring the same technical complexity. We have just disclosed a printed wiring board provided with a solder resist film that can obtain the effect of an original solder resist.

In other words, the solder resist film of the printed wiring board has the ability to actively prevent the adhesion of flux or solder due to the properties of the silicon and/or fluorocarbon resin it contains, and in particular, the solder resist film has the ability to actively prevent the adhesion of flux or solder. By forming a film with the printing ink for solder resist on the other side of the printed wiring board on which the pattern has been formed, it is possible to actively prevent flux or solder from entering from the through-hole or component insertion hole side provided on the printed wiring board. It has an effect that can be prevented.

FIG. 2 is a partially enlarged cross-sectional view showing a printed wiring board provided with the solder resist film. 3 is a connection land in the circuit pattern 2, 4 is a through hole opened in the connection land 3, 6 is a solder resist film coated on the second side of the circuit pattern, and 7 is the other side of the insulating substrate l. This is a solder resist film coated on 1b.

Therefore, the solder resist film 6 is applied leaving the connection lands 3 in the circuit pattern 2, and together with the solder resist film 7, flux and In are applied.
It is formed by coating by means such as silk printing using a printing ink containing insulating silicone and/or fluorocarbon resin that can prevent the adhesion of.

Further, a specific example of the formulation of the solder resist printing ink used to form the solder resist covers v6 and 7 is shown below.

Formulation example l Epoxy acrylate 28 parts by weight Polyethylene glycol acrylate 72 tr
Benzoin alkyl ether 4 ttT
ic)z (# titanium chloride) 5 〃5i
02 (silicon oxide) 3 tt diferdisulfide 2.0 Pigment (
cyanine green) Q, 4 tt diethylhydroxyamine Q, l //
Dimethylsiloxane (antifoaming agent) 2. Ott
Silicone polymer resin 2~5 tt
Formulation example 2 Epoxy acrylate 28 parts by weight Polyethylene glycol acrylate) 72 /
/benzoin alkyl ether 4t
rTi02 (Titanium oxide) 51/ SiO2C silica J) 3
tt diferdi sulfide 2.0
//Pigment (cyanine green) 0.
4 //diethylhydroxyamine 0
1ll/dimethylsiloxane (antifoaming agent) 2
．． 0/1 blending example 3 epoxy acrylate 50 parts by weight polyurethane acrylate) 50
//Benzoin methyl ether 4
ttCaCo3 (calcium carbonate) 5
〃5in2 (silicon oxide) 3
tt cyanine green 0.4
〃Benzothiazole 0.05 /
/ Bethfenone 2J t
tDimethylsiloxane 1.5
tt silicone polymer resin 2~5/
! Formulation example 4 Epoxy acrylate 50 parts by weight Polyurethane acrylate 5Qt
tHenzoin methyl ether 4 tt
Ca CO3 (calcium 57ate) 51/5in2 (
Silicon oxide) 31 / Cyanine Green 0.4 Benzothiazole 0.05 // Bezophenone 2.8 tt Dimethylsiloxane 1.5 Silicone-based polymer resin 2-5 In addition, silicone-based in each of the above-mentioned formulation examples Also, specific examples of fluorocarbon resins are shown below.

Silicon-based Po1on L, Po1on T, KF9B, K
S-700, KS-701゜KS-707, KS-70
5F, KS-708, KS-709, KS-709S.

KS-711, KSX-712, KS-82F, KS
-62M, KS-84゜5ilicolube G-
430,5ilicolube G-540゜5ili
colube G-541 or higher Shin-Etsu Chemical Co., Ltd. 5H-200, 5H-210, 5H-1109, 5H-
3109,5H-3107゜5H-8011,FS-1
285,5yli-off23. DCpan Gla
ze or higher Furan-based 4 ifry manufactured by Toray Silicon Co., Ltd. MS-443, MS-543, MS-74
3, MS-043゜ME-413, ME-810 or higher Daikin Industries, Ltd. Prolade FC-93, FC-95, FC-98, F
C-129, FC-134゜FC-430, FC-43
1, FC-721 or higher Sumiflunon FP-81, FP-81R, FP-82, manufactured by Sumitomo 3M Co., Ltd.
FP-840, FP-84R.

FP-813 and above 'j-7a 5R-100 manufactured by Sumitomo Chemical Co., Ltd. 5R-100X and above-L
Manufactured by Kiyomi Kagaku Co., Ltd.In addition, each formulation example shows the case where a silicone-based or fluorine-based polymer resin is blended alone, but it can be carried out by blending both a silicone-based and a fluorine-based polymer resin. It has been found that the desired effect can be obtained by adding 2 to 5 parts by weight. L L, an increase in the amount of compounding may cause economical problems, but J
It's no good.

Furthermore, it has been found that while the contact angle of conventional solder resist inks is 60 to 70', the contact angle of the solder resist ink according to the formulation example described above can be 90' or more.

Now, according to the printed wiring board having such a configuration, the solder resist covering 11Q formed on both sides of the insulating substrate 1
6.7 is formed by coating with printing ink containing silicone and/or fluorocarbon resin, so the characteristics of silicone and fluorocarbon resin repel flux or solder, and the connecting land 3! It is possible to actively prevent flux or solder from adhering to areas other than the electrically connected portions of v=, and it is possible to prevent the occurrence of bridging phenomena between adjacent adjacent circuit patterns as the density of the circuit pattern 2 increases.

Furthermore, the solder resist coatings 6 and 7 can be formed by coating by means such as silk printing, and have the advantage that they can be formed by the same operation as conventional solder resist coatings.

Further, the other surface tb of the insulating substrate 1 provided with the circuit pattern 2
By providing a solder resist film 7 on the printed wiring board, it is also possible to prevent flux or solder from penetrating through the through holes 4 provided in the printed wiring board.

In the above embodiment, the circuit pattern 2 is formed only on one side 1a of the insulating substrate 1, but it may be formed on both sides, or only the solder resist coating 6 on the circuit pattern 2 side on one side 1a of the insulating substrate 1. Of course, it is also possible to form the solder resist films 6 and 7 on the entire surface of the insulating substrate l. It is also possible to form it only in a local part such as the peripheral part of 4.

According to the printed wiring board described in 4- below, the solder resist film itself can exhibit the effect of preventing flux or solder smearing, and half-E openings when mounting components on the printed wiring board and connecting between circuit terminals can be prevented. Prevent bridging between circuits or component terminals due to work,
This has the effect of improving product accuracy, eliminating the need for bridge correction work, etc., and improving work efficiency.

[Problems to be Solved by the Invention] However, according to a printed wiring board provided with a solder resist film containing silicone and/or fluorocarbon resin, the same problem occurs due to the action of the solder resist film of the printed wiring board. When flux is applied to the solder resist coating surface, the flux adheres to the solder resist coating surface -L in the form of spots, which has disadvantages such as impairing the product accuracy and appearance of the printed wiring board. there were.

Therefore, the present invention has been made in view of the drawbacks of printed wiring boards provided with a solder resist film containing silicone and/or fluorocarbon resin, and the present invention has been made in view of the drawbacks of printed wiring boards provided with solder resist films containing silicone and/or fluorocarbon resin. The object of the present invention is to provide a printed wiring board that can prevent this occurrence.

[Means for Solving the Problems] The printed wiring board of the present invention is a Punto wiring board provided with a solder resist film containing silicone and/or fluorocarbon resin, which is provided on the upper side of the substrate of the printed wiring board. A solder resist coating is provided on the lower side of the substrate by being located at a desired position of the solder resist coating, and a through hole for a flux reservoir is provided in the solder resist coating on both the upper and lower sides of the substrate. part, a solder resist coating portion having a recess for a flux reservoir is provided on the lower side of the substrate, and is located at a desired position of the solder resist coating portion provided on the upper side of the substrate of the printed wiring board; A flux relief part is located in the solder resist crotch part on both sides and has a through-hole part for a flux pool part, and a recess part for a flux pool part where the solder resist film is not coated is provided on the upper side of the board of the printed wiring board. A flux relief part is provided, and a solder resist coating is provided on the lower side of the substrate corresponding to the recess, and a through hole is provided at the center of the recess on the upper side of the substrate and the coating on the lower side of the substrate. Alternatively, a recess for a flux reservoir not covered with the solder resist film is provided on the upper side of the printed wiring board, and a recess for a flux reservoir is provided on the lower side of the board at a position corresponding to the recess on the board side. A solder resist coating portion having a recessed portion is provided, and at least two or more types of flux relief portions are provided among the flux relief portions provided with through-hole portions located in the center of the recessed portions on both upper and lower sides of the substrate. It consists of

[Function] The printed wiring board of the present invention is a printed wiring board provided with a solder resist film containing silicone and/or fluorocarbon resin, in which two or more types of reliefs are provided at predetermined positions of the solder resist film portion. The spotting phenomenon of flux on the upper surface of the solder resist film due to the repelling action of the solder resist film is eliminated through the part, and the flux that has flowed into the through-hole part is distributed around the bottom of the board by the solder resist film 11!2 part on the lower side of the board. can be prevented.

[Example] An example of the printed wiring board of the present invention will be described below with reference to the drawings.

FIG. 1 shows an m-embodiment of the printed wiring board of the present invention, and FIGS. 1a to 1d are partially enlarged longitudinal sectional side views of each relief portion provided in the solder resist coating of the printed wiring board of the present invention. It is.

Thus, the relief shown in FIG. 1a penetrates through-holes 9 for flux reservoirs at predetermined positions in the solder resist film 6, and the through-holes 9 are arranged on the F side 1b of the substrate 1. It is formed by arranging the solder resist coating portion 61 at a position corresponding to the installation position. Further, the coating portion 61 is desirably formed using a solder resist ink having the same composition as the solder resist coating 6 applied to the upper side 1a of the substrate 1. Regarding the outer diameter shape, the through hole portion 9 As long as it has a shape with a diameter larger than the diameter of
In addition, forming this coating portion 61 prior to processing the through-hole portion 9 can simplify the processing of the through-hole portion 9.

The other components in FIG. 1A are the same as those of the printed wiring board shown in FIG.

Next, similar to the relief part shown in FIG. 1A, the escape part shown in FIG.
A solder resist coating portion 62 having a recess 8 for a flux reservoir is provided on the lower side 1 of the through hole portion 9 at a position corresponding to the position where the through hole portion 9 is provided. The coating portion 62 is desirably formed using a solder resist ink having the same composition as the solder resist coating 6 applied to the upper side 1a of the substrate l. The shape is not limited as long as it has a larger diameter than the through hole portion 9, and the recessed portion 8 is formed to have a larger diameter than the through hole portion 9.

Furthermore, when forming the solder resist film 6 by silk printing, the recess shown in FIG. At the same time, it is located at the center of the flux reservoir recess 8, passes through the flux reservoir through-hole, and further corresponds to the flux reservoir recess 8 disposed on the upper side of the substrate l. It is formed by providing a solder resist coating portion 61 on the lower side. Further, it is preferable that the solder resist coating portion 61 is formed using a solder resist ink having the same composition as the solder resist coating 6 provided on the 1= side of the substrate l, and the solder resist coating portion 61 is preferably formed using a solder resist ink having the same composition as the solder resist coating 6 provided on the 1= side of the substrate By forming the through-hole portion 9 prior to the piercing process, the process of forming the through-hole portion 9 can be simplified.

Furthermore, the relief shown in FIG. 1d is similar to the relief shown in FIG. In addition, a flux reservoir recess 8a is provided on the lower side 1b of the substrate 1, and a flux reservoir with approximately the same diameter as the recess 8a is provided at a position corresponding to the recess 8a provided on the side la of the substrate 1. A solder resist coating portion 60 having a concave portion 8b is provided. This coating portion 60 is desirably formed of a coating having the same composition as the solder resist coating 6 on the upper side 1a of the substrate 1, and there is no particular limitation on its outer diameter shape.

Thereafter, a through hole 9 for a flux reservoir is provided in the center of the flux reservoir recesses 8a and 8b provided on both the upper and lower sides of the substrate 1.

Now, in a printed wiring board constructed by arranging a required number of relief portions as shown in FIGS. In addition to being able to obtain the effects of a printed wiring board made of Each flux can be caused to flow into the through-hole portion 9 for a reservoir portion in the relief portion and released,
To prevent spots from remaining on the upper surface of the solder resist film 6.

Moreover, the solder resist coating portion 60 provided on the lower side 1b of the substrate
, 61 and 62 can prevent the flux that has flowed into the through-hole portion 9 from clinging to the lower side 1b of the substrate.

Therefore, it is possible to eliminate the adverse effects of unevenness that occurs on the printed wiring board itself due to the flux spot phenomenon, and to provide the desired printed wiring board without damaging the appearance of the printed wiring board and without problems in quality, precision, etc. It is something.

In addition, although FIG. 1 shows an embodiment in which each relief part shown in FIGS. 1a to 1d is provided, FIGS. 1a to 1d may be shown as necessary. By selecting at least two types of relief portions and arranging them in combination, it is possible to achieve similar effects.

[Effects of the Invention] According to the printed wiring board of the present invention, the intended effects of the solder resist film itself can be exhibited without causing problems in the quality, precision, etc. of the printed wiring board.

In particular, the solder resist coating portion disposed on the lower side of the substrate can prevent the flux that has flowed into the through-hole portion from clinging to the lower side of the substrate.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the printed wiring board of the present invention.
Figures a through 1d are partially enlarged longitudinal sectional side views showing the structure of the relief portion, and Fig. 2 is a partially enlarged sectional view showing a printed wiring board provided with a repellent solder resist film. l...Insulating substrate 2...Circuit pattern 3...Vi connection land 4...Through hole 6.7...Solder resist coating 8.8a, 8b...Flux reservoir recess 9.・
・Through hole for flux reservoir 60.61.6
2...Nruder Resist Coating Department Agent Patent Attorney Takeshi Nara Figure 1 (a) (b) Figure 1 (c)

Claims (1)

[Claims] (1) In a printed wiring board provided with a solder resist coating containing silicone and/or fluorocarbon resin, the solder resist coating is placed on the lower side of the substrate at a desired position of the solder resist coating provided on the upper side of the substrate of the printed wiring board. A flux relief part is provided with a solder resist film part on the top and bottom of the board, and a through hole part for a flux reservoir is provided in the solder resist film part on both the upper and lower sides of the board, and the solder resist part is provided on the upper side of the board of the printed wiring board. A solder resist coating portion having a recess for a flux reservoir is provided on the underside of the substrate by being positioned at a desired position on the coating portion, and a through-hole portion for a flux reservoir is provided in the solder resist coating portion on both the upper and lower sides of the substrate. a flux escape portion provided with a flux relief portion, a recessed portion for a flux pooling portion to which the solder resist film is not applied on the upper side of the substrate of the printed wiring board, and a solder resist coating portion provided on the lower side of the substrate corresponding to the recessed portion, and The solder resist film is not applied to the flux relief part provided with a through-hole part located in the center of the concave part on the upper side of the board and the coating part on the lower side of the board, or on the upper side of the board of the printed wiring board. A recess for a flux reservoir is provided, and a solder resist film portion having a recess for a flux reservoir is provided on the lower side of the substrate at a position corresponding to the recess on the upper side of the substrate, and the center portion of the recess on both the upper and lower sides of the substrate is provided. A printed wiring board comprising at least two types of flux escape parts having through-holes located at and penetrating through the flux escape parts.