JPH0312990A - Printed wiring board - Google Patents

Abstract

PURPOSE:To prevent the generation of crack or peeling off during mechanical processing by forming a coating film produced by heat hardening type ink on a part where a specified mechanical work must be carried out, and carrying out coating process with positional accuracy. CONSTITUTION:A specified part of a printed board 1 is coated with optical hardening type solder resist 3. A part near a machined part 6 is substitutability coated with heat hardening type solder resist 4. In this manner, all the parts near the machined parts are coated with heat hardening solder resist 4. This coating process makes it possible to calculate all positional data required for coating processing by heat hardening type ink based on a specified positional data required for mechanical processing. It is, therefore, possible to carry out coating processing with high positional accuracy and prevent the generation of crack or peeling off during mechanical processing as well.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a printed wiring board, particularly a printed wiring board using a photo-curable type such as Salter Regis I. The present invention relates to pudding 1 to a wiring board in which a film of thermosetting ink is formed on a portion to be subjected to a certain predetermined machining process.

[Prior Art] Generally speaking, solder resists used in wiring boards are broadly classified into two types: thermosetting type and photocuring type.

Looking at the former type of thermosetting solder resist, it has flexible properties.
Although cracks and peeling do not occur due to external forces when performing predetermined machining on a printed wiring board, since the film is formed on the solder resist 1 using a printing method, its positional accuracy may be affected. It is extremely difficult to obtain a shape with a good shape.

On the other hand, the latter photocurable solderesis I
Regarding ・, since the film is formed by the solder resist 1~ using a photographic method, it is possible to obtain a shape with good positional accuracy.
Since it is hard and brittle, cracks and peeling occur due to external force when applying a predetermined mechanical stress to a printed wiring board. There are two.

By the way, in recent years, the wiring density of printed wiring boards has become higher, and in order to increase the wiring density within a certain defined area (near 1'f In the area of Then, when covering the wiring pattern in the vicinity of the part to be machined with solder resist, the machined part itself is also subjected to a coating treatment similar to that of the suru tart cyst1. , If necessary, perform gold plating, etc. in the appropriate place, and when necessary, extend the lead-out pattern for plating to the outside of the board outline of the printed wiring board and wire it.
For this reason, the parts to be coated with solder resist are subjected to mechanical pressure or coating of the substrate's external shape.

However, when the photo-curable solder resist 1 is coated on the part of the printed wiring board that is to be machined, clutter and peeling occur during the machining process, as described above. Then, there may be a problem with the wiring board, or there may be a problem with the wiring board.

On the other hand, when thermosetting solder resist is used, machining is M! Even though it does not cause scratches or peeling when the solder resist is applied, since the film is formed using the printing method, the shape with good positional accuracy and J) can also be obtained. It is difficult to obtain and the use of such a thermosetting sintering cyst is unsuitable for obtaining high density printed wiring boards.

FIG. 4 shows an example of a conventional printer I/wiring board.
Fig. 4 (A) is an illustration of the previous PJ subjected to predetermined machining; It is.

In this Figure 4, the printer I/wiring board (1) is coated with (1, 1, photohard type salter resist 1-(3)), and (6). is a part to be subjected to predetermined machining h), and this machining part (6)
In the vicinity of , there is clutter (5) or raw L7 due to some machining.

FIG.
In Fig. 5, the wiring board (1) is attached to the wiring board (1).
A predetermined conductor pattern (2) is formed on the surface of the circuit board 1, and a photocurable router resist is formed on the surface of the printed circuit board (1) including the surface of the conductor pattern (2). 1-(3) is coated, and there are cracks (5) due to this machining in the vicinity of the machined part (6) that has been subjected to a predetermined machining process. There is.

[Problems to be Solved by the Invention] In conventional wiring boards, as described in 1-1, a photocurable solder resist is used, which forms a film with good positional accuracy. However, since it is hard and brittle, pudding 1
-There was a problem in that there were cracks and peeling caused by external forces when performing predetermined machining on wiring boards. On the other hand, when machining is applied, cracks or ? In order to avoid this, thermosetting salter resists are sometimes used.)
According to this, high-density printed wiring boards are
) The problem is that it becomes extremely difficult to do so.
.

This invention has been made to solve the problems mentioned above, and by eliminating the need for people to be present in the areas where photocurable solder resists and thermosetting salter resists are used, The object of the present invention is to obtain a printed circuit board 1 in which the coating process can be performed with good positional accuracy and prevent the occurrence of undesired racking or peeling.

[Means for Solving the Problems] 2a) The printed wiring board according to the invention has the following features: [In a board in which a photo-curable solder resist is used, the portion to which a predetermined mechanical pressure is applied is One sign of this is that a film is formed using a thermosetting resin.

1 Effect a) In the invention, parts to be machined that do not require strict positional accuracy are coated with thermosetting ink that does not cause any risk of cracking or peeling; For parts that are not to be coated, a coating treatment with a type 11 hard solder resist with high positional accuracy is applied.

[Embodiments] Several embodiments of the present invention will be described below with reference to the corresponding drawings.

First, with reference to FIGS. 1 to 3, which correspond to the first to third practical hlU examples of the present invention,
To give a general explanation of the present invention, predetermined machined parts (6) of the print 1 to the wiring board (1) are coated with a photocuring type smoothing system (3), and then the photocurable The thermosetting Inn A (4) is applied so as to overlap the vicinity of the machined area (6) covered with the hardening Salter Resis 1-(3). In addition, for the thermosetting type solder resin I, there is a marking ink for printing letters, numbers, etc., or there is a risk of clutter or peeling during machining. σ) Anything that doesn't contain cows is fine. In addition, machining refers to general machining, such as forming an outer shape using a mold, counterbore using a router, etc.

1-Embodiment 11'A is a schematic configuration diagram for explaining the first embodiment of the present invention, of which FIG. 1(A) is a plan view and 2.1, FIG. (B) i, -1 sectional view. In FIG. 1, required portions of the wiring board (1) to the print 1 are coated with a photocurable salter resin 113). ,
A portion near the machined portion (6) is coated with thermosetting solder resists 1 to (4) in the manner t). 1 In this first embodiment, thermosetting ink is applied to the vicinity of all machined parts of the Jinon l-wiring board (1), regardless of the presence or absence of wiring patterns in the wiring board (1). Based on the necessary position data for performing machining in order to perform a coating process using a certain solder resist I (4), position data necessary for performing a coating process with the thermosetting ink. can be easily calculated.

2nd Embodiment 71-2U'A is a diagonal schematic diagram illustrating a second embodiment of the present invention. In FIG. 2, the marking ink (4A) is applied to the print 1 in the vicinity of the machined part riγ (6) of the wiring board (1). According to this second embodiment, in the process of printing letters, numbers, etc. using -7-Kink In A- (, = IA), the machined part (6
), the coating process with thermosetting ink is done at the same time, so the desired target can be achieved without increasing the number of steps. The manufacturing process usually includes a printing process of letters, numbers, etc. using marking ink, which is a type of thermosetting ink, and therefore there is no need to particularly increase the number of -L.

Shaving-3-Freezing-TL FIG. 3 is a schematic diagram illustrating a third embodiment of the present invention. In this figure, at J5, only the necessary parts of the machined parts (6) of the printed circuit board (1) are coated with thermosetting ink (4) of an arbitrary shape. 5, that is, this machined part (6)
As a result, the thermosetting ink (4) will be coated with a coating treatment for only the portions where the conductor pattern (2) is close to each other.

In addition, in this third embodiment, the machined part (6)
Shifting so as to cover all of them with the thermosetting ink (4) is effective when the number of takes regarding the thermosetting ink increases.

[Effects of the Invention] As explained in detail in 3.a above, the printed wiring board ζ according to the present invention is characterized in that a film of thermosetting ink is formed on the part to be machined. Tear
), this makes it possible to form a wiring pattern near the parts of the wiring board to be machined, and also prevents cracks and 74+1 cracks from occurring during machining. The effect of having a printed wiring board with high density and a high part ψIll?

[Brief explanation of the drawing]

FIG. 1 shows a schematic diagram 47. for explaining the first embodiment of the present invention. FIG. 2 is a schematic diagram for explaining the second embodiment of the present invention, and FIG. 3 is a schematic diagram for explaining the third embodiment of the invention. Fig. 4 is an example of a conventional printed wiring board R21, and Fig. 5 is a partial cross-sectional view of the printed wiring board after being subjected to a predetermined mechanical pressure in the conventional example. . (1) is Print I/wiring board, (2) is a conductor pattern, (3) is a photocurable solder resist, (4) is a thermosetting ink, (5) is a crack, 1

Claims (1)

[Claims] (1) A printed wiring board in which a photocurable solder resist is used, in which a film of thermosetting ink is formed on the portions to be subjected to predetermined machining. Board.