(2) [PATENT CLAIMS] [CLAIM 1] A printed substrate comprising: a substrate main body; a circuit pattern that is formed on a surface of the substrate ma

Transcription

1 (19) Japan Patent Office (JP) (12) Japanese Unexamined Patent Application Publication (A) (11) Japanese Unexamined Patent Application Publication Number H (43) Publication date: June 21, 1996 (51) Int. Cl. 6 Identification codes File Number FI Technical indications H05K 1/02 E 3/28 B Request for examination: Not Yet Requested Number of Claims: 5 Online (Total of 4 Pages) (21) Application number H (71) Applicant (22) Date of application December 8, 1994 Matsushita Electric Industrial Co., Ltd. (72) Inventor MAEDA, Ken c/o Matsushita Electric Industrial Co., Ltd. (72) Inventor SAKAI, Tadahiko c/o Matsushita Electric Industrial Co., Ltd. (72) Inventor YAKEYAMA, Hideyuki c/o Matsushita Electric Industrial Co., Ltd. (74) Agent Patent attorney KOKAJI, AKIRA (AND 2 OTHERS) SPECIFICATION (54) [NAME OF INVENTION] Printed Substrate (57) [ABSTRACT] [OBJECT] The object is to provide a printed substrate that is able to withstand thermal shock. [STRUCTURE] Comprises: a substrate main body 1; a circuit pattern 2 that is formed on a surface of the substrate main body 1; and a resist 3 that partially overlaps the circuit pattern 2, with a boundary line L as a boundary, and that covers the surface of the substrate main body 1, wherein: a width of the circuit pattern 2 in the vicinity of the boundary line L is increased to form a reinforced portion 2b in the circuit pattern 2. 2b: Reinforced Portion

2 (2) [PATENT CLAIMS] [CLAIM 1] A printed substrate comprising: a substrate main body; a circuit pattern that is formed on a surface of the substrate main body; and a resist that partially overlaps the circuit pattern, with a boundary line as a boundary, and that covers the surface of the substrate main body, wherein: a width of the circuit pattern in the vicinity of the boundary line is increased to form a reinforced portion in the circuit pattern. [CLAIM 2] A printed substrate as set forth in Claim 1, wherein: neighboring reinforced portions are disposed crossing in a staggered pattern. [CLAIM 3] A printed substrate as set forth in Claim 1, wherein: the reinforced portion is a land for soldering. [CLAIM 4] A printed substrate as set forth in Claim 1, wherein: the reinforced portion is formed integrally with a land for soldering. [CLAIM 5] A printed substrate comprising: a substrate main body; a circuit pattern that is formed on a surface of the substrate main body; and a resist that partially overlaps the circuit pattern and that covers the surface of the substrate main body, wherein: an end edge of the resist that covers the circuit pattern is caused to protrude along the circuit pattern. [DETAILED EXPLANATION OF THE INVENTION] [0001] [FIELD OF APPLICATION IN INDUSTRY] The present invention relates to a printed substrate. [0002] [PRIOR ART] FIG. 7 is a plan view of a conventional printed substrate, and FIG. 8 is a cross-sectional view along the section A-A in FIG. 7. In a conventional printed substrate, a circuit pattern 2 is formed using a copper foil on a substrate main body 1, and the circuit pattern 2 is covered with a resist 3, except for the parts that are necessary. 2a is a land for soldering. In recent years, with the miniaturization of electronic devices, there has been a tendency for the circuit patterns 2 to be narrower. [0003] [PROBLEM SOLVED BY THE PRESENT INVENTION] Normally, when soldering electronic components, and the like, this type of printed substrate is often subjected to sudden heating and cooling, and, after such heat treatments, sometimes open circuits are produced in the circuit pattern 2 in the vicinity of one edge 3a of the resist 3. This is because the coefficient of linear expansion is greater for the substrate main body 1 than it is for the circuit pattern 2 (which is copper, or the like), which is greater than it is for the resist 3 (which is an organic material, such as an acrylic resin). That is, in the circuit pattern 2 there are large differences between the coefficients of linear expansion, and it is believed that the thermal stress at the time of the thermal shock, such as sudden heating, is concentrated in the vicinity of the end edge 3a of the resist 3. [0004] Given this, the object of the present invention is to provide a printed substrate able to withstand heat treatments. [0005] [MEANS FOR SOLVING THE PROBLEM] The printed substrate according to the present invention comprises: a substrate main body; a circuit pattern that is formed on a surface of the substrate main body; and a resist that partially overlaps the circuit pattern, with a boundary line as a boundary, and that covers the surface of the substrate main body, wherein: a width of the circuit pattern in the vicinity of the boundary line is increased to form a reinforced portion in the circuit pattern. [0006] [OPERATION] Because the width of the circuit patterns is increased at the part wherein stresses become concentrated in the circuit pattern in the vicinity of the end edge of the resist, to reinforce the circuit patterns, open circuits will not be produced in the circuit pattern even if there is a concentration of stresses. [0007] [EMBODIMENTS] Embodiments according to the present invention will be explained next in reference to the drawings. [0008] FIG. 1 is a cross-sectional view of a printed substrate according to a first embodiment according to the present invention, and FIG. 2 is a plan view of a printed substrate according to the first embodiment according to the In FIG. 1: 1 is a substrate main body; 2 is a circuit pattern made from a copper foil, or the like, that is formed on the surface of the substrate main body 1; 2a is a land for soldering; 3 is a resist that covers the surface of the substrate main body 1, or covers the circuit pattern 2, for protecting those parts of the circuit pattern 2 that are not involved in soldering; 3a is an end edge of the resist 3; and L is a boundary line between the resist 3 and the circuit pattern 2. [0009]

3 (3) Thermal damage of the circuit pattern 2 concentrates in the vicinity wherein the end edge 3a of the resist 3 crosses the circuit patterns 2 (that is, in the vicinity of the boundary line L). Consequently, in the first embodiment the width of the circuit patterns 2 is increased in the vicinity of the boundary line L to form reinforced portions 2b. This is able to effectively prevent thermal damage through increasing the strength in only the vicinity of the boundary line L, without having to increase the strength of the circuit pattern 2 because a whole. [0010] FIG. 3 is a plan view of a printed substrate according to a second embodiment according to the The second embodiment applies the first embodiment, and neighboring reinforced portions 2b are arranged so as to cross in a staggered pattern. While in recent years, given increased complexity of circuit patterns, there has been a tendency for the pitch t between circuit patterns to be narrower in order to achieve a greater number of interconnections on a single printed substrate, in the second embodiment the reinforced portions 2b are arranged in a staggered pattern, enabling compatibility with even a narrow pitch t. [0011] FIG. 4 is a plan view of a printed substrate in the third embodiment according to the In the third embodiment, the shape of the resist 3 has been modified. Specifically, in the resist 3, the end edge 3a that cover the circuit pattern 2 protrude along the circuit pattern 2, in the direction that is not covered by the resist 3. Here, when the end edge 3a of the resist 3 all exists on the boundary line L, as it does in FIG. 1, the tension that acts on the circuit pattern 2 from the resist 3 in the vicinity of the boundary line L will have essentially uniform directionality, aligned with the shape of the end edge 3a, which is a problem in that the tension tends to concentrate in a constant direction. Given this, in the third embodiment, a change is made to the shape of the end edges 3a to disperse the tension that acts on the circuit pattern 2 in all directions, to thereby prevent breakage by preventing concentration in a single direction. [0012] FIG. 5 is a plan view of a printed substrate according to a fourth embodiment according to the In the present embodiment, a land 2a that is wider than the circuit pattern 2 extends under the resist 3, to achieve a function as a reinforced portion. [0013] FIG. 6 is a plan view of a printed substrate according to a fifth embodiment according to the In the present embodiment, the reinforced portion 2b is formed integrally with a land 2a. [0014] Because in the fourth embodiment and the fifth embodiment there is no need to provide a reinforced portion 2b at a position away from the land 2a, this is well suited to increasing the density of the circuit pattern 2 by that amount. [0015] [EFFECTS OF THE INVENTION] The printed substrate comprises a substrate main body, a circuit pattern that is formed on a surface of the substrate main body, and a resist that partially overlaps the circuit pattern, with a boundary line as a boundary, and that covers the surface of the substrate main body, wherein a width of the circuit pattern in the vicinity of the boundary line is increased to form a reinforced portion in the circuit pattern, and thus can effectively prevent damage to the circuit pattern that would be caused by thermal shock. [0016] The printed substrate comprises a substrate main body, a circuit pattern that is formed on a surface of the substrate main body, and a resist that partially overlaps the circuit pattern and that covers the surface of the substrate main body, wherein an end edge of the resist that covers the circuit pattern is caused to protrude along the circuit pattern, and thus the tension that acts on the circuit pattern is dispersed in all directions, making it possible to prevent open circuits in the circuit pattern. [BRIEF DESCRIPTIONS OF THE DRAWINGS] FIG. 1 is a cross-sectional view of a printed substrate according to a first embodiment according to the FIG. 2 is a plan view of a printed substrate according to a first embodiment according to the FIG. 3 is a plan view of a printed substrate according to a second embodiment according to the FIG. 4 is a plan view of a printed substrate according to a third embodiment according to the FIG. 5 is a plan view of a printed substrate according to a fourth embodiment according to the FIG. 6 is a plan view of a printed substrate according to a fifth embodiment according to the FIG. 7 is a plan view of a conventional printed substrate FIG. 8 is a cross-sectional view along the section A-A in FIG. 7 [EXPLANATIONS OF REFERENCE SYMBOLS] 1: Substrate Main Body

4 (4) 2: Circuit Pattern 2b: Reinforced Portion 3: Resist FIG. 1 L: Boundary Line FIG. 8 FIG. 3 1: Substrate Main Body 2: Circuit Pattern 3: Resist L: Boundary Line FIG. 2 FIG. 4 2b: Reinforced Portion FIG. 5

5 (5) FIG. 6 FIG. 7

6 TRANSLATOR CERTIFICATION Translator s Declaration I, Warren Smith, hereby declare: (1) I am a translator fluent in the Japanese and English languages. My qualifications are as follows: 33 years as a professional Japanese-English translator (with emphasis in patent translation) Fulbright Scholar in Japan Engineering professional (2) I have translated the following document from Japanese into English: Japanese Unexamined Patent Application Publication Number H Published on June 21, 1996 (3) The attached English translation is, to the best of my knowledge and belief, a true, full, and accurate translation of Japanese Unexamined Patent Application Publication Number H (4) I understand that willful false statements and the like are punishment by fine or imprisonment, or both (18 U.S.C. 1001). I declare under penalty of perjury that all statements made herein of my own knowledge are true and all statements made on information and belief are believed to be true. Date: _4/11/2017 Dr. Warren Smith