JPH09181403A - Insulating board for mounting electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability against falling shock, vibration and warping of an insulating board for mounting electronic components, by forming a cut portion made of at least a punched hole or a cut-out at a stress concentrating portion caused by an external force on an insulating board for mounting electronic components thereon. SOLUTION: A dielectric filter 20 using a board 16 includes an input/output terminal 7, an earthing terminal 9, dielectric resonator earthing conductors 3a, 3b, and an electric element connecting conductor 6. In addition, a punched hole 17 of elongated (slit-like) shape is formed in the board 16 in such a manner that the punched hole 17 is adjacent to a junction between coaxial dielectric resonators 2, 2' and the earthing conductor 3a provided on the board 16. The cross section of corners of both ends of the punched hole 17 is preferably circular so as to prevent development of crack due to stress load. Also, as a cut-out 19 is provided near the input/output terminal 7 and the earthing terminal 9, an external stress loaded on a mother board, if any, is relieved by the cut-out 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating substrate on which electronic parts are mounted, and more particularly, to mounting electronic parts used on mobile communication equipment or the like which is required to have durability against drop impact, vibration, warpage and the like. Insulating substrate.

[0002]

2. Description of the Related Art As an example of a conventional electronic component mounting substrate, a substrate of a dielectric filter used in mobile communication equipment will be described.

FIG. 5A shows an appearance of a bandpass filter 10 in which two coaxial dielectric resonators 2 and 2'are used as an example of a filter using a conventional substrate. FIG. 5B shows a structure viewed from the component mounting surface of the conventional substrate 1, and FIG. 5C shows a structure viewed from the solder surface [opposite surface to FIG. 5B]. The substrate 1 has grounding conductor patterns 3a and 3b for grounding the coaxial dielectric resonator 2.
Are short-circuited to each other by the through hole 4, and
A conductor 6 for connecting an electric element 5 such as a capacitor or an inductor is provided. The through hole 4 is for short-circuiting the conductors on both surfaces facing each other through the substrate, and is generally a perfect circular through hole having a small cross section. The through hole does not have the function of relieving stress concentration.

The input / output terminal 7 is formed by cutting the end portion of the substrate into a semicircular shape, and the input / output conductors 8a, 8 on the opposite surfaces of the substrate.
b is an input / output conductor 8c provided on the side surface of the semicircular substrate
Are short-circuited with each other. The grounding terminal 9 is similarly formed.

The dielectric resonators 2 and 2'include the outer conductor 11 thereof.
Is grounded to the grounding conductor pattern 3 a on the substrate 1. At this time, the dielectric resonators 2 and 2'adjacent to each other are arranged so that there is no gap, and the dielectric resonators 2 and 2'and the substrate 1 are rigidly configured. .
The electric element 5 such as an inductor and a capacitor is electrically connected to the electric element connecting conductor 6. Further, the inner conductor 12 of the coaxial resonator and the electric element connecting conductor 6 are electrically connected by a terminal pin (not shown).

The entire filter body is covered with a case 14 shown in FIG. 5D and is grounded.

FIG. 6 shows the frequency characteristic of the bandpass filter having the above-mentioned configuration. The center frequency (f ₀ ) is 1
901MHz, bandwidth 25MHz, insertion loss 2.6
It shows that it is 6 dB.

The external dimensions of the substrate 1 are 11 mm × 11 mm
The size is 0.8 mm (L × W × T), and the material is glass epoxy. The dielectric resonator has a mouth of 3.0 mm x 8 mm, and the value of the capacitor used as an electric element is 0.5 pF.
~ 1.0 pF, the outer shape of the filter is 11 mm
It is x 11 mm x 4.0 mm (L x W x H).

Further, as shown in FIG. 7, this filter is
After soldering the input / output terminal 7 and the grounding terminal 9 of the dielectric filter 10 onto the glass epoxy test substrate 15 having a width of 40 mm, a length of 100 mm and a thickness of 1.6 mm, stress is applied from the direction indicated by the arrow. A load was applied and a strength test against warpage of the substrate was performed. As a result, the state where the test substrate 15 is warped is shown by a dotted line. At the time of warping downward by about 4 mm at the position A, the dielectric resonator 2 and the dielectric filter substrate 1 are
Peeling occurred at the joint surface with and the predetermined filter characteristics as shown in FIG. 6 could not be obtained.

[0010]

Among the electronic parts, for electronic parts used in mobile communication equipment such as mobile phones, durability against drop impact, vibration, warpage, etc. is particularly required for the purpose of use. Has been.

As an example of electronic parts related to mobile communication,
Explaining the dielectric filter, the dielectric filter is configured by electrically connecting and mounting electric elements such as an inductor, a capacitor, and a dielectric resonator by solder or the like on an insulating substrate on which a conductor pattern is formed. . Further, in the dielectric filter, the input / output terminal and the ground terminal are mounted on the mother board together with other high frequency electronic components by means such as soldering.

The above-mentioned dielectric resonator is constructed by forming an inner conductor and an outer conductor in a quadrangular prism-shaped ceramic, but the ceramic has a property that it is weak against shear stress and has a low toughness. Also, the strength of the conductor film at the interface between the ceramic and the conductor film is practically sufficiently large.

However, according to the conventional technique, since the dielectric resonator has a larger shape and weight than other parts constituting the dielectric filter, the stress load due to dropping, vibration, warping, etc., is different. This is larger than the parts, and there is a problem that the dielectric resonator may be chipped or the conductor film may be peeled off at the joint surface between the dielectric resonator and the dielectric filter substrate.

Further, since the dielectric resonator has a large bonding area with the dielectric filter substrate, the bonding strength is increased, but due to the rigid structure, when a drop impact, vibration, warpage or the like is applied. However, the stress load is large, and there is a problem that the dielectric resonator is broken or the conductor film is peeled off at the joint surface.

Further, the inductor, the capacitor, and the dielectric resonator are electrically connected to the conductor pattern formed on the insulating substrate by means of solder or the like, but are subjected to external stress due to drop impact, vibration, warpage or the like. However, there is a problem in that the electrodes of the inductor and the capacitor are easily peeled off, the solder is cracked, and the like, which is easily electrically and mechanically damaged.

When an external stress such as a warp is applied to the mother board on which the dielectric filter is mounted, the stress concentrates on the solder joint surfaces of the input / output terminal and the ground terminal, and the input / output terminal and the ground terminal are connected. There are problems such as peeling of the formed conductor and cracking of the solder.

Therefore, the technical problem of the present invention is to provide drop shock, vibration, and the like between the electronic parts and the board on which the electronic parts are mounted by providing the board side with a function of relieving stress.
An object of the present invention is to provide an insulating substrate for mounting electronic components, which has improved durability against warping and the like.

[0018]

According to the present invention, at least one of one or more slit-shaped holes and one or more notches is formed in a stress concentration portion generated by an external force of an insulating substrate on which electronic components are mounted. It is possible to obtain an insulating substrate for mounting electronic parts, which is characterized in that a defective portion made of is formed.

Further, according to the present invention, there can be obtained an insulating substrate for mounting electronic parts, characterized in that a plurality of the defective portions are formed at a predetermined interval.

Further, according to the present invention, there can be obtained an insulating substrate for mounting electronic parts, wherein a plurality of the defective portions intersect each other.

According to the present invention, there is also obtained an insulating substrate for mounting electronic parts, characterized in that the defective portion comprises a first defective portion and a branched second defective portion.

Further, according to the present invention, there can be obtained an insulating substrate for mounting electronic parts, which is characterized in that a bent defect portion is formed.

Further, according to the present invention, there can be obtained an insulating substrate for mounting electronic parts, characterized in that the corners of the edges of the defective portion are formed with an arbitrary curvature.

Further, according to the present invention, the conductors formed on the surfaces of the insulating substrate, which face each other in the vicinity of the defective portion and are opposed to each other, form the conductor on at least a part of the side surface of the defective portion in the substrate thickness direction. By doing so, it is possible to obtain an insulating substrate for electronic component mounting, which is electrically short-circuited with each other.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an insulating substrate for mounting electronic parts of the present invention will be described with a dielectric filter.

FIG. 1A is an external view of a dielectric filter 20 using the substrate 16. FIG. 1B is a view seen from the component side of the board 16 according to the present invention, and FIG. 1C is a view seen from the solder side.

Input / output terminal 7, grounding terminal 9, dielectric resonator grounding conductors 3a and 3b, and electric element connecting conductor 6
However, the substrate 16 according to the present invention further includes the coaxial dielectric resonators 2 and 2'and the grounding conductor 3 provided on the substrate 16.
An elongated cut-out (slit-shaped) hole 17 is formed so as to be adjacent to the joint with a.

As the method of forming the punched holes 17, there are a method of forming two holes with a drill and connecting the two holes with a cutter, or a method of punching in consideration of mass productivity. The cross-sectional shape of the corners at both ends of the punched hole 17 may be square, but a circular shape is more effective because it may cause cracks when stress is applied.

Further, on the substrate 16, the dielectric resonators 2, 2 '
When grounding, the holes 17 are avoided and grounded, so that the dielectric resonators 2 and 2'adjacent to each other are
It is grounded at intervals. Therefore, the space between the dielectric resonators 2 and 2'is configured to be flexible in terms of stress, and against the drop impact, vibration, warpage, etc. of the dielectric filter,
The durability is improved.

Further, by forming the conductor 18 on the side surface of the punched hole 17 in the substrate thickness direction, the grounding conductors 3a and 3b formed on both opposing surfaces of the substrate 16 are short-circuited to each other. It is also possible to combine the function of the through hole 4 described above. The conventional through hole has a problem that it is necessary to make a large number of holes having a small diameter with a drill, and the wear of the drill is severe and the cost is high. However, when using the punched hole 17 of the present invention as a through hole, Since it can be formed by punching with a press, there is an advantage that the cost can be kept low.

Further, by providing the notch 19 near the input / output terminal 7 and the grounding terminal 9, the stress is relieved by the notch 19 even if external stress is applied to the mother board. The durability of the solder joint between the terminal 6 and the grounding terminal 9 and the mother board (see reference numeral 24 in FIG. 4) against drop impact, vibration, warpage, etc. is improved.

As a method of forming the notch 19, there is a method of forming it by a router or punching it by a press in consideration of mass productivity. The corners of the notch 19 may be square, of course, but the circular shape is more effective than the case of the punched hole because it may cause cracks due to load stress. It is the same.

Specifically, the external dimensions of the dielectric filter substrate 16 are 11 × 11 × 0.8, as in the conventional technique.
mm ³ (L × W × T), the slit-shaped hole 17 is
Length 5 mm x width 0.6 mm, notch 19 is 2 m long
m × width 0.3 mm.

Other than that, the filter circuit configuration, the component configuration, the element value and the like are the same as those described in the description of the conventional technique. In terms of electrical characteristics, the same characteristics as conventional ones can be obtained, and
As shown in FIG. 7, when stress is applied from the upper surface of the filter 20, peeling is observed between the dielectric resonators 2, 2 ′ and the substrate 16 until the portion A of the test substrate 15 warps by about 7 mm. I couldn't do it. This state is shown in FIG. A joint surface between the dielectric resonators 2, 2'and the substrate 16 and the input / output terminal 7,
The concentration of the load stress applied to the grounding terminal 9 is prevented by the holes 17 and the notches 19 (not shown in FIG. 2).
It was alleviated, and the warp strength was improved by about 3 mm over the conventional one.

Further, if the hole 17 is formed adjacent to the electric element 5 such as an inductor or a capacitor other than the coaxial resonator, the stress due to the external stress load in the vicinity of the solder joint is relieved, and the solder joint is removed. Improves durability against drop impact, vibration, warpage, etc.

As shown in FIG. 3 (a), as another embodiment, in the case of a relatively long component, if two or more punched holes are continuously formed, the effect is further enhanced. To do.
Also, the shape of the punched hole is as shown in FIG.
(C) + type (22), FIG. 3 (d) T type (23), etc., select the optimum shape according to the shape of the part and the distribution of stress,
Further, by combining them, the mechanical flexibility of the substrate is increased, and the effect of relaxing the load stress is increased. This also applies to the cutout 19.

Further, as another embodiment, as shown in FIG. 4, the holes 17 and the notches 19 may be formed in the mother substrate 24, and in particular, as in the case of a substrate for a mobile phone, it has an elongated shape. In the case of the mother substrate, the rigidity in the longitudinal direction is weak, so that the effect is particularly large. Note that, in FIG. 4, for simplicity, illustration of conductor patterns for routing each component is omitted. Further, if it is formed on both the mounted component (dielectric filter in the embodiment) and the mother substrate, the effect of alleviating the load stress is further increased.

This embodiment shows an example according to the present invention, in which the shapes, numbers, and combinations of punch holes and notches,
Needless to say, the formation location is for the purpose of relieving the concentration of stress and is not limited to this embodiment.

[0039]

As described above, according to the present invention, by forming a hole and a notch in a substrate, stress concentration due to an external stress load can be relieved, and drop impact,
It was possible to provide a substrate having excellent durability against vibration, warpage, etc., and an insulating substrate for mounting electronic components mounted thereon.

[Brief description of the drawings]

FIG. 1 is a diagram showing a dielectric filter using a substrate according to the present invention, FIG. 1 (a) is a perspective view showing the appearance of the filter, and FIG. 1 (b) is seen from the component side of the substrate according to the present invention. FIG. 1C is a view seen from the solder surface of the substrate according to the present invention.

FIG. 2 is a diagram showing a warped state of a dielectric filter using a substrate according to the present invention.

FIG. 3 is a diagram showing the shape of a punch hole and a notch according to the present invention, FIG. 3 (a) is a diagram showing three punch holes arranged vertically, and FIG.
FIG. 3B is a diagram showing an L-shaped hole, FIG. 3C is a diagram showing a cross-shaped hole, and FIG. 3D is a diagram showing a T-shaped hole.

FIG. 4 is a diagram in which a defective portion (a hole, a notch) according to the present invention is applied to a mother substrate.

FIG. 5 is a diagram showing a filter using a conventional substrate, FIG.
FIG. 5A is a perspective view showing the appearance, and FIG. 5B is a view seen from the component side of a conventional board. FIG. 5C is a view seen from the solder surface of the conventional substrate.

FIG. 6 is a diagram showing frequency characteristics of a dielectric filter.

FIG. 7 is a diagram showing a method of warping a dielectric filter.

[Explanation of symbols]

 1 (conventional) substrate 2, 2'coaxial dielectric resonator 3a, 3b, 3c grounding conductor 4 through hole 5 electric element 6 electric element connecting conductor 7 input / output terminals 8a, 8b, 8c input / output terminal conductor 9 grounding terminal 10 (according to conventional configuration) dielectric filter 11 outer conductor (of coaxial type dielectric resonator) 12 inner conductor (of coaxial type dielectric resonator) 14 case 15 (for warpage test) test board 16 (this) (According to the invention) substrate 17 punched hole 18 conductor on the side of the punched hole 19 cutout 20 dielectric filter 21 (using the substrate according to the invention) 21 L-shaped punched hole 22 + type punched hole 23 T-shaped punched hole 24 mother board 25, 26, 27, 28, 29 High frequency components H Filter height L Substrate length W Substrate width T Substrate thickness

Claims (7)

[Claims] 1. A stress concentrating portion generated by an external force of an insulating substrate on which an electronic component is mounted is formed with at least one cutout hole and at least one cutout portion as a defect portion. Insulation board for mounting electronic components. 2. An insulating substrate for mounting electronic parts, wherein the defective portions according to claim 1 are formed at a predetermined interval. 3. An insulating substrate for mounting electronic parts, wherein the defective portions according to claim 1 are formed so as to intersect each other. 4. The insulating substrate for mounting electronic parts, wherein the defective portion according to claim 1 comprises a first defective portion and a second defective portion branched from the defective portion. 5. The insulating substrate for mounting electronic parts, wherein the defect portion according to claim 1 is formed in a bent shape. 6. An insulating board for electronic component mounting, wherein the corners of the edge of the defect portion according to claim 1 are formed with an arbitrary curvature. 7. The conductor formed on the mutually opposing surfaces in the vicinity of the defective portion provided on the insulating substrate according to claim 1, forms a conductor on at least a part of the side surface of the defective portion in the substrate thickness direction. Are electrically short-circuited with each other, the insulating substrate for mounting electronic components.