Weldable composite conductive foam

Abstract

The utility model relates to the technical field of electronic packaging, and particularly discloses weldable composite conductive foam. Comprising a silica gel foam foaming body, a rubber strip adhered to the bottom of the silica gel foam foaming body through an adhesive, a positioning concave part formed in the bottom of the rubber strip, and a conductive film adhered to the peripheries of the silica gel foam foaming body and the rubber strip through an adhesive, according to the weldable composite conductive foam, hierarchical material design and a precision manufacturing process are combined, the performance boundary of traditional conductive foam is broken through, the requirement for high-reliability electronic packaging is met, and the weldable composite conductive foam is particularly suitable for a 5G high-frequency device welding scene and has high practicability.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic packaging technical field, specifically disclose a kind of weldable composite conductive foam. BACKGROUND

[0002] In the field of electronic packaging, weldable conductive foam as key interface material, need to meet electromagnetic shielding, mechanical cushioning and precision welding requirements simultaneously;Current mainstream technology is divided into two categories:

[0003] 1.Rubber wrapped type: through hollow structure design makes product bottom to form concave welding profile (height tolerance ±0.1mm), realizes the straight positioning of SMT mounting using geometry.But its base material uses high hardness rubber, leading to compression resilience rate less than 80%, in long-term vibration environment, plastic deformation is prone to occur, difficult to meet the buffering needs of 5G base station and other high-frequency devices.

[0004] 2.Silicone foam type: adopt open-cell foam silicone (shore hardness 30-40, elastic modulus 0.8MPa) to realize high resilience (resilience rate >95%), but due to the limitation of foam wrapping process, product bottom flatness tolerance reaches ±0.2mm (especially size >10mm×10mm).In reflow soldering process, affected by the difference of thermal expansion coefficient (CTE 25ppm / ℃) and uneven stress, >5° inclination deviation is prone to occur, leading to less than 80% of welding yield, and additional manual correction process is required.

[0005] Industry attempts to reconcile performance contradictions through composite modification (such as rubber / silicone blend), but limited by insufficient interfacial bonding strength of two-phase materials (peel strength <1.2N / mm), phase separation occurs during high temperature vulcanization, and the hardness of final product fluctuates in the range of >15% (shore A hardness 55-70), and the conductivity stability decreases (contact impedance fluctuation >30%).

[0006] Therefore, how to break through the bottleneck of coordinated control of material rigidity-elasticity-morphology precision has become a key technical problem restricting the development of high-reliability electronic packaging. INVENTION CONTENTS

[0007] To overcome the deficiencies of the prior art, the utility model discloses a kind of weldable composite conductive foam.

[0008] To achieve the above purpose, the technical scheme adopted by the utility model is as follows: a kind of weldable composite conductive foam, including silicone foam foam body, rubber strip pasted on the bottom of silicone foam foam body by adhesive, positioning recess portion being opened in the bottom of rubber strip and conductive film being pasted on the periphery of silicone foam foam body and rubber strip by adhesive.

[0009] Further preferably, the shore hardness of the silicone foam foam body is 30-40°.

[0010] Further preferably, the porosity of the silica gel foam body is 70%-80%.

[0011] Further preferably, the Shore hardness of the rubber strip is 88-92°.

[0012] Further preferably, the positioning recess provided at the bottom of the rubber strip is a reverse V-shaped positioning recess.

[0013] Further preferably, the square resistance of the conductive film is <0.2Ω / sq.

[0014] Further preferably, the thickness of the adhesive is 0.03-0.08mm.

[0015] Further preferably, the adhesive is a high-temperature-resistant epoxy adhesive.

[0016] The utility model discloses the following beneficial effects:

[0017] The weldable composite conductive foam provided by the application breaks through the performance boundary of traditional conductive foam by combining hierarchical material design and precision manufacturing process, meets the demand of high-reliability electronic packaging, is especially suitable for 5G high-frequency device welding scenes, and has strong practicability.

[0018] Other features and advantages of the present utility model will be set forth in part in the following description, and in part will become apparent to those skilled in the art upon examination of the following specification or can be learned by practice of the present utility model. The objects and other advantages of the present utility model can be realized and achieved by means of the structures pointed out in the description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments consistent with the present utility model disclosure and serve to explain the principles of the present utility model disclosure, together with the description.

[0020] Figure 1 The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments consistent with the present utility model disclosure and serve to explain the principles of the present utility model disclosure, together with the description.

[0021] In the drawings: 10, silica gel foam body; 20, rubber strip; 21, positioning recess; 30, conductive film; 40, adhesive. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all the embodiments.

[0023] In the description of the utility model, it is understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "periphery" and the like indicate the orientation or positional relationship, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0024] Embodiment

[0025] In order to solve the problem of the existing technology that the solderable conductive foam is used for packaging, referring to Figure 1 The application discloses a kind of solderable composite conductive foam, including silica gel foam body 10 (shore hardness is 30-40 °, porosity is 70%-80%), rubber strip 20 (shore hardness is 88-92 °) by adhesive 40 pasted in the bottom of silica gel foam body 10, positioning recess 21 (preferably inverted V-shaped positioning recess) being opened in the bottom of rubber strip 20 and conductive film 30 (the square resistance of conductive film 30 is less than 0.2 Ω / sq) by adhesive 40 pasted in the outer circumferential body of silica gel foam body 10 and rubber strip 20, the thickness of the above-mentioned adhesive 40 is 0.03-0.08mm, and adhesive 40 is preferably high-temperature resistant epoxy adhesive.

[0026] Among them, the silica gel foam body 10 of the application is used to provide main body elastic support, rubber strip 20 is used to realize self-upright positioning during SMT welding through positioning recess 21, and the risk of inclination is eliminated, and conductive film 30 is used to form a continuous electromagnetic shielding layer.

[0027] Based on the design of the above structure, the solderable composite conductive foam provided by the application is combined by hierarchical material design and precision manufacturing process, breaks through the performance boundary of traditional conductive foam, meets the demand of high-reliability electronic packaging, and is especially suitable for 5G high-frequency device welding scene, and has strong practicability.

[0028] The following is emphasized that the silica gel foam body 10, rubber strip 20, conductive film 30 and adhesive 40 disclosed by the application are known technologies, and the person skilled in the art can normally obtain them on the market.

[0029] In the description of the specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0030] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable the skilled in the art to understand the content of the present application and to implement it, and it cannot limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit and essence of the present application shall be covered within the protection scope of the present application.

Claims

1. A solderable composite conductive foam, characterized in that, The invention relates to a silicone foam (10), a rubber strip (20) adhered to the bottom of the silicone foam (10) by an adhesive (40), a positioning recess (21) formed in the bottom of the rubber strip (20), and a conductive film (30) adhered to the outer periphery of the silicone foam (10) and the rubber strip (20) by the adhesive (40).

2. The solderable composite conductive foam according to claim 1, wherein, The Shore hardness of the silicone foam (10) is 30-40°.

3. The solderable composite conductive foam according to claim 1, wherein, The porosity of the silicone foam (10) is 70%-80%.

4. The solderable composite conductive foam of claim 1, wherein, The Shore hardness of the rubber strip (20) is 88-92°.

5. The solderable composite conductive foam of claim 1, wherein, The positioning recess (21) formed in the bottom of the rubber strip (20) is a reverse V-shaped positioning recess.

6. The solderable composite conductive foam of claim 1, wherein, The square resistance of the conductive film (30) is less than 0.2 Ω / sq.

7. The solderable composite conductive foam of claim 1, wherein, The thickness of the adhesive (40) is 0.03-0.08 mm.

8. The solderable composite conductive foam according to claim 7, wherein, The adhesive (40) is a high-temperature resistant epoxy adhesive.

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