阅读说明：本技术 一种多芯组径向引线多层瓷介电容器的生产夹具及工艺 (Production fixture and process for multi-core group radial lead multilayer ceramic dielectric capacitor ) 是由 谢丽鲜 陈驰 于 2019-11-20 设计创作，主要内容包括：本发明涉及电容器制造领域,更具体地说,它涉及一种多芯组径向引线多层瓷介电容器的生产工艺,旨在解决多芯组径向引线多层瓷介电容器在制造时电容器之间出现外形尺寸超差的问题,其技术方案要点是：包括承载板,所述承载板上开设有多个收纳电容器的排片槽,所述排片槽呈矩形,所述排片槽的四角处设有夹取孔。本发明通过夹具的设计,使得叠片后的多芯组径向引线多层瓷介电容器外形尺寸整齐,解决了外形尺寸偏差不可控的问题。(The invention relates to the field of capacitor manufacturing, in particular to a production process of a multi-core group radial lead multilayer ceramic dielectric capacitor, aiming at solving the problem that the appearance size of the multi-core group radial lead multilayer ceramic dielectric capacitor is out of tolerance during manufacturing, and the technical scheme is as follows: the capacitor clamping device comprises a bearing plate, wherein a plurality of plate discharging grooves for accommodating capacitors are formed in the bearing plate, each plate discharging groove is rectangular, and clamping holes are formed in four corners of each plate discharging groove. According to the invention, through the design of the fixture, the external dimension of the laminated multi-core group radial lead multi-layer ceramic dielectric capacitor is neat, and the problem of uncontrollable external dimension deviation is solved.)

1. The utility model provides a production anchor clamps of radial lead wire multilayer ceramic dielectric capacitor of multicore group which characterized in that: including loading board (1), set up a plurality of storage capacitor's row's piece groove (2) on loading board (1), row's piece groove (2) are the rectangle, the four corners department of arranging piece groove (2) is equipped with to press from both sides and gets hole (3).

2. The fixture for producing the multi-core radial lead multilayer ceramic capacitor as claimed in claim 1, wherein: the depth of the chip arrangement groove (2) is larger than the thickness of a single capacitor, and the depth of the chip arrangement groove (2) is smaller than the total thickness of a plurality of capacitors.

3. A process for producing a multi-core radial lead multilayer ceramic capacitor comprising all the features of claims 1-2,

the method comprises the following steps: selecting a clamp according to the size of the lead multilayer ceramic dielectric capacitor to be manufactured, and horizontally placing the bearing plate (1);

step two: placing the first capacitor into the sheet arranging groove (2) by using tweezers to ensure that two right-angle edges of the capacitor are attached to two right-angle edges of the sheet arranging groove (2) as far as possible;

step three: uniformly coating the surface of the first capacitor with a filling agent;

step four: placing a second capacitor on the surface of the capacitor coated with the filler with tweezers, pressing the surface of the second capacitor to expel any air bubbles that may be present in the stack of the two capacitors and to squeeze out excess filler;

step five, repeating the step three and the step four according to requirements until the number of the capacitors is required by lamination;

step six, curing the laminated capacitor;

step seven, taking the capacitor out of the bearing plate (1), and removing redundant filling agent on the laminated capacitor;

step eight, welding the multi-core chip;

step nine, cleaning after welding;

step ten, encapsulating the epoxy resin layer;

step eleven, printing a mark;

step twelve, curing the epoxy resin layer;

and thirteen steps of procedure testing and packaging.

4. The production process of the multi-core group radial lead multilayer ceramic capacitor as claimed in claim 3, wherein: the filler is organic silica gel, and the type of the organic silica gel is K-704.

5. The process for producing a multi-core group radial lead multilayer ceramic dielectric capacitor as claimed in claim 4, wherein: the step six is divided into three stages,

s1, naturally standing for 1-2 h;

s2, heating for 0.5-1 h at the temperature of 125 +/-5 ℃;

s3, naturally standing for 10h or more.

6. The production process of the multi-core group radial lead multilayer ceramic capacitor as claimed in claim 5, wherein:

in the first step, after the bearing plate (1) is selected and before the bearing plate (1) is horizontally placed, an adhesive layer is adhered to the bottom surface of the bearing plate (1);

in the second step, when the first capacitor is placed in the chip arranging groove (2), the capacitor is adhered to the adhesive layer;

and seventhly, before the capacitor is taken out of the bearing plate (1), tearing off the adhesive layer from the bearing plate (1).

7. The process for producing a multi-core group radial lead multilayer ceramic dielectric capacitor as claimed in claim 6, wherein: the adhesive layer uses a textured paper (4).

8. The process for producing a multi-core group radial lead multilayer ceramic dielectric capacitor as claimed in claim 6, wherein: in the seventh step, before the adhesive layer is torn off, excess filler on the laminated capacitor is cut off through a cutting plate (6); the cutting plate (6) is provided with blade groups (61) which surround into a rectangle, and the blade groups (61) correspond to the blade arrangement grooves (2) one by one.

Technical Field

The invention relates to the field of capacitor manufacturing, in particular to a production process of a multi-core group radial lead multilayer ceramic dielectric capacitor.

Background

With the development of modern technology, customers put forward miniaturization requirements on the whole machine, the main purpose is to save space, and then the PCB is required to be more and more miniaturized, so that the radial lead multilayer ceramic dielectric capacitor gradually develops towards miniaturization.

Under the condition of a certain rated voltage and external dimension, the capacitance of a single multilayer ceramic capacitor has a limit value due to the influence of various factors such as process, materials, equipment and the like. When the radial lead multilayer ceramic capacitor is manufactured, a manufacturer generally adopts a single multilayer ceramic capacitor as an internal chip, and the production flow of the radial lead multilayer ceramic capacitor generally comprises the processes of welding the capacitor chip, cleaning after welding, encapsulating an epoxy resin layer, printing a mark, curing the epoxy resin layer, testing the working procedure and packaging in sequence. Since the individual capacitors limit the capacitance, the capacitance of the resulting encapsulated radial lead capacitor is also limited to a certain range.

In the case where the size of the internal chip is fixed, by bonding the radial leads at both end faces, the mounting pitch of the leads thereof is fixed. Customers often put forward higher requirements on capacitance under the condition that lead wire installation spacing is not changed, and a single multilayer ceramic capacitor cannot meet the requirements of the customers after being packaged, so that a plurality of capacitors need to be connected in parallel to obtain larger capacitance, and the larger the capacitance is, the more the number of capacitors needing to be connected in parallel is.

The multi-layer ceramic dielectric capacitor is welded in parallel and encapsulated by epoxy resin to form a radial lead product, and the main problem is that two or more capacitors are not easily aligned in external dimension, so that the external dimension is out of tolerance.

In view of the above-mentioned deficiencies of the prior art, there is a need for improvement, for which the applicant has made active and useful attempts to find a solution to the problem, which solution is made in the context of the following.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a production clamp and a production process of a multi-core group radial lead multilayer ceramic dielectric capacitor.

The technical purpose of the invention is realized by the following technical scheme: the production clamp for the multi-core group radial lead multilayer ceramic dielectric capacitor comprises a bearing plate, wherein a plurality of chip discharge grooves for accommodating the capacitor are formed in the bearing plate, each chip discharge groove is rectangular, and clamping holes are formed in four corners of each chip discharge groove.

When the capacitor is produced, the capacitor is placed into the chip arranging groove, and the designed chip arranging groove is also rectangular due to the fact that the external dimension of the chip type multilayer ceramic dielectric capacitor is rectangular, so that the capacitor can be attached to the chip arranging groove, the capacitor is difficult to shake in the chip arranging groove, and the capacitor which is placed firstly and then can be attached is guaranteed;

however, the size of the plate arranging groove is fit with the size of the capacitor, so that the capacitor is difficult to put in and take out from the plate arranging groove, the clamping holes are formed, and the capacitor can be taken out and put in more conveniently in the process of putting in the capacitor, or adjusting the capacitor not to be put in.

The invention is further configured to: the depth of the plate arranging groove is larger than the thickness of a single capacitor, and the depth of the plate arranging groove is smaller than the total thickness of the capacitors.

When the chip arrangement is carried out, if the rear discharge container is accurately stacked right above the first discharge capacitor, the position of the former capacitor needs to be observed while the latter capacitor is placed, so the thickness of the chip arrangement groove is not too deep under the condition of ensuring the locking of the capacitor;

therefore, the depth of the chip arrangement groove is larger than that of a single capacitor, the depth of the chip arrangement groove is smaller than the total thickness of two capacitors when the double-core group capacitor is manufactured, and the depth of the chip arrangement groove is smaller than the total thickness of a plurality of capacitors when the multi-core group radial lead multi-layer ceramic dielectric capacitor is manufactured.

A production process of a multi-core group radial lead multilayer ceramic dielectric capacitor is characterized in that,

the method comprises the following steps: selecting a clamp according to the size of the lead multilayer ceramic dielectric capacitor to be manufactured, and horizontally placing a bearing plate;

step two: placing the first capacitor into the sheet arranging groove by using tweezers to ensure that two right-angle edges of the capacitor are attached to two right-angle edges of the sheet arranging groove as much as possible;

step three: uniformly coating the surface of the first capacitor with a filling agent;

step four: placing a second capacitor on the surface of the capacitor coated with the filler with tweezers, pressing the surface of the second capacitor to expel any air bubbles that may be present in the stack of the two capacitors and to squeeze out excess filler;

step five, repeating the step three and the step four according to requirements until the number of the capacitors is required by lamination;

step six, curing the laminated capacitor;

step seven, taking the capacitor out of the bearing plate, and removing redundant filling agent on the laminated capacitor;

step eight, welding the multi-core chip;

step nine, cleaning after welding;

step ten, encapsulating the epoxy resin layer;

step eleven, printing a mark;

step twelve, curing the epoxy resin layer;

and thirteen steps of procedure testing and packaging.

When the capacitor is produced, compared with a conventional production mode, the use of a production clamp is increased, the clamp is used for ensuring that the capacitors placed in advance and placed in the latter can be aligned, and the out-of-tolerance of the external dimension is not generated;

meanwhile, after the capacitors are welded in parallel, air among the capacitors is difficult to remove, and bubbles are easily generated at the joint of the product in the process of encapsulating the epoxy resin, so that the service life of the product is influenced under the condition of low air pressure, the process steps of coating, curing and removing the filler are added, and the adjacent capacitors are filled with the filler before welding, so that the air bubbles are discharged.

The invention is further configured to: the filler is organic silica gel, and the type of the organic silica gel is K-704.

The optional range of the filler is very large, and compared with other fillers and other organic silica gels, the K-704 type organic silica gel has multiple advantages;

first, its dielectric strength is: 16KV/mm, the minimum size of the capacitor participating in lamination is generally 1210 (namely the nominal length is 3.2mm, and the nominal width is 2.5 mm), taking the capacitor of the type as an example, the bandwidth of the end face electrode is 0.5mm, and then the breakdown voltage of the organic silica gel on the 1210 size can reach 2.2mm × 16KV/mm =35.2KV, which is far higher than the highest design voltage of the current ceramic dielectric capacitor;

secondly, the requirement of the ceramic dielectric capacitor on the insulation resistance is not less than 10000M omega or 100M omega.uF, and the insulation resistance of the K-704 organic silica gel can reach 2 x 10¹⁵Omega, much higher than the resistance of the ceramic dielectric capacitor body;

thirdly, the temperature range of the ceramic dielectric capacitor is generally divided into four temperature ranges of-55-85 ℃, 55-125 ℃, 55-150 ℃ and-55-200 ℃, and the temperature range which the K-704 organic silica gel can bear is-60-250 ℃ which is higher than that of the ceramic dielectric capacitor, so that the organic silica gel cannot be damaged and vacancies and bubbles cannot occur even if a product is welded at a higher temperature;

fourthly, the dielectric constant of the K-704 organic silica gel is small and is only 2.96, and even if the organic silica gel is filled between adjacent capacitors, the influence on the overall capacitance is small and can be ignored;

fifthly, the K-704 organic silica gel has higher tensile strength and shear strength, and can not shift even being stressed after the product is bonded and solidified by the silica gel, so that the alignment problem of the product is ensured;

sixthly, the hardness is 30, the hardness is moderate, the thermal stress of the capacitor can be relieved in the lead welding process, and the capacitor is prevented from generating cracks and failing.

The invention is further configured to: the step six is divided into three stages,

s1, naturally standing for 1-2 h;

s2, heating for 0.5-1 h at the temperature of 125 +/-5 ℃;

s3, naturally standing for 10h or more.

During manufacturing, the silica gel is naturally placed firstly, so that air bubbles are conveniently discharged, and the silica gel has certain strength, and the second step is high-temperature treatment to accelerate curing, and the third step is stable after curing, so that the silica gel has good adhesiveness.

The invention is further configured to: in the first step, after the bearing plate is selected and before the bearing plate is horizontally placed, an adhesive layer is adhered to the bottom surface of the bearing plate;

in the second step, when the first capacitor is placed in the chip arranging groove, the capacitor is adhered to the adhesive layer;

and seventhly, before the capacitor is taken out of the bearing plate, tearing off the adhesive layer from the bearing plate.

During coating of silica gel and stacking of capacitors, friction can be pushed to the first capacitor, so that the first capacitor slightly slides in the chip arranging groove, the sliding is small, observation and feeling are difficult, size deviation of a final finished product can be caused, an adhesive layer is pasted on the bearing plate before the capacitor is placed, the first capacitor is pasted with the adhesive layer after being placed in the chip arranging groove, a locking position is achieved, the subsequent capacitor only needs to be placed according to the position of the first capacitor, the first capacitor does not need to be pushed to be inclined, and the situation that the first capacitor is pushed to cause position change during coating is avoided.

The invention is further configured to: the adhesive layer uses a textured paper.

The tearing of the viscous layer needs to be carried out after the silica gel is solidified, but the solidification needs to be carried out at a high temperature of 125 ℃, if common glue is used, when the viscous layer is torn off, partial viscous substances are remained on the capacitor, which not only causes interference to the subsequent process, but also causes poor cleaning;

therefore, the beautiful pattern paper is selected as the adhesive layer, the adhesive substance can not remain on the surface of the product even if the paper is heated to 150 ℃, and the highest heat-resistant temperature can reach 180 ℃, which is enough to meet the use requirement.

The invention is further configured to: in the seventh step, before the adhesive layer is torn off, excess filler on the laminated capacitor is cut off through a cutting plate; the cutting plate is provided with blade groups which are enclosed into a rectangle, and the blade groups correspond to the blade arrangement grooves one to one.

When cutting off the redundant filling agent, the cured multi-core group radial lead multi-layer ceramic dielectric capacitor can be taken down and then cleaned one by an art designer;

the cutting plate can be used for unified cleaning between torn adhesive layers, the position of the multi-core group radial lead multilayer ceramic dielectric capacitor is locked by the adhesive layers, the cutting plate is only required to be vertically pressed down, the circular cutting of the capacitor can be realized, and redundant filler is cut down and separated.

In conclusion, the invention has the following beneficial effects:

firstly, through the design of a special clamp, the external dimension of the laminated multi-core group radial lead multi-layer ceramic dielectric capacitor is neat, and the problem that the deviation of the external dimension is uncontrollable is solved;

secondly, organic silica gel is used as a filling agent, so that air between the surfaces of the multi-core-group radial lead multi-layer ceramic dielectric capacitor can be effectively removed, and the multi-core-group radial lead multi-layer ceramic dielectric capacitor can be compactly combined with an epoxy resin layer, so that the problem of air bubbles generated at the product joint in the epoxy resin encapsulation process is effectively solved;

thirdly, the hardness of the cured organic silica gel is moderate, so that the thermal stress generated in the lead welding process of the multi-core group radial lead multilayer ceramic dielectric capacitor can be relieved, and the internal damage to the multi-core group radial lead multilayer ceramic dielectric capacitor is reduced.

Drawings

FIG. 1 is a schematic structural diagram of the first embodiment;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a schematic structural diagram of a multi-core radial lead multi-layer ceramic capacitor with lead wires welded;

fig. 4 is a schematic structural diagram of the third embodiment.

In the figure: 1. a carrier plate; 11. a vertical limiting hole; 2. arranging a sheet groove; 3. clamping a hole; 4. beautifying paper; 5. a silica gel layer; 6. cutting a plate; 61. a blade set; 62. a limiting rod; 7. a multi-core group capacitor; 71. and (7) leading wires.

Detailed Description

The invention is described in detail below with reference to the figures and examples.