DE10325132A1 - Method for producing a component, in particular an oil condition sensor, and component manufactured using such a method - Google Patents

Abstract

The invention relates to a method for producing a component, in particular an oil condition sensor. In addition, the invention relates to a component produced by such a method, in particular an oil condition sensor. In order to create a component, in particular an oil condition sensor, which is particularly simple to manufacture, a method is proposed with the following steps: production of a plastic body (1, 2) by two-component injection molding with an insulating first injection molding component to form a pre-molded part as a carrier element and with a metallizable second injection molding component for the main molding for forming at least one functional area (9, 19) and structured surface metallization of the at least one functional area (9, 19), in particular for producing a capacitor area.

Description

The The invention relates to a method for producing a component, especially an oil condition sensor. About that In addition, the invention relates to a manufactured by such a method Component, in particular an oil condition sensor.

Oil condition sensors find i.a. in engines, transmissions and hydraulic systems. Next the level of the oil and the oil temperature thereby also quality data of the oil through an electrical Interface delivered to a subsequent control unit, where an evaluation the measurement data takes place. Such an oil condition sensor is also called a QLT or Oil Quality, Level and Temperature Sensor.

In such an oil condition sensor for example the level detected with a capacitor element. Also for measuring the oil quality, which from the dielectric constant of the oil depends a capacitor is used. These capacitors are used in known oil condition sensors realized on a stainless steel sensor tube. The used here On the one hand, manufacturing processes are very complex. On the other hand, they have to known sensor tubes with high assembly costs in a corresponding casing placed and the capacitors connected via complex spring contacts become.

task The present invention is a component, in particular an oil condition sensor create that is particularly easy to manufacture. This task is by a method according to claim 1 or by a component solved according to claim 9.

A The basic idea of the invention is by means of a two-component injection molding process first a pre-molded part as a carrier element to manufacture from a first insulating injection molding component, the metallizable second injection molding component after a subsequent surface metallization as at least one functional area, in particular as a capacitor area of a sensor cell serves. Since covering the capacitor structures with masks or the like. at the production of the component is no longer necessary, the manufacturing effort across from usual Sensor cells reduced. Due to the molded interconnect used Devices (MID) technology for the integration of mechanical elements such as line or circuit carriers on the one hand and electronic components such as conductor tracks or electrodes on the other hand can be used with such components integrated electrically conductive functional areas can be produced particularly inexpensively. Because the capacitor areas already in the plastic body are integrated, the number of assembly parts is minimized, whereby enables simplified assembly becomes. The two-component process allows the smaller one The number of parts is also higher Process safety. About that in addition, the cost of manufacturing the oil condition sensor compared to conventional oil condition sensors reduced.

In particularly preferred embodiment of the Invention is the first injection molding component to be a PPS material (polyphenylene sulfide) used (claim 2). PPS material is used for the sake of it good dielectric property depending on the temperature. The use of a glass fiber reinforced PPS material is particularly advantageous, for example PPS GF 40%.

As second injection molding component is preferably an LCP material (Liquid Cristal polymer) used (claim 3). This material shows for the surface metallization particularly advantageous properties. As particularly geous before has proven the use of a Pd-doped LCP material (claim 4).

At the Metallize the surface of the plastic body is advantageously a first Cu-based base and then a Ni surface applied (claim 5), whereby the metallization is particularly suitable for forming capacitor areas Has properties. The Ni surface protects the copper metallization of the sensor cells, so that even with long-term use in motor oil over one huge Temperature range ensures proper functioning of the sensor cell is.

The electrical connection between the evaluation electronics, for example a printed circuit board, and the sensor cell is made via so-called connection pin contacts, either as an overmolded leadframe structure in the pre-overmolding (Claim 6) or as subsequent Assembly parts can be used (Claim 7). Which of these two variants is used is depending on the sensor type and the selection of the galvanization concept.

The pin contacts are advantageously connected to the metallized capacitor surfaces by means of a soldering process (claim 8). The solder connection is preferably carried out with a lead-free high-temperature solder based on SnAg in order to ensure temperature resistance in the oil in a temperature range from -40 ° C to + 160 ° C. Instead of a soldered connection, conductive adhesive connections can also be used to contact the capacitor surfaces. Also one Direct connection by galvanizing a connection between the pin contact and the surface is possible.

On manufactured by the inventive method Component is in the claims 9 to 14.

The The invention is described below using exemplary embodiments, which in more detail based on the figures explained become. Here shows:

1 a side view of a QLT measuring tube with the outer shell partially removed,

2 a plan view of the front of the in 1 shown measuring tube,

3 a sectional view through another QLT measuring tube,

4 a sectional view taken along line AA in 3 ,

In 1 a first embodiment of the invention is shown in the form of an oil condition sensor. Here is the sensor cell 1 from an outer tube 2 surround. The sensor cell 1 has a quality sensor 3 as well as a level sensor. The outer tube 2 with the sensor cell 1 is in the engine oil or the like. immersed. The engine oil fills the one between the sensor cell 1 and outer tube 2 existing interior 5 from, cf. 2 , The outer tube 2 points on its inside 6 a counter electrode 7 for capacitive measurement with the one on the outside 8th the sensor cell 1 attached capacitor area 9 of the quality sensor 3 on.

That is the sensor cell 1 only partially encompassing outer tube 2 points to its freeers 10 Befestigungswülste 11 on, in the manner of a ball joint in correspondingly provided receiving grooves 12 on the sensor cell 1 intervene and thus a safe and tight closure of the interior 5 guarantee.

Both the sensor cell 1 as well as the outer tube 2 are manufactured using MID technology using a two-component injection molding process. The pre-molded part is there 1 . 2 made of a PPS material, which with a Pd-doped LCP material 13 was molded around to form the capacitor surfaces. This was followed by surface metallization of the later capacitor surfaces in such a way that initially a copper layer 14 and then a Ni layer 15 was applied.

3 shows a further embodiment of the invention. Here is the sensor cell 16 shown without the outer tube. The cylindrical sensor cell 16 consists essentially of a base body or carrier element 17 made of PPS material and in corresponding recesses 18 of the carrier element 17 introduced capacitor areas 19 made of doped LCP material. Between the recesses 18 are the different capacitor areas 19 separating spacers 20 provided as parts of the support member 17 are formed and thus also consist of the insulating PPS material. The spacers 20 are used to guide and hold the sensor cell 1 in the outer tube (not shown). From the front 21 of the carrier element 17 extend connecting channels 22 for pin contacts to the individual capacitor surfaces 19 , The connection channels 22 initially run parallel to the central longitudinal axis 23 the sensor cell 1 and finally open diagonally into the corresponding recesses 18 on. They are also channels 24 for a positive encapsulation of the LCP material to form the capacitor surfaces 19 intended. The channels prevail 24 the carrier element 17 transverse to the central longitudinal axis 23 and connect the support element 17 completely enclosing capacitor areas 19 together.

The LCP functional areas are provided with a surface metallization consisting of a lower copper layer 14 and an upper Ni layer 15 consists. Here is the copper layer 14 preferably constructed from a Cu base with a layer thickness of 1 μm, which is supplemented by a galvanically reinforced Cu layer with a layer thickness of preferably 5 μm. The Ni surface preferably has a layer thickness of 5 μm.

A sectional view along the line AA shows 4 , In the carrier element 17 are two parallel to the central longitudinal axis 23 trending shafts 26 provided, which can be used, for example, to accommodate mounting springs.

1

sensor cell

2

outer tube

3

quality sensor

4

level sensor

5

inner space

6

inside

7

counter electrode

8th

outside

9

capacitor area

10

free end

11

fixing bead

12

receiving groove

13

LCP material

14

Cu layer

15

Ni Pad

16

sensor cell

17

support element

18

recess

19

capacitor area

20

spacer

21

front

22

connecting channel

23

central longitudinal axis

24

channel

25

shaft

Claims (14)

Method for producing a component, in particular an oil condition sensor, with the steps - producing a plastic body ( 1 . 2 ) by two-component injection molding with an insulating first injection molding component to form a pre-molded part as a carrier element and with a metallizable second injection molding component for the main injection molding to form at least one functional area ( 9 . 19 ) and - structured surface metallization of the at least one functional area ( 9 . 19 ), especially for the production of a capacitor surface. The method of claim 1, with a PPS material as the first injection molding component. The method of claim 1 or 2, with an LCP material as a second injection molding component. The method of claim 3, wherein the LCP material Pd-doped. Method according to one of claims 1 to 4, wherein the metallization the application of a first metallization, in particular based on Cu, and the application of a second metallization, in particular based on Ni. Method according to one of claims 1 to 5, wherein an injection molding of lead frame structures to form pink contacts for contacting the functional area ( 9 . 19 ) he follows. Method according to one of claims 1 to 6, with the further step - attaching at least one mounting part as a pin contact for contacting the functional area ( 9 . 19 ). Method according to Claim 6 or 7, with the further step - establishing a soldered connection between the functional area ( 9 . 19 ) and the pin contact. Component, in particular oil condition sensor, with a plastic body produced by two-component injection molding ( 1 . 2 ), comprising a carrier element made of an insulating first injection molding component and at least one surface-metallized functional area ( 9 . 19 ) from a second injection molding component, in particular designed as a capacitor surface. Component according to claim 9, with a PPS material as the first injection molding component. Component according to claim 9 or 10, with an LCP material as a second injection molding component. The component of claim 11, wherein the LCP material Pd-doped. Component according to one of claims 9 to 12, with a first Metallization, in particular based on Cu, and a second metallization, especially based on Ni. Component according to one of Claims 9 to 13, with pink contacts for contacting the functional area ( 9 . 19 ).